Complex Lower Latitude Weather Pattern to Persist Through Next Week

South to West Central Showers and Some Thunder, Most likely near Tampa Bay Later Today

TODAY: Latest satellite image shown above. Those high white clouds are shifting north and streaming off toward the east at the same time. Meanwhile, instability to build into South Central  toward lower North Central; however, the area north of the Beachline looks to remain 'capped off' for much activity other than a drip at most. Most likely area to get storms today along the west coast near Tampa under better sunshine as the east coast sea-breeze meets the near coast west coast sea breeze.


TOMORROW THROUGH TUESDAY: Same general pattern holds without going into details. It is possible that most rain will fall from Southern Dade and all of the Keys during this time frame. The wild card will be upstream of the Bahamas northward toward Palm Beach county where downstream fo easterlies helicity at low levels and shear across the islands could result in convergent bands moving ashore most anytime . Usually, these patterns fit a mold of 'most likely time it will rain within that zone', but exactly when that time will be is difficult to determine. Often though, it is near sunset or shortly thereafter until late morning.

BEYOND> Upper level and mid level lows seem to be trapped in sort of an eddy bubble, not unlike a twig caught between two rocks in a stream that rotates around in place. Current thinking, which has changed since yesterday, is for increasing rains state wide around Friday, with thunder possible. Will leave it at that for now, since it really is a bit of a waste of time to jump into the nitty gritty ..when the pattern is operating in a random chance roulette wheel fashion. 

Beginning of 'Convective Season' on Saturday?

Image showing 850mb (5000 ft) Dew point temperatures Country Wide . An indicator of the amount of moisture at that level in the atmosphere. Note how 'bone dry white' it is over Florida, the Northeast States, and much of the SW U.S

TODAY: That big system that swiped through Florida over the weekend was quite the dynamo in the moisture depletion category. This image above shows just that in the moisture level content over much of the eastern portion of the U.S. This could be close to being the temporal   few day period of relative drier air over Florida once we approach the weekend (as moisture increases) until the first cold snap this  upcoming winter. Very rich, moisture laden air resides toward the lower right hand portion of the image which we can look at in a moment.


All things aside , skin itching , brittle boned, eye watering, near Desert Southwest like (well, not quite) air resides over the Sunshine state through today and Wednesday. Thank goodness it will not last long lest the landmass turn into a dusty metamorphosis of random devaporizing. Poof in a exhale of dust.


All other commonalities aside, this could be the least of the last but not forgotten period of such absurdities in this category as the unclimatological winter of 2011-2012 ends and we head well into yet another season I suspect will also be non-'climatological', although in just exactly what way it is hard to say.


Quite cool this morning with a temperature around 46F at MLB alone, with the A1A strip running in the low-mid 50Fs. Today will be the coolest day of the lot around the clock. Rapid temperature drop in such conditions with the setting sun and very little wind. Wednesday morning near the beaches will be similar to today, but the morning lows will be most cool from a statewide perspective as high pressure now to the west which is squeezing out our atmosphere not only due to northerly mid-level winds off the U.S landmass, but also because we are under the descending side of that approaching system.  Sound the Severe Stability Index Alert, the sky is clear!  Wednesday to be another day like today, but the high pressure system will already be east of the state by mid-day allowing easterly winds to begin to offset the pattern, and slow moisturization commences. Wednesday will be a good 5F or more degrees warmer, but Thursday morn will be briefly 'cool' once again, but much warmer by afternoon. Heading into Friday afternoon we could be looking at  the "Big leap Forward" in temperatures while areas toward the Southern Plains are already well toward the upper 90Fs. 


Meanwhile, the high pressure starts to draw forth water from the Caribbean Well with winds from the southeast, ushering increasing moisture from the south and what looks to be a day of bona-fide thunder on Saturday toward mainly the West side of the state. This is the first day guidance has shown Precipitable water values reaching 2" since last October, and appears to be from late day convergence.

PWAT Saturday. Note all the moisture still yet to the South over the Caribbean.

 It is hard to tell from this image above, that a frontal boundary by this point in time will be sinking southward toward the state, with a better chance of showers and maybe thunder on Sunday nearly statewide, but not all encompassing. Looks like a 30-40% coverage type of day.  The boundary after this point is forecast to loiter and fizzle close to Central Florida but followed by another in similar fashion resulting in easterlies upward into the mid levels which continue to douse the atmosphere with moisture richness. Although rain chances will be bouncing around hither and yon, with rain 'chances' in the forecast more often than not, it is hard to pin point that far out in the future the detailed hows and whys other than SE flow..with possible onshore ocean showers converting to thunder along the west side. So be it, or not; time will tell..it always does.

Excellent Weather Begins Tonight

Images show line of convection moving across the state very early this morning. It appears this will be the end of any storms now in quite some time to come. The heaviest activity occurred in Osceola County into Brevard as can be seen here in both images. On the right is where the  tornado watch existed at that time for Central and South.

In this early morning water vapor image we can see clearly where the upper to mid level low pressure system was located. We can also see what is left of the line of showers and thunderstorms sparsely distributed that had gone through after midnight by the dashed white line. The low is lifting almost due north today, and thus the cold front will dawdle on through only later today into tonight on the toes of WNW winds and drier air 

Thanks to a Sky Appreciando Extraordinaire as well as gifted artist friend for helping create the new header for the blog. I had a vision, and he created it for me with his software and other talents. Kudos Mr. Jim Williams. For both the new image as well as the former banner at    http://dryliner.org/
  
TODAY: Storm system has cleared the area in regard to strong storm (or really about any storm) development. As was expressed yesterday, the atmosphere never did become unstable enough to support widespread convection as suspected would be the case. Even over night in the presence of almost no CAPE as well as some inhibition on top of that there was yet still some storms, with a warning for thunder storm winds and hail in Osceola County though. The winds aloft and other parameters related to energy and wind fields was simply too powerful to ignore, and thus the Tornado Watch. That is a good example of why they are called "Watches"..(not warnings). 


We can recall on Friday there was at one time 7 severe thunderstorm warnings statewide issued and active simultaneously.  In my mind I thought, "Ah yes, the day before the day" (of severe weather that could be very bad)..On the other hand that was quickly followed by the notion, "But is the day before the day going to be the only day?"!  It appears that was the case. ..considering all of the storm reports of hail ranging from 0.25" up to 1.25" and wind gusts in the 44-58mph range occurred on Friday (other than one or two overnight here and there).  Between Saturday and overnight to early this morning I saw no severe reports.  


