"But seeing they could not See; hearing they could not Hear"
“The views expressed herein are those of the author and do not necessarily represent those of the National Weather Service or affiliate/related organizations. Please consult .gov sites for official information”

"From its chamber comes the whirlwind, and cold from the scattering winds." - Job 37:9.

"The wind blows to the south and turns to the north; round and round it goes, ever returning on its course".

Wednesday, June 30, 2010

Changes Are Slow To Manifest

(A Florida thunderhead wears a crown of pileus in the late afternoon)
Although there have been some minor changes in the past 48 hours they aren't of the genre that have influenced the local weather here on the ground. A mid-latitudinal level trough is weakly reflected at the surface as it presses east and south through the mid-Atlantic region into Georgia, and the TUTT low mentioned the other day continues to spin and drift westward and is now located over the north-central Bahamas. Meanwhile, Hurricane Alex has begun the anticipated turn toward the west as will likely make landfall on the Mexican Coast.

SYNOPSIS: We might be starting to see the affects of (1) the TUTT low as per latest from the KSC sounding as I write. Winds at the anvil level have picked up significantly out of the NNE since yesterday which appears to be induced by the circulation around the NW periphery of this feature. Water vapor loops are also showing quite nicely the circulation; however, the drying subsidence result of the low are also being reflected and showing to be encroaching on the offshore waters as we speak. (2) The trough traversing through the mid-Atlantic states and eventually into the Atlantic. As mentioned several times during the past week the GFS was indicating that this trough would push a cold front ...or a trough of lower surface pressures...into the Deep South and even Florida. The NAM has begun to fall in line with this scenario although not quite as aggressively. It does appear that the mid-level trough will make it down to at least Central Florida as we work into the weekend...however, dynamics associated with it are about as close to benign as one can get. Between the TUTT low and this trough the ridge that has been overhead, it now appears, will come to its inevitable demise by the Friday-Saturday time frame. Just exactly what will happen after that at the very local level is nearly impossible to ascertain at this point. But as we stay focused on the shorter term:

TODAY: Much like the past few days. The atmosphere has changed very little from yesterday and might have actually dried just a smidgen. Winds in the mid levels are nearly nil in association with the decaying ridge axis...where as much higher up they have really picked up out of the NNE. All in all, the start to the day should be similar to the past few days. Expect we can once again see some shower activity go up along the west shores of the Indian River (along US 1) and points west of there before noon time anywhere in Brevard or Indian River Counties, but don't anticipate these to be anywhere close to the 'strong thunderstorm' category. As we work into the early afternoon the east coast sea breeze will have set its wheels in motion and begun to propagate well inland toward the Orlando area...scouring out the immediate east coast of any possible rainfall as it does.

About the only difference the coastal communities might see from the past few is that we will not see the cirrus/anvil blow off umbrella overhead today by late in the the TUTT low inches in every so closely, drying aloft is increased, and the direction of the winds aloft will not be favorable for anvil debris transfer in this way.

On the other hand, the west half to 3/4s of the state will see their status quo of scattered to numerous thunderstorms, primarily west of a Lake Okeechobee-Orlando-Ocala axis...along with most of the panhandle region. This would include areas such as Port Charolette, Ft Meyers, Sarasota, Tampa, The Villages, and about anywhere in Lake County. In essence, the area LEAST likely to see good storm coverage or any strong activity is right here at home central (a.k.a. - east central Florida.)

FURTHER OUT: We haven't had rain in Cape Canaveral since June 7th! So when will it finally rain here and other areas near-by? I'll just say a sentence or two concerning this increasingly irritating subject. Nothing stands out and things are looking pretty pitiful. Nothing stands out to negate the fact that it COULD rain county wide...but then again, nothing screams "RAIN" either. I'm expecting to hear about rainfall chances increasing over the media in the next couple of days...but I have this bug in my ear whispering that this is going to be one of those scenarios where that although moisture in the atmosphere will be increasing, particularly by Friday, that it will only manifest itself as increased cloud coverage which will negate what could otherwise be a period of active thunderstorms. The proof is in the pudding so that say, so I'd really like the atmosphere to stir it up good and get things perking so we can get some tasty atmospheric samplings around here. But we need all the ingredients.

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Monday, June 28, 2010

Greater Storm Coverage Again Today

What a change a few days can bring. That has been the case the past two days and this trend will ever so slowly continue as a number of unrelated features attempt to come together in a somewhat ambiguous, if not questionnable, fashion during the next 48-96 hours.

