Severe Thunderstorm Warning 429, NWS Tallahassee, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
403 PM EDT FRI AUG 14 2015

.Near Term [Through Tonight]...

Low-level moisture is on the increase today over the southern half
of the area, as shown by the more robust cumulus field and
limited mixing of dewpoints early this afternoon. Most favored
areas for rain this afternoon will be the Panhandle and eastern
Big Bend, given the southeasterly flow and limited forcing.

Overnight, a weak trough over the northeastern Gulf will slowly
move westward, increasing rain chances over the coastal waters
and immediate coastal areas of the Panhandle west of Apalachicola.

.Short Term [Saturday Through Sunday Night]...

Changes are in store this weekend, with the relatively dry August
air mass eroding in favor of greater moisture and increased rain
chances compared to the past several days. A primary feature of
interest is a +PV anomaly currently translating south across parts
of Missouri. Numerical models also indicate a variety of other
mid-upper level vorticity maxima across parts of the Arklatex and
far northwestern Gulf of Mexico. How these all interact is still
somewhat uncertain, but models do generally agree on evolving some
sort of elongated trough or gap in the subtropical ridge this
weekend, extending from the Ohio River Valley, to Louisiana, to
the northwest Gulf. The net effect should be a transition to
deeper southerly flow, particularly on Sunday. Drier air may
manage to linger through Saturday afternoon in northern sections
of our forecast area, but by Sunday precipitable water values
should be around 2" in most areas. Therefore, on Saturday we
concentrated the highest (50-60%) PoPs along and south of I-10,
and on Sunday indicated a slight northward expansion.

Another source of uncertainty is the possibility of a
convectively induced circulation or MCV, over the adjacent Gulf
waters, as indicated by a number of convection-allowing models.
This would likely evolve out of slow-moving thunderstorm clusters
over the waters. That might have the effect of focusing more
numerous showers and storms south of Interstate-10, while
decreasing coverage further inland. Chances of locally heavy
rainfall would be also increased in the same areas along and south
of I-10. Convection-allowing models also indicate some stronger
updrafts this weekend, raising the possibility of a few
strong/severe storms (wind the main threat) in addition to the
risk of locally heavy rainfall.

.Long Term [Monday Through Friday]...

Southerly low-level flow and high precipitable water values should
persist through Wednesday per the latest operational ECMWF and
GFS runs. This would likely lead to a more active pattern in terms
of rain chances, and we went slightly above model consensus with
50-60% PoPs from Monday-Wednesday in most areas. The GFS and ECMWF
diverge after that, with the GFS maintaining southerly flow and
increasing low-mid level moisture further. The ECMWF shows a ridge
beginning to build into the area, with low-mid level winds veering
and slightly lower precipitable waters. With the ECMWF ensemble
mean close to the operational ECMWF, we trended lower on the PoPs
and warmer on the temperatures for Thursday-Friday for now.

&&

.Aviation...

[Through 18Z Saturday] Best thunderstorm chances through the
afternoon will be at ECP, with VFR conditions expected elsewhere.
The cumulus deck will occasionally be broken this afternoon, but
CIGS should remain above 030. Showers and thunderstorms will be
more numerous on Saturday, especially around ECP and TLH.

&&

.Marine...

The synoptic weather pattern favors fairly light winds and seas of
3 feet or less. However, there is a chance that persistent
clusters of thunderstorms over the Gulf waters could locally
enhance winds and seas for a time, even after the storms
dissipate. Therefore, 15+ knot winds can't be totally ruled out
this weekend, but low confidence on timing and placement has
precluded inclusion in the CWF at this time. Stronger storms over
the waters this weekend appear likely to produce gusty winds.

&&

.Fire Weather...

Red flag conditions are not expected for the next several days.

&&

.Hydrology...

Some locally heavy rainfall will be possible this weekend, mainly
along and south of Interstate-10. Widely scattered totals of 6-8"
of rain appear possible in that area if training bands of heavy
showers and storms can focus in a particular area for several
hours. Most locations in the region along and south of I-10 should
see an average of 0.5 to 1.0 inches of rain this weekend, though.

Numerous showers and storms are expected from Monday to Wednesday,
with a continued threat of locally heavy rainfall.

&&

.Preliminary Point Temps/PoPs...

Tallahassee   72  91  75  91  75 /  20  50  40  60  30
Panama City   75  85  76  86  77 /  30  60  40  60  30
Dothan        69  92  72  90  72 /  10  30  20  50  30
Albany        70  92  72  91  73 /  10  20  20  30  30
Valdosta      69  89  73  90  73 /  10  50  30  60  30
Cross City    72  89  74  89  75 /  20  60  40  70  30
Apalachicola  76  88  76  87  77 /  50  50  40  60  40

&&

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

&&

NEAR TERM...CAMP
SHORT TERM...LAMERS
LONG TERM...LAMERS
AVIATION...CAMP
MARINE...LAMERS
FIRE WEATHER...DVD
HYDROLOGY...LAMERS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
445 PM EDT FRI AUG 14 2015

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

0415 PM     TSTM WND DMG     1 NW TALLAHASSEE        30.45N 84.30W
08/14/2015                   LEON               FL   911 CALL CENTER

            TREE DOWN ON POWER LINE NEAR THE INTERSECTION OF WOODWARD
            AND BREVARD STREET

0415 PM     LIGHTNING        2 ESE TALLAHASSEE       30.43N 84.25W
08/14/2015                   LEON               FL   911 CALL CENTER

            TRANSFORMER BLOWN NEAR INTERSECTION OF APALACHEE PKWY AND
            BLAIRSTONE

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
451 PM EDT FRI AUG 14 2015

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

0415 PM     TSTM WND DMG     2 ESE TALLAHASSEE       30.42N 84.25W
08/14/2015                   LEON               FL   PUBLIC

            POWER LINE ALSO DOWN NEAR BLAIRSTONE AND APALACHEE.
            REPORTED BY RETIRED USAF METEOROLOGIST. ALSO 6 INCHES OF
            WATER ON THE ROAD.

&&

DVD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
529 PM EDT FRI AUG 14 2015

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

0415 PM     TSTM WND DMG     2 NNW TALLAHASSEE       30.47N 84.30W
08/14/2015                   LEON               FL   PUBLIC

            PICTURE SUBMITTED ON SOCIAL MEDIA OF A TREE DOWN ON A
            POWER LINE ALONG REDBUD AVE

&&

DVD