Flash Flood Watch 11, NWS Tallahassee, FL

Coffee County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Clay County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Lee County, GA, Miller County, GA, Mitchell County, GA, Quitman County, GA, Randolph County, GA, Seminole County, GA, Terrell County, GA, Worth County, GA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
816 AM EST WED DEC 30 2015

.Near Term [Through Today]...

The main concern over the next 24 hours is the threat of
additional flooding. At least through the near term, we remain
locked in a large scale pattern that consists of a very large
trough covering the western two-thirds of the country and
unusually strong upper level ridging centered near Bermuda. In
our local area, that leaves us with deep layer southwest flow and
unusually deep moisture for this time of year.

At the surface, a nearly stationary frontal boundary is located
just west of the forecast area. As upper level disturbances move
along the southwest flow, we have seen persistent MCS development
along this slow moving front for the last several days. This large
scale pattern is what has brought us such high rainfall totals
over the last week. For the next 24 hours, we need to watch
closely the evolution of the MCS currently located near Mobile
this morning. The steering flow will likely take that MCS
northeastward this afternoon into our area as it rides along the
frontal boundary. The northwest half of our area is primed for
flash flooding given the antecedent conditions with low flash
flood guidance values of under 3 inches in 3 hours. Any training
of convection with this MCS could easily achieve those values
should it move into our area. A flash flood watch is being
considered depending on how this MCS evolves through the morning
hours.

&&

.Prev Discussion [642 AM EST]...

.Short Term [Tonight Through Friday]...

The large scale upper level flow will begin to look more like a
winter time El Nino pattern as the anomalous west Atlantic ridge
finally breaks down. (This ridge has been a persistent feature so
far this "cool" season). By Friday the subtropical jet stream
will be fairly zonal across the Gulf Coast states, while a
northern stream trough develops over the northeast quadrant of the
CONUS. At the surface, a cold front across the northwest portion
of our forecast area will translate very slowly to the southeast.
This means a cloudy period with slowly cooling temperatures (from
northwest to southeast) and periods of rain. This is actually
more typical of wintertime El Nino conditions than the prolonged
stretch of record heat and bursts of extremely heavy rain we have
experienced over the past several weeks.

High temperatures on Thursday will range from near average values
(lower to mid 60s) in southeast AL to above average (mid to upper
70s) from Tallahassee eastward. High temperatures on Friday will be
a little below average (mid 50s to lower 60s) across much of our
forecast area, with the exception of north FL, where temperatures
will be in the mid 60s to lower 70s. Given the recent stretch of
exceptionally warm & humid conditions, Friday will feel quite raw
to many, with clouds and occasional rain, north winds, and
sharply cooler temperatures.

.Long Term [Friday Night Through Wednesday]...

The upper level flow over the CONUS will remain split, with a long
wave trough in the northern stream over the the northeast quadrant
of the CONUS, and W-SW flow in the southern stream over our region.
Though the aforementioned surface cold front will be south of our
entire forecast area by Friday night, clouds and a chance of light
rain will linger through this weekend as minor short wave troughs
aloft interact with the frontal boundary at the surface. While
the clouds will help keep temperatures from reaching the 30s
across most of the area, they will also keep high temperatures
below average, generally in the mid to upper 50s. A brief period
of mostly clear skies is likely Monday and early Tuesday, with
clouds and low rain chances returning Tuesday night and Wednesday.
Temperatures will be near average, with lows mostly in the upper
30s to mid 40s, and highs in the mid 50s to lower 60s.

.Aviation...
[Through 12Z Thursday] IFR/LIFR conditions will continue at all
terminals through at least mid-morning, before likely rising to
MVFR levels for the afternoon. Showers and a few thunderstorms are
most likely at KECP and KDHN. Low clouds and fog will return this
evening and continue overnight with LIFR conditions expected.

.Marine...

With a weak frontal zone in the vicinity, winds will be light and
rather variable through Thursday. Interestingly, seas at our
offshore buoys early this morning have been rather high (with
relatively long periods), given the weak wind fields. We expect
these higher seas to diminish later this morning.

.Fire Weather...

No concerns.

.Hydrology...

Our storm total QPF (through Friday) has increased, and is now in
the 2-4 inch range across the northwest third of our forecast
area. This region has had the most rain over the past week,
including widespread amounts from 0.50 to 2.0 inches on Tuesday.
Fortunately, the initial crest wave generated by last week's
monumental rainfall has had time to propagate downstream in most
cases. So while there will likely be another rise along the rivers
in southwest GA, southeast AL, and the FL Panhandle, in general it
should not be as high as the previous crests.

The longer term weather pattern (i.e. late this week through next
week) indicates a potential change in the focus for rain across
our forecast area. With a frontal zones to the south and east of
our forecast area, most of the rain will tend to occur across
north FL and south central GA- areas which have not had major
river rises recently.

For more detailed information, please visit:
http://water.weather.gov/ahps2/index.php?wfo=tae

&&

.Preliminary Point Temps/PoPs...

Tallahassee   80  68  74  59  63 /  30  30  50  40  50
Panama City   75  66  69  58  62 /  70  50  60  40  50
Dothan        74  61  64  51  56 /  90  70  70  60  50
Albany        77  65  68  52  58 /  70  60  70  60  40
Valdosta      81  68  76  59  63 /  30  20  40  40  40
Cross City    84  67  80  65  72 /  20  20  20  20  20
Apalachicola  75  68  73  62  66 /  30  30  30  30  40

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 7 PM EST /6 PM CST/ this evening FOR
     Coastal Bay-Coastal Franklin-Coastal Gulf-South Walton.

GA...NONE.
AL...NONE.
GM...NONE.
&&

NEAR TERM...DVD
SHORT TERM...FOURNIER
LONG TERM...FOURNIER
AVIATION...CAMP
MARINE...FOURNIER
FIRE WEATHER...CAMP
HYDROLOGY...FOURNIER