909
FXUS62 KTAE 040746
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
246 AM EST Mon Mar 4 2013


.NEAR TERM [Through Tonight]...
The upper trough axis has moved off the Southeast U.S. coast, with
surface high pressure centered over the central Gulf of Mexico.
This puts the forecast area under a deep layer northwesterly flow
regime. The max temp at TLH on Sunday was only 51 degrees, cooler
than any afternoon during the winter season. The mean temperature
of 41 degrees makes March 3rd the coldest day of the year so far.

Skies are clear and winds calm at most locations. This is allowing
for radiational cooling. Freezing temperatures have already been
observed as of 06Z at TLH, ABY and CTY. Min temps for this morning
were tweaked to introduce some local urban effects, but were
otherwise in good shape. The freeze warning will remain in place
until 14Z. Cirrus clouds will gradually increase and lower over
the area during the daylight and upcoming overnight hours. As the
trough moves further east, our upper level flow will briefly
become zonal. Surface high pressure will shift east to the FL
Peninsula later today as the next frontal system approaches from
the northwest. The front will cross the Lower Mississippi Valley
by daybreak Tuesday. Increasing moisture and light southerly winds
will bring milder temps both today and tonight. Highs should reach
the lower to mid 60s with lows ranging from the mid 30s over the
Lower Suwannee Valley to the upper 40s and lower 50s across the
Florida Panhandle zones west of the Apalachicola River. Any pre-
frontal showers will hold off until Tuesday.

&&

.SHORT TERM [Tuesday Through Wednesday]...
A cold front is expected to cross the area Tuesday into Tuesday
night. Fortunately, this system will be very progressive with only
very light rainfall amounts expected (generally a tenth of an
inch or less.) Therefore, this system should not cause any
additional flooding concerns. Mid level lapse rates are expected
to be unusually steep with this system with 700-500 mb lapse rates
greater than 8C/km forecast by both the NAM and GFS, especially
across our northern zones. This coupled with at least moderate
deep layer shear values and some instability could allow any
storms that develop to be capable of producing some hail. We are
not expecting a significant event at this time with the best lift
forecast to remain mainly north of the area, but it is something
of note nonetheless. The best chance of seeing this occur is
across our northern counties on Tuesday afternoon. It may also be
breezy across our northern counties on Tuesday afternoon with
frequent gusts between 25 and 30 knots possible. High temperatures
are expected to rebound back into the low to mid 70s on Tuesday
ahead of the front before falling again into the upper 50s to
lower 60s behind the front on Wednesday.

&&

.LONG TERM [Wednesday Night through Sunday]...
A very benign Synoptic Pattern appears in store for the region
throughout the extended period. Conditions will be ideal for our
area rivers, many which are still in Flood Stage, to continue to
subside. As for temperatures, we do expect a shot of cooler and
drier air behind the front from Wed-Fri (though not nearly as cold
as this last air mass), with conditions returning to back
towards or even a bit milder than climatology for next weekend.

&&

.AVIATION...
[Through 06Z Tuesday] VFR conditions will prevail throughout the
period with cirrus gradually moving in. Calm winds will become
southerly 5-10 kt by midday.

&&

.MARINE...
As a surface ridge moves east of the area today, winds will begin
to veer to a southeasterly direction. Heading into tonight and
Tuesday, southerly winds are expected to increase into the
cautionary range as the next cold front approaches the coastal
waters from the west. Behind this cold front, a strong Small Craft
Advisory is expected Tuesday night into Wednesday night with gusty
northwesterly winds.

&&

.FIRE WEATHER...
Dry conditions are expected today. While the RH will reach
critical levels today across some of our GA and FL zones, other
indices (wind and fuel moisture) will not meet requirements for
red flag criteria to be met. A chance of rain is back in the
forecast for Tuesday with drier conditions returning by Wednesday.

&&

.HYDROLOGY...
Slow improvement continues to be noted along many area rivers,
although some of the lower stretches remain in flood. Flows are on
the decrease on the Chipola, Ochlockonee, Choctawhatchee, and
Flint Rivers. As a case in point, the Choctawhatchee at Bruce is
just about to drop below its major flood stage, but will take
until Friday to fall below moderate flood. The Chipola at Altha
will do so Tuesday morning with the Ochlockonee at Havana
following suit later today.

