Scientific Forecaster Discussion
fxus62 ktae 200727
Area forecast discussion
National Weather Service Tallahassee Florida
227 am EST Mon Nov 20 2017
Near term [through today]...
Surface ridging will move east across the southeast underneath a
broad full Continental U.S. Trough. Low level flow will become easterly today
as the ridge moves east, resulting in an increase in low-level
moisture and the development of low cloudiness. Low clouds are
forecast to move into the Suwannee Valley late this afternoon and
move through the entire region beginning this evening. Afternoon
highs today will remain a few degrees below normal, generally in the
middle to upper 60s.
Short term [tonight through wednesday]...
An active pattern will commence during the short term period, as
upper level quasi-zonal flow gives way to troughing on Tuesday with
the approach of the first of several shortwave troughs that will
traverse the region. Increasing cloud cover and chances for showers
and isolated embedded thunderstorms across much of the region can be
expected Tuesday, as a surface low develops over the eastern Gulf of
Mexico and moves northeastward. The highest rain chances will likely
be confined to the Florida Panhandle and Big Bend region through
Tuesday night. A second upper level shortwave trough in the southern
branch of the jet will approach the region Wednesday, as a
reinforcing shortwave trough in the northern branch of the
jet stream dives southeastward into the Tennessee Valley/southeast. This
will keep rain chances elevated across portions of the region,
with the eastern half of the County Warning Area likely seeing the best chances
for rainfall Wednesday. This system will linger into the long term
period, discussed below.
Temperatures will remain near average for late November through the
period, with highs in the upper 60s to low 70s and lows in the low
to mid 50s.
Long term [wednesday night through monday]...
The aforementioned system from the short term period will
gradually clear the tri-state region during Thanksgiving day,
giving way to drier and slightly cooler conditions through the
weekend. Near average temperatures will persist through much of
the period, as the overall upper level pattern will remain
stagnant, with ridging across the west and troughing over the
eastern Continental U.S.. operational model guidance indicates the potential
for another cold front to sweep across the region late this
weekend, but remain scant on any potential rain chances at this
Aviation [through 06z tuesday]...
VFR conditions under scattered high clouds will prevail through the
afternoon at all terminals. Low clouds will overspread vld, tlh, and
aby late in the taf period.
The Small Craft Advisory currently in effect will be allowed to
expire this morning, as winds and seas will continue to decrease
through this afternoon. Cautionary conditions will return offshore
tonight, with easterly winds between 15 and 20 knots as seas of 2
to 4 feet. Winds will shift to the northeast Tuesday night into
Wednesday morning, with speeds remaining above 10 knots through
the remainder of the period.
Hazardous fire weather conditions are not expected over the next
several days. The potential for rain returns to the forecast Tuesday
through the end of the week.
Rain chances are increasing this week as a low is expected to
develop in the Gulf. 2 to 2.5 inches of rainfall is predicted near
the coast. 1 to 1.5 inch is expected farther inland. River flooding
is not expected since river levels are still low.
Spotter information statement...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting US @nwstallahassee.
Preliminary point temps/pops...
Tallahassee 68 51 72 54 70 / 0 10 50 30 30
Panama City 64 54 70 55 70 / 0 20 50 30 30
Dothan 63 48 66 50 68 / 0 10 40 20 20
Albany 65 49 70 51 68 / 0 0 30 20 20
Valdosta 68 50 74 54 69 / 0 0 40 40 30
Cross City 70 52 75 56 73 / 0 0 70 40 50
Apalachicola 64 55 72 56 71 / 0 20 60 30 30
GM...Small Craft Advisory until 4 am EST early this morning for
Apalachee Bay or coastal waters from Keaton Beach to
Ochlockonee River FL out to 20 nm-coastal waters from
Ochlockonee River to Apalachicola FL out to 20 nm-coastal
waters from Suwannee River to Keaton Beach out 20 nm-
coastal waters from Apalachicola to Destin Florida out 20 nm-
waters from Suwannee River to Apalachicola Florida from 20 to 60
nm-waters from Apalachicola to Destin Florida from 20 to 60 nm.