HAMweather.com Area Forecast Discussion for County Warning Area TAE

Thu, 16 Feb 2012 11:35:00 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
500 AM EST Thu Feb 16 2012

.Synopsis and Short Term (Now through Saturday)...A very complex 
forecast is in store for the region through the entire short term 
period, one that will likely be filled with many hazards before all 
is said and done. This will be due to a very progressive synoptic 
pattern associated with the sub-tropical jet stream which will 
bring a series of low pressure systems our way. On the bright side, 
while any sunshine during this period will be extremely hard to come 
by, we are likely to see at least some relief from the ongoing 
drought, as many areas could see 1.5 to 2.5 inches of storm total 
rainfall through the next few days.

For this morning, Dense Fog has become a problem once again, but it 
is not as widespread as it was on Wed, morning due to the incoming 
rainfall to the west. Therefore, even though areas of Dense Fog will 
remain a possibility outside of the advisory area this morning, 
decided to limit the Dense Fog Advisory to Gulf County in the Florida 
Panhandle, all of the Florida Big Bend, and eastern sections of 
South Central Georgia until 9 AM EST. Once this fog burns off, a 
large area of showers and thunderstorms will gradually envelop the 
region from NW to SE, with the possibility of some stronger storms 
with gusty winds and locally heavy rainfall included in SPC's 5% 
outlooked area. (essentially the western half of the CWA).

For tonight through Friday Night, the fcst Pops and rainfall will be 
quite difficult, as whatever remains of the first Cold Frontal 
Boundary are expected to be stalled out in an east-west orientation 
in our vicinity, which should favor the higher Pops and QPF over 
southern portions of the CWA, with lower values to the north. Also, 
with much weaker forcing, we can expect mainly showers or rain with 
only isolated thunderstorms at best.

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On Saturday, however, the ingredients appear to be coming together 
for possibly the most widespread and significant Severe Weather Event 
of the season thus far for Southeast Alabama, Southwest and South 
Central Georgia, and the Florida Big Bend and Panhandle! With 0-6km 
Bulk Shear Values quite possibly exceeding 80 kts, 0-3km Bulk Shears 
of 50 to 60 kts, along with an 850 mb jet in excess of 50 kts, 
combined with vigorous 0-1 km Helicities between 300-500 m^2/s^2, 
very strong diffluent flow aloft, a rapidly deepening Sfc Low which 
the models keep trending further and further to our West, Surface 
Dewpoints rising into the mid 60s which could result in ML Capes 
nearing 500 J/KG. This is expected to set the stage for the 
development of a Large MCS with the distinct possibility of 
Vigorous forerunning Supercells capable of producing Significant  
Dangerous Tornadoes, as well as possible widespread straight line 
wind damage. In summary, the above mentioned severe weather 
parameters are very high in this instance, making this a potential 
event of quite rare proportions. 

It should be noted, however, that this event is still a few days 
away, so the timing intensity, and overall threat level could change 
before Saturday, but ALL interests in our CWA should keep abreast of 
the latest forecasts from the National Weather Service in 
Tallahassee, FL and the Storm Prediction Center in Norman, OK, and 
be prepared to take quick and decisive action if needed as this 
could be a very rare event for our region.  

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.LONG TERM...(SATURDAY NIGHT THROUGH NEXT THURSDAY)...Little change 
will take place in the large scale upper level pattern through the 
extended period, anchored by a positive anomaly in the eastern 
Pacific, and a negative anomaly north of Hudson Bay. There are some 
indications of a bit of an eastward shift of the broad positive 
tilted mean trough over the western U.S., which will maintain 
nearly  zonal flow across the eastern half of the country. As usual 
with this type of pattern, the models continue their typical 
divergence, in speed and amplitude of short waves as they drop into 
the mean trough and then exit rapidly to the east northeast. Will 
incorporate a blend of the 00Z GFS and EURO. A strong cold front 
will sweep eastward across the area Saturday night and Sunday 
morning, accompanied by widespread rain and thunderstorms. Cooler 
drier air will spread across the area Sunday night and Monday. 
Expect clouds to begin to increase again on Tuesday, with rain 
chances increasing Wednesday, and another cold front approaching by 
Thursday. Temperatures will cool briefly to near normal on Monday 
and Monday night, and remain significantly above normal for most of 
the remainder of the forecast period. 

.MARINE...Winds and seas should remain below headline criteria for 
today through Friday Night, before winds and seas quickly ramp up to 
Small Craft Advisory Conditions ahead of the next low pressure 
system on Saturday. In fact, this potentially dangerous low pressure 
system could produce Gale or near Gale Force conditions by late 
Saturday through Saturday Night. Additionally, numerous 
thunderstorms, some of which could be strong to severe will make 
boating conditions especially hazardous for all Mariners. Conditions 
should gradually improve across the marine area by early next week 
as High Pressure Builds in from the Northwest. 

.AVIATION (THROUGH 06Z FRIDAY)...
IFR to LIFR ceilings cover the Tri-State Area, along with large 
areas of MVFR to IFR visibilities. A disturbance approaching from 
the west is spreading mostly light rain east and north into portions 
of Southeast Alabama and the Western Florida Panhandle this morning. 
Rain will spread eastward across the entire area and continue 
through the afternoon. There will be isolated thunderstorms embedded 
within the areas of rain, especially during the afternoon. By late 
afternoon, the threat of rain will begin to diminish across much of 
Southeast Alabama and Southwest and South Central Georgia, while the 
threat of showers will continue across Florida through the forecast 
period and beyond. Winds will become southerly around 10 knots with 
gusts up to around 15 knots near the coast. Look for a repeat of MVFR to 
IFR ceilings and visibilities across the area again on Thursday 
night.

.FIRE WEATHER...There are no fire weather concerns through at least 
the weekend. Widespread fog this morning will give way to widespread 
rain and isolated thunderstorms across the entire area throughout 
the day today, due to a combination of a very moist airmass and an 
upper level disturbance. Rain will diminish across most of Southeast 
Alabama and Southwest and south Central Georgia by tonight, with the 
greatest threat of showers remaining across the Florida zones. 
Another widespread wetting rainfall event is expected on Friday 
night and Saturday, before significant clearing and drying takes 
place on Sunday.

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   76  62  71  62  72 /  50  40  60  40  60 
Panama City   73  62  69  61  71 /  60  40  60  50  70 
Dothan        73  57  70  59  68 /  80  20  40  40  70 
Albany        74  57  71  57  69 /  70  20  30  30  70 
Valdosta      76  59  71  58  71 /  50  30  50  40  70 
Cross City    75  62  72  60  75 /  40  40  60  40  60 
Apalachicola  70  63  68  62  70 /  60  40  60  40  60 

.TAE WATCHES/WARNINGS/ADVISORIES...

AL...None.

GA...Dense Fog Advisory until 9 AM EST this morning for Ben Hill-
     Berrien-Brooks-Colquitt-Cook-Grady-Irwin-Lanier-Lowndes-
     Thomas-Tift.

FL...Dense Fog Advisory until 9 AM EST /8 AM CST/ this morning for 
     Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal 
     Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-Inland 
     Dixie-Inland Franklin-Inland Gulf-Inland Jefferson-Inland 
     Taylor-Inland Wakulla-Lafayette-Leon-Liberty-Madison.

GM...None.