LATER TODAY: Appears that the sky is taking on an almost winter appearance. It is quite blue despite the lower level clouds and renegade quick moving showers. It does also remind us that we are going to be entering the 'Convective Season" beginning around May 1, which is not the same as the 'Wet Season". The convective season is a great time for storm photography as storms and clouds tend to be more isolated in an atmosphere not yet saturated in tropical moisture, highlighting crisp edges and blue skies around them. During the Rainy season storms start to take on a slightly 'mush appearance'..but nonetheless threatening.


Today, instability is lacking, but seems to be less so than any model shows based on the Local Data Integration System out of KSC-MLB NWS Network. Some showers are occurring, widely spread, and expect the sky to be partly to sporadically  mostly cloudy here or there through 5pm, with skies becoming clear from north to south from late afternoon toward Central right at sunset. South Florida and all elsewhere will likely be absolutely clear after dark as winds remain WNW-W...as the cold front and wrap around moisture exists eastward toward sunset.  The bigger temperature drops will occur after midnight, with Monday morning lows in the mid-upper 50Fs with a WNW breeze, making it feel quite refreshing. 


MONDAY-WEDNESDAY: Refreshingly cool, window-opening overnights and ceiling fan afternoons under mostly clear skies with a NW wind by Tuesday. All evenings will experience a noticeable drop in outside air temperature within 1-2 hours of sunset through the first hour afterward...but winds will become quite light if not calm by morning on Tuesday and if not by then, Wednesday.  So far, it appears that it might not rain until sometime in early May...or the last two days of April. This month has just flown by so quickly, a sure sign of spring.

Two "Potential" Shots At Severe Weather Central

BOTH ZONES ARE CONDITIONAL ON MITIGATING FACTORS: Best that can be determined at this time , and is not entirely in agreement with official forecasts (Namely, the afternoon red zone)...is for some afternoon storms which could be severe with tornadoes possible (few if any), Gusty winds, and some hail...(possibly). The Red Zone is for this afternoon with a pre-frontal system;  then again toward or after dark toward midnight in the Purple area. Note that Central encompasses both realms of possibility; however, there is low certainty which, if either, will manifest to live up to its potential. Some guidance actually shows NO rain or very little in many areas. Wind fields are simply too tempting  (as well as threatening to ignore, especially tonight.

TODAY: Will not write an in-depth analysis or forecast post, since the upcoming day (being today) has already been looked at in previous posts, and the media is covering the situation. All in all, what is shown above is a bit not in sync with official forecasts I saw, namely for the area toward the Big Bend and east toward JAX.


Pre-system  ejection of vorticity is forecast this afternoon across the North Half. Latest RUC and actuals match up closely in regard to instability. The question becomes, how unstable can it actually become with high clouds over the questionanable area in Red? If this instability can manifest (which may or may not be in progress as I type), severe storms are entirely possible. There is cloud cover out there after all, and If not, there is a chance that only isolated activity will manifest. This forecast post is based mainly on 06z runs, and a bit of the 12Z NAM (and recent RUC). Will say that the RUC and overnight GFS and NAM seem to all hedge in on East Central toward the Brevard area during daylight today... bears keeping in mind. 


All factors of severe possible, although with such a saturated air mass hail is a bit questionable . It might be that the over-saturated air mass will be the saving grace in regard to any severe weather, or even much weather at all. Below is for this afternoon. Note the heavy cloud cover over the South. In the red is where the best wind fields are forecast as well as instability by mid afternoon. If this instability does not manifest, there is a chance it will be generic thunder and rain. Far South though, although not shown toward the Keys..could be another story.

TONIGHT: A second impulse to ride in across the South Half of the state, making an entrance toward Naples and Punta Gorda. Wind fields will enter SW Florida toward sunset and rapidly spread NE  toward Brevard on the east side and all locations South as well. The north seems to be out of the picture over night. At this time, the GFS is showing instability over South Florida and storms by mid-afternoon; however, 'actuals' are not supporting model output in this regard. Note though, that the wind fields will possibly work into that area first!..Thus, might be unwise to discard that area completely today. Basically, 2 out of 3 major models at this time of day say 'no go' for the south until at least late afternoon ...Otherwise, tonight the models all agree the better wind fields with much greater shear and helicity will be over the south half anywhere from Sunset toward 3AM time frame. There is one issue I have. That being, the best bulk shear lags ...in other words, factors MIGHT not sync up. On the otherwise, if they do or come close to doing so, it could be a no holds barred severe weather situation. It is tonight the better Theta E air is drawn nortward and south of a secondary boundary, in which case lack of instability might not be a mitigating factor. Thus, The Storm Prediction Center's outlook closely matches up with the night time scenario drawn in for the south half...as noted by the purple lines in the first image.

All will not be said and done until Sunday late afternoon or a bit earlier. Yet another questionable time frame and again, for North Central. The entire system should clear the state by sunset in the rain chances, and from that time forward cooler and drier air moves in for Monday-Wednesday mornings.

An Isolated Strong Storm Not Out of The Question, Severe Weather Threat Remains Saturday

Rain fall (green) as showers to Thunder Orange To Purple Strong storms after 4:00pm today are possible as noted in the discussion below. Note in this 1:20pm image the 'Lake Shadow" NE of Lake Okeechobee; the clearing area due to SW winds blowing across the lake and stabilizing the atmosphere upstream of those winds along the NE side of the Lake

TODAY: A bit like yesterday, just more of it. Sea breezes both coasts will play in to today. Today looks like a summer day out there, and the air feels a bit like one. There is one big difference today from yesterday, that being higher Convective Available Potential Energy (CAPE). There is more of 'that' today than we have seen in quite some time and local data integration system from KSC backs up the model's claim, if not more so of the cast near Vero and South. That air will be transported into Central after the sea breezes set up and spread around. 


