Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 011446
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
946 AM EST Sat Mar 1 2014
.Near Term [Through Today]...
The large scale pattern shows an Gulf of Mex upper ridge building
modestly EWD over local region with a dry deep airmass underneath.
H5 shortwave moving Ewd across local region overnight has oushed
offshore this morning with assocd mainly mid clouds beginning to
exit W-E. At surface...high off New England coast with weak ridge
extending Swwd into local region then into Gulf of Mex. Assocd low
stratus CIGS lingering across SE Big Bend and adjacent GA Counties
should erode in the next hour.
During the rest of today...with building ridge and NW flow above H9
yielding rising heights plus loss of clouds...near calm winds below
and partly to mostly sunny...high temps will rebound to seasonal
norms, from upper 60s north to lower 70s south. RAP13 soundings show
only about 0.5 inch PWATS.
[Through 12Z Sunday] The earlier low ceilings at VLD have lifted
to VFR levels and VFR is expected everywhere for the rest of the
day. Overnight, a persistence forecast was followed with another
round of IFR moving in from the east after 09z.
.Prev Discussion [601 AM EST]...
.Short Term [Tonight Through Monday]...
For tonight, an area of surface high pressure will extend from the
Carolinas southwest into Georgia. This should place the eastern
half of our forecast area in calm winds, with the flow just above
the surface light out of the east. Combined with clear skies, this
could be a recipe for some fog, so we included areas of fog across
much of the eastern half of our area, with patchy fog further west.
On Sunday, the boundary layer flow begins to increase out of the
south and the weak WAA pattern will increase 850mb temperatures to
around +11 to +12C. On well-mixed days, this typically corresponds
to highs in the upper 70s. That is very close (slightly warmer) to
what models are showing. Given sunny skies and increasing WAA, we
nudged the highs up by a degree over model consensus.
For Sunday Night and Monday, a low amplitude wave will eject ENE
from the southern Plains and support weak surface cyclogenesis
over the Tennessee Valley and southern Appalachians. As a result,
a cold front is expected to eventually push through our forecast
area on Monday. Forcing along the front is expected to grow weaker
with time as the upper level wave quickly ejects off the Atlantic
coast on Monday. Therefore, the best chances of rain should be in
the northwest corner of our area on Monday morning (~60%) tapering
down to only a slight chance (~20%) in the eastern Florida Big
Bend. There will be some marginal instability, so isolated
thunderstorm wording was included.
.Long Term [Monday Night Through Saturday]...
The extended range forecast will be much more active than the
weekend. Expect a shortwave trough to roll through the Southeast
on Monday, dragging a cold front through the local area. For now,
it appears as though the front will weaken as it moves through the
region, bringing mostly showers with an occasional rumble of
thunder. The more potent system will come near the end of the week
when a strong, positively tilted trough moves into the western
Gulf, spawning strong Gulf cyclogenesis. The surface low is
forecast to move into the northeast Gulf, but whether we get "warm
sectored" which would favor severe thunderstorms is a bit
uncertain at this time. Expect temperatures to generally remain
seasonable through the extended range, in the upper 60s for highs,
and mid 40s for lows.
Weak winds will support relatively calm conditions with seas 2
feet or less through Monday morning. After that, a cold front will
move through, causing an increase in northerly winds - especially
west of Apalachicola. As of right now, SCEC conditions look more
likely than advisory conditions. Winds and seas will subside on
Tuesday with easterly flow setting up and increasing on Wednesday
as a Gulf low begins to develop.
Although it will still be fairly dry today, it will not be nearly
as dry as yesterday and red flag criteria will not be threatened.
The moistening trend will continue into Monday when the next
chance for a wetting rain will occur. Another cold frontal passage
will bring in drier air once again for the midweek period, but
again red flag criteria will not be met. Substantial rains will be
possible late in the week.
With the exception of the Apalachicola River at Blountstown, all
river points are below flood stage and generally subsiding from
recent rains. However, Blountstown is likely to fall below flood
stage at some point today as well. Early next week, a cold
front will bring another round of rain to the area, though average
totals appears as though they`ll remain below a half of an inch.
.Preliminary Point Temps/PoPs...
Tallahassee 73 42 78 50 76 / 0 0 0 10 40
Panama City 70 49 73 58 69 / 0 0 0 10 40
Dothan 70 45 77 55 66 / 0 0 0 10 60
Albany 69 44 77 52 70 / 0 0 0 10 40
Valdosta 73 45 80 51 76 / 0 0 0 10 40
Cross City 74 44 80 50 78 / 0 0 0 0 20
Apalachicola 68 48 69 58 72 / 0 0 0 10 40