Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tallahassee Florida
850 PM EDT Wednesday may 27 2015
Near term [through tonight]...
Afternoon convection dying out with the sunset. Surface high
pressure settled into northern Georgia will make for a quiet
Thursday morning. Slightly drier air mass...with middle 60 dew
points...moving in from the east should keep regional dew point
depressions just high enough to inhibit any significant fog
development. A near calm wind...along with clearing skies...will
allow some patchy shallow inland fog to form just before sunrise.
[through 00z friday]...
VFR. Early evening cirrus left over from today's convection will
break up through early Thursday morning. A variable to light
easterly wind allowing drier easterly air to move in should
preclude any significant fog development...nothing more than
short-lived shallow patchy fog around sunrise. Upper ridging in
tandem with the lower level dry air will likely suppress areawide
Thursday storm activity. Can't completely rule out an isolated
storm along the breeze but confidence on location/timing is too
low to include in the latter period of this taf package.
Previous discussion [350 PM edt]...
Short term [thursday through Friday night]...
The weak middle-upper level trough over our forecast area will fill,
as a much drier airmass advects into our region from the east.
This drier air will suppress deep moist convection, especially on
Friday afternoon, when surface dewpoints may drop into the upper
50s. Rain chances will be confined to areas west of the Albany
and Tallahassee, with probability of precipitation ranging from 20 to 50 percent (highest
west) Thursday, and only around 20 percent Friday. Temperatures
will be near average, with highs around 90 and lows in the 60s.
The lower humidity will aid in sweat evaporation, making it feel a
bit more comfortable.
Long term [saturday through wednesday]...
A broad upper level low will develop and become centered in the
vicinity of Arkansas later this weekend through middle next week. Our
forecast area will become increasingly under the influence of the
southwest flow aloft on the southeast flank of this cyclone. The increase
in q-g forcing, along with a return to at least average precipitation
water values and MLCAPE, will bring our probability of precipitation back to climatology levels
(30-50 percent) each afternoon late this weekend and into next
week. Temperatures will remain near their climatology values, with lows
near 70 and highs in the lower 90s.
An east-west oriented ridge will remain north and east of the
forecast area for the next several days. This will continue to
provide mostly east to southeast winds. These winds will tend to
be a bit stronger and from the east overnight, then lighter and
more onshore during the afternoons.
A drier air mass advancing in from the east through late Thursday
will one...aid in suppressing more widespread afternoon thunderstorm
activity while two...lowering eastern two third forecast area
relative humidities into the upper 30s to lower 40s both Thursday
and Friday afternoons. A background light easterly early day
wind....possibly decoupling and becoming calm overnight while
veering near the coast to more southeasterly per the inland
advancing breeze. Overnight inland inversion will keep mixing depths
to the hundreds of feet...breaking by 9 am and reaching near 6
thousand feet by early afternoon.
24-hour rainfall totals as of Tuesday evening showed a rather
concentrated area of 1 to 3 in values across much of the Florida
Panhandle and southeast Alabama. There were isolated amounts of 4 to 6
in. This large volume of rain has caused some sharp rises in some
of the Panhandle rivers. While most rivers were well below their
action stage, Mossy Head has recently reached its action stage.
Fortunately, after today, much less rain is expected, which will
give the rivers time to subside before rain chances increase next
Preliminary point temps/pops...
Tallahassee 67 90 67 90 68 / 20 10 10 10 10
Panama City 70 84 71 84 71 / 20 40 10 20 10
Dothan 67 87 67 89 67 / 40 40 20 20 10
Albany 67 90 66 90 66 / 30 10 10 10 10
Valdosta 67 90 64 89 66 / 10 10 0 10 10
Cross City 67 90 63 90 66 / 10 10 0 10 10
Apalachicola 70 85 70 85 71 / 10 20 20 10 10
Florida...high rip current risk until 11 PM EDT /10 PM CDT/ this evening
for coastal Bay-coastal Franklin-south Walton.