Special Marine Warning 236, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
125 PM EDT Wed Jul 28 2021

.AVIATION...
[Through 18Z Thursday]

VFR conditions are expected to prevail throughout the remainder of
the day; however, widespread showers and thunderstorms are
expected to develop/expand in coverage across the region. If these
showers and thunderstorms move over a terminal, MVFR to LIFR
conditions will be possible. Through the early morning hours,
slightly lower CIGs and VSBYS will be possible at ABY and VLD;
however, they should quickly recover to VFR conditions through the
mid morning hours. VFR conditions are expected at all other
terminals through the overnight and morning hours.

&&

.PREV DISCUSSION [1020 AM EDT]...

.NEAR TERM [Through Tonight]...

Another active day is expected today with a similar scenario to
yesterday, just shifted southward slightly. Weak vort maxima remain
embedded in a tropical environment characterized by precipitable
water values over 2 inches in a light northwest steering flow. The
favored areas for the heaviest convection this afternoon are
expected to be across the Florida panhandle and big bend and
adjacent sections of southwest Georgia. In these areas, the
afternoon seabreeze trying to push inland against the prevailing
light northwest flow will lead to enhanced convergence and be a
focus for storm development. The light steering flow and high
precipitable water values are expected to contribute to another day
of pockets of heavy rain and localized flooding. High temperatures
will generally range from the upper 80s to mid 90s with peak
afternoon heat index values in the 102-107 range. Overnight lows
will be quite muggy in the mid 70s, except upper 70s along the
coast.

.SHORT TERM [Thursday Through Friday]...

The axis of a strong upper ridge noses into our area from the
northwest to begin the short-term; prompting a return to typical
summertime convection (PoPs up to around 50%), while also setting
the stage for hazardous heat conditions. The combination of high
temperatures (in the 90s) and relative humidity is forecast to push
heat indices into advisory levels (108-112 degrees) across much of
the region on Thursday. Inland shower and thunderstorm activity
diminishes after sunset, followed by maritime convective development
overnight. Low temperatures are expected to be in the mid 70s.

Below-average rain chances (generally less than 30%) are on tap for
Friday, as the ridge axis further penetrates our area. As a result,
high temperatures should sore to the upper 90s away from the coast.
It would not be surprising if some isolated spots reach the century
mark (e.g., MOS guidance suggests so for Tallahassee). Widespread
heat indices in the low 110s arrive in the afternoon, with some
locations possibly reaching our Excessive Heat criteria (>=113
degrees)! Heat safety tips and resources can be found in the
following link: www.weather.gov/safety/heat.

.LONG TERM [Friday Night Through Wednesday]...

The dangerous heat continues through the weekend, with borderline
excessive heat/high-end advisory conditions on Saturday areawide,
followed by a slight decrease in coverage and magnitude on Sunday.
Forecast high temperatures remain in the upper 90s away from the
coast during that timeframe (lows mostly in the upper 70s). A broad
upper trough then swings down across the eastern US and causes the
heat-inducing ridge to retreat westward. This synoptic shift will
effectively knock apparent temperatures below advisory levels. The
tradeoff is a notable increase in rain chances through the remainder
of the period as there should be ample upper support and lift from
an attendant frontal boundary within a moist/unstable airmass. Some
storms may be strong to marginally severe, capable of producing
heavy rain, gusty/strong winds, and frequent lightning. The expected
uptick in precipitation and cloud cover likely keeps high
temperatures from exceeding 90 degrees on Monday and Tuesday, while
we see low temperatures in the 70s.

.MARINE...

Light west to southwest winds persist over the next few days, but
increase to around 15 knots this weekend. Favorable boating
conditions prevail outside of thunderstorms, but cautionary levels
are possible on Sunday.

.FIRE WEATHER...

There are minimal fire weather concerns expected for the next
several days.

.HYDROLOGY...

One more day of scattered to numerous showers and thunderstorms are
expected across the area within a moist airmass and weak steering
flow. These factors are ideal for slow-moving and effective rain-
making convection, thus posing a renewed threat of localized flash
and/or nuisance flooding. The targets of opportunity appear to be in
the FL Panhandle/Big Bend and adjacent southwest GA. A Marginal Risk
(level 1/5) for excessive rainfall is in place for those locations
in the Day 1 Outlook by WPC (valid 12Z Wednesday). A temporary
return to typical summertime (or even below-average) rain chances is
on tap beginning on Thursday before widespread precipitation appears
poised to affect us early next week. As far as rivers are concerned,
several remain in action stage in the Ochlockonee and Suwannee
basins, but are mostly cresting or falling. The exceptions are Rock
Bluff, Wilcox, and Manatee Springs, which are forecast to rise over
the next few days.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur (while following all local, state, and CDC guidelines) by
calling the office or tweeting us @NWSTallahassee.

&&

.PRELIMINARY POINT TEMPS/POPS...

Tallahassee   75  94  74  98  78 /  30  40  10  20  10
Panama City   77  91  77  93  81 /  20  50  10  20  10
Dothan        74  94  74  97  77 /  30  10   0  20   0
Albany        75  96  76  99  79 /  30   0   0  20   0
Valdosta      74  95  74  98  77 /  30  20  10  20   0
Cross City    75  91  75  93  78 /  30  30  20  30  20
Apalachicola  77  91  77  92  81 /  30  50  20  20  10

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&

NEAR TERM...DVD
SHORT TERM...IG3
LONG TERM...IG3
AVIATION...Bunker
MARINE...IG3
FIRE WEATHER...DVD
HYDROLOGY...IG3