Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 312143
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
443 PM EST Sat Jan 31 2015
.Near Term [Through Tonight]...
Surface high pressure will slide off to the east overnight as the
next storm system takes shape over the southern/central Plains.
Low level flow will turn to the southeast by morning, with an
increase in high cloudiness. This will keep temperatures warmer
overnight, with lows generally in the lower 40s. Any rainfall is
expected to hold off until after sunrise.
.Short Term [Sunday Through Monday Night]...
Through the period, a deepening surface low will track almost due
east from around Kansas City Sunday morning to southern New Jersey
by Monday afternoon. The strengthening but progressive cyclone
will be accompanied by a cold front to the south and southwest,
and that front should sweep through our forecast area early
Monday. Showers are expected in advance of the front; there will
also be some marginal instability so a few thunderstorms can`t be
ruled out. However, severe weather is not expected at this time.
A noteworthy trend in the 12Z models shows two QPF maxima centered
mainly to the north of our area (N/C AL and N/C GA) and to the
south of our area (NE Gulf of Mexico). That sort of rainfall
distribution makes sense with much stronger mid-upper level height
falls staying north of our area, and somewhat limited moisture
return with higher mixing ratios staying offshore. This would
place our forecast area in a relative QPF minimum. Therefore,
while we are forecasting a 60% to 70% chance of rain across most
of our area - mainly Sunday night - the rainfall totals will
likely be under 0.5 inches.
.Long Term [Tuesday Through Saturday]...
High pressure will dominate the first 36-48 hours of the extended
period (Tuesday to Wednesday), with another progressive wave
ejecting through the southern states by Thursday. The strongest
PVA aloft should be focused out over the Gulf of Mexico, roughly
coinciding with a lingering low-level front. Therefore, surface
cyclogenesis should occur over the Gulf with an area of rain
possible to the north of the low track, along the I-10 corridor.
Operational models and global ensembles are consistent in showing
a good chance of rain, so we have bumped PoPs up to 60% in most
areas on Wednesday Night and Thursday. Dry and cool weather should
follow on Friday and Saturday.
[Through 12Z Sunday] VFR conditions will continue through the
overnight hours at all terminals. Cloud will increase after
sunrise, with MVFR CIGS possible at KECP and KDHN by mid to late
SCEC level winds are likely to continue through Monday evening,
with a chance of a brief period of conditions warranting a Small
Craft Advisory - most notably on Sunday. For now, no SCA has been
issued, but the SCEC headline has been maintained. A brief lull on
Tuesday to Wednesday will be followed by an increase in winds and
seas with an approaching low pressure system on Thursday.
Red Flag conditions are not expected throughout the next week. RH
values will be low today in the 30s, but will not reach critical
levels. Moist air will move in by Sunday as a frontal system
approaches. Rain is likely Sunday through early Monday. Dispersion
values will be over 75 on Sunday and Monday for South Central
Georgia and eastern parts of Big Bend Florida.
With the exceptions of the Withlacoochee and Suwannee, our local
rivers have crested and begun falling since our last event and no
flooding is occurring or expected for the next few days. A frontal
passage Sunday-Sunday night is posed to produce less than 1" of rain
across the area, which may cause a small rise in river levels,
but is unlikely to result in a return to flood stages at any of the
A second system during the Wednesday-Thursday time frame may be a
bit more significant with more rain possible. When combined with
the rains from the first system and already above average stream
flows, a few rivers may approach minor flood stage late in the
week. At this time, the progressive nature of the pattern is
expected to keep rainfall amounts from getting high enough to
produce more significant flooding.
.Preliminary Point Temps/PoPs...
Tallahassee 42 70 59 62 34 / 0 20 60 30 0
Panama City 50 65 56 57 38 / 0 70 60 20 0
Dothan 42 66 48 52 32 / 0 80 80 10 0
Albany 39 69 53 55 31 / 0 40 70 20 0
Valdosta 42 72 59 61 35 / 0 20 60 40 0
Cross City 43 74 60 66 34 / 0 10 60 60 0
Apalachicola 50 67 60 63 38 / 0 30 60 30 0