High Surf Advisory 8, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
1245 AM EST Sat Dec 21 2019

.AVIATION...
[Through 06Z Sunday]

Widespread cloudiness with cigs gradually lowering to MVFR levels
and possibly as low as IFR at ECP. MVFR vsbys are also expected as
widespread rains move into the region from west to east this
afternoon into the overnight hours. Winds will be from the
northeast to east around 10 knots or less but will be gusty at
times.

&&

.PREV DISCUSSION [732 PM EST]...

.NEAR TERM [Through Tonight]...

Clouds will increase through the evening and overnight hours as a
developing surface trough over the Gulf deepens ahead of an upper
trough swinging through the southern Plains. The evening should be
dry with slight chance for rain across SE AL and the western FL
panhandle overnight. The clouds will inhibit much radiational
cooling overnight with lows some 10-15 degrees warmer as compared to
the past few mornings; readings will range from the mid 40s across
the Flint river valley to the low 50s in the FL Big Bend by daybreak
Saturday.

.SHORT TERM [Saturday Through Sunday Night]...

The center of an anomalously deep surface low will move NE across
the area Saturday night into Sunday Morning. This system is
expected to produce heavy rainfall accumulations with most of the
precipitation falling overnight Saturday through Sunday. The
consensus of the available model forecasts suggests at least 2 to
4 inches of rainfall widespread. Isolated heavier totals of 6 to 8
inches are possible.

There is increased agreement among models about the low pressure
system occluding and bringing a dry slot across N. Florida. This
should keep rainfall accumulations slightly lower across this
area compared to SE Alabama and SW Georgia. Gradual river rises
will occur through the weekend. Most rivers are expected to enter
at least action stage with a few rivers likely to enter minor
flood stage by Monday.

The environment will not be very conducive for strong
thunderstorms to develop. Thus, the threat for severe weather is
expected to be near zero for this system. Since yesterday, WPC
has increased the area of marginal flash flood threat to encompass
the majority of our warning area. However, given the rainfall will
be spread out over several days, the flash flooding threat
remains low.

Strong winds will be another concern with this system. Offshore
wind gusts will frequently reach gale force. There is gale
advisory for Saturday late afternoon. Gusty winds over land are
also possible with this system. Some wind gusts may mix down to
the surface from a strong easterly jet ahead of the system.
Especially near developing thunderstorms. With strong winds in
place, offshore wave heights will be around 10-12 feet. Closer to
the coast, especially along or far western counties (e.g., Walton
and Gulf), surf heights could be around 4-5 ft. With respect to
coastal inundation, the threat remains low.

.LONG TERM [Monday Through Friday]...

Some light showers will continue throughout the morning hours on
Monday as the system pulls away from the region. A period of calm
weather with clear skies will begin Tuesday and last through at
least the rest of the work week. Expect slightly above average
temperatures during this time.

.MARINE...

Strong offshore winds with frequent wind gusts up to gale force
starting Saturday early evening. Currently, a small craft advisory
is now in effect. With the strong winds in place expect wave
heights to increase to around 6-8 ft across our near shore waters
and 8-12 ft further offshore. Surf heights will remain around 3-4
ft along most our beaches. Some strong thunderstorms could
develop ahead of the incoming system bringing in temporary
stronger gusts.

.FIRE WEATHER...

Hazardous fire weather conditions are not expected over the
next several days as a wet pattern is expected due to an area of
low pressure emerging from the Gulf.

.HYDROLOGY...

The main concern with this system will be river rises and minor
flooding along poor drainage areas. Most rivers across the region
will enter at least action stage by the end of the weekend. The
most susceptible river basins will be those located across SE
Alabama and SW Georgia where 3 to 4 inches of rain is expected
from Saturday through Sunday. Localized amounts of +6 inches is
possible. These areas have also seen plenty of rainfall in the
past week or two thus soils will be slightly less efficient at
absorbing large amounts of water.

Close attention should be paid to the Kinchafoonee River north of
Albany, the Choctawhatchee near Dothan, and the Apalachicola
river south of lake Seminole. These rivers have the highest
chances of going into minor flood stage and potentially moderate
flood stage.

Down into the Florida Big Bend, flooding is not anticipated along
the Withlacoochee or Suwannee Rivers as the rainfall expected with
this system will not be sufficient to generate a river flood threat.

Because the rainfall is expected to be spaced out over 2-3 days, the
overall flash flood threat remains low with this system.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.

&&

.PRELIMINARY POINT TEMPS/POPS...

Tallahassee   66  53  65  48  60 /  40 100 100  50  40
Panama City   63  55  65  51  60 /  70 100 100  40  30
Dothan        59  48  57  47  57 /  70 100 100  70  50
Albany        61  49  58  48  59 /  40 100 100  90  60
Valdosta      68  53  64  48  59 /  30 100 100  70  50
Cross City    72  58  69  52  63 /  30 100 100  60  50
Apalachicola  65  57  67  53  60 /  40 100 100  30  40

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...Gale Watch from this evening through Sunday morning 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.

     Small Craft Advisory until 7 PM EST /6 PM CST/ this evening 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...Scholl
SHORT TERM...DiCatarina
LONG TERM...DiCatarina
AVIATION...Barry
MARINE...DiCatarina
FIRE WEATHER...Harrigan
HYDROLOGY...DiCatarina

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
322 AM EST SAT DEC 21 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1209 PM     TORNADO          2 NNE OSIERFIELD        31.70N 83.11W
12/17/2019                   BEN HILL           GA   NWS STORM SURVEY

            EF2 TORNADO FROM IRWIN COUNTY CONTINUED INTO
            BEN HILL COUNTY. THIS IS THE END POINT.

&&