Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 231009
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
609 AM EDT Thu May 23 2013
.UPDATE...The combination of surface wave and approaching axis of
upper trough generated ample convection overnight that moved
slowly ewd across mainly south central Georgia. Impressive
lightning and heavy rain marked this system. By 6 am EDT...this
activity moved east of I-75. Grids updated accordingly.
Near Term [Today]... The axis of an upper level trough will slide
across and just to the east of our CWA by tonight. At the surface,
a weak trough will push through this morning with winds shifting
to the northwest. The deep layer northwesterly flow will bring a
drier airmass into the region. Surface dew points are forecast to
drop into the upper 50s to lower 60s most areas this afternoon.
PoPs will be 10% or less. Highs will range in the upper 80s along
the coast to the lower 90s inland.
.SHORT TERM [Tonight Through Sunday]...
TONIGHT...the large scale longwave pattern remains highly amplified
with full latitude trough over Wrn, ridge over Cntrl and trough over
Ern states followed by ridge over extreme Wrn Atlc. Low assocd with
Ern trough continuing to weaken as it shears NEWD. At surface, low
vcnty PA with weakening cold front Swd to N GA then SWWD across SE
AL. During the rest of overnight hours, axis of Ern trough to move
to Ern seaboard with rapidly weakening mainly dry front reaching
extreme Nrn Gulf waters by sunrise FRI.
FRIDAY THRU SUNDAY...By Fri eve, trough axis and assocd low just
off Ern seaboard. In their wake, upper ridge will build NWD from
Wrn Gulf of Mex while surface high pressure builds SWD from the
OH/ TN Valleys to the Nrn Gulf. Assocd ridge will continue to
build SEWD Fri night into SAT with high centered NNE of region.
Locally this places local area between departing trough and
advancing upstream ridge yielding a much cooler and drier airmass
with NW steering flow. Flow aloft becoming WNW by Sun, and with
NLY flow at lower levels veering to NE on Sat and ESE on Sun. The
result is a reinforcing dry airmass heralding an ideal weekend
with mostly clear skies, low dew points and cool nights.
10% pops tonight then no POPs thru period. Inland Lows tonight low
to mid 60s dropping Fri and Sat nights in wake of front to mid 50s.
Highs generally mid to upper 80s. Invading drier air should limit
fog chances thru period.
.LONG TERM [Sunday Night through Wednesday]...
Upper ridging will build over the area through Memorial Day and
into the middle of next week. This will leave somewhat tranquil
conditions in place with a seasonably cool start to the period and
a gradual warm up into the early part of the week, with little or
no rain outside of possible isolated showers along the sea breeze.
.Aviation...[Through 06Z Friday]
Areas of fog will develop in the pre-dawn hours. Some of the fog may
become dense especially in places that received rain. VFR conditions
will return across the entire region after 14Z. Winds will be from
the west to northwest in the 10 to 15 knot range with higher
Fairly low winds and seas will persist into Friday, when offshore
winds will increase in the wake of a surface cold front late
Friday night into Saturday. Seas will eventually build as well in
the offshore legs with cautionary wind speeds expected Friday night.
winds will veer and along with seas decrease thru the rest of the
A much drier airmass will be filtering into the region over the next
few days. Today the minimum relative humidity should stay above
critical levels but is forecast to drop at or just below 28 percent
over interior portions of the Florida Panhandle and western Big Bend
Friday afternoon. This combined with elevated ERC values and
sustained winds at or above 15 mph will possibly meet Red flag
conditions. A fire weather watch has been posted and may be upgraded
to a warning later today. A fire weather watch will also be issued
for our SE Alabama counties Friday due to a combination of long
durations of low RH, KBDI over 500 and sustained winds at or above
10 mph. Low relative humidities are also expected across our Georgia
zones Friday but the 10-hour fuel moisture should remain above 6
percent. Red Flag conditions are also possible across portions of
north Florida and our southeast Alabama counties again on Saturday.
On top of all this, dispersions will be very high across north
Florida this afternoon and again on Friday with forecast values
No issues are forecast along area rivers for the foreseeable future.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 91 66 89 56 87 / 10 10 10 10 0
Panama City 87 75 87 66 81 / 10 10 10 10 0
Dothan 92 66 87 55 86 / 10 10 10 10 0
Albany 91 64 85 55 85 / 10 10 10 10 0
Valdosta 90 63 87 56 85 / 10 10 10 10 0
Cross City 89 67 89 58 86 / 10 10 10 10 0
Apalachicola 84 72 87 66 82 / 10 10 10 10 0
FL...FIRE WEATHER WATCH from Friday afternoon through Friday
evening for Calhoun-Gadsden-Holmes-Inland Walton-Jackson-
AL...FIRE WEATHER WATCH from Friday afternoon through Friday
evening for Coffee-Dale-Geneva-Henry-Houston.