[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 041628
SWODY1
SPC AC 041626

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1126 AM CDT MON SEP 04 2006

VALID 041630Z - 051200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MIDDLE AND
UPPER MS VALLEY...

...MID/UPPER MS VALLEY...
COLD UPPER LOW OVER IA IS EXPECTED TO CONTINUE MOVING ESEWD INTO NRN
IL THIS AFTERNOON AND EVENING. ALTHOUGH THE MID LEVELS OF THE
SYSTEM HAVE WARMED SLIGHTLY COMPARED TO YESTERDAY...500 MB
TEMPERATURES OF -16 TO -18C WILL CONTRIBUTE TO MODERATELY STEEP
LAPSE RATES ABOVE MODEST LOW LEVEL MOISTURE FIELD.  VISIBLE IMAGERY
SHOWS WIDESPREAD CLOUDS IN ADVANCE OF THE UPPER LOW OVER ERN IA/SRN
WI AND NRN/CENTRAL IL...HOWEVER SEVERAL CLEAR SLOTS ARE EVIDENT OVER
IL WHERE ENHANCED DIURNAL HEATING IS EXPECTED TO OCCUR.  THIS WILL
RESULT IN MESOSCALE ZONES OF GREATER INSTABILITY WHERE MLCAPE WILL
REACH 500-1000 J/KG...WHICH SHOULD SUPPORT WIDELY SCATTERED
THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING.  MARGINALLY
SEVERE HAIL AND ISOLATED STRONG WIND GUSTS WILL BE POSSIBLE WITH
STRONGER CELLS.

...SRN APPALACHIANS...
MOIST AIR MASS IS IN PLACE ACROSS THE SERN STATES WHERE SURFACE DEW
POINTS ARE IN THE UPPER 60S/LOWER 70S. STRONG DIABATIC HEATING
ACROSS NRN AL/NRN GA MAY ENHANCE THERMAL GRADIENT/DIFFERENTIAL
HEATING BOUNDARY ACROSS THIS REGION AS CLOUDS PERSIST OVER ERN TN/
FAR NRN GA/SWRN NC AREA.  HEATING WITHIN WEAKLY CAPPED ENVIRONMENT
SHOULD ALLOW PARCELS TO REACH THEIR LFC WITH RESULTANT DEVELOPMENT
OF SCATTERED THUNDERSTORMS.  20-30 KT WSWLY MID LEVEL WINDS WILL BE
SUFFICIENT FOR MULTICELLULAR CLUSTERS TO DEVELOP WITH POTENTIAL FOR
ISOLATED STRONG/MARGINALLY SEVERE STORMS THIS AFTERNOON AND EVENING.


...CO/NRN NM FRONT RANGE...
WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH MOVING SSEWD TOWARD
THE CENTRAL HIGH PLAINS WITH 25-30 KT NWLY MID LEVEL WINDS ACROSS
THIS REGION.  WIND PROFILES ARE EXPECTED TO EXHIBIT CONSIDERABLE
VEERING WITH HEIGHT LATER THIS AFTERNOON WITH DEEP LAYER SHEAR OF
35-40 KT.  LIMITING FACTOR FOR DEEP CONVECTION THIS AFTERNOON AND
EVENING WILL BE THE MARGINAL LOW LEVEL MOISTURE WHICH WILL LIMIT
MLCAPE VALUES TO AROUND 500 J/KG.  ISOLATED STRONG THUNDERSTORMS MAY
DEVELOP NEAR THE FRONT RANGE LATER THIS AFTERNOON AND EVENING WITH
THREAT FOR HAIL/GUSTY WINDS BUT OVERALL COVERAGE APPEARS
INSUFFICIENT TO SUPPORT A CATEGORICAL RISK AREA.

..WEISS/GUYER.. 09/04/2006