NEAR TERM [Through Tonight]...
Low clouds have been slow to clear over portions of the area so far this evening, and a large patch remains over the middle of the forecast area.
Most model guidance has a poor handle on this patch, and only the HRRR and NARRE appear to be aware of its existence.
The 00z KTAE sounding (although launched before the clouds made it to Tallahassee) shows an extremely thin moist layer between 1500-2000 ft, so perhaps the layer is too thin for the vertical resolution of most models to capture it.
The HRRR keeps the low clouds around most of the night with a slow erosion from north to south late tonight.
However, as it erodes the low clouds, it develops areas of fog around its edges. There is some evidence of this already happening with a few sites outside of our forecast area already showing reduced visibilities.
The evening update will side more with the HRRR given its superior
initialization and observational evidence of its forecast verifying closer to reality.
Sky grids have been updated to show more cloud cover overnight with patchy fog around the edges where the forecast sky grids are less than or equal to 50%.
SHORT TERM [Monday Through Tuesday Night]...
Monday should be a dry day with seasonal temperatures.
Another cold front will cross the region Monday night.
Some weak DPVA and mid level frontogenetic forcing will result in the possibility of some light rain accompanying this frontal passage.
Lower levels will remain fairly dry, so any rain that falls will be light.
Temps will be about 5 degrees cooler across the forecast area on Tuesday behind the front.
A vort lobe will be shearing out over TX on Tuesday. However, there will be enough energy to induce weak cyclogenesis over the southwestern Gulf of Mexico.
Some weak overrunning over the stalled frontal boundary to our south could result some very light rain again on Tuesday night.
We kept PoPs in the slight chance category for now to account for the weak forcing.
LONG TERM [Wednesday Through Sunday]...
A progressive upper level pattern will persist across the CONUS from
midweek through the weekend.
One long wave trough will swing past the area on Thursday.
While most of the energy associated with the trough will be to our north, some of that TX energy mentioned earlier will work its way across the northern Gulf of Mexico.
The models are still not in very good agreement in depicting how the
surface low in the Gulf will evolve.
The NAM is most aggressive with its forcing for ascent with QPF well above a model consensus. The GFS is the driest scenario. We always favor a model blend in the long term periods and show PoPs increasing gradually from Wednesday into Thursday.
A strong cold front will shunt any precipitation south of the area Thursday night.
The airmass behind this front will have modified considerably from what it is now, but will still be pretty chilly.
Look for temps to be well below climatology on Friday and Friday night.
Highs Friday will only be in the 50s with overnight lows dropping a few degrees below freezing.
Friday night has the potential to be the coldest night of the winter thus far, which is not saying much.
We are not anticipating a hard freeze at this time.
A moderating trend in temps is forecast for the weekend with slight rain chances returning to the forecast on Sunday ahead of the next frontal system.
The low level cigs which were supposed to dissipate never quite did before sunset, which has only compounded the problem of the trapped in low level moisture.
This moisture is already forming a new saturated inversion which by all accounts will lead to a night of MVFR or worse Cigs at most of the
terminals, with IFR conditions a distinct possibility.
This will may be most likely at DHN, where the once solid Cigs will likely break, with fog and even lower Cigs building in behind them.
The main question is how long will the MVFR or worse conditions
persist, and this could range anywhere from late tonight into the
early morning hours of Monday, and will have to defer to the next
shift to refine the timing of this rapidly evolving fcst.
Light to moderate offshore winds are expected through Tuesday night.
Winds speeds may briefly reach cautionary levels Tuesday morning and again Tuesday night.
Winds will shift to the east by Wednesday.
A strong cold front will shift winds back to offshore Thursday night
with wind speeds increasing to advisory levels in its wake.
Relative humidity values will remain well above critical values at
least for the next several days.
No fire weather concerns are anticipated.
Most areas had rainfall accumulations of 1-2 inches in the past 24
hours which has led to elevated rivers and creeks.
The Apalachicola River at Blountstown is at minor flood stage and is
forecast to remain there through at least January 3rd with releases from Woodruff Dam.
The Choctawhatchee River is forecast to reach minor flood stage at Caryville and Bruce this week.
Several other area rivers and creeks are forecast to crest in action stage but remain below minor flood stage at this time.
The most up to date, specific river forecast information can be found http:/water.weather.gov/ahps2index.php?wfo=tae.
PRELIMINARY POINT TEMPS/POP...
Tallahassee 45 65 43 61 41 / 0 10 30 20 20
Panama City 47 64 48 60 45 / 0 10 40 20 20
Dothan 42 61 42 55 38 / 0 20 20 10 20
Albany 42 62 41 58 36 / 0 10 20 10 20
Valdosta 44 64 44 61 39 / 0 10 30 20 20
Cross City 48 67 46 66 41 / 0 10 30 20 20
Apalachicola 47 63 49 61 46 / 0 10 40 20 20