Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 261355
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
955 AM EDT Fri Sep 26 2014
.Near Term [Today]...
The 8 am EDT regional surface analysis showed a large area of high
pressure across the Southeast, and a weak, quasi-stationary front
across central FL and off the Southeast coast. Vapor imagery and
upper air data showed a weak flow pattern over our forecast area,
between a ridge in the western Atlantic and a broad trough across
much of the central CONUS. Precip Water values were still below
average for much of our region, but they were gradually increasing
from the southeast. Like yesterday, a large deck of low clouds
enshrouded our forecast area, though there were a few breaks here
and there. We think that there will be just enough sunlight for it
to be slightly warmer this afternoon than yesterday, with highs
from the mid 80s in north FL to around 80 around Dothan and
Albany. Rain chances will primarily be limited to our north FL
zones (around Cross City), where there is more deep layer
[Through 12Z Saturday]...MVFR to occasionally IFR cigs were
affecting all of our terminals this morning. There is good
agreement among the MOS, SREF, and HRRR in a gradual lifting of
these cigs through the day, possibly reaching VFR by mid to late
afternoon. However, a return to low cigs is likely overnight
(though the various NWP guidance differs on just how low).
.Prev Discussion [337 AM EDT]...
.Short Term [Tonight Through Sunday]...
Deep moisture will continue to increase through the short term as
the deep layer flow turns more southeasterly and then southerly by
Sunday ahead of an upper trough. There is good agreement amongst
the model guidance on precipitable water values rising to well
above 2 inches across the area by Saturday and especially on
Sunday. With the approach of the upper trough on Sunday, a weak
surface low is likely to develop along the Gulf coast. These
factors point to increasing rain chances from south to north this
weekend with the highest chances on Sunday when some heavy
rainfall amounts could occur. The most likely area for heavy
rainfall appears to be along the Florida panhandle coast closest
to the better forcing from the upper trough on Sunday, and heavy
rain wording was inserted into this area. Afternoon temperatures
will be a bit below normal with all of the cloud cover expected.
.Long Term [Sunday Night Through Friday]...
Deep moisture will be in place through Monday as the inverted
surface trough interacts with an upper trough over the central
Gulf Coast. This should result in elevated rain chances continuing
into Monday, with locally heavy rainfall possible given
precipitable water values above 2 inches. Things should begin to
dry out by Monday night or Tuesday as the upper energy shears out
to the northeast. The global guidance differs in the timing on
when the deep moisture moves out, so have left some low end PoPs
in the forecast for much of the forecast period. With the tropical
airmass for the first part of the period and no significant
airmass change expected behind this system, expect temperatures to
run near or just above normal into the middle of next week.
Northeasterly flow will continue through tonight before shifting
to easterly on Saturday and southeasterly Saturday night into
Sunday. Conditions will likely be at or near exercise caution
levels this weekend before winds weaken early next week.
As we transition to a very wet pattern, there will be no fire
weather concerns through at least early next week.
General rainfall amounts of 1 to 2 inches are likely across the
forecast area through Monday, except 2 to 3 inches with locally
higher amounts along the panhandle coast. These amounts are not
expected to result in any river flooding due to low flows from the
recent dry summer. However, isolated instances of flash flooding
cannot yet be ruled out for Sunday, mainly along the panhandle
coast. It is too soon to consider any watches, but this trend will
have to be monitored.
.Preliminary Point Temps/PoPs...
Tallahassee 82 70 86 72 86 / 10 10 50 40 70
Panama City 81 71 84 74 86 / 10 10 60 70 80
Dothan 79 67 84 70 84 / 10 10 40 40 70
Albany 80 67 85 70 85 / 20 10 40 40 60
Valdosta 81 69 86 70 86 / 10 20 50 40 60
Cross City 84 71 86 71 87 / 40 40 60 40 60
Apalachicola 81 73 84 75 83 / 10 30 70 70 70