Temperatures aloft today are cold all things considering so there is an added storm potential bonus. The key factor for stronger storms toward the east side will be in the timing and cloud/shower extent prior to 4pm across Central Florida. For now, will gamble on hedging toward pretending it is summer in regard to timing, and throw in the cold air along with respectable vertical velocities shown on the questionable NAM model, although other models are showing 'values' as well. Would add some 'umpf' late day along the east coast near I-95 from DAB to Vero, with a focus toward Brevard/Volusia/Indian River, and St Lucie Counties...with the chance of stronger activity noted in the purple for a variety of reasons beyond the usual 'technical difficulties" that either could be stronger parameters than guidance shows or be non-existant. Rains could persist until after sunset but not much longer as it appears now as activity moves offshore and or loses the 'juice' .


SATURDAY: This is a big question mark day in regard to severe weather. Suffice it to say it is not a day for the beach, as cloud cover or a very big bad storm threat will loom. If cloud cover is less, all the greater the storm threat, so either way...a watchful eye will be necessary. I had made up a graphic earlier today before the 12z runs, so will use that one instead of recreating the wheel which will change on the next run anyway...due to ever changing model resolutions.


Consensus now as gone back to previous reasoning, in regard to where Severe Weather in the form of 'damaging hail could fall' as well as where/how/why there could be some tornadoes on Saturday. 


Instability (CAPE) is not all so impressive (not at all actually) , and the wind fields have been bouncing around a bit in regard to whether or not there will be anything beyond an isolated spin up VS. an actual full blown tornado or so...if not a few. Last nights hodographs which show the curvature and strength of the winds aloft portray a definite chance of tornadoes during brief windows of  so called "opportunity" from SW Florida up toward Ormond Beach, (if not outside those realms) with the conditions spreading north from mid-morning toward late afternoon as the day progresses. Otherwise, other showers could occur elsewhere. There has been some trepidation from official outlets against the chance of strong updrafts, as noted yesterday, due to weak instability.


However, I have noticed that low lifted condensation levels continue to be forecast by early afternoon (values we'd normally expect not to see until near dark, when summer storms get there strongest) to be unusually low, meaning LOW storm bases...and that factor compiled with Rich Theta-E air well up through the mid-levels and good helicity values could overcome any weakness in instability regardless.


One other factor to point out is that this does not appear to be an in and out of here situation by any means. With a threat of severe weather as far north as JAX toward Tallahassee and as far south as the Keys at various time frames due to what might be TWO warm fronts swiping from south to north..timing is literally impossible from my perspective at this point. The important thing to bring forth and stress is to STAY AWARE! This will not be your standard 'severe hum-drum fare" type of day, especially if a worst case scenario were to evolve. Do note, the low is forecast to form near the Loop Current, so unexpected intensification of that surface feature over those warm waters could make the difference between a slight risk of severe to a booster shot up toward a rare moderate risk, unless a high overcast and the theta-E air does not manifest as forecast. In which case, one will be left wondering what the fuss was all about for the get go. The above statement was not made by any office, but best to stress worst case than be  nonchalant and off guard to any sudden 'potential'.

This image as noted is based on the 06z NAM run valid for 3z tomorrow night (11pm). Later runs match closely in regard to the main features but change with the finer details as to where, when, or even IF severe weather  will occur. The image portrays  Helicity in the lower levels of the atmosphere. Since that time, the values have changed in the forecast, but who is to say they will not change right back again later on before tomorrow morning,? Thus, I posted this as an example showing a warm front location and surface low for Saturday night around 11pm. Values by this time have spread for South Florida northward during the day with a severe threat as that occurs in this 'Example". Those values are high for Florida and not messing around. Serious stuff in other words.

The good thing is, guidance does show that it might not be a good day AT ALL to plan outdoor activities, so there is literally NO EXCUSE not to have a TV on Channel 13 (Central local channel), or your favorite news channel, tuned in and ON otherwise. If things do get cranking, your news channels will be covering tomorrow Live and Real time, possibly commercial free during any high points. So far, tomorrow has had a greater potential for severe weather than we have seen since last spring in the hail and twisting winds category.


Here is another interesting observation, the  forecast sounding based hodograph. The big loop , or arc, shows how winds curve with height within a Theta-E rich atmosphere. In fact, one of the downfalls for severe tomorrow will be that the entire column of the atmosphere in any storm will be saturated beyond recognition..but low level forcing along northward moving boundaries with energy criss crossing from the west could set just about anything off, any time from late morning through early evening.

In the upper right is the winds with height. Note how quickly they turn, or shift in the low levels. Also note how close the vertical red and green lines are. That shows gobs of moisture without any dry slots to aid in lift, or buoyancy. The lower left is the main point I wanted to point on in thee wind fields...LOOP! To the right, we see this hypothetical 'sample' is for a location near Titusville.

BE AWARE point blank. Things can change in later forecasts, and I expect everyone on TV will be saying the same. Or they should be.


BEYOND: Activity could continue into early Sunday toward noon time with a lull in activity somewhere along the line, but it appears any tornado threat will be gone after the wee hours of the night. There is a chance the entire mess will be over with by noon most locations with rain and thunder North Central to North, but as noted already, there is simply too many timing issues to make even close to a believable or rather trustworthy forecast regarding Sunday's weather. Need to get past Saturday yet still.


Otherwise, no rain for many days seems to be in the cards with much cooler morning lows interior Central and North, and quite cool comparatively speaking elsewhere for several mornings. North Central could feel 'chilly' prior to 10A<. Afternoons will be quite pleasant though.

Showers, Isolated Thunder after 5pm Through Mid Evening / Possible Severe Saturday

Forecast GFS Plot for Saturday near sunset. Low in Eastern Gulf, with
possible two warm front like boundaries, and cold front extending south. Purple arrow crosses the cold front and toward South Florida. That indicates strongest jet stream winds. See below for more information.

TODAY: Old frontal boundary remains and decays far north Florida as shown below. Although light showers and some thunder are occurring now, it appears the best or potentially most likely time that storms will either increase in number OR in strength will be after 6-7pm toward the interior with a trend toward the east side due to lifted condensation levels dropping off at or near sunset. Often, the magic hour is around 6pm in the summer, so given the time of year 5pm might be closer to transition from showers to more thunder. However, given that the atmosphere is not really all that unstable, the drop off hour might not result in much activity since instability will also drop off with lower sun angle. Otherwise, most areas will be dry tonight across the state..but a 35 -50 % coverage at some point in time when all is said and done might not be too far off the mark. Naturally, the other % wonders what one is talking about as they sit high- and - dry. A storm or two could have stronger wind gusts and a brief spit of tiny hail, but really am not considering the possibility at this time.

