EF0 tornado, Kinderlou, Georgia, December 23, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1036 AM EST Tue Dec 23 2014

...Severe Weather and Flooding Remain Possible Across the Region
Today and Tomorrow...

.Hydrology...
Periods of heavy rain and thunderstorms will result in widespread
rain amounts of 3-4 inches with higher amounts in excess of 6 inches
through Wednesday. Rain will end across southeast AL and the FL
panhandle by noon Wednesday, and across southwest GA and northern FL
Wednesday evening. Most rivers have started out at low levels, so
even significant rises will result in stage increases to only minor
flooding. A few points will reach moderate flooding later in the
week, such as in the Ochlockonee basin.

&&

.Prev Discussion [1022 AM EST]...

.Near Term [Through Today]...
Surface analysis this morning shows two warm fronts over our area-
the synoptic front along the FL-GA border that extends NWward across
central AL and an offshore warm front around 50 nm offshore along
the FL coastline. A cold front lies to our west across the Arklatex.
Moisture is plentiful with southerly flow at the surface and deep
layer southwesterly flow continuing to bring warm, moist air from
the Gulf. The 12Z TAE sounding showed a PWAT of 1.68", which is 2
standard deviations above normal. Some spots in the western FL Big
Bend having already received about 2-3" of rain. Continued heavy
rainfall on top of already wet soil makes flooding is a main concern
with this system. Rainfall totals for today and tomorrow are
expected to be 3-5.5" with isolated amounts even higher possible.

There is a severe weather threat with these storms, with the
potential for isolated tornadoes, damaging straight-line winds and
hail. Model MLCAPE for the warning area is around 500 J/kg with
0-6km shear of 40-50kts. This high shear low CAPE environment will
be favorable for supercell development. The 12Z sounding shows steep
lapse rate from 800-550mb as well. Our low level (0-1km) shear of
15-20kts, which will support tornado development in supercells that
form, especially if they form behind the currently offshore warm
front. Overnight, as the main squall line approaches, the low level
jet will set up over our area, which will mean the potential for an
isolated tornado to be embedded in a QLCS line and and will increase
the potential for damaging straight-line winds.

.Short Term [Tonight Through Thursday]...

The severe weather and flooding threat which is already beginning in
earnest across the region today will continue through the area
tonight and linger into Wednesday, will result in the greatest
potential for additional severe storms to linger into tonight.
However, since the ground will already be well saturated from
earlier rainfall from the past several days, the flooding threat on
Wednesday could still be quite significant, especially across
eastern portions of the CWA where the deep layer moisture will be
last to leave the region. We will finally experience a respite on
Wednesday night and Thursday as a strong cold front plows through
the region and brings a return to fair, cool, and dry weather just
in time for Christmas over the CWA.

.Long Term [Thursday Night Through Tuesday]...

The fair, dry, and seasonable weather that will be building in
behind the cold frontal passage on Wednesday night should hold until
the end of the week. By next weekend and early next week, however, a
new corridor of moisture is expected to setup between a ridge of
high pressure over the Carribean and a developing upper trof over
the lower plains. While this pattern will will keep temperatures
above climatology for the entire period, it will also begin to
increase rain chances over the region once again, as a potentially
large area of deep layer moisture is funneled NE in between these
two systems.

.Aviation...
[Through 12Z Wednesday] LIFR ceilings and visibilities will
gradually improve this morning but ceilings will likely be in the
IFR range for much of the day. Widespread showers and thunderstorms
should be expected at all terminals throughout the day and night.

.Marine...

A developing low pressure system off to our west will continue to
increase onshore winds across the coastal waters today. These winds
and seas will gradually reach Small Craft Advisory levels by this
evening while conditions continue to become more hazardous. Winds
and seas will then gradually diminish behind the passage of the next
cold front on Wednesday night and Thursday when all headlines will
be able to be removed.

.Fire Weather...

Hazardous fire weather conditions are not expected for the next
several days.

&&

.Preliminary Point Temps/PoPs...

Tallahassee   68  64  72  43  62 / 100  90  80  30  10
Panama City   68  66  68  43  59 / 100  90  70  20  10
Dothan        69  63  67  40  59 / 100  90  60  20  10
Albany        69  63  71  41  60 / 100  90  80  30  10
Valdosta      70  63  73  46  61 /  90  90  90  40  10
Cross City    72  64  74  48  64 /  70  90  90  40  10
Apalachicola  68  67  70  45  59 / 100  90  80  30  10

&&

.TAE Watches/Warnings/Advisories...

FL...Flash Flood Watch through Wednesday evening for Calhoun-Central
     Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal
     Gulf-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-South
     Walton-Washington.

     RIP CURRENT RISK through late tonight for Coastal Bay-Coastal
     Franklin-Coastal Gulf-South Walton.

GA...Flash Flood Watch through Wednesday evening 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...Flash Flood Watch through Wednesday afternoon for Coffee-Dale-
     Geneva-Henry-Houston.

GM...Small Craft Advisory from 7 PM this evening to 1 PM EST Thursday
     for Apalachee Bay-Coastal waters From Ochlockonee River to
     Apalachicola FL out to 20 NM-Coastal waters from Suwannee
     River to Keaton Beach FL out 20 NM-Coastal waters from
     Apalachicola to Destin FL out 20 NM-Waters from Suwannee
     River to Apalachicola FL from 20 to 60 NM-Waters from
     Apalachicola to Destin FL from 20 to 60 NM.

&&

NEAR TERM...MOORE
SHORT TERM...GOULD
LONG TERM...GOULD
AVIATION...MOORE
MARINE...GOULD
FIRE WEATHER...HARRIGAN
HYDROLOGY...HOLLINGSWORTH