SWODY1
SPC AC 231618
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1118 AM CDT SAT OCT 23 2010
VALID 231630Z - 241200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO/MID MS VALLEYS
INTO THE SRN PLAINS...
...SRN PLAINS INTO OZARK PLATEAU...
SHORT WAVE TROUGH CURRENTLY PROGRESSING EWD THROUGH NM...FAR WRN TX
AND NWRN MEXICO WILL DEAMPLIFY THROUGH THE DAY ONE PERIOD WHILE
ACCELERATING NEWD THROUGH THE REGION INTO THE LOWER/MID MS VALLEY.
LOW-LEVEL MASS RESPONSE TO THIS IMPULSE WILL MAINTAIN A 30-40+ KT
SLY/SWLY LLJ FROM PORTIONS OF CNTRL/ERN TX INTO THE MID MS
VALLEY...EFFECTIVELY ENHANCING THE NWD FLUX OF A MOIST BOUNDARY
LAYER CHARACTERIZED BY DEW POINTS IN THE MID/UPPER 60S. WHILE
WIDESPREAD CLOUDINESS WILL TEMPER DAYTIME HEATING...THIS MOISTURE
COUPLED WITH STEEP MIDLEVEL LAPSE RATES WILL CONTRIBUTE TO A
MODERATELY UNSTABLE AIR MASS BY AFTERNOON WITH MLCAPE VALUES
APPROACHING 1000-2000 J/KG.
FORCING FOR ASCENT ATTENDANT TO MIDLEVEL TROUGH COUPLED WITH THE
DESTABILIZING WARM SECTOR SHOULD SUPPORT THE INTENSIFICATION OF
ONGOING QLCS TODAY FROM ERN OK SWD/SWWD INTO CNTRL TX. ADDITIONAL
MORE DISCRETE STORMS WILL BE POSSIBLE DOWNSTREAM WITHIN CONFLUENT
LOW-LEVEL REGIME OVER ERN TX. THE PRESENCE OF A 45-60 KT MIDLEVEL
JET STREAK ATTENDING SHORT WAVE TROUGH AND THE SUSTAINED BELT OF
STRONGER LOW-LEVEL FLOW /AS MENTIONED ABOVE/ WILL RESULT IN VERTICAL
SHEAR PROFILES SUPPORTIVE OF BOWING/LEWP AND SUPERCELL STRUCTURES
CAPABLE OF DAMAGING WINDS...HAIL AND A FEW TORNADOES. THIS SEVERE
WEATHER THREAT MAY DEVELOP EWD/NEWD INTO PARTS OF WRN AR AND SWRN MO
LATER TODAY INTO TONIGHT AS THE BOUNDARY LAYER CONTINUES TO
MOISTEN/DESTABILIZE IN ADVANCE OF EJECTING MIDLEVEL SYSTEM.
...MID/LOWER MO VALLEY...
CLOSED MIDLEVEL LOW OVER WRN PARTS OF NEB/SD WILL PROGRESS EWD
THROUGH THE MID MO VALLEY IN CONJUNCTION WITH ASSOCIATED SURFACE LOW
WHICH WILL DEVELOP FROM NWRN KS INTO ERN NEB BY THIS EVENING.
MORNING VISIBLE SATELLITE IMAGERY INDICATES CONSIDERABLE CLOUDINESS
OVER NEB/IA...WITH POTENTIAL FOR STRONGER DIABATIC HEATING OVER
PARTS OF KS INTO MO. THIS DIFFERENTIAL HEATING HAS RESULTED IN THE
DEVELOPMENT OF A WARM FRONTAL SEGMENT EXTENDING FROM NWRN KS EWD
THROUGH NWRN MO TO N OF STL.
STRENGTHENING SLY FLOW AHEAD OF THE DEEP-LAYER CYCLONE IS EXPECTED
TO ENHANCE THE FLUX OF A WARMER...MORE MOIST AIR MASS IN PLACE OVER
PARTS OF CNTRL/ERN KS/WRN MO NWD THROUGH THE MID MO VALLEY
TODAY...CONTRIBUTING TO AN AXIS OF MODERATE INSTABILITY /I.E. MLCAPE
VALUES OF 1000-2000 J PER KG/ BY AFTERNOON ALONG AND S OF
ABOVE-MENTIONED WARM FRONT. 12Z MODEL GUIDANCE SUGGESTS THAT
SURFACE-BASED STORMS WILL BECOME INCREASINGLY LIKELY BY MID/LATE
AFTERNOON FROM NE OF SURFACE LOW OVER NERN NEB/SERN SD/NWRN IA SWD
INTO NERN KS/NRN MO. GIVEN THE PRESENCE OF VERTICALLY-VEERING WIND
PROFILES WITH MODERATELY STRONG LOW AND DEEP-LAYER
SHEAR...ENVIRONMENT WILL BE SUPPORTIVE OF ORGANIZED STORM
MODES...INCLUDING SUPERCELLS IN LOCATIONS WHERE STRONGER
DESTABILIZATION CAN OCCUR. WHILE HAIL AND LOCALLY DAMAGING WIND
GUSTS WILL BE THE PRIMARY HAZARDS...ISOLATED TORNADOES WILL BE
POSSIBLE WITH ANY SUSTAINED...SURFACE-BASED SUPERCELLS.
..MEAD/BROYLES.. 10/23/2010
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