AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
320 AM EDT Tue Aug 14 2012

.NEAR TERM [Through Today]…
An upper TROUGH will continue to dig into the region today along
with the associated cold FRONT approaching from the northwest.
Although the front will remain well to the northwest, an OUTFLOW
boundary can be seen advancing ahead of an UPSTREAM MCS currently moving across north and central Alabama. This boundary combined with increasing INSTABILITY, deep layer MOISTURE and daytime heating will
provide all the ingredients for scatterd CONVECTION today. POPS
have been increased to show good CHANCE roughly west of a line from
Tifton, GA to Tallahassee then taper them down to slight chance
across the southeast Big Bend. We still feel that a FEW storms could
be strong to severe during the late morning and afternoon mainly for
our western zones.

&&

.SHORT TERM [Tonight Through Thursday]…
The upper FLOW is forecast to flatten through the period AS an east
to west oriented RIDGE stretches across the Gulf. The aforementioned
cold front becomes diffuse and stalls to our north with the axis of
the surface ridge staying to our south. Thus, onshore flow will
commence with deep westerly flow above the boundary layer. Some
drying is evident in the MID levels on forecast time HEIGHT cross
sections. Expect SCATTERED summertime-type convection (30-40%)
each day with TEMPS at of just above CLIMO.

&&

.LONG TERM [Thursday NIGHT through next Tuesday]…
The large scale longwave pattern commences with ridging over WRN
states, broad trough over CNTRL states EWD to Appalachians, weak
SHORTWAVE ridge Ewd to ERN seaboard and trough from LOW Canadian
Maritimes SWD down WRN Atlc. At the surface, main features surface
ridge axis extending from the WRN Atlc to across the Cntrl Gulf and
a cold front from Ontario S then SW THRU VCNTY Memphis then across
TX Panhandle. This places local region in semi-zonal flow aloft and
WSW flow at surface.

During the rest of the period, ECMWF/GEFS/UKMET in good agreement
with both upper and lower features. Aloft, aided by passing short-
waves, upstream trough amplifies and digs SEWD with anchoring closed
low over Hudson Bay and axis SWD into ERN Gulf on Fri. Amplified
troughiness will exist over local region thru weekend. Trough then
lifts NEWD on Mon and especially on Tues with drier NW flow and
SUBSIDENCE overspreading NE Gulf from NW-SE. At surface, as the
upper trough digs, GFS lifts ridge axis NWD and Canadian low moves
progressively ESE with impulses helping to drag cold front SEWD into
N/Cntrl AL/GA by FRI EVE and to SRN AL/GA on SAT with PWs,
increasing to over 2 inches, before becoming stationary thru early
Mon. This places local area in favorable zone for deep tropical
moisture, ample locally heavy RAIN and possible strong to severe
storms especially if shortwaves pass during times of MAX DIURNAL
heating. Front begins to lift NWD on Mon and progressively weakens
under influence of lifting upper trough.

Will go with daytime POPs of HIGH SCT Fri thru Sun then mid sct Mon
and low sct on Tues. Generally WDLY sct-low sct pops at night. With
local area in the warm CLOUDY sector, MIN temps will persist at 2 to
4 degrees above climo and max temps around climo thru the period.
(AVG inland Min/Max is 70/91 degrees).

&&

.AVIATION…[Through 06z Wednesday]
VFR conditions are anticipated through at least 09z. Expect areas of
MVFR visibilities to develop around daybreak at all sites except
ECP. Convection is expected to develop around 12z off the Florida
Panhandle and being to affect ECP by mid-morning. HI-res guidance
spreads this convection inland throughout the region primarily in
the 17z to 21z timeframe and this thinking has been reflected in
TAFs. After sundown, VFR conditions.

&&

.MARINE…
The subtropical ridge is forecast to remain south of the waters
through much of the week. This will keep light west to southwest
flow and minimal SEAS in place over the coastal waters outside of
convection.

&&

.FIRE WEATHER…
The airmass will begin to moisten up today and Wednesday with
scattered showers and storms. This will preclude any red flag
concerns even though elevated mixing heights and transport winds
will lead to high dispersions. Ample low level moisture is
expected during the rest of the work week so no red flag concerns
are anticipated.