Severe Weather Forecast

U.S. Convective Outlook

599 
acus01 kwns 051941 
swody1 
Storm Prediction Center ac 051939 


Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0139 PM CST sun Feb 05 2012 


Valid 052000z - 061200z 


..no severe thunderstorm areas forecast... 


Shunted Florida general thunderstorm line southward a bit as visible imagery 
depicts cumulus field having trouble growing past weak cap and dewpoints 
mixing into the upper 50s f. Best chance of isolated thunderstorms 
should be over central and southern portions of Florida where better moisture 
resides. 


Elsewhere...adjusted Texas thunder line a bit. This area too will only 
see isolated lightning strikes. 


.Jewell.. 02/05/2012 


Previous discussion... /issued 1024 am CST sun Feb 05 2012/ 


..sern states... 
Removed general thunderstorms from the Carolinas and Georgia. Rest of forecast 
unchanged. 


Deep-layer dry air advection/subsidence was in full swing across the 
Carolinas and Georgia as low/mid-lvl flow has turned westerly ahead of the 
synoptic cold front. The decreasing instability and only weak frontal 
convergence/upper support will limit deep moist convection over the 
Carolinas and Georgia. 


Farther S...comparatively rich low level moisture was present over much 
of Florida. Seabreeze/frontal convergence and increasing low level buoyancy 
may be enough for a few thunderstorms over northern/central Florida this afternoon. No severe 
weather is anticipated owing to meager instability. 


Meanwhile...upper disturbance has been strengthening over the northwest 
Caribbean/scntrl Gulf of Mexico. Downstream...convection was 
increasing over western Cuba and the Keys in vicinity of surface reflection/trough. 
Although copious amounts of high cloud cover will envelope southern Florida to 
limit heating...convection will increase through tonight with at 
least isolated thunderstorm probabilities. Weak wind fields/buoyancy will 
limit severe risks. 


..cntrl/southern Texas... 
No changes needed to general thunderstorm risk. 


Primary convective event last night/early this morning was tied to a 
h25 subtropical jetstreak. Majority of the deep moist convection is 
now over the western Gulf waters. New thunderstorms have recently formed over 
The Big Bend region...likely associated with tail-end of a weak 
disturbance moving through northern Mexico/southern nm. 


Sporadic thunderstorms will occur over central/southern Texas through tonight...with 
higher probabilities confined to The Big Bend region eastward across the 
southern Edwards Plateau and into scntrl Texas/coastal Bend. Activity will 
be elevated atop the cold dome that settled into place yesterday 
with forecast MUCAPE sufficiently weak to preclude severe hail. 






Mesoscale Discussion

704 
acus11 kwns 042246 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 042246 
alz000-msz000-laz000-050015- 


Mesoscale discussion 0113 
National Weather Service Storm Prediction Center Norman OK 
0446 PM CST Sat Feb 04 2012 


Areas affected...far southeastern la...far southeastern MS...far southwestern Alabama 


Concerning...severe potential...watch unlikely 


Valid 042246z - 050015z 


A few storms may produce strong wind gusts into early evening across 
far southeastern la...far southeastern MS...and far southwestern Alabama...with a weakening trend 
expected after 01z. A ww is not needed. 


A prefrontal squall line continues moving eastward around 20 knots... 
currently extending from east of the Hattiesburg MS area southward toward 
the east end of Lake Pontchartrain to near Grand Isle la. Low-level 
ascent at the leading edge of convective outflow amidst a weakly 
buoyant -- MLCAPE of 500 to 1000 j per kg -- and anomalously moist 
troposphere -- precipitable water values of 180 to 190 percent of normal per blended 
AMSU/SSMI data -- should allow storms to continue moving eastward along 
the central Gulf Coast. Only modest amounts of deep-layer shear per 
area vwp data will contribute to maintaining some convective 
organization...with locally gusty winds owing to water loading 
processes and weak/broad...line-embedded mesoscale circulations. 
However...weak low-level flow per Mobile vwp data...the lack of 
deep-layer forcing for ascent...the absence of greater 
buoyancy...and the absence of a more organized cold pool will 
greatly minimize any threat for severe wind gusts. After 
01z...nocturnal stabilization will be associated with a reduction in 
the threat for strong storms. 


.Cohen.. 02/04/2012 


..please see www.Spc.NOAA.Gov for graphic product... 


Attention...WFO...mob...lix... 


Latitude...Lon 30418780 30158816 29668875 29068918 29298980 30028962 
30708926 31208880 31318826 31148779 30758771 30418780