To start the day its seemingly no different than any other normal summer day across the area. I noticed a few scrappy attempts at cumuliform development as early as 8am this morning and although they seem to be dissipating already at this time it is still a sign of things to come (like yesterday) as we work into the afternoon hours. Latest KSC sounding indicates that moisture in the upper levels of the atmosphere has increased quite a bit and temperatures at this level have dropped a degree or two. That's a good thing. On the other hand, at the mid levels is where the greatest drying has occurred in parallel with a slight warming at that level, which is not a good thing (as for as precipitation prospects are concerned). Otherwise, the infamous ridge axis remains parked across Central Florida in general, just a tad further to the north at the surface but more directly overhead to just a tad further south aloft.

Elsewhere, but of possible significance to our local environment in the upcoming 48-72 hours, is what is happening in other regions far from home. Three things stand out right away. (1) Of course, there's TS Alex..(2) then the cold front and associated upper level trough just now beginning a dig from Canada which in the near future will impact the east coast in various ways from New York to at least Central Florida.. (3) and finally another item I had inadvertently failed to mention yesterday is a TUTT low east of the Bahamas which has been circulating out that way for a number of days now and has been slowly creeping just north of due west. It's fun to watch on satellite and water vapor loops but has little active weather associated with it.

Keeping those items in mind we can briefly shift gears to the local area and today's weather makers. As noted earlier, the morning XMR sounding was warmer and driest in the mid-levels. This indicates to me that earlier day convection will essentially be held at bay to nearly non-existent. Steering winds at this level are nil...that is until we get up to the 20,000 to 25,000 foot level where they are about 10 kts from the west. PWAT values throughout the column are about the same as yesterday...but as noted earlier most of this is found either very close to the surface or way up there in the heavens.

There really is no reason why thunderstorms cannot once again erupt by mid-afternoon once sea breeze and lake breezes boundaries begin to interact under a generally light SSE surface flow regime. Like yesterday, storms will erupt along or just west of I-95 and move little to none. About the only difference I see the potential for today from yesterday is that the east coast could see some storms anywhere from Daytona Beach north to JAX under a weak west to east steering flow...but as one works further south toward Brevard areas east of I-95 will be hard pressed to see the wet stuff since any steering currents that exist (or will exist) will essentially be from south toward the north for any convection that gets going in earnest. Since the atmosphere is very moist very high aloft, expect that the storm tops (anvil blow-off) will hold together and spread toward the east and over the coastal communities. This means that by late afternoon into the early evening many of the beach side cities will be under a cirrus umbrella with a dark look to the sky as one looks least this would put a damper on uncomfortably hot late afternoon temperatures when combined with the sea breeze. Any storm(s) that get going well enough to make a serious punch through the mid-levels could produce some small hail or close to severe wind gusts as they collapse, but for now it appears that any such storm will only manifest itself along I-4 in the interior away from either coast...not discounting the DAB reporting station however.

Expect to see other storm activity, although maybe not quite as potentially vigorous across interior Osceola County, almost anywhere in Orange County and Seminole, then further east and north the closer to Daytona one gets.

As we progress through tomorrow and into Wednesday things become even more interesting with regards to storm coverage / location potentials. It still appears that the trough along the U.S. east coast will dig at least as far south as the Deep fact the evening GFS run was even more vigorous than any run yet over the past 4 days! Whether that comes to fruition in quite that fashion of aggressiveness or not, the combination of "a trough of sorts" along with that 'passive' TUTT low east of the Bahamas will at least erode the ridge at the upper levels that has loomed overhead almost entirely by Wednesday. This is important in that this would result in the upper level temperatures to cool by at least a few more degrees resulting in an unstable environment juiced enough to induce storms with a greater punch and lasting power...and with an increased number of them other than just the one or two Central Florida has seen the past several days. The GFS is STILL continuing to form at least a closed low circulation along the Florida-Georgia border by Saturday then strengthening that low as it moves off the southeast U.S. coast. Circulation behind this low in combination with high pressure building south along the Appalachian Chain pushes the trailing wind shift line (frontal boundary) through Central Florida by early NEXT week. Although the GFS has followed this train of thought for several days now...just as aggressively as ever...the timing of all these factors to come together has been pushed out be nearly 48 hours since it initially portrayed these implications.

The low down if we look at the very broad, unfinished picture is that storm coverage will increase most notably across all of Central Florida by Wednesday through Friday...there is no indication that the area from Brevard County and points south will see a strong push for storms to assuredly penetrate eastward right to the coast at that time...but on the other hand these are no pointers out there stating this couldn't happen either. That will be contingent more on daily if not hourly localized circumstances which can be fine tuned as we get closer to that time frame.

