Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 011011
Area Forecast Discussion
National Weather Service Tallahassee FL
611 AM EDT SAT OCT 1 2016
.AVIATION [Through 12Z Sunday]...
Recent VAD wind profile data indicated that a low-level nocturnal
jet stream had developed across northeast FL and southeast GA,
affecting KVLD. Non-convective wind shear is possible here in the
lowest 500 ft AGL, but this will abate by mid to late morning.
Otherwise, we expect ideal conditions for aircraft operations will
continue through early Sunday, with light winds, no cigs, and no
.PREV DISCUSSION [346 AM EDT]...
.NEAR TERM [Through Today]...
The 10 pm EDT regional surface analysis showed a quasi-stationary
front from NC through central FL, and slightly higher pressure
behind it across much of the Southeast. Vapor imagery and upper air
data showed a sprawling, vertically-stacked height minimum over KY,
with multiple short wave troughs rotating around the main gyre. A
few of these disturbances will translate across our forecast area
today, but so much of the troposphere is so dry and stable that
there won`t be enough moisture/lift for clouds, let alone rain.
There was still some weak "cold" air advection at 850 mb, so we have
opted to slightly undercut the guidance consensus high temperature
forecast, which was a little too warm for Friday. Highs will be in
the lower to mid 80s with low relative humidity.
.SHORT TERM [Tonight Through Monday]...
The cutoff upper low that had been entrenched over the Ohio River
Valley will drift northward toward the Great Lakes tonight, and
eventually become absorbed by the northern branch of the jet
stream Sunday into Monday. As this occurs, a large upper trough
axis will develop from the Appalachians southwestward through our
western areas (southeastern AL and the FL Panhandle) and into the
Gulf. At the surface, high pressure will dominate much of the
southeastern CONUS, although a quasi-stationary front will stretch
across northeastern FL into the northern Gulf throughout this
Very dry conditions will prevail tonight into Sunday, with
projected PWAT values still under 1" across much of our area. One
exception could be near Cross City, where enough moisture could
return by Sunday afternoon to warrant a slight chance of showers
and thunderstorms. Moisture is expected to return to more normal
values on Monday, with PWATs around 1.5" across the FL Big Bend
region and southern GA. Also, the aforementioned front could drift
a bit farther north on Monday, providing a better chance of
showers and thunderstorms during the afternoon hours. Highest
chances will remain over our far southeast zones, but Tallahassee
and Valdosta could see some isolated showers and thunderstorms.
High temperatures will warm into the mid-upper 80s each day, with
lows tonight in the mid-upper 50s inland and 60s near the coast.
Lows will moderate slightly Sunday night as moisture increases,
with low-mid 60s inland and upper 60s near the coast.
.LONG TERM [Monday Night Through Saturday]...
The upper level trough mentioned in the short term discussion will
persist across the southeastern CONUS through Tuesday before
dissipating during the middle of the week. Forcing from the trough
and a stationary front just offshore should continue to support
scattered showers and thunderstorms, mainly across the FL Big Bend
region and offshore from Monday night through Tuesday.
Meanwhile, Hurricane Matthew is expected to move northward across
eastern Cuba early in the week, with models beginning to diverge
on its track beyond that point. The latest ECMWF shows Matthew
taking a sharp turn to the east-northeast and moving out to sea as
an upper level trough pushes offshore, which is a large change
from the previous run that showed it stalling near the Bahamas for
several days. However, the GFS continues to take it north/northeast
just offshore of the Atlantic coast as the upper level trough
remains over the eastern CONUS. The GFS solution could bring
slightly more moisture and wind during the middle of the week,
with a few showers and thunderstorms possible across our eastern
areas. Under either scenario, dry conditions are expected from
Friday into the weekend as much drier air moves into our area
behind a cold front. Highs from the mid 80s to near 90 and lows
from the mid 60s to lower 70s are expected throughout this
Winds from 10 to 15 knots will likely result in seas of 2 feet or
less through Monday night. On Tuesday and Wednesday, winds could
increase to 15 to 20 knots over our marine zones. Seas could also
reach 3 to 5 feet on Wednesday, since the pressure gradient may
tighten over our area as Matthew moves northward to our east.
RH values may briefly dip below 35 percent this afternoon, but Red
Flag conditions are not expected.
No significant rainfall or flooding is expected during this
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 85 59 89 66 88 / 0 0 0 10 20
Panama City 82 64 84 67 85 / 0 0 0 0 10
Dothan 83 58 87 60 89 / 0 0 0 0 10
Albany 84 57 88 63 88 / 0 0 0 0 10
Valdosta 85 58 88 66 88 / 0 0 10 10 20
Cross City 86 64 89 69 87 / 0 0 20 20 40
Apalachicola 82 64 84 68 85 / 0 0 0 10 20