[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 311249
SWODY1
SPC AC 311248

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0648 AM CST FRI MAR 31 2006

VALID 311300Z - 011200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE GREAT
LAKES INTO THE MID SOUTH/NERN TX...

...OH RIVER VALLEY NWD INTO THE CENTRAL GREAT LAKES...
WELL-DEFINED UPPER SYSTEM NOW EJECTING ACROSS THE NRN/MID MS RIVER
VALLEY THIS MORNING WILL CONTINUE RAPIDLY SHIFTING NEWD ACROSS THE
GREAT LAKES TODAY.  SURFACE COLD FRONT ASSOCIATED WITH THIS SYSTEM
TRAILS SSWWD FROM LOW CENTER OVER MN INTO SERN MO AND INTO SERN OK
EARLY THIS MORNING.  SURFACE DEW POINTS HAVE INCREASED 10-15F ACROSS
MUCH OF IND AHEAD OF THIS SYSTEM.  EXPECT THIS TREND WILL CONTINUE
TODAY AS COLD FRONT MOVES QUICKLY EWD INTO THE CENTRAL GREAT
LAKES/OH RIVER VALLEY...WITH 50+F SURFACE DEW POINTS INTO  LOWER MI
THIS AFTERNOON.

CONVECTION WEAKENED OVERNIGHT AHEAD OF SURFACE COLD FRONT FROM THE
OH RIVER VALLEY NNEWD INTO MI AS ACTIVITY PROGRESSED EAST OF
MARGINAL INSTABILITY REMAINING NEAR THE MID MS/LOWER OH RIVER
VALLEYS.  HOWEVER...RECENT INCREASING TRENDS OVER SWRN IL INDICATE
SUFFICIENT INSTABILITY REMAINS IN PLACE FOR STRONG THUNDERSTORMS
THIS MORNING FROM THE MID SOUTH EWD INTO WRN/CENTRAL KY AND FAR SRN
IND.  SHEAR IS QUITE STRONG ACROSS THE ENTIRE REGION...AND WILL
REMAIN SO THROUGH THE DAY UNDER BROAD ZONE OF 50+ KT WLY H5 WINDS. 
ALONG WITH ISOLATED LARGE HAIL...DAMAGING WINDS AND POSSIBLY A
TORNADO MAY ACCOMPANY THIS ACTIVITY AS IT MOVES EWD EARLY TODAY.

MORE VIGOROUS SEVERE THUNDERSTORM DEVELOPMENT WILL LIKELY OCCUR
ALONG SURFACE TROUGH/FRONT FROM SRN LOWER MI ACROSS IND...WHERE
OVERNIGHT MODELS ARE IN AGREEMENT IN REDEVELOPING CONVECTION AROUND
21Z.  FORECAST SOUNDINGS INDICATE ENVIRONMENT WILL BE QUITE
CONDUCIVE FOR ORGANIZED LINES/SUPERCELLS WITH LOW LEVEL SHEAR
REMAINING QUITE STRONG DESPITE A SWLY DIRECTION TO THE SURFACE WINDS
THIS AFTERNOON.  EXPECT AXIS OF 1000-1500 J/KG MLCAPE WILL DEVELOP
INTO CENTRAL IND...WITH 500-1000 J/KG MLCAPE INTO SERN LOWER MI BY
21Z.  THUS THE TORNADO THREAT WILL INCREASE DURING THE MID TO LATE
AFTERNOON...ALONG WITH LARGE HAIL AND DAMAGING WINDS.  SEVERE THREAT
IS EXPECTED TO SPREAD EWD ACROSS OH AND TOWARDS THE UPPER OH RIVER
VALLEY THROUGH THE MID/LATE EVENING.

...MID SOUTH INTO THE LOWER MS RIVER VALLEY AND NERN TX...
SURFACE FRONT WILL STALL OR MOVE ONLY SLOWLY SSEWD ACROSS THIS
REGION TODAY...WHILE BOUNDARY LAYER MOISTURE INCREASES AHEAD OF IT. 
THOUGH LARGE SCALE ASCENT WILL SHIFT NEWD AWAY FROM THIS
REGION...LARGE RESERVOIR OF MODERATE INSTABILITY IS EXPECTED THIS
AFTERNOON FROM CENTRAL TX INTO NRN LA/SRN AR.  IN ADDITION...REGION
WILL REMAIN UNDER 40-50 KT WLY FLOW AT MID LEVELS PROVIDING 40+ KT
OF EFFECTIVE SHEAR TODAY.  EXPECT AREAS OF DEEP MOIST CONVECTION
WILL INCREASE THROUGH THE MID/LATE AFTERNOON WITHIN SUFFICIENT SHEAR
FOR SUPERCELLS AND ORGANIZED LINES.  LATER TONIGHT...INCREASING
SSWLY H85 FLOW SHOULD FOCUS ELEVATED STORMS WITH THE THREAT OF LARGE
HAIL INTO PORTIONS OF ERN OK/AR INTO WRN TN/NWRN MS.

...NRN CA...
PRONOUNCED MID/UPPER LEVEL LOW NOW JUST OFF THE NRN CA/SWRN ORE
COAST WILL SHIFT SLOWLY ESEWD ACROSS NRN CA LATER TODAY AND TONIGHT.
 AHEAD OF THIS FEATURE...WINDS ALOFT WILL BECOME QUITE STRONG WITH
50+ KT SSWLY H5 WINDS EXPECTED ACROSS THE NRN HALF OF CA.  AFTERNOON
HEATING WILL LIKELY BE SUFFICIENT FOR STEEP LOW/MID LEVEL LAPSE
RATES AND MARGINAL INSTABILITY BY 22Z. THUS...ENVIRONMENT WILL
BECOME FAVORABLE FOR MARGINALLY SEVERE HAIL WITH THE STRONGER CORES.

..EVANS/RACY.. 03/31/2006