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Sunday, June 27, 2010

Current Changes Slow to Affect The Area

(Image: The typical summer afternoon view to the west which has been close to nonexistent for several days).
As has been the case for what seems like eternity the rain chances remain low today, although not as low as has been the case for the past several days. As discussed previously, a low pressure trough will be digging down the U.S. East coast for the early portions of the week which will most assuredly swoop a cold front trough the Northeastern states. Also, the high pressure ridge axis that was stretched from east to west across the Deep South and well north of the state has shoved south and is now directly over Central Florida if not a little south of the region. This ridge axis will waver north/south within the parameters of Central Florida through Tuesday as the aforementioned trough makes its final dig along the east U.S. coast. This process began to a very small degree yesterday and will continue through Tuesday...and as such, thundershower activity will be on a gradual increase but not likely affect the immediate coastal communities at least not through Monday.

Early start to some morning cumulus clouds, although sparse, are at least indicative of the gradual changes taking place this morning. Yesterday we saw a thundershower of two near I-95 in S. Brevard, and expect to see at least if not more of the same today as moisture ever so slowly is allowed to slowly increase in the next few days. This process actually began yesterday as reflected on earlier...but the moisture influx and weakening of the ridge aloft will become more apparent as we work into the upcoming week.

As mentioned the other day, the GFS was most aggressive with the east coast trough...and actually pulled a cold front into the peninsula. Nothing has changed in that light as of last night's model run...but the way in which this occurs (per that model) has shifted gears. It is now joining the trough associated with Tropical Storm Alex with the NE U.S. trough into one huge robust system...and as such draws gobs of moisture (and resultant storm activity) across the state beginning Wednesday-Thursday. Additionally, it was one of the 'outlier' models to actually draw Alex well north and east of nearly all of the other forecast models toward Louisiana. Believe this entire scenario, at least at this time, is highly unlikely and will disregard such aggressive behavior.

Regardless of that unlikely scenario, it does appear that once Alex moves yet further west and the east U.S. coast trough digs even more the ridge axis aloft will be close to non-existent or at least relax considerably if only for 2-3 days toward the middle - end of the upcoming week, which will result in what one would be considered normal rainfall/thunderstorm coverage over Central Florida once again.

Meanwhile, for today expect to see some thunderstorms sprout up, which like yesterday, will at least be visible from a distance at the coast, but will remain along or west of I-95. Because the ridge axis has sunk considerably south of its location late last week the steering current, albeit very weak, is more from south to north, thus any rampant offshore activity is unlikely to reach coastal communities. The surface winds have veered to more of a SE-SSE component as a result of the sinking ridge axis as well. Once the sea breeze begins in earnest this afternoon that should be enough to stabilize the atmosphere along the coast so that by the mid-late afternoon all the convection will be west of I-95. The most favored areas for storms today will be along the west side of the state from Tampa toward Ft. Meyers as well as all along the panhandle and toward just south of St. Augustine further north along the east coast.

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Thursday, June 24, 2010

"When Thunder Roars, Go Indoors"

(Image: Scenes we'd like to see in Central Florida again)
June 20th though the 26th is national lightning awareness week as declared by the National Weather Service. But for the most part this state has been nearly lightning free (although not entirely), particularly right along the east coast. But changes are lurking as we head toward the beginning of next week.

Almost no change in thinking from yesterday's post so not much to highlight. A high pressure ridge axis both at the surface and aloft extends from the Atlantic westward across S. Georgia this morning and into Texas. Unsettled weather continues in the Caribbean showing little sign of organized development.

Basically no change in this configuration through Friday and essentially Saturday as well. Of interesting note, as mentioned yesterday, is the trough of low pressure forecast by the GFS to dig along the U.S. east coast, especially as the area of disturbed weather in the Caribbean shifts west toward the Yucatan and the high pressure ridge erodes from the west and shifts further into the Atlantic as we work into Sunday. It is worth noting that the GFS has not once developed the tropical area in the Caribbean into a full blown system during the past two days, yet on the flip side has been adamant on developing the east coast trough into a full blown frontal boundary that penetrates the Florida peninsula which would be quite a climatological anomaly for this time of year.