The Withlacoochee at Pinetta recently crested about 9 inches below
its major flood stage. Recession will be quite slow with the river
not forecast to drop below flood stage until Thursday night. There
still is a lot of water to drain down the Withlacoochee toward the
Suwannee River, so flooding along the eastern portion of Madison
County, particularly south of the Pinetta gage, will also be slow
to subside.

The primary focus for river flooding from here on out will shift
to the Suwannee River. Unusually high inflows from the
Withlacoochee and Alapaha Rivers will help drive the Suwannee
River at Ellaville to flood stage by Tonight with Dowling Park to
follow by Thursday night. Interestingly, the Alapaha River at
Statenville is only just now about to crest. Because we continue
to see Top 4 or better flows on the Alapaha and Withlacoochee
Rivers, we feel increasingly confident that moderate flood stages
will be reached along the Suwannee River at Ellaville and likely
further downriver to Dowling Park by the weekend.

As the flood wave continues down river, we expect at least minor
flooding from Luraville through Branford, though there is potential
of reaching moderate flood stage at Branford. However, this has
less confidence than upriver at Dowling Park. Further down the
Suwannee River, much depends on how backwater flow up the Santa Fe
River influences the Suwannee River crestwave. Moreover,
attenuation of the flow downstream is possible given the drier
soil conditions in place across Southern Lafayette and Dixie
Counties. Thus, it is still a little too early to make a firm
prediction on whether flood stages will be met on the lower
Suwannee River (Rock Bluff and beyond).

---Points still to crest or cresting now---

Withlacoochee at Pinetta - Moderate flood stage
Aucilla River at Lamont - Minor flood stage
Suwannee River at Ellaville and points downstream

---Points that have crested but are still in flood stage---

Choctawhatchee River at Caryville - Minor flood stage
Choctawhatchee River at Bruce - Major flood stage
Chipola River at Altha - Moderate flood stage
Ochlockonee River near Concord - Minor flood stage
Ochlockonee River near Havana - Moderate flood stage
Apalachicola River at Blountstown - Minor flood stage
Withlacoochee River above Valdosta - Minor flood stage.

---Flood Outlook for the Suwannee River---

Forecast confidence is now very high for at least minor flood
stages being met at Ellaville and Dowling Park. There is
increasing confidence that these sites will eventually reach low
end moderate flood stage by the weekend.

Further downriver, there is more uncertainly but still a good
chance of reaching minor flood stage at Branford.

Updated predicted crest ranges and crest times as of 230 pm Sunday

At Ellaville - 60 to 62.5 feet (March 9th)

At Dowling Park - 51.5 to 53.5 feet (March 10th)

At Luraville - 44.5 to 47.5 feet (March 11th)

At Branford - 31.5 to 34 feet (March 12th)

For specific crest levels and initial timing of flood stage and
crests, please consult our AHPS page by clicking on Rivers and
Lakes on our website. This can be found at the following web
address.

water.weather.gov/ahps2/index.php?wfo=tae

&&

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   63  42  73  43  62 /  0   0  20  30   0
Panama City   62  53  72  46  60 /  0  10  20  20   0
Dothan        64  49  72  41  58 /  0  10  30  30   0
Albany        63  44  71  42  59 /  0  10  30  40   0
Valdosta      62  39  72  42  60 /  0   0  10  30  10
Cross City    64  37  73  46  62 /  0   0  10  20  10
Apalachicola  58  49  70  47  60 /  0  10  20  20   0

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WARNING until 9 AM EST /8 AM CST/ this morning for
     Calhoun-Central Walton-Coastal Dixie-Coastal Franklin-
     Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-
     Holmes-Inland Bay-Inland Dixie-Inland Franklin-Inland
     Gulf-Inland Jefferson-Inland Taylor-Inland Wakulla-Inland
     Walton-Jackson-Lafayette-Leon-Liberty-Madison-Washington.
GA...FREEZE WARNING until 9 AM EST this morning for Baker-Ben Hill-
     Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-
     Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
     Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-
     Turner-Worth.
AL...FREEZE WARNING until 8 AM CST this morning for Coffee-Dale-
     Geneva-Henry-Houston.
GM...None.

&&

$$

Near Term/Aviation/Fire Wx/Hydrology...Wool
Short Term/Marine...DVD
Long Term...Gould