Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tallahassee Florida
331 am EST Tuesday Dec 1 2015
Near term [through today]...
Southwesterly flow will continue aloft across the tri-state region
ahead of a large upper low moving through the northern plains
and upper Mississippi Valley today. At the surface, an early
morning subjective analysis placed a mostly stationary front
through the lower Mississippi and Tennessee valleys. Another more
progressive front moving out of the Southern Plains was about to
catch up to the easternmost front. Even with the fronts in close
proximity, they will still not make into the local area today.
But, as the surface ridge moves northeast, our low level flow will
veer southerly and there may be just enough isentropic ascent from
the warmer east- central Gulf to the cooler northeast Gulf to
force a few light showers late this morning into the afternoon.
Any showers that do develop will likely remain east of a line from
Tallahassee to Albany, or right along the Panhandle coast. If
nothing else, there will likely be a fair amount of cloud cover
which will help keep temperatures a few degrees cooler than the
past few days. Still, expect above average temperatures around the
middle to upper 70s.
Short term [tonight through thursday]...
Probabilities for lower visibility in fog are elevated tonight
across our forecast area ahead of an approaching cold front. This
will be due to a shallow layer of moisture below 1000 ft. We added
areas of fog to the forecast.
The front will then push through the area on Wednesday. The 00z
operational runs of the GFS and European model (ecmwf) both show moderate amounts
of quantitative precipitation forecast despite a general lack of instability. We expect steadier
bands of rain associated with strong forcing along and just behind
the surface cold front. Pops were increased based on good model
agreement on moderate quantitative precipitation forecast focused during the daytime on Wednesday.
Likely pops were included for all but the far southeast parts of
the area. High temperatures may actually occur in the morning
hours over much of the area, as the combination of the advancing
cold front, thick cloud cover, and rain may cause temperatures to
decrease in the afternoon hours. We followed an hourly temperature
trend closer to raw model guidance.
Models then usher rain out of the area quickly on Wednesday night
setting up a dry and cooler day on Thursday.
Long term [thursday night through tuesday]...
A large surface high will then settle into the eastern US, with
slightly cooler (and dry) weather expected to last through much of
the extended forecast period.
[through 06z wednesday] LIFR visibilities and ceilings are very
slowly encroaching on ecp and dhn from the west this morning.
Expect them to reach those terminals within a couple hours of
sunrise, clearing a few hours after. Expect considerable
cloudiness today, though it will likely have a base just above
MVFR levels. Expect more widespread dense fog and low ceilings
tonight, likely impacting all terminals.
Fairly light southerly winds will continue through Wednesday in
advance of the cold front. Behind the front, winds will shift to a
northerly direction and increase by Thursday. Scec-level winds are
likely beginning Thursday, with some advisory-level winds possible
at times (particularly offshore).
Hazardous fire weather conditions are not expected over the next
Rivers across the area were all below flood stage. Rain is likely
on Wednesday, with rainfall amounts around one half inch expected.
This will be unlikely to significantly affect river stages.
Preliminary point temps/pops...
Tallahassee 78 63 74 54 64 / 20 10 70 30 10
Panama City 73 65 72 53 62 / 20 30 70 20 10
Dothan 76 60 67 47 59 / 10 20 70 20 0
Albany 77 62 70 48 61 / 20 20 70 30 0
Valdosta 78 62 75 54 63 / 20 10 60 40 10
Cross City 80 63 78 59 68 / 20 10 40 40 10
Apalachicola 73 65 73 55 64 / 20 10 60 30 10