NATIONAL WEATHER SERVICE TALLAHASSEE FL
253 PM EST Sun Jan 12 2014
NEAR TERM [through Tonight]...
High pressure centered over the area this afternoon will slide
A gradual increase in high clouds is expected overnight with lows ranging mostly from the mid 30s to lower 40s.
SHORT TERM [Monday Through Tuesday Night]...
We should quickly have another shot at rain later Monday, with the
last cold front having only just cleared our area on Saturday evening.
The bulk of the numerical model runs this morning have come into good agreement on the general evolution of the Gulf low.
They show a surface low forming near southern Louisiana around 18z Monday, quickly ejecting ENE to near Valdosta by 06z Tuesday.
The surface low will be developing ahead of a deamplifying wave aloft
that will be ejecting out of northern Mexico - evident as a closed
circulation on water vapor loops right now.
While the track of the surface low would suggest that the southern
half of our area may get into the "warm sector", the quality of that air mass is not expected to support vigorous updrafts.
First, the deeper moisture and higher surface dewpoints have been cleared well south of the area today (generally south of 25N over the
Gulf). The air mass would have to recover tremendously in just
over 24 hours, which is not expected.
Second, the shallower shelf waters near our coast - particularly over Apalachee Bay – have continued to cool and now are as low as the low-mid 50s offshore of the Big Bend counties.
Therefore, we expect a stable layer in the lowest 1-2kft AGL influenced by the cooler marine environment offshore, and this is supported by model forecast soundings.
Even the typically more aggressive 4km WRF models only bring 100-200 j/kg of MLCAPE onshore near Apalachicola.
Stronger storms could occur over the coastal waters, generally more than 20NM offshore.
We kept the thunderstorm wording at "isolated" and only along and
south of Interstate-10. PoPs were increased to categorical range.
The initial round of CAA behind the developing low should keep highs several degrees cooler on Tuesday.
However, the much colder air will not arrive until later Tuesday Night behind a secondary cold front.
LONG TERM [Wednesday Through Sunday]...
CAA will continue behind the secondary cold front on Wednesday with 850mb temperatures falling from around +1C at 12z Wednesday (avg. of GEFS, SREF, GFS, ECMWF) to -7C by 00z Thursday.
The strong CAA regime should keep highs in the 50s despite sunny
The subsequent night (Wednesday Night) should be fairly cold with a chance of a hard freeze. Current forecast lows are between 24 and 28 degrees.
The minimum temperatures will probably depend on how fast the surface high builds in behind the departing low. GFS is faster with this, ECMWF slower.
A high becoming centered over the area by 12z Thursday would likely increase the odds of a hard freeze.
The top 5 CIPS analogs based on the 12z GFS show at least a few stations in the area receiving a hard freeze.
Wind chills could also approach 20 degrees before the high builds
Beyond that, the models diverge a bit, but there is general agreement on a reinforcing cold front on Friday.
VFR conditions will continue through the period.
High clouds will be on the increase by Monday morning, but lower ceilings will hold off until after this short term period.
Winds will veer to the SE-S by Monday afternoon and increase to
SCEC levels as a Gulf low approaches.
The winds will shift to the NW behind the low on Monday night and Tuesday morning, with a chance of brief advisory level winds offshore.
Winds will hover around SCEC levels until a secondary cold front arrives, with advisory conditions likely Wednesday into Wednesday night.
A high will build in quickly late Wednesday night, so winds are expected to drop off quickly on Thursday morning.
Low level moisture will rapidly increase Monday with rain becoming
likely on Monday night as the next low pressure system impacts the
Some drier air is expected behind this system, but red flag conditions are not currently expected for the next several days.
Rainfall totals with Saturday`s frontal system were generally near
an inch with the exception of the coastal counties of the FL Big Bend where 1-2 inch totals were observed.
Since most of the heavier rainfall fell in the lower stretches of area rivers, only minor rises are forecast.
The Choctawhatchee River at Caryville is forecast to approach, but stay below flood stage on Wednesday.
Rainfall totals associated with the next system to impact the area
Monday afternoon and evening should be around 0.50-0.75", which is
not expected to cause significant rises on area rivers.
Preliminary Point Temps/PoPs...
Tallahassee 38 69 52 65 42 / 0 40 80 20 10
Panama City 48 68 51 63 45 / 0 80 80 10 10
Dothan 41 65 46 61 39 / 0 80 70 10 10
Albany 38 67 47 62 38 / 0 40 70 10 10
Valdosta 38 70 55 65 41 / 0 20 70 30 10
Cross City 37 71 57 70 44 / 0 20 80 40 10
Apalachicola 47 66 53 64 47 / 0 50 80 20 10