"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".

Sunday, February 6, 2011

Dreary Central But Much Nicer South Florida Today

Images: (1)Haven't posted an image like this before. This is data from one of the 915Mhz Profilers at KSC which provide the wind profile in the lower levels of the atmosphere. It shows the winds over a length of time in the lower levels. We can see the northerly winds from the surface right up to about 925mb, conveniently a standard height used as guidance in various models like the NAM and GFS. They both show the SW-WSW winds at that level as can be actually observed with this information with northerly component winds in a shallow layer in the bottom 2000 ft or so; (2) Additionally in the second image is the sounding from KSC showing the same thing. The sounding also shows a nearly saturated atmosphere from the surface to about 10,000 ft (or around 700mb). We can see the very shallow layer near the ground of northerly winds over-run by the increasingly stronger WSW winds above. (3) Shows the morning temperature regime with the approximate location of the stationary boundary at the surface very close to Ft. Pierce, bisecting the Lake with the warmest temperatures south of the boundary. (4) Satellite image shows no shortage of cloud cover streaming from SW (to WSW) from the Gulf and across the state (5) A recent sampling of current radar with a surface boundary overlay sketched in.

TODAY: Little really to write about as what we see now as far as boundaries and satellite imagery will remain relatively status quo (stationary in regards to boundary movement) throughout the day. The best chance of rain today will be further north as we see is currently (and has been) occurring since very early morning. The folks south of I-4 will more than likely be out of the rain the majority of the time, and even more so along and south of the Beach Line, dwindling to non-existent toward South Brevard.

In the clearing zone NW of the clouds in the west 1/2 of the Florida Panhandle this morning it was below freezing! Brrr...But, under the clouds and some rain showers the temperatures remain in the low-mid 60s, upper 60s to lower 70s further south close to the boundary (50s further north).

South of the boundary this afternoon upper 70s and low 80s especially on the east side of the state around Miami metro toward West Palm Beach where a mid 80 or two might could occur. It is also possible that with some day time heating and ample low level moisture in place over South Florida that abundant puffy stratocumulus clouds will be in place as the areas of fog down there this morning burn off and transition to that a new state of existence. Regardless, it will be warm down there and partly to mostly cloudy from time to time close to the boundary and north of it. Some showers in the same warm zone can't be totally discounted as portrayed by one of the models (especially close to the surface boundary), but they would be very low topped and relatively brief if they manage to manifest.

TONIGHT/EARLY MONDAY: Mid level trough (the same one that might affect the 4th Quarter of the Super Bowl game tonight with a very low threat of some snow flurries) grinds through the Deep South overnight and across North Florida Monday. In precedence, the surface boundary over South Florida will buckle northward through South Central to Central Florida after midnight through 9AM Monday. There could be some low and mid-level moisture covergence along the north bound leading edge as this process ensues which would up the rain chance from 2am - 7am, mostly through Central and North Central Florida as the boundary moves north through early morning with clearing south of the boundary.

MONDAY LATE MORNING - LATE AFTERNOON: No change South Florida from today so not much to elaborate on there although they should have less clouds than today without the pesky boundary around. Immediate Central to North Central and North is where all the 'action' is in regards to clouds and rain on Monday, as well as where the cut off gradient of 'lots of rain to barely any' will exist.

As mentioned yesterday, the NAM model was showing the greatest extent of rain fall potential to be along and north of I-4, and I was hedging toward the idea at the time. Later various model trends are supporting that notion, and as such I'm inclined to remove any rain chance at all south of a line running from Melbourne to Ft Myers where much warmer afternoon high temperatures will reside under generally a partly cloudy sky.

It currently appears that the boundary will get about as far north as the Volusia / Brevard County line or a bit further north than that on the east coast and be aligned with the prevalent upper level flow toward South of Tampa Bay (or very close to I-4) that is shown by the morning sounding from KSC in the image above.

Rain chances tomorrow will be highest where they are today, but to a much greater extent in regards to EASILY measurable amounts as the mid-level trough that will be crosses Texas tonight crosses north Florida and strong low-mid level winds round the base of the trough as it does so which confront/ interact with the strong high pressure to the east of South Florida that has been referred to in numerous previous postings.

The Beach line (east side of the state) seems to be the make or break point of where any rain at all could fall, but the predominant mode there will be rain free and much warmer than today until very late in the afternoon (but not as warm as yesterday). Still can't discount a shower entirely though, and any minor undulation in current model depictions will have a significant impact for folks in the critical area which will run along a line from just south of Tampa Bay to Titusville should those depictions sink just 30 miles further south.

MONDAY NIGHT/TUESDAY MORNING: The mid-level trough and associated trough will meet up with the stationary boundary across North Central Florida as it continues to move off the SE U.S. coast. The ensemble forms a cold front and swipes through all but perhaps far South East Florida by sunrise Tuesday. Rain chances as a result go up after dark Monday night through the pre-dawn hours for all of the south half of the state, but to lesser degree the further south one goes. There might be an additional spoke of moisture rotating around the developing low pressure system as it makes its exit further away from the state to create a small secondary rain chance or additional clouds early for East Central portions of the state, but all in all by 9am the front will have cleared entirely and rapid cloud dismisal will follow.

TEMPERATURES: It will be cooler on Tuesday every where once all is said and done in the wake of the cold front, essentially by 10-15 degrees in regards to daytime afternoon high temperatures as well as morning lows heading into Wednesday morning, less so South Florida.

WEDNESDAY: Pleasant with modify temperatures as high pressure passes east of the state to the north and an onshore flow regime ensues. Coolest temperatures along A1A close to the ocean waters with a partly cloudy sky. Close to seasonal, but perhaps a bit below normal for this time of year inland and west side.

OVER NIGHT WEDNESDAY INTO FRIDAY: Next system, which is now about to exit the Bay of Alaska will drop SSE through the Rockies during the course of the week upping snow chances for cities like Denver and Salt lake City, will be approaching Florida by later in the week with details on this next system to come in future posts.

Still doesn't look all so bad for that system either in regards to low temperatures; as it stands now it appears the main energy and subsequent surface high pressure with that system (like the one to occur on Monday/ well as with the previous two before that) will pass to the north of Central Florida which puts the west side of the state in the coldest air once the system has cleared. No freezing temperatures foreseen for South Central or South Florida for starters.

BEYOND NEXT FRIDAY: After another very cool spell next weekend, the gravy train of low pressure systems which has been the predominant mode the past two weeks transitions to one of high pressure areas separated by mostly dry, weak cold front passages as the flow becomes more zonal and systems in general track further to the north of Florida and Texas.

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