When all is said and done, it does appear at this time that a trough will deepen down the U.S. east coast during the course of the next 72 hours and the ridge axis will relax, especially as whatever happens in the Caribbean shifts west toward the Yucatan peninsula. This is 'important' for us because it will mean a change in the overall weather pattern across the peninsula beginning late Sunday which will notable by Monday afternoon.

In the meantime, persistence will be the ruling factor as deep layer / relatively dry easterly flow persists. By Sunday this flow will shift to more of a SE to SSE component and allow higher atmospheric PWAT values to encapsulate the region. What will become of the frontal boundary remains as much, if not greater, a mystery than what is happening (or forecast to) in the tropics. Namely because it would be extremely unusual for a frontal boundary, as it were, to penetrate Central Florida as depicted by the GFS.

When push comes to shove for the time being, at least through Tuesday, is that we will be undergoing some notable changes beginning overnight Saturday into all of Sunday as the ridge loses its prevailing influence and a trough develops down the Appalachian Chain into the deep southeast U.S. I have a hard time believing that a frontal boundary will actually make it this far south at this point, but do believe that regardless of whether that occurs or not an increase in shower/thunderstorm activity is in the cards beginning Sunday (initially for the inland areas) which will be more widespread and possible for even the east coast Monday through Wednesday. This conclusion will undoubtedly need to be refined as the time draws nigh.

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Wednesday, June 23, 2010

A Few More Quiet Days in Store

(Image: What is left of a drive-in theater in 'no where' Texas. What is showing at this theater is reflective of what is showing in our atmosphere today...NADA)

High pressure reigns supreme across the Western Atlantic and the Deep South today as far west as across N. Louisiana and extreme Western Texas. Subsidence along the ridge axis which exists both at the surface and aloft will inhibit convective activity (thunderstorms) across all of our area today. In the meantime, an active storm pattern remains across the northern tier of states from far eastern Wyoming the whole way east to the Jersey shore. This is the area of interest, once again, as a train of severe MCS storm clusters treks along a stationary frontal boundary which is slowly sinking south particularly over Kansas this morning. This has been the case now for several days already as we down here in Central Florida experience a completely different set ofcircumstances of benign nature.

Today, no change from yesterday's thinking both in the short-term and as we work into the weekend. High pressure will be the dominant force in control of the weather across East Central Florida easily through Friday. The morning KSC sounding and the profilers easily confirm the dominant easterly flow both at the surface and aloft along with overall lowered PWATs and environmental subsidence inconducive for even a rain shower. Low temperatures will remain around 80 along the coast with highs near 89 in the afternoon before the sea breeze becomes fully established by noon time at which time they will actually lower to around 87. Temperatures well inland in the lower to mid 90s.
In the longer range as we head into next week this pattern will begin to break down as an upper level trough begins to deepen south from the Canadian Border and the Great Lakes (and into the northestern U.S) by Monday and the flow becomes more southeasterly both aloft and at the surface. Overnight land breezes (from the W-SW) will take shape by Monday or more likely Tuesday in response to this trough for the Florida east coast. The GFS model is indicating that rain chances could increase for our area commencing Friday or Saturday, but at this time I'll hold fast to our previous notion that things will remain relatively least for the east coast until early next week as the GFS has been overly generous with the precipitation fields in our area as of late.

For the tropics: Believe that any activity that does manage to coalesce into an organized entity will remain well south of the area...or of the state for that matter. It does appear that 'something', possibly of the eventually named form, could develop down there...but no matter what shape it takes there will be no direct impacts. Indirectly though, as this system progresses west into the Western Caribbean and the S. Gulf the low-and mid level circulation from whatever form it takes will veer from easterly to more of a southeasterly component which will usher increased atmospheric moisture into our neck of the woods...and thus increase the rain chances initially inland. By early next week the aforementioned trough along the U.S. east coast in combination with higher moisture transport..along with the usual sea-breeze convergence parameters at play with little to none convective inhibition will once again instigate thunderstorm develop across the state. This could be realized as early as Saturday for inland areas to a small degree as moisture amounts increase throughout the overall layers, but as reflected earlier probably won't be a fully viable reality until Monday or Tuesday as the diurnal land breeze/sea breeze cycle becomes fully established.

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Tuesday, June 22, 2010

Convection Machine Shut Down Has Commenced

(Image: "Pant Alert"! Summer heat and humidity is not well tolerated by our furry friends")

The ridge of high pressure has become firmly established across the southeast U.S. this morning extending from extreme Eastern Texas through Southern Alabama and Georgia, in part, and most extensively into the Western Atlantic and across Georgia and South Carolina. This puts all of peninsular Florida in a deep easterly flow. Drier air resides upstream in the mid-upper levels over the Bahamas and is already moving in to the area.

Thus, for today we can say "goodbye" to afternoon thunderstorms pretty much anywhere along the east coast from Daytona Beach to Miami and east of I-95 as the drier air mentioned above is already evident on the latest KSC sounding data with the PWAT value having dropped to 'non-preciptable' values for this time of least under the current synoptic set up. Drying is also evident on water vapor imagery which is no surprise. This alignment of the forces appears to remain somewhat permanent (or so it will seem) for at least the next 6 days so might as well slop on the sunscreen and squeeze out some lemons.

In summary, no thunderstorms today for the most part. Perhaps a storm or two near the Tampa area or along I-75...but those will be isolated. Even the more favored inland areas will be 'slow' today. Morning temperatures, as noted this morning over southeast Florida, will be around 80 degrees if not warmer every morning along the coast through the remainder of the week, but afternoon high temperatures in these same areas will remain below or right at 90 degrees east of US-1 due to the influence of the prevailing easterly winds off the near shore Atlantic waters.

We might want to start eyeing the region along the Dominican Republic into into the Yucatan Channel for tropical development. Yesterday, the ECMWF model was indicating there could be a hurricane by next Tuesday/Wednesday right over the infamous oil spill region, but that possibility has 'not so miraculously' totally disappeared off the map as of this morning. The joys of 'crystal ball' forecasting at its finest.

The challenge, as it is, of forecasting tropical systems is slowly rearing its pretentious I'm preparing for the over-hyped barrage of "ifs, ands, or buts" to infiltrate every form of media outlet that disperses meteorological information known to mankind during the coming months. Let the rumors and bad information fly out the mouths of folks in the grocery store's all coming. Suddenly it seems everyone is a hurricane expert, including those who probably never take a second look at the sky the remaining 9 months of the year! False rumor alert preparation time.

In any case, for the most part we will have quiet weather for the next 2-3 days almost guaranteed. Will be watching for nocturnal-late morning coastal showers moving on shore later this week..but for the most part even that possibility is looking weak. Expect all kinds of things could be changing by this time next week...which I suppose isn't saying much from a forecasting perspective. But I will be watching for an increase in storm activity, especially beginning Monday over the Central Peninsula...and by then we can take it from there.

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Monday, June 21, 2010

Astronomical Summer Has Begun

Summer came to its official start early this morning so we are now in it for the long haul. Finally...lest we forget the horrors of the past winter. I'll take the warmth any time and the thunderstorms that come with it. Now, for our first official summer day's weather...

Today we'll have the summers warmth and the thunderstorms, just not right along the coast which seems the prevalent mode this year. A ridge of high pressure aloft has already impinged across the Central portion of the state as of early this morning, but the mid-level portion is still somewhere across St. Lucie County on the east coast to near Ft. Myers on the west coast. As such, the winds at the lowest levels are already from the SE...whereas higher up they remain neutral. During the course of the day this ridge will work its way north and place all of east central Florida in a deep layer mean S-SE wind component.

Interestingly (but probably of no consequence), there is a teeny disturbance, as it were, about to pass over the area near the Space Center as indicated by water vapor imagery loops and the enhanced low level instability in that area noted on the hourly LDIS plots. The latest sounding I saw indicated a convective temperature of only 86 degrees there too which can be reached prior to noon, but the down side is that lapse rates are less than close to impressive. PWAT is higher though today than it has been lately which is encouraging. Under such circumstances, I'd hope to at least see a cumulus field up that way...but none is evident at the time of this writing. So hopes aren't too high for action least not yet...but it still has some time. If anything is going to happen along the coast of Brevard or Indian River County, which it very well may, it will have to happen before 12:30pm. Further south, the only hope of showers will be from land falling activity from the Atlantic as it approaches the coast. But at this time most of what little activity there has been is evaporating off the radar scope before reaching the coast. The DLM ridging will be more in play by mid-late afternoon which will steer any activity that does happen to form from south to north initially, but then more gradually toward the inland areas where bountiful storms will be in play once again (and as would be expected given the time of year) in combination with the sea breeze wedging in from the east-southeast. The ridging aloft isn't all that strong as it could be, yet, to inhibit percolation of the atmosphere...and least not for today.

When push comes to shove, folks along the immediate coast won't realize that there are some atmospheric differences today going on over their heads from what has been going on 'up there' the past several days, namely because it hasn't rained there no matter how one slices the pie. The only fly in that ointment will be to see if anything can initiate primarily before noon as the atmosphere sets the gears in motion. And, the folks inland won't know anything is happening either because they will conversely have showers and storms all over the place just like any other day.

For the remainder of the day (by early afternoon) we'll look at a status quo scenario with inland storms west or right along the no man's land of I-95 as well as along the favored I-4 corridor plus or minus 25 miles in either direction. The other area that could see good activity would be in the Sarasota- Ft Meyers zone late in the afternoon further south along with Western portions of the inland counties of Central Florida.

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Sunday, June 20, 2010

Active Thunderstorm Day A-'Brewin'

(Image: Distant thunderhead over Palm Bay in South Brevard yesterday)

Several atmospheric differences today which should enhance the potential for afternoon thunderstorms across the Central Florida Peninsula. Although yesterday was quiet per se across the Central part of the state it did eventually light up in the evening with a 3/4" hail report in the Orlando area. Most of the activity didn't really get going though until well after dark. Do not believe this will be the case today. At least not as of 9am this morning.

Today: A number of things jump out immediately:

#1: There appears to be a remnant outflow boundary (or mid-level 'wave') that's progressed steadily south down through the Deep South since yesterday per water vapor/satellite loops and surface observations. That boundary is now situated from near St. Augustine on the east coast to near Crystal River on the west coast. Further to the north and east...this boundary appears to be connected to, and associated with, a cluster of shower activity off the Carolina coast. It seems to have slowed its southward push over the land mass...but is continuing south over the Gulf. Looks like it might get hung up along I-4 or just south and east of this bears watching.

#2: Like Friday morning, there is more early morning activity over the Gulf and a little along the Atlantic coast from near Miami toward West Palm Beach. Most of the activity is nearly stationary though. This activity was absent on Saturday. Expect this activity to slowly creep up the coast in the late morning and very early afternoon hours.

#3: Morning instability (convective indices) per the KSC sounding and LDIS plots is already becoming evident at 8-9am. Especially in the area yesterday where there was 'relatively' little indicated all day as compared to other days this past week (over Central Florida).

#4: Winds aloft per the KSC sounding, although very light, are showing a west-east direction the whole way up to nearly 500mb. Although they are generally less than 10kts...the fact that the direction is pretty much uniform all the way up indicates to me that the boundary that has moved into N. Florida is indicative of possibly more than what that the models (from last night) are alluding to at this time. The latest RUC model seems to have a clue as to what is going on though...which is encouraging. Also, averaged winds through the mid-levels are showing cyclonic circulation along the coast near Crystal River (which would correlate with the boundary mentioned earlier). The steering currents depict a broad swath of SW flow across all of Central Florida...whereas yesterday morning the winds were totally disorganized and all over the place).

#5: The sounding does not show much change in the PWAT value this morning from yesterday...but higher PWAT is forecast by this afternoon. This would coincide with the remnants of the boundary to the north sinking into the Central Peninsula. The convective temperature on the sounding has come down a few degrees from this time yesterday. At this time yesterday it was 94, whereas today it is only 90 which is totally reachable over the Cape.

#6: The dry area that has been perpetually in place across extreme East Central Florida (namely over all of Brevard and parts of counties to the north and south) on the water vapor imagery has almost completely eroded away...but not entirely. I think this is why the sounding at KSC is still 'drier' than surrounding areas...but the area has shrunk so much that it will take very little to be eroded away.

Now, further to the south from St. Lucie County and points south almost nothing has changed much. An over all on-shore component is already yielding the 'close to the coast/early in the day' activity which will progressively work its way west and north during the day...and set off a boundary which will work up the peninsula much like yesterday. In fact, there's already a shower near West Palm Beach and another just off the coast of Fort Pierce at this hour.

When push comes to shove, it looks like there could be some good storm coverage along the I-4 corridor today pretty much almost anywhere. Like other days, the coast east of US-1 or I-95 will have a hard time seeing anything north of Indian River County, although I wouldn't be surprised to see outflow of sorts in the form of a remnant gust front (unaccompanied by rain) to reach the coast between 6-8pm along with a cooling wind shift. However, I do expect some strong storms today, no matter where they may (particularly after 4pm and inland), mostly due to wet microburst winds and sub-severe sized hail.

The fly in ointment today will be to see if activity will hold off for the most part until at least 3pm. If it gets going too soon and spreads out too broadly than the atmosphere will be worked over before it can reach the maximum level of potential instability..and thus more vigorous storm intensity.

