"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, April 6, 2011

Very Pleasant North/Central, Clouds South Today - Unsettled Later Next Week

Squall Line Lightning Over the Banana River south of Kelly Park

RECAP: Squall line cleared all of Central Florida by early afternoon, continuing through South Florida and the Keys by 4pm.  This organized line of storms originated from near the Ohio River Valley region 36-48 hours earlier...and has left it's dying energy, mostly moisture over far South Florida and the keys. A waterspout was sited about 7 miles offshore the Cape, and another was seen about 1 mile east of Patrick Air Force Base as well. There was some severe category level storm reports from wind in Florida, but not of the intensity or coverage as those observed last week. This was expected to be the case, since winds aloft were not as strong and temperatures up there were not as cold either. 

Here is the radar image as the system crossed along "The Great Dividing Line". It was at this time the squall encountered the richest dew point temperatures of 70F and above and the more unstable air over the South half of the state which had developed after sunrise. Also note the rotating single celled storms CLEARLY outlining the Gulf Stream. Kind of neat! Multiple waterspouts were supposedly reported from those offshore storms. I'm not surprised at all. It would have been fun to paddle out there with a long board equipped with a GoPro Video Camera to go "Storm Chasing, Doggie Paddle Style

There was some weak subsidence in the air mass immediately preceding the line which precluding the southbound system from efficiently "inhaling" the juicy air mass immediately ahead of it over Central and South Florida. This, in fact, seemed to be a factor with this line during it's entire journey from the mid Country. My personal observation of this fact could confirm that, at least over Central Florida. As the system approached, the atmosphere acquired a 'hazy. muffled' appearance  10-20 miles in advance of the squall within the sinking air. 

Additionally, the sound of thunder seemed to be 'ducted'...only close to the ground. Thunder did not roll and roll..did you notice that if you are a reader and were in an area that had lightning? I did not see any cloud to cloud or in-cloud lightning. Only cloud to ground...and most of the lightning preceded the rain or occurred as the rain began. Might have been just where I was at though.

 An enhanced section of the line popped just a mile or so to the north over the Air Force station at the Cape, passing just east and north of Port Canaveral. That can be seen if you look closely at the above radar image. This occurred as the line met the higher dewpoints, cross sectioned with the higher low level helicities off shore.

NOT SURPRISED: Low level helicities were being analyzed and forecast for the coast and just offshore for 24 hours prior to the line's approach.
THIS IS THE NAM FORECAST FOR 11AM..1 HOUR SLOWER THAN WHAT OCCURRED.. However, this shown was a 33 HOUR forecast. NOT BAD!! We can see the gradients of Cape being pointed out over South Florida by the black arrow's text. Whereas this image (red arrow) portrays the low level helicities in the bright colors. NOTE the area off shore and over the Gulf Stream in faded orange...which eventually MET the south bound values east of Brevard County. They met and POOF...waterspouts and lightning, which the Port area had the benefit of experiencing as can be seen by the image at the top of this post.

TODAY: Front has cleared all but extreme South Florida..mainly the Keys. Ample low level and some mid level moisture remains, enough to generate clouds which thin and lessen the further north one gets where the air is drier at those levels. Just enough over Central to generate some flat topped stratocumulus clouds.  Could be a rain shower by the time the day is through over far SW Florida near the coast.  High pressure is located just East and North of the area this afternoon. This will sink south through the weekend, and as such clockwise flow around it will become SE overnight tonight which will advect higher dew point temperature air into all of Central Florida over night and through tomorrow. Over night lows will be a good 8 degrees warmer tonight than last night over Central and even warmer than that along the coast. Clear skies overnight Central and North.

TOMORROW: A warmer start to the day...and a warmer day overall everywhere in the afternoon. Winds along the East Coast will be SE-SSE at times and breezy at 12-18mph during the late afternoon especially as mid -upper 60F degree dewpoint air rides up the East Coast along and east of the Gulf Stream toward Sun Glow Fishing Pier. This will be the theme of tomorrow, with partly cloudy skies...of more puffy cumulus nature. 

There is a very small chance of some showers or even a thunderstorm from near Lake Okeechobee to just west of Orlando along Route 27 (Clermont/Bok Tower area) and/or over toward Central Osceola County and into Central Brevard very late afternoon to late evening due to a sea breeze collision.  The chance is close to zero; however, one model suggests this to occur 'somewhere' within ONE of those areas (not all of them), whereas another model shows zip.  That same model has shown it to occur on 4 consecutive runs, whereas the other consecutively shows nothing. The reason for this lies in the forecast of the mid-level temperatures. One of them is too warm aloft and 'caps' the atmosphere for upward moisture transport, and shows increased convective inhibition, which totally jives. However, the other is quite generous in comparison with a thunderstorm somewhere with air aloft just a few degrees cooler. My bet is it will rain somewhere with the upper trough in place and upward warming slow to occur as opposed to that at the surface, but this will be reassessed in future models with plenty of time for an official forecast made public should conditions warrant. Probably way before the next blog post of tomorrow morning we will see or hear a rain chance from the National Weather Service or on the news...but so far all is mute regarding a rain chance..

