Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 250019
Area Forecast Discussion
National Weather Service Tallahassee FL
819 PM EDT Fri Mar 24 2017
A cold front will advance eastward into the Lower Mississippi
River Valley overnight. Showers and thunderstorms will precede
the front but will not reach our western zones before daybreak.
The forecast is on track and no changes are necessary.
.PREV DISCUSSION [730 PM EDT]...
.NEAR TERM [Through Tonight]...
The upper ridge will gradually move east overnight as an occluded
low cuts off while moving into the Middle Mississippi Valley. The
response at the surface will be veering winds as we become
positioned closer and closer to the western periphery of surface
ridging. The more southerly component should result in some low
cloudiness beginning late tonight as isentropic ascent increases on
the 295K surface. Otherwise, no rain is expected with lows forecast
to fall into the upper 50s inland and lower 60s along the coast.
.SHORT TERM [Saturday Through Sunday Night]...
An upper level +PV anomaly and associated cut off low that can be
seen over the western OK Panhandle this afternoon in satellite
imagery. This low will move into the eastern OK/KS border Saturday
morning, lift northeastward to MO/IL border by around midnight, then
sweep off to the Great Lakes by Sunday night. The low pressure
system will be more or less vertically stacked through the weekend,
with the low aloft running out ahead (east) of the surface low
Sunday evening, which means the system is decaying. The surface
front associate with this weakening anomaly, currently stretching N-
S along central KS, OK, and TX, will lift northeastward through the
period and the front itself will never actually enter our area.
Still, scattered convection out ahead of it is expected to develop,
so there`s around a 20-40% chance for showers and thunderstorms
Saturday and Sunday across much of the area, with higher chances
(around 50%) in western edge of our CWA Saturday afternoon/evening.
Model MLCAPE with this system will be around 500 J/kg locally, with
the highest values again being on the western edge of our forecast
area. The low level jet will be decaying and lifting northeastward
as the system approaches, so 0-1 km shear locally will be around 10
knots. Likewise, the mid and upper level jet will be weaker by the
time the system arrives here, so the deep layer shear will be around
30-40 knots. Damaging winds will be possible with these
thunderstorms Saturday afternoon/evening, though threat remains
marginal. Rainfall totals this weekend are expected to be around an
inch or less, with the highest totals west of a line from Dothan, AL
to Panama City, FL.
.LONG TERM [Monday Through Friday]...
An upper level shortwave trough will move into the lower Mississippi
valley Monday morning and lift northeastward to the mid-Atlantic
through Tuesday. Locally, this will mean 20-30% chances for showers
and thunderstorms Monday through Tuesday, mostly northwest of a line
from Valdosta, GA to Perry, FL. We`ll see a brief break in the
cloudiness and chances for rain mid-week, but our next system will
push from the southern Plains into the lower Mississippi valley by
Thursday, bringing back 20-30% chances for showers and
.AVIATION [Through 00Z Sunday]...
Fair weather and VFR conditions will continue overnight. MVFR cigs
(2500 ft AGL) will develop across much of the region early
Saturday morning, then lift to VFR cigs by afternoon.
Southeast winds around 15 to 20 knots and 3 to 5 feet seas will
persist through Saturday. Winds and seas will lower Saturday night
as an approaching low pressure system weakens and lifts
northeastward. South winds and 1 to 3 feet seas will prevail
through the remainder of the period.
A weakening upper level disturbance will bring a slight chance of
rain to the region this weekend, mainly north and west of
Tallahassee. Otherwise warm and relatively humid conditions (for
this time of year) will persist.
Storm total rainfall from the low pressure system moving through
this weekend is expected to be around an inch or less. This amount
of rain will not cause our local rivers, which are currently all
well below flood stage, to spike up. No flooding is forecast.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 56 79 60 80 58 / 0 10 10 10 10
Panama City 63 73 65 75 63 / 0 30 30 20 10
Dothan 58 78 60 81 61 / 0 40 40 20 10
Albany 58 80 60 82 60 / 0 10 20 20 10
Valdosta 55 81 59 81 57 / 0 10 10 20 10
Cross City 55 81 58 80 56 / 0 0 10 10 10
Apalachicola 62 75 64 76 62 / 0 10 20 10 10
FL...High Rip Current Risk until 8 PM EDT /7 PM CDT/ this evening for
Coastal Franklin-South Walton.