[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 071250
SWODY1
SPC AC 071248

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0748 AM CDT SUN MAY 07 2006

VALID 071300Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CENTRAL GULF
COAST AND SOUTHEAST...

...THERE IS A SLGT RISK OF SVR TSTMS INTO THE CENTRAL AND SRN HIGH
PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS OVER SWRN TX...

...LOWER MS RIVER VALLEY ACROSS THE SOUTHEAST...
BOUNDARY LAYER REMAINS QUITE MOIST AHEAD OF SHORTWAVE TROUGH NOW
PROGRESSING EWD ACROSS THE CENTRAL GULF COAST STATES THIS MORNING
WITH SURFACE DEW POINTS IN THE MID/UPPER 60S.  WITH HEATING THIS
SHOULD BE SUFFICIENT FOR MODERATE INSTABILITY EAST OF WEAK SURFACE
LOW AND ASSOCIATED COLD FRONT FORECAST TO SHIFT EWD FROM CENTRAL AL
INTO GA/SC TODAY.  CONVERGENCE AND DEEP ASCENT ARE EXPECTED TO
SUPPORT WIDESPREAD THUNDERSTORMS ACROSS THIS REGION THROUGH THE
DAY...WITH SEVERE THREAT INCREASING IN BOTH INTENSITY AND COVERAGE
WITH HEATING THIS MORNING.  FORECAST SOUNDINGS INDICATE DEEP LAYER
SHEAR WILL BE SUFFICIENT /I.E. EFFECTIVE SHEAR AROUND 40 KT/ FOR
SUPERCELLS AND SMALL LINES...WITH PRIMARY SEVERE THREATS OF DAMAGING
WINDS AND LARGE HAIL.  

...PLAINS STATES...
NARROW AXIS OF SURFACE-BASED INSTABILITY WILL DEVELOP TODAY OVER THE
PLAINS ALONG WRN PERIPHERY OF LARGE SURFACE ANTICYCLONE CENTERED
OVER THE NORTHEAST.  FROM PORTIONS OF WRN TX INTO THE CENTRAL/ERN
DAKOTAS...SLY LOW LEVEL FLOW WILL BECOME FOCUSED AHEAD OF A SURFACE
TROUGH/COLD FRONT ADVANCING EWD OUT OF THE WRN PLAINS. MODELS HAVE
BEEN CONSISTENT FOR SEVERAL RUNS IN INITIATING THUNDERSTORMS ALONG
THIS FEATURE FROM CENTRAL/ERN ND INTO FAR ERN CO/WRN KS AND THE
OK/TX PANHANDLES BY THE LATE AFTERNOON.  ACTIVITY WILL INCREASE
AHEAD OF A FAST MOVING SHORTWAVE TROUGH NOW SPREADING ACROSS THE
NRN/CENTRAL ROCKIES WITH ASSOCIATED 25-35 KT WLY H5 FLOW INCREASING
DEEP LAYER SHEAR AND SUPPORTING ORGANIZED CONVECTION.  THOUGH AIR
MASS IS NOT FORECAST TO DESTABILIZE SIGNIFICANTLY...BOUNDARY LAYER
MOISTURE IS EXPECTED TO BE SUFFICIENT FOR MODEST MLCAPE NWD INTO
PORTIONS OF WRN KS/NEB...WITH WEAKER INSTABILITY AND A DIMINISHED
SEVERE THREAT NWD INTO THE DAKOTAS.  SUPERCELLS AND MULTICELL
CLUSTERS/LINES WILL EVOLVE EWD OUT OF THE CENTRAL/SRN HIGH PLAINS
WITH THREATS OF ISOLATED LARGE HAIL/DAMAGING WINDS.  SEVERE THREAT
EXPECTED TO DIMINISH AFTER DARK...THOUGH THUNDERSTORM CLUSTERS WILL
CONTINUE EWD FOR MUCH OF THE NIGHT.  EXCEPTION MAY BE INTO PORTIONS
OF WRN OK/NWRN TX ALONG NOSE OF 40 KT SLY LLJ WHICH IS FORECAST TO
DEVELOP THIS EVENING.  INTENSE STORMS/CLUSTERS OVER THE OK/TX
PANHANDLE REGION AND SWRN KS/SERN CO MAY EVOLVE INTO A MCS WITH A
MORE PERSISTENT SEVERE THREAT LINGERING SEWD INTO THE RED RIVER
VALLEY THROUGH THE LATE EVENING.

...SWRN TX...
STRONG HEATING WILL PROVIDE A VERY WEAK CAP ALONG NWRN EDGE OF RICH
GULF MOISTURE EXPECTED TO NOSE INTO SWRN TX THIS AFTERNOON.  12Z
SOUNDING AT DRT INDICATED ABUNDANT LOW LEVEL MOISTURE ALONG WITH A
WEAK CAP.  THOUGH CAPPING SHOULD INCREASE UNDER WLY FLOW ALOFT AS
EVIDENCED BY 20C H85 TEMPS AT ELP THIS MORNING...SURFACE HEATING
THROUGH THE 80S SHOULD WEAKEN CAP SUFFICIENTLY FOR A THREAT OF
VIGOROUS UPDRAFTS LATER TODAY. SHEAR WILL REMAIN STRONG UNDER 40+
KT WLY MID LEVEL FLOW WITH FORECAST SOUNDINGS MAINTAINING EFFECTIVE
SHEAR IN EXCESS OF 50 KT.  THOUGH SEVERE THREAT IS MORE CONDITIONAL
ACROSS THIS REGION GIVEN LACK OF LARGE SCALE ASCENT UNDER RIDGING
ALOFT...FORECAST SOUNDINGS SUGGEST  SUPERCELLS WOULD BE LIKELY
SHOULD INITIATION OCCUR ALONG DRY LINE/WEAK LOW CENTER EXPECTED TO
FORM OVER SWRN TX.  LARGE HAIL WILL BE PRIMARY SEVERE THREAT...ALONG
WITH ISOLATED DAMAGING WINDS.  TORNADO POTENTIAL MAY BE MODULATED BY
WEAK LOW LEVEL SHEAR FORECAST ACROSS THE AREA.

..EVANS/JEWELL.. 05/07/2006