River Flood Warning 6, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
548 AM EST Thu Feb 6 2020

.AVIATION...
[Through 12Z Friday]

SHRA/-TSRA are currently draped across the
northwestern half of the CWA. Southerly winds have been steadily
increasing throughout the night, with many terminals reporting
30+ kts this morning. Increased winds should keep fog from forming
at the surface, though low CIGs will prevail throughout the
period. Conditions will generally remain IFR/LIFR, with winds
becoming gusty early in the morning, increasing even more ahead of
a strong/severe line of storms that will approach from the west.
A brief lull of winds behind the cold front towards the end of the
period will eventually give way to gusty northwesterlies as the
upper level trough swings through our area.

&&

.PREV DISCUSSION [239 AM EST]...

.NEAR TERM [Through Tonight]...

A very active today and tonight period is expected as a very
anomalous positively tilted trough currently across SW Texas is
expected to propagate eastward and develop a more negative tilt as
it moves over the norther Gulf coast.  As the aforementioned upper
level trough propagates eastward, a 500mb jet streak of 100+ kts is
expected to develop across the northern Gulf.  In association with
this jet streak, a strong surface low pressure system is expected to
move northeastward out of the lower Mississippi valley and into
northern Alabama and Georgia where it will experience a favorable
environment to intensify.  This will likely lead to impressive
pressure falls across our region.

As the upper level trough approaches our area, height falls in
excess of 150m will add to an already unstable environment in
place as surface dewpoints have already begun to climb into the
low 70s across much of our region. A LLJ is forecast to strengthen
throughout the morning and afternoon as the trough approaches our
region, with 850mb winds approaching 60+ kts. This will only
enhance the development of the expected squall line that is
currently developing across the lower Mississippi valley. The
squall line currently across the south central Mississippi will
likely be the main threat today; however, there is the possibility
that discrete supercell thunderstorms will develop out ahead of
this squall line. These supercell thunderstorms will likely have a
favorable environment to produce tornadoes. There is still also
the chance if the 0-3km shear vector becomes perpendicular to the
main squall line that embedded tornadoes can develop given that
surface winds will likely be backed out ahead of it.

As a whole, even without the tornado threat, the squall line will
likely produce widespread gusts of 50+ kt winds across our area, and
should be taken seriously.

.SHORT TERM [Friday through Saturday]...

The squall line and associated severe weather threat will be gone
from our CWA to begin the short term. Mostly dry conditions follow
as a much cooler and more stable airmass moves in from the
northwest in the wake of the freshly passed cold front. High
pressure also builds at the surface over the southeast, resulting
in mostly clear skies. Despite plentiful sunshine, high
temperatures will struggle to reach 60 on Fri. The combination of
subsidence aloft, excellent radiational cooling conditions, and
cold-air advection is expected to bring down temperatures to the
mid 30s (except for the immediate coast) on Sat in the overnight
and early-morning hours. High temperatures are forecast to be a
few degrees warmer on Sat.

.LONG TERM [Saturday Night Through Thursday]...

Surface high pressure gradually slides eastward this weekend,
causing winds to veer from east to the south. This shift will
cause moisture to increase for our area thus allowing
temperatures to moderate and begin a warming trend. High
temperatures will be mostly in the 70s with each successive day
being warmer, with low temperatures generally in the low 60s.

Zonal flow aloft is expected to become more southwesterly to begin
the work week as a cutoff low tracks east from near the US/Mexico
border. This pattern will bring rain chances back to our area Mon
afternoon (30-40% PoPs for the AL and western FL Panhandle
counties) as a frontal boundary develops at the surface. Models
are suggesting that the front may temporarily stall, so kept PoPs
relatively unchanged through Tues. By Wed, a shortwave trough
moves east through the OH Valley and mid-Atlantic states and lifts
the boundary, thus causing showers to taper off slightly.

Meanwhile, a longwave trough is expected to dive down the western
US and help eject the energy of the aforementioned cutoff low to
trigger surface cyclogenesis over the midwest. This new system
will track northeast and drag a formidable cold front to its
south. As a result, rain chances increase from northwest (up to
nearly 60%) to southeast on Thurs, with a slight chance of thunder
for our western CWA.