Latest satellite presentation on the visible spectrum with comments for rain shower sor  possible "orange thunder"  up until nearly mid-night

FRIDAY: 'Space saver'. More like today with greater likelihood of thunder further south.


SATURDAY: As noted previously, it appeared as of later yesterday the big trough to kick on by over the weekend could drop further south than was being depicted which indeed proved to be a valid assumption . However, the latest GFS of this morning seems to correlate well with the ECMWF now, with the NAM being odd man out by about 75 miles further south (at most). 


Every mile counts though especially when  under the guise of potential severe weather. Without going into great depth, the strongest upper level winds appear will eject around the base of the trough into south Florida and the Keys, but the better wind profiles for rotation will be closer to North Central, with winds becoming more unidirectional (all from the same direction with height) further south. However, there may be more than one ripple  of energy running through the base of the trough, so for now  nearly a state wide chance of strong to severe storms is possible. The GFS implies best chance to severe and possible tornado to be dead Central, with heaviest rains further north.  Image is for 8pm ala GFS mode. Worst weather now appears to occur late morning through sunset on Saturday.

Same Image as a top of blog post for 8pm Saturday night

  SUNDAY: Continued clouds, wrap around rain and possible thunder continues mainly north 1/2 of state until late afternoon, possibly ending sooner. All rains should be over with by sunset or shortly thereafter. NOT a state wide rain day though, so some will not get wet.


BEYOND: Other than maybe one day of brisk onshore winds, high pressure follows low pressure..and dry air ensures. Just take a big BIC eraser across the state and forget about plotting rain on there that is measurable for much of next week the way it is looking now.Cool inland lows most of the week, cooler that recent days...with mainly 60Fs to near 70F some of the coastal areas some of the time prior to and near sunrise. Otherwise, afternoons will be a bit cooler, but nothing to be concerned over. All in all, looks like a nice week ahead going into mid week.

Evening Showers/Rumbles Spread East Today - Severe Threat Increases For Weekendr

Latest mid-afternoon radar. Showers could spread east later today and to the east coast well past dark as impulse passes over head, Little chance of thunder East of the State's Spine tonight. Details below.

TODAY: Frontal boundary and weak low pressure circulation is in the Western Panhandle extending north and east. The boundary can be seen by the extent of rain showers and thunder into the Gulf . There is heavier activity even further south in the Gulf, and storm tops are being sheared off, appearing across the Central portions of the state as cirrus clouds, whereas south Florida and other areas are seeing some harbingers of summer like cumulus clouds today.  Instability is weak across the peninsula though. Thus, in sticking with yesterday's post, believe most rain showers after dark will fizzle as they move east to west due to lack of mid -level moisture per forecast soundings and weak upward forcing combined with the meager instability. Forecasts I see are showing thunder, but if so, I'd think it would have to be very isolated. There has been consistency that showers and maybe thunder could persist until after sunrise along the east coast just offshore from JAX toward MLB or TIX..although this looks a bit questionable. This could be a back building type situation though from off the Gulf Stream waters, since some energy remains aloft.


THURSDAY/FRIDAY: As noted yesterday, it continues to appear that although the surface boundary near the Panhandle will begin to pull out, it merely gets replaced with mid-upper level waves of energy ejecting eastward from the gathering upper level dynamics still well west of the state. Otherwise, no changes from yesterday's reasoning of the Baja upper low merging with the upper level storm system moving into the US NW Coast. 


The timing could be critical, but as conspired toward the other day, rain/thunder chances look to be a good bet both days, and some could be strong in a few cases due to cold air aloft and the east coast sea breeze merger east of Orlando, up and down the state late day one or both days. 


Also, on one or both days activity could might be more restricted to the north or south half of the state. On a side bar, it is noted that the GFS seems to having a typical bias love affair with far East Central in the rainfall department with totals toward 2" by the end of Friday. This can mean though some areas receive little to none, whereas other areas could receive more than 2.00" if a heavy storm or two passes of the same region. I suspect these days will start with activity mainly toward the west side and far interior but spread rather quickly east  now that sufficient (but not impressive) instability develops as opposed to today, little capping or convective inhibition in place, and cold air aloft conducive for strong storms, possibly more likely toward and east of I-95. This will NOT be like summer conditions though when  instability and sea breezes are  the sole reason for activity. Upper level energy should be at play coupled with cold air aloft. If activity gets started too soon though we 'could' end up with a lot of rain showers by late day, although rain is shown to begin and last well into both evenings.


++SATURDAY/SUNDAY UPDATE++:
As advertised, the time is drawing closer to the weekend now, and details although varying from yesterday are following a trend. Latest guidance indicates per the GFS (last night's ECMWF was close in line)...that an upper level trough will dig yet deeper than previous forecast. Likewise, jet stream winds aloft approach the state toward South Florida, with Central located toward the right entrance region of the jet core. This is important because that is the area where the greatest upper level divergence occurs above low level convegence within an atmosphere of veering wind profiles. 


There is one fly in the ointment! If storms form to the west over the Loop Current, they could   spread high clouds across the state, greatly dampening any severe threat on Saturday, although rain and thunder remains quite possible to likely state wide. The other variable to down play a severe threat would be TOO MUCH moisture stacked up through the atmosphere. Severe weather loves 'dry slots or layers' which aid in storm strength (lift).


ON THE OTHERHAND: Latest GFS seems to indicate a late day pre-frontal trough  to approach the West Coast mid-afternoon or earlier to spread eastward during the mid-late afternoon with respectful low level southerly winds and increasing jet stream winds aloft as shown below: In this case, regardless of cloud cover, instability might not matter all so much anyway. If so, storms could be hard to see on the approach due to clouds preceding their approach. 

Saturday afternoon shows trough and low in Gulf.   Note the SSE winds along the east coast (orange arrow). Purple arrow  is the jet stream winds. The low will track along the red line (warm front) into Sunday. As we can see, the state is in the 'warm sector' south of the warm front with veering wind profiles as we go up into the higher atmospheric levels. Note how the orange arrow indicating surface winds is CROSSED with the jet stream winds (purple). Storms growing upward into the atmosphere will be forced to rotate with greater upward lift, resulting in rotating thunderstorms and/or Supercells . Stronger winds, hail, and tornadoes can manifest from Supercell Thunderstorms, although not all supercells generate tornadoes. Do note once again, despite these favorable wind profiles for weak -mdt rotation, a storm must be able to generate first. If there is too many high clouds in place, that chance decreases...in the absence of   strong  or sufficient vorticity (wind energy) passing overhead.

