Flash Flood Warning 16, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
637 AM EDT Mon Aug 19 2019

.AVIATION...
[Through 12Z Tuesday]

Tricky set of TAFs this morning with patchy IFR and MVFR cigs
across the area this morning, on and off rounds of showers and
thunderstorms throughout the day, and potentially some more
BR/low cigs late tonight. The lowest cigs that develop this
morning should lift to (or at least scatter out to) VFR, but low
vis could develop in rounds with storms. For now, only have sites
dropping to MVFR on and off through the day, with the only exception
being IFR cigs at VLD this morning.

&&

.PREV DISCUSSION [344 AM EDT]...

.NEAR TERM [Through Today]...

A narrow upper trough will continue across the region today with a
weak surface trough as well. Deep tropical moisture will also remain
in place with precipitable water values over 2 inches. As a result,
a high coverage of showers and a few thunderstorms is expected
through the day today across the area. Some of the rain will be
heavy at times. The main issue is what to do with the flood watch
across the southeast big bend, either let it expire, extend it for
just those counties, or extend it and expand it northward? Guidance
indicates that the main focus for heavy rain today will be north of
the flood watch area across southwest and south-central Georgia.
However, there could still be a few bands of heavy rain that develop
across the southeast big bend through the morning hours before
activity tends to lift northward in the afternoon. As for areas
farther to the north, the flash flood guidance values are generally
3-4 inches in a 3-6 hour time period. Some of the storms today
appear capable of producing these amounts, but this will generally
be in small pockets rather than over a large area. Our local
ensemble of hi-res guidance indicates about a 20-30 percent chance
of exceeding flash flood guidance today across most of the forecast
area. Since the threat of flooding is expected to be localized
rather than widespread at this time, the preference is to not
blanket a large area with a watch. We will continue to monitor radar
trends and later guidance closely through the morning hours and make
a decision at the last minute on whether to extend and expand the
three county watch currently in effect through 8 am.

.SHORT TERM [Tonight Through Wednesday]...

Overall chances for showers and thunderstorms will come down
slightly from about 80% to 60%. The narrow upper level trough will
begin to weaken and slowly drift northeastward, allowing for
diminishing upper level enhancement of convection the next few days.
PW values of 2"+ are expected to continue across the area through
Tuesday. Then Tuesday night into Wednesday, slightly drier air (PW
of 1.5-2") will work its way into western portions of the area,
while the axis of deeper moisture shifts eastward into the eastern
FL Big Bend and NE FL. Highs will be in the upper 80s to low 90s and
lows will be in the low 70s.

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

A more diurnal, seabreeze driven pattern will resume with a weak
pressure pattern in place at the lower and upper levels. Deeper
moisture (as seen in PW values increasing) will return to western
portions of the area on Thursday and remain in place into early next
week. As a result of the increase in moisture, PoPs will increase
again during the long term period. Highs will be mostly in the low
90s with lows in the low 70s.

.MARINE...

Winds around 10 to 15 knots today will fall overnight and remain low
for the rest of the week. Likewise, wave heights will fall to 2 feet
tonight and remain 2 feet or less for the rest of the week. Daily
chances for showers and thunderstorms will continue through the
period.

.FIRE WEATHER...

Red flag conditions are not expected for the next several days with
relative humidity values remaining above critical levels.

.HYDROLOGY...

As mentioned above, pockets of heavy rain will be the main threat
today across the area. Some localized areas of flash flooding are
possible. In addition, the Steinhatchee River is continuing a slow
rise. This basin will be near the southern edge of the bands of rain
this morning.

.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   84  73  88  72  92 /  70  30  40  10  40
Panama City   85  75  87  75  89 /  70  30  40  20  40
Dothan        89  72  88  71  90 /  70  40  60  30  50
Albany        86  73  87  73  91 /  70  50  60  30  50
Valdosta      83  72  87  72  91 /  80  20  30  20  40
Cross City    84  72  91  73  91 /  60  10  20  30  50
Apalachicola  84  76  87  75  88 /  80  30  30  10  30

&&

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

     Flood Watch until 2 PM EDT this afternoon for Coastal Taylor-
     Inland Taylor-Lafayette.

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

NEAR TERM...DVD
SHORT TERM...Nguyen
LONG TERM...Nguyen
AVIATION...Nguyen
MARINE...Nguyen
FIRE WEATHER...DVD
HYDROLOGY...DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
700 AM EDT MON AUG 19 2019

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

1145 PM     FLASH FLOOD      1 NW ALLANTON           30.04N 85.47W
08/18/2019                   BAY                FL   911 CALL CENTER

            OLD ALLANTON ROAD REPORTED TO BE FLOODED
            FROM LAST NIGHT.

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
831 AM EDT MON AUG 19 2019

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

0829 AM     FLASH FLOOD      1 SE PARKER             30.12N 85.59W
08/19/2019                   BAY                FL   LAW ENFORCEMENT

            TYNDALL PARKWAY CLOSED DUE TO FLOODING IN
            THE CALLAWAY/PARKER AREAS.

&&

PC