U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus03 kwns 250730 
Storm Prediction Center ac 250729 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0229 am CDT Friday Apr 25 2014 

Valid 271200z - 281200z 

..there is a MDT risk of severe thunderstorms for the arklatex area... 

..There is a slight risk of severe thunderstorms from the MO valley to the western 
Gulf Coast... 

Outbreak of severe storms possible on Sunday across parts of the 
central states with large hail...damaging winds...and tornadoes. 

A vigorous shortwave trough expected to be centered in the Lee of 
the southern rockies at 12z/sun will substantially slow as it progresses 
towards Nebraska. An attendant middle-level jet /aoa 50 knots at 500 mb/ will 
persist from the desert SW...curling northward from the Red River to the 
MO valley. At the surface...a cyclone should drift eastward over the 
Central Plains with a warm front arcing eastward across the corn belt to 
the lower Ohio Valley. A dryline/weakening Pacific cold front should 
reach eastern Kansas/OK into deep S Texas in the late afternoon. 

..MO valley to the western Gulf Coast... 
The warm sector will become increasingly broad/moist beneath an eml 
with lower 60s surface dew points becoming established near the warm 
front and middle to upper 60s into the lower/mid-MS valleys and 
arklatex by Sun afternoon. Initially steep middle-level lapse rates 
along with moderate to strong deep-layer shear will support an 
expansive area of organized severe potential. 

Areas of convection should be ongoing at 12z/sun across parts of the 
Southern Plains to middle-MO valley. Some of this activity may already be 
surface-based or will transition to becoming so as diurnal heating 
ensues. Clusters of isolated to scattered severe storms will be 
possible as convection likely develops N/E. 

The most probable severe risk should develop along and ahead of the 
dryline towards peak heating...with confidence greatest in this 
occurring near the southern periphery of early day storms /centered over 
the arklatex/. With robust heating occurring across Texas...MLCAPE 
should push 2500 j/kg ahead of the dryline. Hodographs appear quite 
conducive to supercells...capable of producing very large hail and 
strong tornadoes. With the dryline stalling across northestern Texas sun 
evening...training supercell clusters may continue into the night. 

Along the dryline farther north into the MO valley...early day 
convection may tend to limit a greater severe risk. But with strong 
insolation...moderate buoyancy may develop within a steep lapse rate 
environment. Although deep-layer wind profiles should be largely 
meridional...sufficient curvature to the low-level hodograph would 
support updraft rotation...with all severe hazards possible. 

.Grams.. 04/25/2014