"Strong" Storms "Possible" Friday - Saturday

August 29, 2016 Off Cape Canaveral

TODAY: One more day of slightly warmer than normal temperatures as air mass modification begins the slow, post-tropical translation through the vertical extent of the atmosphere. 

Temperatures aloft remain in that way of warmer aloft as tropical air-masses are. On the other hand, with the wind fields of the past days having been resolved away which prevented sea-breeze/lake breeze convergence manifestations, we should be able to realize a better chance of storms or showers later in the day near the I-75 to Route 27 corridor and northward all along I-10 where showers and thunder are already underway.

Wouldn't expect 'wide-spread' thunder to be at hand. Better chances of 'thunder itself. appears to be over Southwest Florida northward toward Lake County (in general) with the better 'late day' chance in the more northern arena.

FRIDAY-SATURDAY:  "Summer Resumes" - For now will take the 'sweepingly broad over-generalization' approach to these days as there are specifics being implied by guidance that could potentially put a major crimp in the forecast, especially in the areas north of I-4 where cloud cover 'might be more prevalent' throughout the day. Big 'if" though. So for now...

Upper level temperatures , especially at 500mb are forecast to cool toward the -8- -10C realm with mid-level temperatures a bit slower to catch up (if at all). Additionally, there are implications of the upper levels being nearly saturated the more north of SR 528 one goes. which could mean that cloud cover could hinder 'strong' storm development in those areas. 

The issue further south is a remnant dry layer around the 700mb level. This could either hinder storm strength or add to it, depending on how vertically deep that layer will actually end up being.

Regardless, given continuity in the GFS model going into two days now and between 4 model runs will load the gun and prepare to pull the trigger on making the 'Stronger Storm' call. 

Was tempted to write 'even isolated marginally severe', especially near I-95 from Ormond Beach south toward Vero Beach late in the day" but that might be over doing it a bit. 

Either way...for either one or both days...shower and cloud coverage will be increasing..most persistently it appears over the the northern 1/3 of the state, where even pre-dawn showers with thunder might be in process near the big bend and into the pan handle regions.   

South-Southwest Flow to Southwest will be in place but not so strong as to prevent the east coast sea breeze from forming and making progress toward I-95 as it appears now. Overall, Saturday does not look like a good day for late - day activities.

SUNDAY: Temperatures aloft warm as light easterly flow resumes it's course. Moisture availability becomes much more 'spotty' in nature so making a call as to where rain may or may not fall becomes increasingly difficult. 

Overall, chance of earlier day (pre-sunrise to late morning) showers might be in the calling for certain areas along the east coast,  working inland and increasing toward the west coast later in the day.

EXTENDED: The general pattern noted for Sunday persists through at least Tuesday and/or Wednesday. Latest GFS shows an early season 'cold front' making the sweep into the Deep South, even Northern Alabama, Mississippi, and Georgia regions. If so, a more 'thundery' pattern state-wide, even perhaps toward the immediate east coast might enter the picture. Assuming the GFS is correct.

"IRMA": Seeing talk wide and broad over the internet concerning how this Storm System 'might' be a threat to almost anywhere along the U.S. East Coast. In some regard, suspect some of the amped up chat is due to Harvey's Impact and fears of 'more of the same' are at the fore-front; however, those fears do not make anything else any more or less true than would be the case for any other system, whether Harvey had been or not.

As of early this morning, the only model that shows a potential 'threat' to be the case out of several that I've looked at is the ECMWF (European) model. The CFSV2 model shows a similar more southerly track toward the Southeast Bahamas  with the storm being approximately 120 NM east of Cape Canaveral next Saturday moving northward...other guidance points to more of a threat to Bermuda and possibly the Northeast States (if even that). 

Point blank, it's just too soon to say, and that a 'threat' is not utterly out of the question.

Dry For Eclipse Monday : 'Unsettled' With Rain -- Storm Chances Tuesday & Beyond

"Arcus Accessory on the Archway!" - Canaveral Cruise Terminals -
Friday, August 18, 2017

An unsettled weather pattern of showers and thunder being possible (even at times over night (especially over the Atlantic) with some 'early on-set ' days possible with varying others modes of operation at hand beginning mid-day Tuesday or as late as earlier on Wednesday through end of month (a few details further in post)...as for today...

SUNDAY: Remnants of a tropical wave already encroaching in on the southeast 1/3 of state to glide over the state today mainly south of I-4.  Wind will be light in the moisture laden air-mass though mainly east to southeast up through the column less than 12 knts.  Guidance is split on how far 'east and north' rain could occur today with greater agreement that points to Southwest Florida.

The area from mainly Indian River and Brevard toward Osceola and eastern Orange Counties is a 'questionable region' in regard to whether they will experience mainly cloud cover or actual rain-showers/storms. The HRRR (High Resolution Rapid Refresh) model is consistent on saying 'no chances' (at least early this morning) whereas the 4KM NAM model for the same time is and has been  consistent on saying 'Yes' to the chances for this AOI (Area of Interest). 

The greater chance of storms/ rain for the mid-late afternoon is along Southwest Florida where the best chance of the combination of moisture and low level convergence along the West Coast sea breeze will occur. 

If the areas of Brevard/southern Volusia/Indian River and maybe even St Lucie are to see showers/storms it would be from south to north between 11AM heading toward the 2pm hour (generally speaking).

MONDAY: Sunday's activity will be the first in the next wave of the set to move in, which is on Tuesday. Between waves will be a lull in the action. Enhanced water vapor imagery clearly shows the respite timed nicely for "Eclipse Monday 2017". GFS does show rain storm potential however earlier in the day with a rapid decrease moving to the 'critical eclipse time-frame' of early to mid afternoon as the remaining moisture from Sunday's wave moves west and out of the picture. 