.MARINE...

Terrible boating conditions are expected today through Friday as a
powerful system affects the area. Frequent gale force gusts are
expected ahead of the front today and behind the front tonight into
Friday. The potential for severe thunderstorms also exists ahead of
the front today. Conditions will improve on Saturday. Moderate
easterly winds are expected to develop on Sunday and veer to onshore
for Monday.

.FIRE WEATHER...

A squall line capable of producing severe storms will move through
the forecast area on Thurs. Heavy rainfall and damaging winds are
expected with this system. Dry conditions follow the exit of the
squall line early Fri with high dispersions beginning in the
immediate coast around daybreak and then becoming widespread
through most of the afternoon. Despite the dryness, minimum RH
values will not meet red flag criteria. There are no fire weather
concerns.

.HYDROLOGY...

An additional 1 to 3 inches of rain is expected across the area
today. This results in storm totals of 4 to 6 inches in the
western half of the region and 2 to 4 inches of rain elsewhere.
These rainfall amounts will result in the potential for flash
flooding during the time of heaviest rainfall, particularly across
Southeastern Alabama, Southwestern Georgia, and the Florida
Panhandle. A flash flood watch remains in effect for these areas.

Additionally, river flooding is expected to follow, with at least
minor flooding in the Choctawhatchee, Chipola, Apalachicola basins
as well as the Kinchafoonee Creek expected by the end of the
weekend. Some of these basins may also approach moderate flood
levels, depending on the placement of the heaviest rain. Elsewhere,
rivers should rise into action stage, outside of the Suwannee Basin.

For coastal flood interests, high tide today in Apalachee Bay is
around 130 pm ET, with an additional high tide late tonight. Should
the system be a little slower than predicted, the period of highest
surge could overlay this last high tide and result in moderate
coastal flooding. This is possible, mainly from the Steinhatchee
River southward. That being said, the latest guidance, both PETSS
and deterministic ESTOFS/ETSS data suggest that the maximum water
levels in Apalachee Bay will be between 2 and 3 feet MHHW, which is
on the higher side of our coastal flood advisory criteria, and a
coastal flood advisory is in effect.

.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   74  42  57  36  65 / 100  80   0   0  10
Panama City   73  44  57  45  65 / 100  50   0   0  10
Dothan        71  40  53  37  64 / 100  50   0   0  10
Albany        72  42  53  36  63 / 100  60   0   0  10
Valdosta      75  45  56  36  64 / 100  80   0   0  10
Cross City    77  48  60  37  66 / 100  90   0   0   0
Apalachicola  72  46  55  43  63 / 100  70   0   0  10

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...Wind Advisory until 7 AM EST /6 AM CST/ Friday for Coastal Bay-
     Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal
     Jefferson-Coastal Taylor-Coastal Wakulla-South Walton.

     Coastal Flood Advisory from 10 AM this morning to 3 AM EST
     Friday for Coastal Dixie-Coastal Franklin-Coastal Jefferson-
     Coastal Taylor-Coastal Wakulla.

     Wind Advisory until 7 PM EST this evening for Gadsden-Inland
     Franklin-Inland Jefferson-Inland Wakulla-Leon-Liberty-
     Madison.

     Flash Flood Watch through this evening for Calhoun-Central
     Walton-Coastal Bay-Holmes-Inland Bay-Jackson-North Walton-
     South Walton-Washington.

     Wind Advisory until 3 PM EST /2 PM CST/ this afternoon for
     Calhoun-Central Walton-Holmes-Inland Bay-Inland Gulf-
     Jackson-North Walton-Washington.

     High Rip Current Risk through Friday evening for Coastal Bay-
     Coastal Franklin-Coastal Gulf-South Walton.

     High Surf Advisory until 3 PM EST /2 PM CST/ Friday for Coastal
     Bay-Coastal Gulf-South Walton.

     Wind Advisory until 9 PM EST this evening for Inland Dixie-
     Inland Taylor-Lafayette.

