- 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
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.