High Surf Advisory 6, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
651 PM EDT Mon Aug 24 2020

.AVIATION...
[Through 00Z Wednesday]

Most TAF sites are experiencing VFR conditions. During shower and
thunderstorm activity, TAF sites may briefly go down to MVFR or
IFR conditions. These conditions are expected to continue through
the evening and early overnight hours. With continuous rain
occurring at DHN, IFR to LIFR conditions are likely continue off
and on over the next several hours.

&&

.PREV DISCUSSION [337 PM EDT]...

.NEAR TERM [Through Tuesday]...

Impacts associated with Marco are expected to wane by the
overnight hours tonight as Marco dissipates as it makes landfall
west of our region. By Tuesday, the upper level vorticity
associated with the remnants of Marco are expected to move north and
west into central Mississippi and Alabama. This upper level
vorticity will be the main focus for shower and thunderstorm
activity during the afternoon hours on Tuesday. This is mainly why
PoPs have been kept higher along our SE Alabama and western
Florida Panhandle counties tomorrow, and taper off towards the
east in our Georgia and Florida Big Bend zones. Aside from the
afternoon shower activity, deep layer ridging is expected to build
over the region tomorrow from the east. This will play a
significant role through the short term period in steering
Tropical Storm Laura west of our region. With Muggy conditions
expected, and highs climbing into the mid 90s, heat index values
may surge into the 105-110 range across the Florida Panhandle and
Big Bend regions. This may warrant a heat advisory for these
regions.

.SHORT TERM [Tuesday Night Through Wednesday Night]...

Through the early part of the short term period, deep layer
ridging will continue to build and settle over the region. As was
previously alluded to in the near term discussion, this will play
a significant role in the overall steering of Tropical Storm
Laura. This steering pattern should induce a west/northwestward
motion on Tropical Storm Laura as it deepens in the south central
Gulf of Mexico on Tuesday and Tuesday evening. Tropical Storm
Laura is forecasted to become a hurricane by Tuesday evening. With
Laura quickly deepening in the central Gulf of Mexico, long period
swells are expected to propagate into the northeastern Gulf waters
and coastline. These swells will likely lead to dangerous
beach/marine conditions through the short-term period.

With a potential hurricane passing south of the region through
the central Gulf of Mexico, the peripheral impacts expected will
likely remain over the marine zones. Currently points in our
western marine zones extending south from Panama City have less
than a 1 in 10 chance of seeing tropical storm force winds of 34
knots as Laura passes south of the region. These probabilities
will likely change with future advisories from NHC. Overall, as
the region remains under a rich tropical airmass, the possibility
remains for a few thunderstorms associated with the outer bands
of Laura to make their way into our offshore waters.

Aside from from the peripheral impacts expected over the coastal
waters and beach zones, PoPs across interior portions of the region
are expected to remain near climatological values, or roughly
30% on Wednesday. Temperatures will remain warm with much of the
region climbing into the low to mid 90s. With Muggier than normal
conditions expected, Heat indices may push into the 105-110 range
across the Florida Panhandle and Florida Big Bend on Wednesday.

.LONG TERM [Thursday Through Monday]...

As Laura passes to our south, and makes landfall along the
northwestern Gulf coast, deep layer ridging is expected to
continue to settle over the region. With high PW values greater
than 1.75 inches expected to remain over the region, a more
typical summertime pattern of diurnal convection will return.
Depending on the over path that Laura takes once it makes
landfall, a main focus of shower and thunderstorm activity could
develop across our region. Current model guidance is suggesting
that an east/west orientated elongated ribbon of vorticity
associated with the remnants of Laura will become quasi-stationary
across our region. This may be a focus for increased shower and thunderstorm
activity from Friday through the remainder of the weekend. Overall
Temperatures will remain in the low 90s across the region, and
lows will fall to around the mid 70s.

.MARINE...

Tropical Storms Marco and Laura will continue to produce dangerous
marine conditions this week as long-period swells produce wave
heights up to 13 ft in some areas. Therefore, a Small Craft
Advisory is in effect through Wed morning for all but our eastern
nearshore waters. A High Surf Advisory is also in effect for the
coastline extending from Walton to Franklin County through today.
Conditions will be slow to improve as winds and seas are expected
to remain elevated for much of the remainder of the period. Outer
rainbands and tropical moisture will also continue affecting our
marine waters through the remainder of today, and through the
early half of the overnight hours. Some embedded thunderstorms may
be capable of producing gusty winds and waterspouts. Some of these
thunderstorms have already had tornadic/waterspout signatures just
offshore.

.FIRE WEATHER...

Wet conditions are expected over the next couple days as moisture
associated with Tropical Storms Marco and Laura funnel into our area.
Rain chances diminish by mid-week with winds out the east to southeast.
Other than low dispersions Monday evening and high dispersions Tuesday
afternoon in the headlined areas, there are no fire weather concerns.

.HYDROLOGY...

Much of the region is currently under a slight risk for excessive
rainfall. Overall today a widespread 2-3 inches of rain has fallen
across the Florida Panhandle. There are isolated areas that have
received up to 4 inches so far across coastal regions in Bay and
Walton counties. The heaviest rain is expected to slowly move
onshore in the next few hours across the Florida Panhandle. We
will likely see another 1-2 inches with pockets of 2-3 in addition
to what has already fallen across this region.

Looking ahead to tomorrow, the region is currently under a
marginal risk for excessive rainfall. Overall rainfall totals are
expected to be less compared to today, however pockets of heavy
rain from scattered thunderstorms could pose a localized flood
threat, especially given that much of the areas soils are
saturated from the rains we've received over the last two days.
In general, most of the heaviest rain has fallen along coastal
regions. This has subsequently not caused any major river
flooding concerns.

.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   74  94  75  93  75 /  40  30  20  30  10
Panama City   77  90  78  90  78 /  40  50  30  40  10
Dothan        73  91  74  91  73 /  30  50  20  30  10
Albany        75  93  75  94  75 /  40  30  10  20  10
Valdosta      74  93  74  93  73 /  50  40  10  30  10
Cross City    75  95  74  94  73 /  30  40  20  30  10
Apalachicola  79  88  78  89  78 /  40  40  30  30  20

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Wednesday evening for Coastal Bay-
     Coastal Franklin-Coastal Gulf-South Walton.

     High Surf Advisory until 8 PM EDT /7 PM CDT/ this evening for
     Coastal Bay-Coastal Franklin-Coastal Gulf-South Walton.

GA...None.
AL...None.
GM...Small Craft Advisory until 8 AM EDT /7 AM CDT/ Wednesday for
     Coastal Waters From Ochlockonee River to Apalachicola Fl
     out to 20 Nm-Coastal waters from Mexico Beach to
     Apalachicola FL out 20 NM-Coastal waters from Mexico Beach
     to Okaloosa Walton County Line FL out 20 NM-Waters from
     Suwannee River to Apalachicola FL from 20 to 60 NM-Waters
     from Apalachicola to Mexico Beach FL from 20 to 60 NM-
     Waters from Mexico Beach to Okaloosa Walton County Line FL
     from 20 to 60 NM.

&&

NEAR TERM...Bunker
SHORT TERM...Bunker
LONG TERM...Bunker
AVIATION...Bunker
MARINE...Bunker
FIRE WEATHER...Montgomery
HYDROLOGY...Bunker