SUNDAY: With the prefrontal trough passing through, next comes the cold front. It still looks like this will be a squall line type situation with embedded bow echos and small cells possibly forming ahead of the line, although not as much so as yesterday. Actually, it looks more like a continuation, or resurgence of similar activity of Saturday beginning after sunrise and spreading east . 


**Note the close proximity of the surface feature below by sunrise Sunday.

AGAIN we see conflicting wind directions with height... with the white this time showing surface winds and purple showing jet stream winds..criss-crossing. South Florida really looks to be under the gun being located under the stronger jet stream winds, and Central to North is located along the greater divergence which aids in lift. This is definitely going to be 'play it as it comes situation', so preliminarily it would be considered  wise to heed statements issued by the National Weather Service or News Channels or other media outlets. 

 OVERALL: Granted, this blog is not an official relay station, but in a worst case scenario for  both late Saturday into Sunday it is STRONGLY advised as a baseline to remain abreast, attuned, advised, aware, etc.. to future outlooks via reliable outlets. I do not believe I've seen Florida in a DAY4 (4 days in advance) OUTLOOK before from the Storm Prediction Center .  

This means confidence is high or relatively enough-so that the chance of a severe weather event or events is increasing but not yet pegged down to specifics regarding just HOW severe, and what form 'the severe' will take..timing remains a major issue as well in regard to how various parameters will meld together.  


Lastly, experience says these upcoming events seldom unfold as expected, so we will need to watch for the 'windows of opportunity" (time frames).of greater severe likelihood..as time draws closer. 


Worst case scenario would be, I expect,  a tornado watch for most of the state for early to mid-day Saturday until the entire event is deemed to conclude, or separate watches for both events. The other option contingent upon the vast array of factors involved is that a Severe Thunderstorm Watch (s)will fit the given scenario (s). In this particular situation as posed before us. Activity should conclude by sunset Sunday based on morning model runs.with lingering showers and clouds into Monday. 


*Note: given the latest guidance , and this "quite the unofficial post" any tornadoes will not be Garden Variety Florida spin ups, but the real thing. 


BEYOND THE WEEKEND: A few cool mornings as high pressure tracks across the state behind the system, mainly away from the coasts. Lows in the mid 50s- 40Fs far north, with coasts in the 60Fs. Dry. The threat of strong onshore winds  went to the way side in later runs after the post was put on line yesterday, as expected might be the case. In other words, pleasant for sometime to come.

Rain Chances Begin Wednesday Toward Possible Severe Storms: Weekend

Image for late today at 500mb (see lower left of image). Notes in Red squared off by purple relate to this weekend. Also note the two upper level troughs (which also show in the mid levels) to pass by Florida before this weekend. More information below for discussion purposes is in the post.

TODAY: "Another Beautiful Day in Paradise"

WEDNESDAY: The first of several disturbances will cross over or near Florida as the ebb and flow of the tide rises with a succession of waves coming ashore overhead and washing through. Meanwhile, high pressure in the lower levels to the east of Florida with its clockwise circulation will usher increasing moisture across the state under the influence of SE to South surface winds in coming days. Guidance is split on Wednesday on the rain chances, with the NAM showing thunder toward the East Coast from near Lake Okeechobee northward to Brevard. On the other-hand, although the GFS implies the same 'pattern' it is mostly non-rain producing. Hedging more on the GFS for possible showers inland west side spreading toward the east late afternoon and after dark but weaking to perhaps mere clouds after dark, lingering near the coast toward the north side of the state. 


Based on a variety of parameters not really amounting to much against the prevalent atmospheric conditions we have been under for quite some time, do not think the atmosphere will be 'turned over' quite enough yet to yield thunder. This will be re-evaluated tomorrow morning for thunder chances from near NE Okeechobee County to Titusville and offshore as the first upper waves passes across (as shown above). Instability looks too meager to be able to hold fast to deep convection in the face of convective inhibition and cool onshore flow, although if winds become side-shore late in the day, isolated inland thunder is not out of the question if not East Central near or after dark.


THURSDAY: Second wave will now have greater influence as the first one will have carved a clearing for further waves to move in..like a set of waves in the ocean comes the waves (of uncertainty) from above in a stormy sea. By Thursday moisture increases across the state, sea breezes play a part combined with energy from the next wave in the set combined with increasing atmospheric instability. Consistency since yesterday shows early-mid afternoon showers and thunder with plentiful cumulus clouds by mid-morning or so and warm temperatures in the low-mid 80Fs. The gun is loaded and has a trigger now, so thunder looks to be a much better bet state wide. The GFS goes for good coverage but the NAM holds back or simply has poor aim. I'm siding more with the GFS though, as the NAM has a tendency to 'isolate' selective areas, good for short term but not so good for mid-range guidance. This line of reasoning could easily prove to be incorrect though, but bears watching. Watching to see if later runs follows suit with the GFS which has been showing a better to good chance of rain for several runs now on Thursday with 60% coverage, although the official forecast says 20% (which would be the NAM).


FRIDAY: For now, we can say carbon copy or 'repeat sign' in this medley of Thursday. Activity on either day could remain off the east coast well into the evening over or near the Gulf Stream waters. Note again, from the image above as well discussed next, we'll be watching the annotations along the U.S. West Coast.


SYNOPSIS FOR WEEKEND: Note in the image the upper low off the Pac NW and lingering low off Baja. Guidance is now consistent with a 'merger' of these two features while the high pressure to the east of Florida moves out an  as a result of the two previous shortwave troughs on Thursday and Friday. As a result, the Southern Branch jet Stream now running south of the state is lifted north in a bit of a medley concerto with a repeat sign and a coda thrown in, harmonizing and merging with a crescendo on Saturday and Sunday as a now strong upper low rolls across Southern Bama. The drummers and cymbals join the chorus.


