"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".

Thursday, February 16, 2012

Rain, Storms (Strong/Severe) Possible Friday & Sunday Florida

NOW: Frontal boundary sliding into the Panhandle Resulting in Greater Cloud Coverage in North Florida North of the I-4.
Later today, East Coast sea breeze with increased atmospheric moisture could result in some sprinkles or a shower due to sea breeze convergence away from the coast, inland. Colder ocean temperatures should essentially 'cut off' or preclude any shower activity closer to the coast due to loss of rising air currents above and near the cool ocean and river waters

TODAY: Two cold front boundaries will be playing havoc with the Florida Peninsula weather forecasts through Sunday beginning today. Although today does not appear 'sticky' regarding significant weather (especially South of the Beach Line), the main factor within this same area (North Half of State) looks to be the variability of cloud coverage with a better rain chance north of I-4. As noted in the caption , sea breeze convergence or simply a sea breeze and weak inland winds could result in weak convergence (surface to mid-levels) resulting in some sprinkles which looks only minimally possible if at all namely due to the cool waters and the cool air just above them cutting off the lifting currents normally present in the summer months when waters are much warmer. 

FRIDAY: The cold front will get an extra boost southward after wafting toward the east, with the main energy being pulled well north and east of the state. Regardless, the front should be entering North Central (Ocala / Gainesville) area during the noon time hours and finally reaching Central Beach Line Corridor toward Tampa by late afternoon during and after peak heating hours. Wind fields do not look overly impressive; albeit, if this was the summer with the same wind fields this would be a day to watch for very strong thunderstorms no-doubt. Regardless, given the wind fields and ample instability, there could easily be a thunderstorm chance with good winds in them from northern parts of South Central and Northward. As we can see here:

NOTE the winds are shown at the surface to be only around 10 knots, but convergence along the frontal boundary will work in favor of storms along it and south. This is the GFS depiction from the morning model run (7AM), valid for 1pm Friday. This front is expected to make it about as far as Ft. Pierce toward Sarasota before lifting back northward as a warm front overnight Friday night into Saturday.  Therefore, it would be wise to be prepared for rain when heading out across Dead Central beyond the 2pm time frame through at least mid-evening. The front appears will stall out across a portion of Central before lifting back north. During the time, rain chances will remain.

SATURDAY: More interesting chain-of-events unfolds. First time in months since we've seen a scenario such as this. In fact, outside of the tropically related entities of fall, it was possibly last April or May that such a boundary could generate severe weather in a broad scale, or have that inkling, over a part of Florida. Thus, this will be a day to keep the ears and eyes pealed for statements and newscasts.

The cold front of old will lift northward as a warm front (as shown below), with an attendant low pressure system pulling eastward north of the state. A new cold front will be entering the picture with much stronger wind fields associated  at ALL LEVELS OF THE ATMOSPHERE.

Given directional wind shear in a clockwise fashion from the ground and up toward 30,000 ft (climbing upward through the veering wind fields with height), there will be a best chance for severe storms and possibly a tornado from near St. Augustine as far south as Ormond Beach (at least) and west across the state. This entire scenario is still 'in the making' as far as being depicted on paper is concerned, so most assuredly this portion of the post will need further refinement in the next 36-48 hours as time allows. Here is the morning depiction for 7AM Sunday morning.


NOTE the stronger wind fields even at the ground (as shown) as opposed to Friday. Blues show winds in the 25 kts range over water, as opposed to 10 kts on Friday. No joke, winds aloft are much stronger
on Sunday than they will be on Friday as well.
Also note the text in red showing that the old cold front has lifted well to the north as the next low pressure (much stronger this time) moves across the Deep South. Undoubtedly, our friends on The Weather Channel will be milking this one for whatever it will be worth in the severe weather mode realm across Dixie and into the Carolina's at least, as well as parts of North Florida from early Saturday through Sunday. Especially over portion of Alabama and Mississippi!!

Since it is yet early for finer details, it is worth watching for a fast moving squall line type feature to race across most of the peninsula from mid-morning through late afternoon. Precipitation totals are not shown to be high, but bear in mind it will be fast moving which correlates to little time for rainfall totals to add up. Meaning, not much rain does not directly mean some stronger winds will not be briefly possible.

Regardless, that does not mean, nor should we assume, that strong winds (at least) will not be possible, especially North of Lake Okeechobee mainly, not to play any 'favors' just yet in regard to who might escape the rains. As seen today at this point from scanning over a few resouces, most everyone could get a quick dose of rain and wind on Sunday from before sunrise (far north) to the keys by late afternoon/early evening.

BEYOND: It will be much cooler Monday morning behind the front, but not as cold as this prior event. Winds are expected to clock around toward the NE to east within 36-48 hours after frontal passage which means already any cold air supply will be tainted by Atlantic winds. Additionally, the jet stream will be north of the entire state. That is important to Florida since the coldest temperature at ground level in most cases is found under and north of it's flow and ebb around the hemispheres.

No comments: