AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
313 AM EST Thu Jan 3 2013
.NEAR TERM [Through Today]…
The long wave pattern this morning features a Rex block out west, a
positively tilted trough from eastern Canada southwestward to the
Southern Rockies, and a ridge over the Caribbean. Water vapor
imagery shows moisture feeding northeastward between the trough and
ridge. Surface analysis shows a stalled front draped across the
northern FL Peninsula stretching southwest across the Gulf of Mexico
to low pressure in the Bay of Campeche. Regional radars indicate a
shield of mainly light rain extending from the North Central Gulf
northeastward into the Carolinas.
Today`s forecast will be similar to yesterday`s with mainly cloudy
skies and areas of light rain. Rain chances are a bit higher than
yesterday as the right entrance region of the 170- to 190-kt 250-mb
jet extending from the Mid Mississippi Valley northeastward to
Southern New England moves closer to the region. This will increase
upper divergence and large scale lift over the southeastern states.
PoPs are in the categorical range across the western zones lowering
to likely farther the east. All of the clouds and rain will keep max
temps below normal, ranging from the lower 50s northwest to the
lower 60s in Dixie County.
.SHORT TERM [Tonight Through Saturday]…
Cooler and drier air will move into tonight with slight to low rain
chances restricted to the FL Big Bend zones. A brief light freeze is
forecast for Coffee, Dale, Henry, Geneva, Quitman and Clay Counties.
Durations are expected to be insufficient to reach warning criteria,
except perhaps across northwest Coffee County. Feel this is too
marginal for a watch at this time and will let the day shift
evaluate the need for any warnings. Friday should be a dry day for
most of us with slight chance PoPs restricted to Dixie County. Max
temps will be just a degree or two shy of normal. Friday night and
Saturday will see near normal temps. This period will also see a
gradual increase in PoP from the south as isentropic ascent over the
stalled boundary to our south commences once again. By Saturday
afternoon, PoPs will range from 50 along the FL Big Bend coast to 20
over our northeast zones north of the VLD vicinity.
.LONG TERM [Saturday Night through Wednesday]…
An unsettled weather pattern will begin the period with abundant
moisture in place. An upper trough will approach Sunday and swing
through the region Sunday night scouring out the moisture to our
south and east. Deep layer ridging quickly builds in overhead along
with a very dry airmass Monday into Tuesday. Short term models show
a developing low pressure system over Texas Tuesday that moves into
the Lower Mississippi Valley Wednesday and then becomes vertically
stacked as it lifts northeastward into the Missouri Valley Thursday.
Showers and possible thunderstorms ahead of the associated cold
front should begin to spread into our western zones late Wednesday
sweeping across the remainder of our CWA Wednesday night and
Thursday. Too far out to be confident with this scenario, especially
on the timing so will just introduce slight PoP for now.
Temperatures will be near to above seasonal levels through the
.AVIATION [Beginning 08Z Thursday]…
Brief conditions of MVFR cigs/vsbys are possible through daybreak
especially during periods of light rain or drizzle. Otherwise,
VFR will prevail with cigs around 4-5kft. Rain should end around
midday today. Winds will be light from the northwest to northeast.
The gradient is expected to tighten across the marine area today
with exercise caution conditions overspreading the waters from west
to east. Winds will remain elevated through tonight before subsiding
below headline criteria on Friday and remaining 15 kt or less
through the weekend. Winds will then increase to cautionary levels
once again Sunday night into Monday.
No fire weather concerns are expected for the next several days, as
an unsettled pattern persists over the region.
The Choctawhatchee River at Bruce has crested below action stage and
other rivers across the northwestern HSA are receding. Rainfall over
the next couple of days is expected to be light enough to prevent
any significant rises on area rivers.