The weekend is sketchy in the timing realm (given how far out in time it is)...  the growing grass is slow  ..but the seeds seem to be planted for a severe weather event on Saturday and/or Sunday.  Monitoring is like 'watching the graphs grow".  Stronger winds in the mid-upper levels, divergence in the jet stream winds, and convergence at the surface with the help of a side shore 'sea-breeze' along the east coast (more moisture added) with instability and cold air aloft in the midst of increasing veering wind profiles with altitude (clockwise as on goes in the vertical)...gives rise to counterclockwise circulations at the surface becoming outwardly clockwise aloft creating a vacuum in upward rising air currents.

Red - surface wind  Purple/Lavender - Jet Stream winds; crossing  surface and veering mid level winds
Sunday morning depiction

 It appears that there will be a QLCS Squall Line on Sunday, but possibly preceded by a "POTENTIAL ONLY AT THIS POINT" severe weather event on Saturday of lesser proportions. The evening European Model (ECMWF) run comes in close, but given the lack of greater details in that model on the internet free-service are lacking it is hard to tell just exactly how well they come to agreement. At this point, would not be surprised to see a Severe Thunderstorm and/or Tornado Watch for Florida on Saturday and/or Sunday. So far, this is not showing to be an overnight event (s)...and much can change in the next several runs. Already, the offices are eyeing the potential though, and the Storm Prediction Center seems to be waiting for consistency as well before loaded the gun to make a call of caution. 


BEYOND?: Good question. Guidance shows the eventual frontal boundary to sweep through with a rapid transition to onshore flow, thus..very little cold air follows, at least at this stage. This would make sense considering much or part of this system stems from the Southern Branch Jet. Boundary should lie east west across the Straits area and possibly retrograde back north. Earlier run showed onshore flow with winds of 30G40 mph Sunday night or Monday...but that scenario fell to the way side in the morning run. Still cannot discount it yet though, but the ECMWF did not appear to show that possibility..and tend to agree.

Increasing Rain/Thunder Chances Wednesday - Saturday

Latest satellite image Monday afternoon with rain chances (PRELIMINARY) For Wednesday afternoon into early evening

Brief post today to provide lead way into a more active discussion period through Saturday at least. Suffice it to say for now, that cloudiness will begin to break up somewhat (or a lot) toward early evening depending on one's location. Really no changes to the current pattern outside by all appearances through Tuesday as well.


WEDNESDAY: Did you hear about the tornadoes in the Plains created by a storm system over the weekend? A bit hard not to have unless one has not watched any news. That frontal boundary will be moving in toward the Panhandle region on Wednesday, which by all perspectives is a long time for a front to progress that far in nearly 4 days. Regardless, it will not clear the state, but perhaps reaching North Central to Central at most. Net result will be a chance of showers and maybe thunder in the interior late day to evening as a result of a sea breeze collision. Active sea breezes with their seasonably cool air this time of year should prevent activity from reaching the coast with any gusto power as it appears now.

THURSDAY/FRIDAY/SATURDAY: With the linger boundary somewhere near the north 1/2 of the state, shower and thunder chances will increase in this time frame. Activity may very well not be waiting to form until late day as is often the case. Current thinking is activity could begin as soon as noon time or shortly thereafter by Friday and shift toward the east coast, as well as on Saturday. It is too soon to pin-point exactly where and when storms will manifest with the greatest likelihood, but suffice it to say that by the time Sunday is over many areas could have received a good soaking at some point along the line, but not absolutely guaranteed. I would not be surprised to hear rain chances advertised at 50 to 6o percent though, with thunder thrown in, especially on the east half of the state. Details will follow on a case by day basis in follow ups.


BEYOND: Reversal of Fortune?  GFS shows for a few runs now a BIG cool down by Monday and Tuesday mornings. Cool down relative to the weather the past few weeks. History tells us that the GFS tends to over-play morning lows in the longer range, so this will be watched for verification purposes as we head toward Friday and Saturday. If so, however, we could be seeing lows in the mid-upper 40Fs north 1/2 interior and low-mid 50Fs coastal for two mornings, with much cooler afternoon high temperatures. The gist is..hope one is gained acclimation to warm temperatures, because it could feel chilly.

Showers / Isolated Thunder (Mainly South) Today

Weak pseudo-low circulation Over The Glades area to remain fixed in this region today before becoming diffuse later today into this evening. Although some brief  rumbles have occurred in the South already, it appears that not much more, other than an isolated incident is likely to occur today. Otherwise, further north we see a dashed orange for a conditional chance with conditional shower chances yet further north. See below for details.

TODAY: Weak low pressure over the South coupled with equally weak to moderate atmospheric thermal instability in the absence of sufficient surface boundaries has generated some showers and thunder South. Further north, instability will be lacking north of 528, but some moisture could result in a few showers although clouds only seems will be the prevalent modus operandi .

An impulse in the mid-level flow later today or early evening could bring showers or thunder (as shown in the dashed orange and northward extent of the green)...but those chances are conditional upon whether this impulse will actually manifest as indicated on model guidance or is merely a figment of model out put. Yet further north, instability is meager (per latest data), despite the clouds which can be seen on visible satellite imagery, it would seem unlikely that much beyond a quick shower at best will occur north of I-4, except in the Ormond Beach toward Jax area in from the coast.  There is almost zero convective inhibition in place over the state today. What this implies is that the any convective available potential energy (CAPE) will not be inhibited from escaping into the atmosphere, and thus will not be able to build up to result in thunderstorms without respectable low level boundaries or mid-upper level triggers in place despite that cold air aloft is in place, as noted yesterday.  Therefore, and again, late afternoon and early evening activity is 'conditional' upon the impulse (disturbance) being realized.

SATURDAY-WEDNESDAY: Winds could remain as is today through Saturday into Sunday and be perhaps a bit stronger one or both days from the ESE-SE as high pressure moves off the U.S. SE Coast and into the  SW Atlantic toward Bermuda. Although a few light showers could occur at any given point in time, the prevalent condition appears will simply be rather comfortable/seasonal temperatures with some periods of greater cloud cover, but nothing worth noting at this point in time.


Next Chance of Broader Coverage of Measurable Rainfall? : Appears in the Late Wednesday and Thursday time frame.

East Coast/South FL Shower/Thunder on Friday?

Latest visible imagery shows a smoke plume descending SSW from near the Florida / Georgia Border (white annotations). Otherwise, although some showers could occur toward South Florida today, the better chance from Brevard and Southward appears will occur on Friday from near sunrise through the day and into the night, as long as into noon Saturday.