SATURDAY-MONDAY: Continued muggy and warmer with highs in the mid-upper 80Fs, and some low 90Fs far SW Florida. Winds SSE initially becoming S-SSW late Monday or Monday night. During this time frame warm air aloft over runs the peninsula as continuing warmth of the peninsula rises without impedance to the mid levels...this would be due to the fact we will have another system approaching from the west later next week..and the flow ahead of it will 'buckle'..or rather..Ridge/. So ,do not foresee a chance of showers. But plenty of moderate cumulus away from the east coast during the afternoons (inland) and most of all South Florida, with post sea breeze subsidence behind the east coast sea breeze each afternoon to further squelch the chance significant cloud coverage east of I-95 north of Ft. Pierce.

MONDAY NIGHT/TUESDAY: A storm system highly worth noting  for a small area of the Central/South Central Plains will be that area beginning tonight and into tomorrow and beyond will move east across the Mississippi River Valley Basin and toward the Mid-Atlantic by late Monday. The high pressure will sink south even more and allow winds to become more SSW. The associated cold front as it is so portrayed both all models will move into Central Florida on Tuesday around noon time or shortly thereafter. This front could be accompanied by some thunderstorms or showers, mostly along got it.."The Great Dividing Line of Central Florida" which runs from Tampa to the Port. Other showers and storms could occur futher north, but due to the timing of this boundary passing through North Florida overnight and early morning instablity for thunder will be somewhat, but not entirely limited. The front could stall and pull out to the east during Tuesday. Leaving the South Half of East Central and South Florida in a rain chance through Wednesday.

 Chance of showers and thunderstorms on Tuesday as noted above, decaying shortly after nightfall as the boundary moves into South Florida or goes stationary very close to the location the boundary of today now lies over South Florida where rain shower chances will continue the following day.

***NOTE: Timing of this front will likely change as the time approaches. Therefore, the above stated is purely theoretical at this time. The front might never even reach South Florida at all.

GOING INTO LATE WEEK/THURSDAY: It's becoming close to the point that we can safely say that a very unsettled weather pattern over all of the state at various times will be the wild card in regard to rain and storms.So far, especially the South Half of the state, but initially all of NW Florida and the Panhandle. Another major storm system is going to affect much of the country working into next week. Wide spread severe weather is anticipated from the Gulf to the Great Lakes and parts of the NE States...and I expect there will be a higher number of tornado reports with this system than with the squall line of the past 2 days. Most of the exact same areas will be impacted by this system as well, including Florida.

However, the nature of this system, as it now appears, will manifest itself in an entirely different least for a portion of the time, as it crosses the states North of Florida. It probably will not be preceded by a shallow layer of subsidence and a squall least not for the early to mid-time portions of its 'existence'.

The impacts on the state of Florida, and the timing of when exactly these will be sketched in stone remains a bit fuzzy as of the latest model runs, but all models are agreeing that a big change is in store sometime around April 14th for at least a three day period.  There is an indications that a large upper level 500mb low pressure area  (rather than a swiftly moving east bound trough) will cut off over or just west of Florida  resulting in very cold air aloft, yet warm air at the surface until there is a frontal passage. This could end up just being a cloudy/ rainy series of day (s) or very stormy ones. There does appear to be a least one window of opportunity for severe weather over Florida as much as a full day before the actual system moves in (or around April 14th).  

It is not shown yet, but what I will be watching is the area over the Loop Current. Should a surface low form here...things get very interesting. But as of now, there is hardly but one minute hint of something 'fishy in the waters of the loop current other than tarpon and Sailor's Choice".

Low and mid-level wind fields with this system as it appears now will be very it does not look like a tornado threat will be in the making at this time; however, there is still much to be determined at this point in time. The configuration this far out in time concerning this "POTENTIAL" system leaves a lot to be desired in regard to the low level features this far out in time. Something doesn't look quite right. Perhaps a secondary surface low will from in the Deep South near Florida..,seems possible. That would change everything.

For instance. at no time during its 3-5 day visit is a cold front portrayed to pass through the state by the time all is said and done once the upper low lifts out. In fact, we do not know how long it could linger, or if it even will. If it does not cut off, as only the latest GFS model portrays this morning, the impacts will be more significant, but the chances of rain fall and/or storms will be of short during. Could be a two day event...or a 5 day event.  

" Round and Round and Round "she" goes, where "she' stops...Nobody Knows"...Knowbody.

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