"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, January 24, 2010

Here Comes Da' Front - Tomorrow

(Images show fronts passing through the Deep South, the KSC Morning Sounding, and Current Helicity/Shear Values Across the State)

What a mild morning! We only got down into the mid-60s everywhere last night with an increasing southeast wind. Yesterday I was questioning as to the timing of exactly when our next front would be going through. As it ends up the timing looks like it will be right down the middle of the road (or an average of all the models put together). This means it won't be 10am nor 6pm..but rather around 1pm Monday. In the interim....

Today: The stationary front that layed dormant over South Florida yesterday essentially washed out as it moved north as a weakening warm front. The only sign of its passing here was cloud deck near sunrise and some off shore rain showers. Winds are a steady southeasterly this morning and had not become more southerly as models depicted they would yesterday. This is a for sure indicator that the frontal boundary to our west and any associated weather is holding off to the west a bit longer for us.

As you can see from the morning KSC Sounding (click on it to enlarge)...the inversion that was 2500 Ft. above us yesterday is now only a mere 800 Ft. over us today. As shown, our E-SE wind exists in only a very shallow layer along the fact, if you were to go to the top of the Cape Royal Building it could be from a different direction all together..or maybe even calm (practically).

All in all, expect the wind to become more southerly through the morning and remain almost straight, due south from noon time through the rest of the day. It could get pretty darned breezy too (like Thursday)...under partly cloudy skies. It will feel kind of 'sticky' today as moisture in the atmosphere's lowest levels increases in the southerly flow. Rain chances are pretty much NIL today into tonight...with a high temperature along the coast around 78...away from the coast (west of the Indian River) it will get into the low 80s.

Late Tonight into Early Monday: The first front shown in the plot above will have slowed considerably and the second one will nearly catch up to it. All this occurs as low pressure tracking much further north starts to phase with a much larger low already near the Hudson Bay region up in Canada. The two systems will phase together during the course of the next 36 hours and carve a much larger trough across the entire eastern United States (mainly east of the Mississippi River) which will be our big weather impact for the majority of next week.

In any case, it currently appears that the leading edge of this frontal ensemble will first be affecting North Central Florida near the Ocala area sometime between midnight-4am Monday morning down into N. Lake County. The leading edge of what will likely be a weakening squall line will be right on Brevard's front porch at 7am with rain showers and possibly a strong to severe thunderstorm (due to strong wind gusts). As you can see from the attached graphics 1 KM shear and helicity are already in place across mainly the N. 1/3 of the state, and I expect these to remain there and in fact work a tad further south with time. Tomorrow morning looks like another one of those high shear/low CAPE situations (CAPE: Convective Available Potential Energy)...which often results in convection (storms) being torn apart before they can really amount to anything. But any embedded cells that hold together along the line south of a N. Brevard to Brooksville line will have the potential to exhibit rotation given the high shear and helicities across the region which would support a marginal threat of a brief, weak tornado or strong wind gusts. The leading line of this convection, again...will have passed the Orlando area right at or before sunrise and be approaching the coastal communities in the hour or two thereafter.
I wouldn't be surprised to hear some severe thunderstorm or tornado warnings being issued for parts of north and central Florida between midnight and 8am. So be advised.
As the line continues to move east and south the upper level support will be weakening, and as such so will be the severe threat (not to discount a continued remote possibility as far south as a Palm Beach -Okeechobee-Sarasota line by late morning).

Monday Afternoon: At this time it looks like the main front will have passed the I-4 corridor by 11am Monday...and will be over Brevard during the lunch hour (12:30pm -1:30pm Monday)...after which it will have passed. There will likely be some lingering clouds into the mid-late afternoon with a stray shower...but by sunset the show will be over as cloud air advection ensues in earnest.
Tuesday-Thursday: This period will initially be characterized by nearly clear skies and cool temperatures in typical post cold front fashion. All indications are that the areas west of the Indian River and particularly down the spine of the state will experience the coldest of temperatures. It's worth noting that some numerical model output is spitting out lows for the Melbourne area around 41 degrees by Wednesday morning; however, at the same time the temperature forecast for Patrick AFB is 52! That's a BIG difference. But given we'll have a light west wind with the true freezing line well north of the's not entirely out of the question and in fact not all that unusual. So leave it as this, if your west of the Banana River and north of Orlando expect two very cool to cold mornings to start the day up until about 10am. Down right cold up near Ocala. After that time we'll have abundant sunshine to warm the days with a high in the mid-upper 60s at least thru Wednesday..maybe get into the low 70s Thursday. But remember, that high temperature will occur only at max for the majority of these days it will be in the 60s with a noticeable cooling within one hour of sunset.

Have a light jacket or sweater at hand all times next week through Thursday.

Friday-Saturday: Major air mass modification will begin on Thursday night going into Friday as the next system approaches. We can elaborate more on that as the time draws nigh. Just as a heads could get even cooler (to cold) for the next one by next Sunday going into Monday..but not least not in Central and South Florida.

IN SUMMARY: Partly cloudy, breezy and warm today. Cloudy, rain/storms (some strong to severe first half Monday)...wind shifting to west and weakening Monday afternoon under gradually clearing skies...jacket weather Tuesday thru Thursday under clear to partly cloudy skies.

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