Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 120633
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
233 AM EDT Fri Sep 12 2014
.Near Term [Through Today]...
The 11 pm EDT regional surface analysis showed a weak ridge along
the FL-GA and FL-AL borders, a cold front from western NC to
northern LA, and a 1014 mb low pressure system centered off the
southeast FL coast. Deep moist convection with this system was
poorly organized, and tropical development is unlikely today as it
moves west around 10 MPH across South FL. The aforementioned cold
front is forecast to stall just north and west of our forecast
area later this afternoon.
With light southeast winds in the lower troposphere, the sea breeze
will be slow to move inland. The ensemble of Convection Allowing
Models (ECAM), which performed well on Thursday under a similar
synoptic scale environment, forecast only a limited amount of deep
moist convection along the sea breeze fronts this afternoon.
However, late this afternoon, several of the CAMs forecast scattered
storms near and north of a line from Dothan to Tifton, in
association with the approaching frontal system. Our PoP, a blend of
MOS, the previous forecast, and ECAM, ranges from 20% in FL to 30%
in GA & AL. There`s nothing in the NWP guidance (in terms of CAPE or
bulk shear values) that would suggest a significant risk for severe
storms. High temperatures will be in the lower to mid 90s.
.Short Term [Tonight Through Sunday]...
Although weak upper ridging will continue locally, we will see a
gradual increase in deep local moisture through the weekend. The
stalled front to our north will get slowly nudged to the south on
Saturday becoming quasi-stationary across our CWA on Sunday.
Meanwhile, a tropical wave well south of our coastal waters is
forecast to stay on a westward coarse heading toward Texas. Our
position with respect to this system, the frontal boundary, and
return of deep moisture, all lead to increasing PoPs into the
chance/good chance range the next few days. Max temps will be in
the lower 90s inland areas Saturday and then around 90 for Sunday.
.Long Term [Sunday Night Through Friday]...
The elongated east-west oriented ridge axis will still be in place
at the start of the period. However, it will begin to break down
early in the work week as a long wave trough begins to amplify into
the Southeast. This trough will help push the front currently draped
across the Ohio Valley toward the Gulf Coast. It is still uncertain
just how far south the front will make it before stalling. There
appears to be model consensus that there will be enough energy
upstream in the long wave trough to induce weak waves on the front
that will help inhibit its southward progress. The proximity of the
boundary through much of the period will result in unsettled
conditions with above normal PoPs for the most part. Max temps will
correspondingly be generally below normal from Monday onward.
[Through 06Z Saturday] We expect generally VFR conditions, except
for a brief period of IFR cigs/MVFR vis at KVLD (following GFS MOS
and the 02z HRRR). Winds will be light and rather variable (6 KT
or less), except for a south wind near 10 KT developing this
afternoon at KECP. The PoP is low this afternoon (20-30%), so no
TSRA is currently forecast at any of the terminals.
A very weak pressure gradient is forecast to remain in place. This
will keep winds and seas well below any headline criteria.
Red Flag conditions are not expected through at least this
Rainfall totals over the next few days are expected to be below
normal and not have an impact on area rivers. However, QPF is
expected to increase next work week.
.Preliminary Point Temps/PoPs...
Tallahassee 94 73 93 72 91 / 20 20 40 30 50
Panama City 90 77 90 76 87 / 20 20 40 30 50
Dothan 94 73 92 72 90 / 20 20 50 30 50
Albany 95 73 92 72 91 / 30 30 50 30 50
Valdosta 94 72 92 71 90 / 20 20 40 30 50
Cross City 93 71 93 70 89 / 20 20 40 30 40
Apalachicola 90 76 89 77 87 / 20 20 30 30 40