SWODY1
SPC AC 131951
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0251 PM CDT MON JUN 13 2011
VALID 132000Z - 141200Z
...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT FROM THE
CENTRAL HIGH PLAINS AND MID MO VALLEY SSEWD TO THE LOWER MS
VALLEY......
...LOWER MS VALLEY...
SEVERE MCS WITH MATURE COLD POOL CONTINUES TO PROPAGATE SWD VICINITY
AND JUST E OF MS RIVER. WITH MLCAPES RANGING UPWARDS TO 2500 J/KG
AND DCAPES IN EXCESS OF 1200 J/KC...DAMAGING WINDS STILL EXPECTED TO
ACCOMPANY THE COMPLEX AS IT TRACKS SWD AT 35KT...POSSIBLY REACHING
GULF THIS EVENING PRIOR TO DISSIPATING.
...SE NEB/NE KS/NW MO...
PER MODELS AND ACARS SOUNDINGS THE WARM SECTOR REMAINS STRONGLY
CAPPED ACROSS KS INTO WRN MO. WITH MUCAPES NOW RANGING UPWARDS TO
4000 J/KG AND VERY STEEP MID LEVEL LAPSE RATES IN PLACE COUPLED WITH
BRN SHEAR OF 50-60KT...A VERY FAVORABLE CONDITIONAL ENVIRONMENT IS
IN PLACE FOR SUPERCELLS INCLUDING A VERY LARGE HAIL THREAT. MODELS
PROVIDING MIXED AND INCONCLUSIVE SOLUTIONS AS TO IF/WHEN AND EXACTLY
WHERE INITIATION COULD OCCUR. THUS WILL CONTINUE THE POTENTIAL FOR
SIGNIFICANT HAIL ALTHOUGH THE OVERALL PROBABILITIES CONTINUE TO
REFLECT THE UNCERTAINTY CONCERNING INITIATION.
LITTLE CHANGE IN OTHER AREAS INCLUDING THE CENTRAL HIGH PLAINS AHEAD
OF THE APPROACHING S/WV TROUGH.
..HALES.. 06/13/2011
.PREV DISCUSSION... /ISSUED 1130 AM CDT MON JUN 13 2011/
...LOWER MS VALLEY THIS AFTERNOON...
INITIALLY ELEVATED STORMS OVER SE MO/NE AR WILL EVOLVE INTO CLUSTERS
OF SURFACE-BASED STORMS BY EARLY AFTERNOON IN NE AR/WRN TN/NW MS AS
THE BOUNDARY LAYER DESTABILIZES ALONG AND S OF THE STALLED SURFACE
FRONT. BOUNDARY LAYER DEWPOINTS OF 68-72 F AND TEMPERATURES WARMING
WELL INTO THE 90S WILL SUPPORT MODERATE INSTABILITY SWD ACROSS MS
THIS AFTERNOON...AS WELL AS STEEP LOW-LEVEL LAPSE RATES. GIVEN THE
25-30 KT NNWLY STEERING FLOW IN THE MIDLEVELS...EXPECT A
CONSOLIDATING COLD POOL AND ASSOCIATED STORMS TO MOVE SWD/SSEWD
ACROSS MS THROUGH THE AFTERNOON WITH THE POTENTIAL FOR A CORRIDOR OF
DAMAGING OUTFLOW WINDS. THIS CONVECTION MAY PERSIST ALL THE WAY TO
THE I-10 CORRIDOR WITH A GRADUALLY DIMINISHING RISK OF DAMAGING
WINDS BY LATER THIS EVENING.
...SE NEB/NE KS/NW MO THIS EVENING...
STRONG SURFACE-BASED INSTABILITY /MLCAPE 3000-4000 J PER KG/ WILL BE
PRESENT ALONG THE SLOW-MOVING WARM FRONT FROM WRN MO NWWD TO NEAR
THE KS/NEB BORDER. THIS AREA WILL BE NEAR THE NE EDGE OF THE
WARMEST EML...AND THE CAP SHOULD BE WEAKENED BY SURFACE HEATING AND
LOW-LEVEL ASCENT ALONG THE FRONT. IF STORMS DEVELOP LATE THIS
AFTERNOON...THERE WILL BE THE POTENTIAL FOR SUPERCELLS WITH VERY
LARGE HAIL AND TORNADOES...GIVEN THE STRONG INSTABILITY... EFFECTIVE
SRH AOA 200 M2/S2...AND EFFECTIVE BULK SHEAR AOA 40-50 KT. ANY
STORMS THAT FORM WILL THEN PROGRESS SEWD ALONG THE WARM FRONT INTO
WRN/CENTRAL MO THIS EVENING INTO EARLY TONIGHT.
OVERNIGHT...THERE WILL AGAIN BE THE POTENTIAL FOR ELEVATED STORMS
FROM SRN IA INTO N/NE MO IN THE ZONE OF ENHANCED LOW-LEVEL WAA ON
THE NOSE OF THE SWLY LLJ. LARGE HAIL WILL BE THE MAIN THREAT WITH
THIS ACTIVITY.
...CENTRAL HIGH PLAINS THIS AFTERNOON INTO TONIGHT...
A LOW-LEVEL UPSLOPE FLOW REGIME WILL BECOME ESTABLISHED LATER THIS
AFTERNOON AS SURFACE PRESSURES FALL IN THE LEE OF THE CENTRAL
ROCKIES...IN ADVANCE OF A SHORTWAVE TROUGH MOVING EWD FROM NV/UT.
BOUNDARY LAYER DEWPOINTS IN THE 50S TO NEAR 60 F WILL BE DRAWN WWD
LATER THIS AFTERNOON/EVENING...WHERE SURFACE HEATING OVER THE E
SLOPES OF THE HIGH TERRAIN COULD INITIATE STORMS. ANY STORMS THAT
FORM COULD DEVELOP SUPERCELL STRUCTURES GIVEN THE PRESENCE OF
MODERATE MOISTURE/INSTABILITY AND SUFFICIENT DEEP-LAYER VERTICAL
SHEAR. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN SEVERE
THREATS...THOUGH AN ISOLATED TORNADO OR TWO WILL ALSO BE POSSIBLE.
OVERNIGHT...STORMS COULD EVOLVE INTO A CLUSTER OR TWO THAT WILL
PROGRESS EWD OVER THE HIGH PLAINS...IN ADVANCE OF THE APPROACHING
MIDLEVEL TROUGH FROM THE W.
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