[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 021956
SWODY1
SPC AC 021955

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT SUN APR 02 2006

VALID 022000Z - 031200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
ERN MO / FAR SERN IA / PORTIONS OF CNTRL AND SRN IL / WRN KY...

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM
THE SRN GREAT LAKES AND OH VALLEY SWD INTO ERN TX AND THE TN
VALLEY...

...IA/MO EWD INTO THE SRN GREAT LAKES AND OH VALLEY...

LATEST MESOANALYSIS INDICATES SURFACE LOW OVER SWRN IA /SW OF DSM/
WHICH WILL CONTINUE TO DEVELOP NEWD...EVENTUALLY REACHING SRN LOWER
MI MONDAY MORNING.  ASSOCIATED WARM FRONT /NOW ANALYZED FROM THE LOW
EWD ACROSS SRN IL/SWRN IND INTO CNTRL KY WILL CONCURRENTLY LIFT NEWD
WHILE TRAILING COLD FRONT PUSHES EWD THROUGH MO INTO THE OH VALLEY.

DIABATIC HEATING COUPLED WITH INFLUX OF LOW-LEVEL MOISTURE FROM THE
SRN LOW PLAINS HAS CONTRIBUTED TO AIR MASS DESTABILIZATION S OF WARM
FRONT AND E OF PACIFIC COLD FRONT WITH 18Z SGF SOUNDING INDICATING
MLCAPES OF AROUND 2000 J/KG.  SATELLITE AND RADAR DATA INDICATE
SURFACE-BASED STORMS DEVELOPING FROM CDJ SWD TO SGF OWING INCREASED
LARGE-SCALE FORCING ASSOCIATED WITH SHORTWAVE TROUGH OVER ERN NEB/KS
ERODING REMAINING PORTION OF CAP ALONG WRN EDGE OF INSTABILITY AXIS.


REGIONAL VADS/VWPS ACROSS WARM SECTOR INDICATE 40-50 KTS OF
DEEP-LAYER SHEAR...SUPPORTIVE OF SUPERCELLS CAPABLE OF
LARGE...DESTRUCTIVE HAIL...DAMAGING WINDS AND A FEW TORNADOES. IT
APPEARS THE BEST POTENTIAL FOR A STRONG TORNADO OR TWO WILL EXIST
WITHIN ZONE OF BACKED SURFACE WINDS AHEAD OF SURFACE LOW AND NEAR
WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE MAXIMIZED.

EXPECT THAT A GRADUAL UPSCALE GROWTH INTO LINE SEGMENTS OR
QUASI-LINEAR MCS/S TO DEVELOP TONIGHT WITH THREAT OF PRIMARILY
DAMAGING WINDS AND LARGE HAIL SPREAD EWD INTO THE OH VALLEY.


...AR/E TX EWD INTO THE TN AND LOWER MS VALLEYS...

STRONG DAYTIME HEATING COUPLED WITH DEWPOINTS IN THE 70S AND STEEP
LAPSE RATES HAVE CONTRIBUTED TO A MODERATELY UNSTABLE AIR MASS THIS
AFTERNOON WITH MLCAPES OF 2000-2500 J/KG AHEAD OF PACIFIC COLD FRONT
OR ADVECTIVE DRY LINE. ALOFT...WATER VAPOR IMAGERY INDICATES A
CYCLONICALLY CURVED BELT OF WEAK ASCENT AHEAD OF CNTRL PLAINS
SHORTWAVE TROUGH FROM CNTRL AR SWWD THROUGH THE ARKLATEX INTO SERN
TX...WHICH SHOULD CONTINUE EWD TODAY.  GIVEN THAT STRONGEST
LARGE-SCALE FORCING  AND LOW-LEVEL CONVERGENCE WILL REMAIN N AND NE
OF REGION...THERE IS SOME UNCERTAINTY REGARDING EVOLUTION OF
CONVECTIVE CLUSTER OVER NERN TX/NWRN LA...AS WELL AS POTENTIAL FOR
ADDITIONAL DEVELOPMENT ALONG SURFACE FRONT.

VISIBLE SATELLITE IMAGERY WOULD SUGGEST THAT PRE-FRONTAL
BOUNDARY-LAYER IS BECOMING CONDITIONED SUCH THAT ADDITIONAL DEEP
CONVECTION MAY BECOME INCREASINGLY LIKELY THROUGH THE AFTERNOON FROM
WRN/CNTRL AR SWWD INTO ERN TX. GIVEN THE MODERATE INSTABILITY AND
PRESENCE OF 50-60 KT WSWLY MID-LEVEL FLOW...POTENTIAL WILL EXIST FOR
THE DEVELOPMENT AND MAINTENENCE OF SEVERE STORMS...INCLUDING
SUPERCELLS CAPABLE OF LARGE HAIL...DAMAGING WINDS AND POSSIBLY A
COUPLE OF TORNADOES.

FARTHER TO THE E...SMALL MCS CONTINUES THIS AFTERNOON OVER NRN
MS/WRN TN WITH RECENT DEVELOPMENT NEWD INTO MIDDLE TN...TO THE S OF
WARM FRONT LIFTING NWD THROUGH REGION. HERE TOO...AIR MASS HAS
BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1000-1500 J/KG. 
ADDITIONALLY...CURRENT BNA VWP INDICATES A FAVORABLE VERTICAL SHEAR
PROFILES FOR ORGANIZED STORMS INCLUDING SUPERCELLS.  THUS...EXPECT
THAT ONGOING MCS SHOULD CONTINUE TO INTENSIFY THROUGH THE AFTERNOON
WITH ADDITIONAL SEVERE STORMS POSSIBLE DOWNSTREAM FROM THIS COMPLEX.
WHILE LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREATS...A
BRIEF TORNADO OR TWO WILL BE POSSIBLE.

..MEAD.. 04/02/2006