***Thank you for comments to this blog, from as far back as a year ago . I found some comments had been posted to previous posts during the past year but  receive no personal notification they had / have been made. Found them this morning.  Appreciated! ***

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TODAY: Upper trough off the U.S. East coast with Florida along the SW Periphery of said trough, with mid level disturbance dropping along the backside of the trough and across Florida appears could impact parts of South Florida today with a few showers. Otherwise, status quo weather of yore continues,  with light on shore winds and afternoon cumulus clouds away from the coast (where subsidence behind the sea breeze front could result in mostly clearer skies). In regard to the above image, the clouds off shore are dropping south. Not seen now was a healthy thunderstorm cluster (Sir-prize!) that dropped south from east of central and all of the state (no longer visible). This was picked up well by the NAM model, which bears as preamble for what it shows tomorrow..at least in theory.


TONIGHT/TOMORROW: Appears the mid-level vorticity/boundary will get locked up toward South Florida and retrograde toward Central late tonight as surface high pressure presses SE of the state, resulting in a E -ESE surface wind by Friday...a bit complicated to explain, but we can suffice it to say that pockets of 'vorticity' (coiled wind energy as noted passing overhead and retrograding) combined with very cold air aloft for this time of year "schould" (choose which word fits best) result in a coastal trough with very reasonable upward extend as high as 10,000 -13,000 ft (as opposed to 2-4000 ft under "normal  circumstances" for coastal troughs.). 


Convergence in the low-mid levels combined with moisture being tapped into with  E-ESE winds  along and behind the trough could result in moisture convergence  working upward toward 10-15,000 ft along and behind this trough.  This (stress 'assumed') moisture combined with the mid-level energy already in place and upward vertical Velocity fields ..most likely along the east side of this trough... could result in showers and maybe even thunder as far north as the Cape by later tomorrow, but more likely from St. Lucie County and South. Most activitiy will occur East of Orlando southward working inland the further South one progresses.


Otherwise, seeing as how this a new manifestation which developed in model guidance during the past 18 hours, this rain chance "~en-masse chance ~" bears watching for a good rainfall total potential if the NAM model runs of the past 12 hours have any merit along the east coast from the Cape and South (although, its track record has been below less than stellar for quite some time now). 


Given the cold air aloft and veering (but rather weak) wind profiles...would not be surprised to see worst case coastal waterspout potential popping up somewhere along the east coast some time tomorrow toward the coast. On the other hand, most areas will more than likely see increased cloudiness through noon Saturday at least along and South of I-4.


SATURDAY: Rain chances/clouds diminish mid-morning through afternoon from East Central fairly quickly toward Southwest Florida as the trough washes out and high pressure reigns supreme.  No true chance of measurable rainfall (if even) is indicated well into next week after Saturday's 'potential slight chance of showers' when "Bermuda High Syndrome" kicks in, resulting in SE-SSE winds round the clock , day and night prior to the next boundary in question toward later next week.

Isolated Showers/Thunder..Most Numerous South Central/South

Image shows 11AM Front Position. Color codes show chance of ISOLATED fast moving showers and possible thunder heading toward the East Side of North Central being possible, with most likelihood existing
South Central and South Florida today prior to frontal passage

TODAY: Front sinking south from North Florida should slow down a bit today with heating of the day, but nonetheless press through dead Central around 3-4pm at the latest. Ahead of the boundary isolated showers and some thunder is possible, most likely toward SE Florida and Eastern portions of South Central as the day winds on. Some lightning is occurring as I type over South Florida..meanwhile, a thin band of showers which could grow toward thunder producers heading toward noon time and beyond  now occuring over NorthCentral and pressing east while sinking south with convergence along the front itself.


The front should be crossing Central Mid-afternoon and continue south through the early evening hours where the strongest of storm 'chances' would seem most likely.


TONIGHT/SATURDAY: Behind the front a surge of north to NE winds still appears likely, with gusts in the 20-25mph range and a chance of light showers from the Cape and South. The wind should die down most notably at first by early evening on Saturday working down the coast and through Saturday evening with partly to sometimes most cloudy skies at times, mainly again from the Cape South. 


Shower chances after Saturday morning might be limited to sprinkles and maybe a some localized measurable amounts right near the east coast from  Brevard County to Miami...as the winds level off in the 15-22mph range during the day.


EASTER: Winds from the east around 10-18mph, with maybe some higher gusts earlier in the day, with very isolated sprinkles near the coast under partly cloudy skies. Winds decrease throughout the day though, so that by Monday and Tuesday these winds will be all but completely diminished to light under partly afternoon skies.

Strong/Severe Storms "Possible?" Late Today - Friday (South half)3p

3PM Visible Satellite Imagery shows: (1) The departing MCS (Mesoscale convective system) to the east of Florida. This system prompted severe storm warnings last evening near Tampa and heavy rains and thunder south Florida early this morning, but mostly created only light showers and clouds elsewhere (2) At least 2 separate systems to the west and NW of Florida. These (the first) will be entering the western Panhandle while another approaches NW Florida in only a few hours to then cross the north 1/2 of Florida. Further impacts through mid-afternoon Friday are largely 'up in the air' ...with a threat further south after dark toward midnight

TODAY: Complicated and 'numerically convoluted forecast modelling' makes for an 'intrepid waters' and delicate forecast  scenario   late this afternoon into late afternoon Friday for the state. A shorwave vort max, turned "MCS" as indicated on yesterday's post survived the trek to Florida, mostly impacting the Southern 1/3 of the state in the wee hours. Two storms that I am aware of were severe warned or being watched, or exhibited near severe potential near Daytona late yesterday with .70" sized hail, and another was closely monitored in Osceola County in the early evening hours. Those storms were not associated with the MCS that moved across later and overnight. The dilemma with that system was that virtually not one model indicated the scenario to unfold the way it did EXCEPT the High Resolution Rapid Refresh Model. More complications today.


For today's forecast, we'll ride mainly on the coat tails of the Storm Prediction Center (SPC) watching for near severe or actual Severe Storms with a tornado potential nearly state wide, but highest across West Central Florida late today and/or tonight. As can be seen above, there is three meteorological foci of interest to be monitoring from late afternoon through tomorrow afternoon.


