Area Forecast Discussion
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FXUS62 KTAE 181944
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
344 PM EDT Thu Sep 18 2014

.Near Term [Through Tonight]...

Now that the surface front has pushed through most of the area we
are seeing dewpoints range from the upper 50s at Dothan and
Albany to upper 60s at near the coast. PoPs are low tonight with
the greatest chance (20-30%) over the Gulf, similar to what we saw
last night. Winds will be light overnight and lows will be in the
upper 60s.


.Short Term [Friday Through Saturday Night]...

A relatively low-amplitude wave currently near Arkansas should
continue digging southeast, leading to the development of a broad
mid-upper level trough centered just east of our area by Friday
afternoon. Models indicate that this may close off into a low
briefly on Saturday near the northeast Florida coastline. Either
way, our forecast area is expected to be on the back side of the
mid-upper level trough axis. Because of this, isentropic descent
is noted at most layers (295-315K), associated with weak
subsidence given our position relative to the trough axis. We
will, however, remain in a low-level easterly flow regime near the
base of a surface ridge axis. With PWATs close to September median
values at TLH, this is a flow pattern that can lead to some
isolated to scattered showers from the mid afternoon to evening.
Given negating factors for large scale vertical motion, we opted
to keep PoPs closer to the low end of guidance both Friday and
Saturday (20-30%, with 40% far east). While model guidance does
indicate some convective instability, these sort of patterns tend
to favor low-topped convective showers versus thunderstorms, so
the forecast wording reflects a lower chance of storms.

The expanding low-level surface ridge and east to northeast flow
should lead to some CAA in those layers. Model consensus 850mb
temperatures are forecast to decrease about 3-4C from this
evening through Saturday evening. The result should be a gradual
cooling trend through the period, with highs on Friday from the
upper 80s to around 90, and highs on Saturday in the mid 80s. It`s
worth noting that Tallahassee has not observed a day with below
normal temperatures (by avg temp) since August 1st, and that may
finally occur during this forecast period (especially Saturday),
although it will likely be very close.


.Long Term [Sunday Through Thursday]...

There is a little uncertainty in the models regarding the exact
evolution of the mid-upper level flow pattern next week, although
it has been a consistent trend to show significant amplification
over North America. The one consistent trend has been the
establishment of a persistent easterly low-level flow regime
across our area as another strong surface high builds into the
Northeastern US. This should keep isolated to scattered showers in
the forecast (mainly in the late afternoon and early evening),
with temperatures moderating close to seasonal normals.

&&

.Aviation...

[Through 18Z Friday] VFR conditions and light winds should prevail
through the period at all terminals. The only exception is a
period of IFR at VLD from 9-14Z.

&&

.Marine...

Much of the forecast period will be dominated by a surface high
pressure ridge over the eastern US, which will place the coastal
waters in an easterly flow regime on most days. Several periods of
enhanced easterly flow seem likely: (1) from Friday to Saturday
with SCEC winds possible offshore -AND- (2) beginning Wednesday
with SCEC winds likely.

&&

.Fire Weather...

RH values and other parameters are not expected to approach red
flag levels during the next several days.

&&

.Hydrology...

Generally light rainfall amounts are expected for the foreseeable
future, except in very localized instances. Therefore, we are not
expecting any significant flooding issues over the next week.

&&

.Preliminary Point Temps/PoPs...

Tallahassee   69  90  68  86  67 /  10  40  30  30  20
Panama City   72  89  71  87  70 /  10  30  30  20  20
Dothan        66  89  68  85  65 /   0  20  20  10  10
Albany        68  88  68  85  65 /  10  30  20  20  10
Valdosta      69  87  66  84  66 /  10  40  30  40  20
Cross City    70  87  66  86  66 /  30  40  30  40  20
Apalachicola  71  87  72  84  71 /  10  30  30  30  20

&&

.TAE Watches/Warnings/Advisories...

FL...None.
GA...None.
AL...None.
GM...None.

&&

$$

NEAR TERM...WESTON
SHORT TERM...LAMERS
LONG TERM...LAMERS
AVIATION...WESTON
MARINE...LAMERS
FIRE WEATHER...DVD
HYDROLOGY...LAMERS





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