GA...Wind Advisory until 7 PM EST this evening for Baker-Ben Hill-
     Berrien-Brooks-Colquitt-Cook-Decatur-Dougherty-Grady-Irwin-
     Lanier-Lee-Lowndes-Mitchell-Terrell-Thomas-Tift-Turner-
     Worth.

     Flash Flood Watch through this evening for Baker-Calhoun-Clay-
     Decatur-Dougherty-Early-Lee-Miller-Mitchell-Quitman-
     Randolph-Seminole-Terrell-Turner-Worth.

     Wind Advisory until 3 PM EST this afternoon for Calhoun-Clay-
     Early-Miller-Quitman-Randolph-Seminole.

AL...Flash Flood Watch through this evening for Coffee-Dale-Geneva-
     Henry-Houston.

     Wind Advisory until 2 PM CST this afternoon for Coffee-Dale-
     Geneva-Henry-Houston.

GM...Gale Warning until 10 AM EST /9 AM CST/ Friday for Apalachee Bay
     or Coastal Waters From Keaton Beach to Ochlockonee River FL
     out to 20 Nm-Coastal Waters From Ochlockonee River to
     Apalachicola Fl out to 20 Nm-Coastal waters from Suwannee
     River to Keaton Beach FL out 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...IG
LONG TERM...IG
AVIATION...Bunker
MARINE...DVD
FIRE WEATHER...IG
HYDROLOGY...DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
310 AM EST THU FEB 6 2020

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

0258 AM     NON-TSTM WND GST HOLMES COUNTY AIRPORT   30.83N 85.60W
02/06/2020  M38 MPH          HOLMES             FL   AWOS

            AWOS STATION K1J0 HOLMES COUNTY AIRPORT.

0304 AM     NON-TSTM WND GST 5 NE WEST BAY           30.35N 85.80W
02/06/2020  M35 MPH          BAY                FL   ASOS

            ASOS STATION KECP PANAMA CITY.

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
400 AM EST THU FEB 6 2020

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

0353 AM     NON-TSTM WND GST MARIANNA MUNICIPAL A/P  30.83N 85.18W
02/06/2020  M38 MPH          JACKSON            FL   ASOS

            ASOS STATION KMAI MARIANNA.

0353 AM     NON-TSTM WND GST NAPIER FIELD            31.32N 85.45W
02/06/2020  M37 MPH          DALE               AL   ASOS

            ASOS STATION KDHN DOTHAN.

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
500 AM EST THU FEB 6 2020

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

0453 AM     NON-TSTM WND GST MARIANNA MUNICIPAL A/P  30.83N 85.18W
02/06/2020  M45 MPH          JACKSON            FL   ASOS

            ASOS STATION KMAI MARIANNA.

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
557 AM EST THU FEB 6 2020

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

0530 AM     NON-TSTM WND GST DOAK CAMPBELL STADIUM   30.44N 84.30W
02/06/2020  M36 MPH          LEON               FL   MESONET

            MESONET STATION 0043W DOAK CAMPBELL STADIUM
            (WEATHERSTEM).

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
610 AM EST THU FEB 6 2020

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

0550 AM     NON-TSTM WND GST 2 E MACON COMMUNITY PAR 30.49N 84.25W
02/06/2020  M39 MPH          LEON               FL   MESONET

            MESONET STATION 1296W 2.0 SW KILLEARN
            ESTATES (WEATHERSTEM).

0555 AM     NON-TSTM WND GST 1 E SAINT ANDREWS STATE 30.13N 85.72W
02/06/2020  M36 MPH          GMZ750             FL   MESONET

            MESONET STATION XSTA ST. ANDREW BAY.

0555 AM     NON-TSTM WND GST ENTERPRISE MUNICIPAL A/ 31.30N 85.90W
02/06/2020  M39 MPH          COFFEE             AL   AWOS

            AWOS STATION KEDN ENTERPRISE.

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
643 AM EST THU FEB 6 2020

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

0633 AM     NON-TSTM WND GST HOLMES COUNTY AIRPORT   30.83N 85.60W
02/06/2020  M41 MPH          HOLMES             FL   AWOS

            AWOS STATION K1J0 HOLMES COUNTY AIRPORT.

&&

DVD