409
FXUS62 KTAE 201908
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
308 PM EDT Mon May 20 2013


.NEAR TERM [through tonight]...
The 16 UTC mesoanalysis showed a very weak pressure/wind field
across our forecast area, much like a typical day in the middle of
summer. There were no obvious mesoscale boundaries, but visible
satellite imagery continued to show a cyclonic "twist" near
Tallahassee- probably associated with an MCV from Sunday`s
thunderstorm complex. Vapor imagery and upper air data showed a weak
trough from VA through North FL, with much of our forecast area
under northerly flow aloft on the backside of this trough.

The large scale environment, GFS MOS PoP, and some of the Convection
Allowing Model (CAM) runs suggest that the highest rain chances will
be over our eastern zones, while some of the CAM (like the HRRR and
11 UTC & 12 UTC local WRF runs) continue to forecast scattered
storms across a large portion of our forecast late this afternoon
and evening. The answer is assumed to be somewhere in between,
except that the CAM guidance often has a tendency to be a few hours
late in developing convective cells. Our PoP is 30-40% for most of
our forecast area for the remainder of this afternoon and early
evening. The spatial distribution matches well with the best
thermodynamics, which are most favorable in GA. Although the wind
field is very weak (from the surface to 500 mb), there could be a
few pulse strong to severe storms this afternoon due to the steep
lapse rates. The main threat...though small...will be dime to
quarter size hail and/or microbursts of 50-60 MPH.

&&

.SHORT TERM [Tuesday Through Thursday]...
Slow moving mid level low pressure area will transition into a low
amplitude trough as it shifts slowly ewd across the southeastern
U.S. over the next several days. This will keep unsettled weather
around into at least Thursday with a chance of afternoon showers
and thunderstorms. Rain chances will be a bit greater over our
eastern counties where moisture will be more plentiful. Clouds
and residual outflow boundaries may make afternoon highs a bit
tricky to forecast, however in general expect similar temperatures from
today with highs in the upper 80s to lower 90s and overnight lows
in the 60s. A few stronger storms can not be ruled out each
afternoon, although overall severe threat will remain fairly low.

&&

.LONG TERM [Thursday Night through Monday]...
Unsettled weather pattern will continue into the late part of the
week, but will replaced by drier weather for the weekend as a
slow moving trough finally shifts away from the area. A mid/upper
level ridge of high pressure will begin to establish itself over
the area for the holiday weekend into next week which should
preclude more than isolated afternoon showers/tstms. Temperatures
are expected to remain seasonal with highs in the upper 80s/lower
90s and overnight lows in the 60s.

&&

.AVIATION [through 18Z UTC Tuesday]...
Isolated to scattered TSRA will develop this afternoon, mainly
from 19 UTC through 01 UTC, and mainly around KABY and KVLD where
the probability of rain is 40%. A few storms could produce strong
to severe wind gusts and/or marginally severe hail. The
probability of TSRA elsewhere is 30% or less. Outside of TSRA, VFR
vis and cigs are expected. Patchy fog and/or low clouds are
possible for a brief time Tuesday morning, though confidence is
not high enough to explicitly mention in this TAF package.

&&

.FIRE WEATHER...
Red Flag conditions are not expected for the next several days, as
minimum RH values will likely remain above locally critical levels.

&&

.MARINE...
Pleasant weather and seas will remain the norm through the weekend
with light winds.

&&


.HYDROLOGY...
Unsettled weather pattern will continue into the late week and
support scattered, slow moving thunderstorms each afternoon.
Although some localized flooding could occur with the heavier
storms, overall impacts should remain minor and no meaningful rise
is expected along area rivers.

&&

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   67  90  66  89  67 / 30  20  10  40  20
Panama City   70  84  69  83  70 / 20  20  10  20  20
Dothan        68  92  68  92  68 / 30  20  10  30  20
Albany        69  91  69  90  68 / 30  20  30  40  20
Valdosta      66  88  66  87  66 / 30  30  30  50  20
Cross City    66  89  65  87  64 / 30  40  30  40  20
Apalachicola  69  82  68  82  69 / 20  20  10  20  20

&&

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

&&

$$

SHORT TERM/LONG TERM/MARINE/HYDROLOGY...Evans
REST OF DISCUSSION...Fournier