Heat Advisory 5, NWS Tallahassee, FL

Bay County, FL, Calhoun County, FL, Dixie County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Jackson County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Madison County, FL, Taylor County, FL, Wakulla County, FL, Washington County, FL, Brooks County, GA, Decatur County, GA, Grady County, GA, Lanier County, GA, Lowndes County, GA, Seminole County, GA, Thomas County, GA

Area Forecast Discussion
National Weather Service Tallahassee FL
147 AM EDT Thu Aug 19 2021

.AVIATION...

[Through 06z Friday] Some patchy fog and low ceilings are possible
around DHN and VLD early this morning, otherwise VFR conditions
are expected to prevail. Isolated to scattered showers and
thunderstorms are expected to develop this afternoon with the
greatest chances near ECP, TLH, and VLD.

&&

.PREV DISCUSSION [955 PM EDT]...

.NEAR TERM [Through Thursday]...

The 00z TAE balloon sounding showed that the Precipitable Water
(PW) value had decreased to 1.64". Meanwhile, the 500 mb height
had risen 40 meters in the past 24 hours and had reached 5970
meters. This indicates the development of strong high pressure
aloft. The most noticeable effect is that it will constrain the
coverage of afternoon convection to some extent on Thursday.
Convection should mainly be confined to the seabreeze front, with
coverage likely being a little less than today.

.SHORT TERM [Thursday Night Through Friday Night]...

We'll continue to gradually return to the usual summertime pattern
as deep layer ridging slides SW over our region. Sea breeze and
diurnally forced convection will be the primary modes of precip
development. However, with subsidence in place, widespread and
robust convection is not anticipated. Expect daytime highs in the
low to mid 90s with overnight lows in the mid 70s.

.LONG TERM [Saturday Through Wednesday]...

The aforementioned ridge will continue to move westward throughout
the long term with a potential temporary weakening in the ridge
over the weekend as a trough in the Midwest rides over the ridge
and tries to extend southward across the Eastern Seaboard. This
could allow the trough to drop a backdoor cold front across the
region on Saturday and into Sunday evening. As the trough lifts to
the NE early next week, we will see the ridge building once again
right over our region, bringing us back into the current weather
patter. Expect daytime highs in the low to mid 90s with overnight
lows in the mid 70s.

.MARINE...

Buoys 42039 and 42036 are observing placid conditions over the
Gulf this evening, with the latter reporting 1-foot seas at 3
seconds.

However, long-period southerly swell are expected to enter the
northeast Gulf on Thursday afternoon, thanks to the swell that
Hurricane Grace is currently generating south of the Yucatan
Channel. The initial swell that arrives may come with a period of
15 seconds, indicating a lot of wave energy for only have a
significant wave height of 2-3 feet. This may cause surprisingly
rough conditions at inlets during ebb currents and in shallow
nearshore areas.

Otherwise, light and gentle breezes will prevail. Protected waters
will be mostly smooth to a light chop.

.FIRE WEATHER...

A seasonably moist and unstable air mass will persist through this
weekend. Hot and muggy conditions will lead to heat index values
peaking in the 105-110 degree range each day. Otherwise, erratic
and gusty winds near thunderstorms will be a concern.

.HYDROLOGY...

Estimated rainfall amounts over the next 7 days are generally around
1 inch or less, but isolated higher values are always possible from
heavy downpours caused by the stronger storms.

A Flood Warning remains in effect for the following rivers:
Steinhatchee (US-19) and Suwannee Wilcox/Rock Bluff/Manatee
Springs. The latter are forecast to stay in minor flood stage
(borderline for Wilcox) through the weekend, while the former
should continue its slowly downward trend.

.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   95  75  93  75  92 /  40  10  50  30  70
Panama City   91  76  89  76  89 /  30  10  40  30  70
Dothan        93  74  88  72  88 /  20  20  60  20  70
Albany        94  76  90  74  92 /  20  20  60  30  70
Valdosta      93  75  93  74  93 /  40  20  60  30  70
Cross City    93  76  93  75  91 /  50  20  50  30  60
Apalachicola  89  76  90  76  89 /  30  10  30  30  50

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory from noon EDT /11 AM CDT/ today to 7 PM EDT /6 PM
     CDT/ this evening for Calhoun-Coastal Bay-Coastal Dixie-
     Coastal Franklin-Coastal Gulf-Coastal Jefferson-Coastal
     Taylor-Coastal Wakulla-Gadsden-Inland Bay-Inland Dixie-
     Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor-
     Inland Wakulla-Jackson-Lafayette-Leon-Liberty-Madison-
     Washington.

GA...Heat Advisory from noon today to 7 PM EDT this evening for
     Brooks-Decatur-Grady-Lowndes-Seminole-Thomas.

AL...None.
GM...None.
&&

NEAR TERM...Haner
SHORT TERM...Oliver
LONG TERM...Oliver
AVIATION...DVD
MARINE...Haner
FIRE WEATHER...Haner
HYDROLOGY...Oliver