With that said, not to be surprised (just in case) if showers and cloud cover are still sensible (especially along the east coast) early in the day on Monday.

TUESDAY-BEYOND:  

Expect forecasts to shift around rather significantly , almost on a daily basis,  from Tuesday on out at times due to the uncertainty of where, when, or even if an area (or areas) of low pressure might form, especially in the Wednesday - Sunday time frame. 

 A rather complex scenario is at hand in regard to surface and mid level features in regard to the evolution of circumstances, though there appears to be agreement. more or less. that abundant tropical moisture in the mode of PWAT air (precipitable water) values being near to well above the 2.00" mark (comparably speaking, in winter months it is normally 1/2" - 1/4" (or even less at times - aka 'dry air'))

The onset of the moisture is along the leading edge of an AOA being watched by the Hurricane Center which is not forecast but by one model to develop beyond an 'organized wave'. There does seem to be some agreement later on though after this area moves over the southern 1/2 of the state that a weak surface to even mid-level area of low pressure will form either over or just to the east of the state, but it's just too soon to say with any confidence if , when, or where that might occur.  

Apart from a wide mode of potentialities, regardless of what transpires there has been at this point no risk of a bona fide 'tropical threat' outside of perhaps what eventually might evolve for some areas of localized flooding in flood prone areas due to heavy rainfall (mainly during the afternoon and evenings) with consecutive convective days occurring back to back. And if a system does evolve into the realm of the naming convention type it is seen so far to do so east of the state and remain far enough away to not have a direct impact.

Arcus Shelf Accessory from Parent Thunderstorm over the Banana River - Port Canaveral, August 2017

Initially rain fall could occur most anywhere at any time (though mainly later morning through late afternoon) south of I-4 (Tuesday/Wednesday time frame), but as an upper level trough builds south from northern latitudes in response to ridging over the Western U.S., the steering flow becomes progressively more southwest toward the northeast especially as we head  into Friday through Next Weekend. If a low pressure area does form east of the state there could be one or two days of decreased activity with northerly flow to the west of the system, but it's too far out in time to hedge any bets on if that will occur; so far , even if that does occur as the GFS has been implying, moisture is foreseen to remain ample from 'some rain' chances even if so .

Emily's Offspring to Provide Rain to North Central - North Florida

"Rain-Storm" - July 28, 2014 Near Satellite Beach 

TODAY: Things have changed rapidly (though not unexpectedly) overnight. A surface boundary associated with departing Emily left a surface front across South Central by late yesterday. That boundary has retreated as a 'warm front' north to almost I-10 as of 10AM.   South of the boundary, as can be seen below, Emily's offspring in the form of a 'vorticity max' (more than one) is on the trail toward North Florida today, with another apparently awaiting in it's wings for tomorrow further to the Southwest over the Loop Current. What exactly will occur with that is questionable, but for today...

Cloud cover already beginning to over-spread areas that were earlier thought might see a 'good shot at thunder'  so earlier model runs to be tossed. How pervasive the in-coming high - mid level clouds into parts of Central or even South Central  will determine where, if any where, strong thunder will be realized, if in fact, much at all.

For now based  on watching satellite loops , and based on latest wind-profiler information from around the Space Center along with surrounding Rawinsode Sounding Data out of MIA and MLB will go with increasing cloud cover especially along and north of I4. Chance of thunder there still exists but am hesitant to call for 'stronger storms'. Further south and east the chance might improve depending on how much prolonged insolation is received before 2pm or so.

Steering for rain showers and storms is from the WSW-SW at around 17kts from cloud base on up into the mid levels but not strong enough near 'the deck' to off set the development of the east coast sea breeze from Daytona and South. Thus, rain-thunder storms to move easily from west to east today and straight off the coast. Best guess for now is that the east coast sea breeze will form but remain close to the coast, especially for Brevard / Volusia. Best area of insolation and sea breeze/outflow convergence appears to be the coast of Brevard and Indian River Counties then curving inland a bit toward northern side of Lake Okeechobee, and western half of Martin County. Other storms could form further south from St Lucie County to Palm Beach, Broward and Miami/Dade.  

Hazard mainly would be lightning as usual, and heavy rain. Thankfully the majority of the largest rainfall totals appears to be over areas that were least impacted by Emily the other day, though areas that did receive high totals will still see more rain chances today and tomorrow to add insult to injury. Outside of the pervasive lightning threat, stronger wind gusts could occur in the area in 'red' (only as an example). The area in purple is highlighting where it looks like the highest two day rainfall today will be.

THURSDAY: Again, a somewhat similar situation at hand that will likely evolve in a different way. Drier air is to   advect  around the west side of High pressure building in from the Western Atlantic first to South Florida then up though all of South Central by late in the day. Though there could be 'some rain ' in those areas though not very likely but in isolated cases, the better chances for thunder/rain on Thursday appears will be along a line running from near Palm Bay toward Sarasota and north..with an even better chance along and north of I-4 (generally speaking).

FRIDAY: Looks so far like a 'dry slug' will move in with most rain chances restricted to North Florida.

SATURDAY: Shifting again to respectable thunder /lightning risk in what appears to be a  'typically on the wetter type of 'Summer' type of Day ' regime as the ridge axis continues to lift north from South Florida to Central Florida. 

SUNDAY: Same regime as ridge lifts even further north. Rain chances from here on out going into at least mid week next week go down appreciably many areas. Some consecutive dry days in some areas are thus forthcoming. possibly for nearly a week toward next weekend at the rate it's looking now...with most rain chances restricted to SE Florida in the mornings and the interior and west coast in the latter parts of the day.