After today, the show will likely be over as far as good thunderstorms goes for the east 1/2 of the state. So enjoy a light show if you can get one today...lets get one for dear old Dad.

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Saturday, June 19, 2010

"Not Too Exciting" Thunderstorm Prospects Today

The atmosphere seems to have closed the chapter on any late morning prospects for thunderstorms today, and late afternoon isn't looking so great either at this point. The morning KSC sounding is showing appreciable, but less PWAT values today than yesterday, and there is no discernible (even when I try hard to use my imagination) surface boundaries in place other than perhaps a ridge axis extending from Cocoa Beach to just west of Orlando. This axis is becoming evident aloft on the sounding as well...indicative of the shut down of coastal thunderstorm chances to come (no later than Monday).

An overall east-west storm steering current appears to be in progress from Indian River County and points south toward Miami which would take any activity that goes up along I-95 off to the west down that way. Brevard appears to be under nil flow...but hints of the east to west push are already evident in the mid-upper levels of the atmosphere per the sounding. The atmosphere, overall, is less unstable today (for the start of the day at least) and as indicated by both the RUC and NAM this may very well be the case for the rest of the day.

This is not to say that there won't be storms today. But at this time it appears that the earliest activity will not eventually get going along the east coast sea breeze primarily until it works its way west of I-95 ...then storm eruption in standard fashion will be the rule of the day. For the most part, though, not expecting particularly strong storms today due to the lack of the necessary thermal/moisture profiles in the vertical (which are needed for strong downburst winds or small hail).

I was wondering yesterday what the early day activity on the west side of the state would end up resulting in. Essentially, it resulted in the entire area being washed out or 'nullified' of greater late afternoon instability leaving the region nearly void of storms by 4-5pm. This should not be the case today...but then again parameters overall do not look as good for overall storm intensity. Don't think we'll be seeing 'sloppy seconds' today..but the first serving might not be all so tasty.

Seeing as how this is Florida without any real inhibiting factors at play, can't rule out a decent storm or two in the mid-late afternoon once the dice are rolled...but those should be isolated and very short lived in nature.

Areas south of Indian River or St. Lucie County will not likely see much of anything today until one gets well west of I-95. Further north where the easterly flow has yet to set up in earnest there will remain the ever present chance of a storm going up along US-1 or I-95 as the sea breeze makes its initial presence known, but for the most part all activity should be west of I-95 once the pressure cooker pops and lightning gets crackin'. Was hoping to go for a 'scenic drive' today into Osceola County today to a least get up close and personal to one of these storms and will continue to monitor as things develop but as of this time the atmosphere looks like it's going to be less than enthusiastic to have any peeping Tom's lurking in on its activity this afternoon. Just going to have to grin-n-bear it...and watch to see what happens. Beach goers should have a fine day enjoy the surf (the knees slappers that is).

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Friday, June 18, 2010

Tricky Thunderstorm Forecast Again Today

(Image: Wall Cloud over West Cocoa)

Yesterday's atmosphere yielded some isolated but hefty thunder boomers, and two severe thunderstorm warnings were issued for the general area of East Central Florida (Holopaw and Titusville). Storms showed very little motion although there was a general eastward drift in some pockets which allowed activity to reach the coast along the southern tier of Brevard, northern Volusia, and near Ft Pierce. Overall though, as anticipated, motion/propogation was dictated by sea/lake/out-flow boundary interactions.

A few minute differences at this time this morning from yesterday might be worth mentioning. Number one. The morning sounding from KSC showed an increase in the PWAT value. This probably means very little to the overall outcome of things other than that it confirms the existence of abundant moisture at all atmospheric levels. The water vapor imagery shows a shrunken 'drier air' area from yesterday over Brevard, but this played little into the overall scheme of things yesterday and expect this will be the case for today as well. Also, winds aloft this morning were even lighter (if that's possible) than yesterday with not much more than a 7 kt puff the whole way up to 30,000 feet. Indicative once again of the type of storm motion we will have today. Interestingly, activity in the Gulf this morning has gotten off to an early start and there's already some showers around the Tampa area. Again, not sure if this will have any bearing on the weather outcome for East Central Florida this afternoon as the Gulf activity is showing zero motion. The last item of note is that there appears to be a weak surface boundary extending from SW to NE from basically just south of Sarasota to just north of Daytona Beach (similar to the position of yesterday morning's surface boundary).