The first one (which by now should not exist per some models) appears to be approaching NW Florida and  will likely stay north of I-4 this evening; however, any further growth southward could breakout a threat with it into much of Central Florida toward dark. Virtually every model shows that convective inhibition will over-take much of Central (however), with much of the remaining activity shearing out after dark (dying off). If this is the case, zero severe weather will occur, if even rain for that matter.

Latest radar trend shows dying storms. These 'could' rejuvenate as they cross the state
but no model shows this to be the case

 Based on the strong wind fields (Especially heading into Friday across the South half of the state, as well as cold air aloft accompanied by sufficient low level instability, it would be a bit presumptuous to rely on model guidance in regard to precipitation fields, especially if this system mimics that of yesterday which presumably was to not hit the state at all. In fact, last night at the time storms were being warned as they approached Tampa, none of the main player models even showed that any rain was falling ANYWHERE or was supposed to be....so much for model reliability.


THROUGH FRIDAY: Although Severe Weather certainly looks possible, actually any severe storm will remain isolated ...as opposed to a squall line type 'event'. Another disturbance associated with a cold front itself is forecast to enter Central Florida from the north by early afternoon (if not sooner) on Friday. Timing of this feature is not at all pegged down, thus as a precautionary measure it is best to raise the level of awareness that should the feature be delayed into early afternoon, strong storms will again be possible along and south of SR 528 toward Tampa Bay after 10AM Friday and southward as the day progresses.


LASTLY: I will again stress the models show virtually close to Nil Severe weather potential except perhaps later today north of I-4. Thus, best to stay attuned to later develops as a tornado potential cannot be ruled out either. We can see how this is depicted by the SPC based in Norman, Oklahoma.

Per spc.noaa.gov   website. Do note the color coded schematic. The threat  overall is very low, but nonetheless exists. Highest potential above 15% toward the 45% start to be associate with MDT- HIGH RISK severe weather events. The area bounded in green is a 'General Risk" area. Also possible is near severe or actually severe category winds and 1" hail. All under the assumption that storms will manifest in the atmospheric environment over the state later today into tonight through and past midnight.  ALSO: Another potential threat area remains for the South 1/2 of the state from mid day Friday through a part of Friday afternoon (per model guidance as well as the SPC)  

SATURDAY: Stronger ENE-NE winds still anticipated with some cloudy skies mainly near the East Coast. This front has now sped up in timing by about 6 hours from yesterday's post. Either way, at some point between Friday night to early Saturday morning breezy and non-beachy weather anticipated with cooler temperatures in the 70Fs.  


EASTER: Winds will be letting up before Sunset Saturday evening, and in the 10-18mph range from the east on Easter Morning with scattered clouds, and 'possibly mostly cloudy' near the coast from the Cape and South to Miami.

Rain Chance Thursday/Friday: Much Improved For Easter

Clustered line of Showers/Thunder is pressing east and south across the Northern Gulf early this Wednesday afternoon. It appears most if not all of this activity will wane out after it gets beyond the Loop current, and thus holds no threat to the Peninsula. Otherwise, Showers and some thunder (isolated ) toward I-10, and maybe a quick shower along the SE Coast of the state much later today. Temperatures aloft are quite cold, but suspect that even though those could help in storm growth we first have to get one to generate. Moisture is rather sparse though aloft, and 850mb temps would take quite a bit of upward forcing for much to manifest, so isolated at best for a shower or the far chance of thunder seems to be a precautionary measure more than anything else. This area IS worth watching though, just in case.

TODAY: Warm interior to east side today with highs in the low 90Fs all interior areas and near the mark at the beaches as well by 3pm. A sea breeze does not look very likely, but if it does manifest, it will remain pegged east of I95, and prevent highs from reaching the 90F mark where it reaches. Some possible increase in higher clouds overnight after dark as a result of remnant clouds from activity over the Gulf. Otherwise, today's rain chances are noted in the above image.


THURSDAY/FRIDAY: Much better 'chance' of rain and thunderstorms from north to south late morning through sunset Thursday, and even earlier on Friday. Although guidance shows temperatures to be very cold and winds aloft increasing through Friday as well with instability in place, there is a problem in regard for much beyond general to isolated coverage or rain and/or thunder will actually exist. That being, the potential for high level clouds to shut off the storm producing atmospheric mechanisms, in the absence of only pockets of deeper moisture. Additionally, most of the precipitable water on forecast soundings is showing up above or near 10.000 ft as opposed to low levels, thus negating the potential for low level moisture convergence in the absence of sea breeze boundaries.  


The misnomer for both Thursday and early Friday will be if there is an ABSENCE of high clouds to start the days or heading into the early afternoon hours. There is a chance of strong to severe storms most anywhere over the state both days contingent upon at least the high cloud coverage scenario, the less amount of high clouds, the better chance of storms. ..coupled with the lack of any well defined (if any) sea breeze boundaries and fast steering currents from west to east. It may be that thunder will be restricted to off the east coast and just off or near the west coast on Friday and/or Thursday.


This scenario has been unfolding in the mid range models in various ways since Sunday, so we'll need to be monitoring both days for strong storm potential.

Forecast First Shot for Friday afternoon. Since previous post, model run continuity within and between models shows the front to pass through the state at least 12 hours sooner the previously surmised with a boundary being located close to that shown above around 2pm FRIDAY (the image is mis-labelled) 

SATURDAY: Frontal boundary to press rapidly down the state Friday, followed by a period of stronger NE-ENE wind later Saturday afternoon and evening. Saturday does not look like the best kind of day for beach goers, with low level clouds possible although not entire cloudy by any means and possible light showers especially along the SE Coast. The atmosphere becomes quite dry above 7000 ft or so and dries through Sunday beyond Saturday evening. The most windy conditions appears will Friday afternoon through late afternoon Saturday.


EASTER SUNDAY: LOOKING BETTER than previous forecast model runs.


Continued ENE winds around 12-18mph with a few low clouds and morning lows close to 65F at the beaches and cooler inland with highs in the mid-upper 79Fs., with winds gradually dying on out further into Monday and eventually becoming more WSW by Tuesday as the next boundary (show above ) approaches. So far, no rain expected with that boundary due to the nature of this particular synoptic scale set up not allowing atmospheric moisture to recover to high enough levels to formulate rain making type clouds. A small cooling trend appears to be in the offing from Saturday onward. most notable inland Sunday/Monday mornings and toward the west side of the state.