[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 131251
SWODY1
SPC AC 131250

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0750 AM CDT THU APR 13 2006

VALID 131300Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID AND
UPPER MS VALLEY...

BROAD UPPER RIDGE REMAINS IN PLACE ACROSS THE SOUTHERN PLAINS
TODAY...WITH BAND OF MODERATELY STRONG MID/UPPER LEVEL FLOW FROM THE
NORTHERN ROCKIES INTO THE GREAT LAKES REGION.  SEVERAL WEAK
SHORTWAVE TROUGHS ARE EMBEDDED IN THIS FLOW PATTERN.  ONE FEATURE 
EVIDENT IN WATER VAPOR IMAGERY OVER MT IS FORECAST TO TRACK EASTWARD
INTO MN BY THIS EVENING.  SURFACE LOW IS FORECAST TO DEVELOP OVER
SOUTHERN MN BY 14/00Z...WITH WARM FRONT EXTENDING EASTWARD INTO
NORTHERN IL/IND.  EVOLUTION OF BOUNDARY LAYER SOUTH OF LOW/FRONT
WILL BE QUITE COMPLEX...BUT APPEARS FAVORABLE FOR RAPID
MOISTENING/DESTABILIZATION THROUGH THE AFTERNOON.  MODEL FORECAST
DEWPOINT VALUES MAY BE SLIGHTLY OVERDONE...BUT MID 60S VALUES APPEAR
REASONABLE.  IT APPEARS THAT SUBSIDENCE IN THE CAPPING
LAYER...COMBINED WITH INFLUX OF LOW LEVEL MOISTURE FROM THE
SOUTHWEST...WILL RESULT IN LOCAL POOLING OF SURFACE DEWPOINTS IN THE
MID 60S ACROSS PARTS OF MO/IA.

...MN/WI/IL...
PRESENT INDICATIONS ARE THAT ISOLATED STORMS WILL DEVELOP BY LATE
AFTERNOON/EARLY EVENING OVER SOUTHEAST MN/SOUTHWEST WI ALONG WARM
FRONT. THESE STORMS WILL BE IN A FAVORABLE VERTICAL SHEAR
ENVIRONMENT FOR SUPERCELL STRUCTURES CAPABLE OF LARGE
HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES.  THIS ACTIVITY WILL
SPREAD EASTWARD INTO PARTS OF NORTHERN IL/IND OVERNIGHT.

...IA/MO/IL/IND/KY/OH...
OTHER STORMS ARE POSSIBLE OVER EASTERN IA ALONG TRAILING
DRYLINE...WHERE WEAK CAP AND STRONG HEATING WILL OCCUR.  THIS
ACTIVITY WILL LIKELY SPREAD SOUTHEASTWARD ACROSS NORTHEAST
MO/CENTRAL IL DURING THE EVENING WITH A THREAT OF LARGE HAIL AND
DAMAGING WINDS.  ACTIVITY WILL LIKELY DEVELOP UPSCALE INTO AN
MCS...SPREADING ACROSS PARTS OF IND AND INTO OH/KY BY 14/12Z.

...NY INTO MID ATLANTIC REGION...
MORNING VISIBLE SATELLITE IMAGERY SUGGEST THAT STRONG DAYTIME
HEATING WILL OCCUR TODAY FROM CENTRAL/EASTERN NY INTO VA AND
NORTHERN NC.  THIS REGION IS BENEATH UPPER COLD TROUGH...WITH 500MB 
TEMPERATURES RANGING FROM -17C OVER NC TO -25 OVER NY. PRESENT
INDICATIONS ARE THAT SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS
THIS REGION DURING THE AFTERNOON.  STEEP LAPSE RATES AND SUFFICIENT
INSTABILITY SUGGEST A THREAT OF HAIL IN STRONGER CELLS.  ACTIVITY
SHOULD DIMINISH QUICKLY AFTER SUNSET.

..HART/TAYLOR.. 04/13/2006