Expect east coast sea breeze to kick-in between 12:30-1:30pm in its entirety along the coast, but believe the west coast boundary will kick in sooner and initially be more active . Some activity may pop initially along the east coast sea-breeze as well, particularly along Volusia and extreme N. Brevard as it pushes inland, but not nearly as active as the west coast one will be. The initial east coast activity should only have the generic impacts of getting one wet with a few lightning strikes. The real activity won't get started in earnest until between 2-3pm after day time heating has allowed lake, sea, and initial convective/collapsed activity breezes to work against each other in a variety of ways establishing localized pockets of low level convergence (and hence upward vertical motion). If the west coast sea-breeze is indeed more active today than usual, storms could be enhanced as we look toward Osceola and Orange counties going into the mid-late afternoon hours, so this will be something to watch for.

Finding a 'most likely area of activity' today is close to impossible...but believe after all is said and done that things will evolve 'similar' to yesterday (and I say similar because no two days are exactly alike, so variations in storm evolution are inevitable). There are no sig pockets detectable of cold temperatures aloft or triggering mechanisms in storm intensity will likely be the same as yesterday without that added instability ingredient, but a possible severe warning or two could be issued somewhere across the area.

As for the east coast today, with the slight increase of moisture indicated by the KSC sounding, and based on the latest LDIS upper level/steering currents plot...the chances appear at this time to be a little higher for the immediate coast to at least experience some rain today, but the greatest likelihood of the big storms will still be west of I-95 or perhaps US-1. However, if the west coast boundary does evolve early and really get going it tends to be 'self perpetuating' (enhanced)...thus, outflow boundaries could give the storms that additional boost needed to work their way against the east coast seabreeze and propogate closer to the coast.

Current thinking is for the final show being from Western Volusia and all of Seminole Counties eventually working south toward N. Okeechobee County. Not to leave out Osceola County where activity there should spread in from the North and West from 3:oopm onward. Then, as noted before, it'll be a wait and see game as to just exactly which activity can penetrate to the immediate coastal communities.

Saturday now appears that it will display more activity coverage wise than today. Sunday will again be active across the region but a decline is on the horizon. If we can squeeze it out, Monday would be the last gasp for the rest of the week as far as afternoon thunderstorms along the east 1/4 of the state.

Still watching for early morning, coastal shower activity to potentially show its face beginning Wednesday, making for some pretty awesome sunrises.

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Thursday, June 17, 2010

Thunderstorms On The Increase Today Through Sunday!

(Gust front over Osceola County from a severe thunderstorm)
The ridge of high pressure aloft and at the surface that has been over the state has weakened considerably and become almost nonexistent over the peninsula over night. A portion of it aloft exists over the Gulf and the other portion is well out in the Atlantic, leaving the peninsula in a COL, void of any steering currents aloft. On the other hand, the atmosphere is forecast to become much more moisture laden aloft today in the absence of the ridge. The richer, available moisture and increased atmospheric instability will be the classic breeding ground for afternoon and early evening thunderstorms today. Early afternoon temperatures along the coast will be especially uncomfortable today because of a later onset of the sea breeze! Makes for great lawn mowing...NOT!

This morning's surface data indicates a weakened trough of low pressure extends from ENE to WSW across the central peninsula (i.e., from near Titusville to just north of Sarasota). This in combination with a thermal trough which will extend down the spine of the state by late afternoon, could generate some good storm coverage over East Central Florida by late afternoon. Storms will be significant lightning producers and may produce some very small hail and marginally severe wind gusts.

Most favored area for storms today will be just along and west of I-95, but can't count out the immediate coast entirely. Storm motion will be dictated by propagation along the sea breeze boundary and eventually by outflow from earlier collapsed storms. Further inland storm motion will be additionally dictated by lake breeze boundaries combined with all the aforementioned ones.
Wouldn't be surprised to see an outflow boundary induced pseudo-gust front formation meander toward the coast (not accompanied by rainfall). These can look interesting but harbor nothing but cloudiness in the long run. Other wise, areas west of I95 (and maybe even US1) should be the areas must likely to bare the brunt of some respectable thunderstorms today.

Thunderstorm activity will continue to be more likely than the past week has been through Sunday. Beyond Sunday, it appears that the ridge of high pressure will become re-established across the northern part of the state (and eventually even further north) and a more persistent on-shore flow will be developing, favoring the west half of the state for any thunderstorm activity that could develop. On the other hand, the east coast could be more likely to see early-late morning coastal shower activity beginning Tuesday. That possibility will have to be looked into further as the time approaches.

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