Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 280122
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
822 PM EST Sat Dec 27 2014
.Near Term [Through Tonight]...
As a sharp vort lobe enters TX overnight, a wave of low pressure
will develop and move northeast along a cold front that will cross
Mississippi overnight. This will also lift a developing warm front
north across the region. Most forcing for ascent will occur north of
this boundary and ahead of the cold front. High chances for rain
across the northern tier of our zones will retreat northward
overnight with lowering PoPs with time the result. We could see an
advection fog develop and move inland. Some of the guidance is very
bullish concerning the fog. We have areas of fog on the forecast,
but it remains to be see how dense it will get. The mild temps will
continue with overnight lows generally in the mid 50s inland and
around 60 near the coast. This is some 15 to 20 degrees above normal.
[Through 00Z Monday] As low level flow gradually veers to onshore,
log clouds or perhaps an advection fog will lower conditions into
the LIFR range at most terminals overnight. The low conditions could
persist until close to midday before ceilings lift to MVFR or low
end VFR during the afternoon. The only terminal that should expect
some showers is DHN. In fact an isolated thunderstorm cannot be
ruled out Sunday afternoon.
.Prev Discussion [328 PM EST]...
.Short Term [Sunday Through Monday Night]...
The shortwave over Texas at the beginning of the period will
dampen out as it moves eastward into the Central Gulf Coast
region by Sunday night. The associated cold front will sweep
through the local area Sunday night through Monday bringing with
chances for showers and isolated thunderstorms. QPF with this
system should generally be around one-half inch or less with a few
locations possibly reaching one inch, mainly over the western
zones. Temps will be be above seasonal levels with highs in the
70s and lows Sunday night in the lower 60s.
.Long Term [Tuesday Through Saturday]...
The upper level pattern will be nearly zonal through Wednesday
night followed by backing flow to the southwest as a deepening low
pressure system develops in the Southern Plains and begins to
advance eastward. This will bring the next cold front and chances
for rain to the region by the end of the work week into the first
part of next weekend. Temps will be near or just below seasonal
Light to moderate winds and low seas are expected to prevail
through at least the middle of next week. Winds will be onshore
through Sunday night and veer to become offshore by late Monday
as a weak cold front pushes through the waters. Offshore flow
will continue until late in the week before they swing around to
become onshore again ahead of the next approaching cold front.
Atmospheric conditions will remain too humid to allow any fire
weather concerns over the next week. Dispersion indices will be on
the low side on Sunday, near 30 in some areas. Even lower dispersion
indices are forecast for Monday, with areas north and west of
Tallahassee peaking well below 30.
Current river data this afternoon shows that the crest wave in the
Ochlockonee has passed the Havana gage and is discharging into the
upper end of Lake Talquin. Flows above Concord are in recession,
though it will take some time before water levels at Concord drop
enough to lessen impacts in the northern portion of Leon County.
Inflows into Lake Talquin and operations at Jackson Bluff will
result in rises at Bloxham to near flood stage today, though with a
slightly lower crest at Havana today, Bloxham should stay just below
flood stage. However, with 21000cfs discharging downstream, rises at
Smith Creek to minor flood stage are likely by Monday.
In the Withlacoochee System - Both Hahira on the Little River side
and Skipper Bridge on the Withlacoochee side have crested. Combined
flow between these two sources is around 35000cfs. Due to a
variety of factors, a reduction of this combined flow by 15 percent
historically has produced a decent prediction for the US-84 gage.
This suggests a crest in the 28.5 to 29 foot range late Sunday
night. While the timing of the crest wave through the system is
matching up with recent flood events, the rate of rise at US-84 is
outpacing expected trends. Thus it looks like there`s an increased
chance to hit major flood stage there by Sunday night. These
conditions suggest that the Withlacoochee at Pinetta will continue
rising through action stage into the coming week and potentially
exceed flood stage after the first of the year.
Elsewhere in the hydro area, releases from Woodruff will keep the
Apalachicola at Blountstown above flood stage for the next couple of
The Choctawhatchee River at Caryville has already crested and with
the flood wave moving downstream receiving minor contributions from
Bruce Creek and Holmes Creek along the way, Bruce should easily rise
above flood stage late tomorrow. There is some potential for
moderate flood stage to be met at Bruce by Tuesday morning.
Our next system will deliver another chance of 1 to 2 inches of rain
starting Sunday night and continuing through Monday night. With this
rain spread over a 24 to 36 hour period, limited impact is expected
on existing river levels. A short period of quiet weather is
expected throughout the remainder of the week before a stronger
storm system approaches the area next Saturday. With little
opportunity to dry out from the recent heavy rains, the flood
potential will remain elevated across the region with river flows
now well above normal.
For the most up to date information, please visit:
.Preliminary Point Temps/PoPs...
Tallahassee 53 77 62 75 54 / 10 10 50 50 20
Panama City 59 75 63 71 54 / 20 20 60 30 10
Dothan 54 76 60 71 48 / 70 30 70 40 10
Albany 51 77 61 73 50 / 20 10 60 50 10
Valdosta 53 77 61 76 55 / 10 10 30 50 30
Cross City 56 78 62 77 60 / 10 10 20 40 30
Apalachicola 58 73 63 72 57 / 10 10 50 40 10