Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 221934
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
334 PM EDT Wed Oct 22 2014
.Near Term [Through Tonight]...
The main forecast concern was low temperatures for tonight, as high
pressure building in will keep skies clear with no precipitation.
The 12Z Tallahassee sounding had PWAT of 0.42", and that is expected
to drop to around 0.25" by 12Z tomorrow morning. Those values of
precipitable water are near minimum values in the radiosonde record
for this time of October. Given the lack of atmospheric moisture,
relatively light or calm winds overnight, and clear skies,
radiational cooling should be very efficient overnight. For this
reason we trended the forecast closer to the cooler ECMWF MOS. This
produce widespread lows in the lower 40s, except closer to the
low-mid 50s right at the Gulf coast. Also, low temperatures in the
city of Tallahassee could be about 10 degrees warmer than at the TLH
airport (low 50s vs low 40s).
.Short Term [Thursday Through Friday Night]...
As the large upper low lifts northeastward, it will be replaced by a
short wave trough moving through the Great Plains. This trough axis
will then sweep east of the area Friday night. The surface high
centered over the Great Lakes will slide steadily southward to a
position over the Northwest Gulf Coast by 12Z Saturday. This pattern
will maintain the dry weather we have enjoyed for a week now. We
will see cooler than normal conditions through most of this period,
although Friday`s highs will be pretty close to seasonal averages.
Thursday`s highs will run about 4 degrees below normal with mid 70s
north to upper 70s south. Low temps will be back down into the lower
40s for most inland areas Thursday night and modify slightly to the
mid to upper 40s for Friday night.
.Long Term [Saturday Through Wednesday]...
As the trough exits east of the area, the flow across the CONUS will
become more zonal. Some weak upper ridging will work eastward across
the Gulf Coast and FL through the period with the next long wave
trough just starting to deepen across the Plains on Wednesday. This
means temps will warm once again with 80s for highs and 50s for
lows. It will remain dry with slight chance PoPs only working their
way back into the forecast by Tuesday night and Wednesday. It should
be noted that the 12Z ECMWF now takes the remnant of TD 9 from
the northwest Caribbean Sea and lifts it northward into the
Central Gulf of Mexico on Wednesday. The 06Z GFS was doing
something similar with an even stronger system, but the latest
version has backed off. Until we see some run-to-run consistency
in the models, we will not give too much regard to this scenario.
[Through 18Z Thursday] Clear skies (VFR conditions) and light winds
should prevail through the TAF period.
Offshore flow will persist across the waters through much of the
period. Wind speeds will increase to cautionary levels tonight, and
may briefly approach advisory levels, before decreasing below
headline criteria on Thursday. Moderate offshore flow will then
persist into the weekend with winds weakening on Sunday and veering
to the east by Monday.
Very dry air will continue to filter into the region from a ridge of
high pressure off to our northwest. Although conditions are expected
to remain below Red Flag levels at this time, slightly longer
durations of low relative humidities and slightly higher ERC values
could put a small portion of the Florida Big Bend in Red Flag
conditions. Therefore, the situation will be monitored closely over
the next few days.
There are no hydrologic concerns across the region since it hasn`t
rained in a week and no rain is expected for about another week.
.Preliminary Point Temps/PoPs...
Tallahassee 41 77 42 80 45 / 0 0 0 0 0
Panama City 51 76 52 78 54 / 0 0 0 0 0
Dothan 42 74 44 78 47 / 0 0 0 0 0
Albany 41 75 43 79 46 / 0 0 0 0 0
Valdosta 42 75 43 78 46 / 0 0 0 0 0
Cross City 44 78 43 80 46 / 0 0 0 0 0
Apalachicola 52 76 51 77 51 / 0 0 0 0 0