Severe Thunderstorm Warning 111, NWS Tallahassee, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
842 PM EDT Thu Jun 27 2013

.NEAR TERM [Rest of Tonight]...
Current satellite and radar analysis shows an MCS developing over
Central Georgia and Alabama. This MCS will propagate southward
overnight and increase our rain chances for our GA and AL
counties. Models disagree on the persistence of this MCS through
the overnight, with our local WRF and EastARW WRF showing a
persistent MCS that moves off the FL Panhandle in the pre-dawn
hours, and the HRRR showing a system that collapses a few hours
after sunset. The 00Z sounding shows ample CAPE above 3500 J/kg,
PWAT values at 1.89 in, and weak vertical wind shear. While we do
anticipate this system to weaken and propagate more to the SW as
current trends are showing, we do think the MCS will hold together
in some capacity, increasing rain chances for SW Georgia, SE
Alabama, and possibly the FL Panhandle. This MCS will be capable
of producing strong to severe storms with straight line winds
being the primary concern.

&&

.SHORT TERM [Friday Through Saturday Night]...
The mean upper trough axis is forecast to remain east of the
forecast area through Friday. This will lead to one more day of
northerly mid-level flow and the potential for convection to push
southward into the area late the afternoon or early in the
evening. The timing and location of this convection will be
tricky, as lingering early morning convection over the Florida
zones could influence development later in the day. High-res
guidance reflects this uncertainty, showing a variety of
evolutions for convection on Friday. With this uncertainty in
mind, have gone conservatively with high chance PoPs for most
locations Friday and Friday evening. With the expected late start
to convection once again, expect high temperatures to reach the
mid 90s for many locations.

By Saturday, the wetter pattern that has been advertised for
several days will begin to develop as the upper trough deepens and
retrogrades to the west. This will shift the deep layer flow to
the southwest with significantly deeper moisture in place. In
addition, a shortwave moving into the base of the trough will help
to enhance convective development as well. Will go with likely
PoPs for most of the area for Saturday, with highs only topping
out in the upper 80s to near 90.

&&

.LONG TERM [Sunday through Thursday]...
Unseasonably deep upper trough is forecast to continue slowly
retrograding through the middle of next week, keeping most of the
forecast area under the influence of a moist and unsettled
southwesterly deep layer flow. At the surface, a relatively
stationary frontal boundary will remain in place, roughly
bisecting the forecast area from northeast to southwest early in
the period, before sliding back to the west by the middle of the
week. Areas to the east of this boundary will have the greatest
potential for heavy rain, with lighter amounts expected west of
the boundary. Exactly where this boundary is on a day-to-day basis
remain uncertain, so have kept the PoP gradient somewhat broad,
with the highest PoPs (60s-70s) in the east and lower PoPs
(30-40s) in the west.

&&
.AVIATION...[Through 00Z Saturday]
There is still significant model discrepancy on the timing of the
line of thunderstorms currently moving through Central GA. Have
weighted forecast with our local WRF to reflect flight
restrictions later in the TAF period. The highest confidence in
thunderstorms occurring at all terminals is between 03-07Z,
bringing MVFR flight restrictions. During the afternoon there is
higher confidence in thunderstorms at TLH and VLD, otherwise went
with a VCTS for ABY, ECP, and DHN. Outside of thunderstorms VFR
conditions will prevail.

&&

.MARINE...
Southwesterly flow over the waters is forecast to gradually
increase into the weekend as a frontal boundary approaches from
the north, and the Bermuda high strengthens over the western
Atlantic. This may lead to cautionary conditions by Saturday
afternoon, with brief Advisory level conditions Saturday night
into Sunday morning. Thereafter, moderate southwesterly winds are
forecast to continue into early next week.

&&

.FIRE WEATHER...
Average to above average summertime moisture levels will keep Red
Flag conditions out of the forecast for the foreseeable future.
Above average rain chances are expected through the weekend.

&&

.HYDROLOGY...
As upper level troughing digs into the SErn U.S., we will enter a
wet pattern. Expect a rainy weekend with around 2-2.5" of rainfall
across the forecast area with locally higher amounts where showers
are heaviest. While this is over a more widespread area than we've
been seeing lately, it is over the course of a 3 day period, and
there are currently no area rivers that are in flood or action
stage. No area rivers are anticipated to reach flood stage at this
time. Some storms with locally higher rainfall amounts may cause
flooding of urban and/or low-lying areas.

&&

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   74  94  75  89  72 / 60  50  40  70  50
Panama City   78  91  79  87  77 / 70  50  40  60  50
Dothan        75  95  75  90  73 / 60  50  50  70  50
Albany        75  95  75  91  72 / 70  50  50  70  50
Valdosta      73  93  75  89  72 / 50  50  40  70  50
Cross City    73  91  74  89  73 / 40  40  30  60  40
Apalachicola  77  90  79  87  77 / 60  50  40  60  50

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.

&&

NEAR TERM...WALSH/WOOL
SHORT TERM/LONG TERM/MARINE...CAMP
AVIATION...NAVARRO/HARRIGAN
HYDROLOGY...MOORE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
439 PM EDT THU JUN 27 2013

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

0415 PM     TSTM WND GST     ADEL                    31.14N 83.42W
06/27/2013  M55 MPH          COOK               GA   PUBLIC

            ALSO REPORTED 0.50-0.74 INCHES OF RAIN.

&&

WOOL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
521 PM EDT THU JUN 27 2013

FLZ017-018-272200-
LEON FL-INLAND JEFFERSON FL-
521 PM EDT THU JUN 27 2013

...A SIGNIFICANT WEATHER ADVISORY IS IN EFFECT FOR WESTERN JEFFERSON
AND EASTERN LEON COUNTIES IN THE FLORIDA BIG BEND...

* UNTIL 600 PM EDT

AT 516 PM EDT...THE NATIONAL WEATHER SERVICE HAS DETECTED A STRONG
THUNDERSTORM 15 MILES WEST OF MONTICELLO...OR NEAR MOCCASIN GAP...
MOVING SOUTHEAST AT 20 MPH.

NICKEL SIZE HAIL...AND WINDS AROUND 50 MPH ARE EXPECTED WITH THIS
STORM.

REPORT SIGNIFICANT WEATHER TO THE NATIONAL WEATHER SERVICE AT (8 5 0)
9 4 2 8 8 3 3. OR...CONTACT LAW ENFORCEMENT.

&&

LAT...LON 3042 8377 3038 8411 3065 8418 3067 8405
TIME...MOT...LOC 2121Z 325DEG 17KT 3060 8409

38-GODSEY