[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 291612
SWODY1
SPC AC 291610

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1110 AM CDT MON MAY 29 2006

VALID 291630Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE MIDWEST
STATES AND CENTRAL PLAINS...

LARGE UPPER RIDGE REMAINS OVER THE EASTERN UNITED STATES
TODAY...WHILE SERIES OF SHORTWAVE TROUGHS ROTATE AROUND LONGWAVE
TROUGH OVER THE WESTERN STATES.  MAIN SURFACE BAROCLINIC ZONE HAS
SHIFTED EASTWARD INTO PARTS OF MN/IA/NEB/KS TODAY...WHERE POTENTIAL
EXISTS FOR SCATTERED THUNDERSTORMS.  OTHER ACTIVITY WILL ONCE AGAIN
OCCUR ALONG DRYLINE OVER PARTS OF OK/TX.  FINALLY...STRONG
INSTABILITY AND AMPLE MOISTURE MAY LEAD TO ISOLATED THUNDERSTORMS
OVER PARTS OF THE MS/OH/TN VALLEYS AND SOUTHEAST STATES.

...UPPER MIDWEST INTO CENTRAL PLAINS...
MORNING SURFACE ANALYSIS SHOWS FRONT EXTENDING FROM WESTERN MN INTO
CENTRAL KS AND THE TX PANHANDLE.  AIR MASS ALONG AND EAST OF FRONT
REMAINS MOIST AND MODERATELY UNSTABLE WITH DEWPOINTS IN THE UPPER
60S AND AFTERNOON MLCAPE VALUES EXPECTED TO EXCEED 3000 J/KG. 
MORNING SOUNDINGS AND MODEL GUIDANCE SUGGEST THAT CAP HAS WEAKENED
SINCE YESTERDAY...WHICH SHOULD ALLOW SCATTERED THUNDERSTORM
DEVELOPMENT ALONG THE FRONT THIS AFTERNOON AND EVENING. 
HOWEVER...MAIN UPPER FORCING AND VERTICAL SHEAR IS WELL WEST OF
BOUNDARY EXCEPT OVER MN.  SHEAR IS SUFFICIENT FOR SUPERCELLS AND
BOWS OVER PARTS OF CENTRAL/NORTHERN MN...WHERE HIGHER SEVERE
PROBABILITIES HAVE BEEN MAINTAINED.  HOWEVER... ACTIVITY WILL BE
RATHER DISORGANIZED FARTHER SOUTH UNLESS UPSCALE ORGANIZATION CAN
OCCUR THIS EVENING AS CONVECTIVE CLUSTERS GROW.  DEGREE OF
INSTABILITY WILL POSE A THREAT OF LARGE HAIL AND DAMAGING WINDS IN
STRONGER CELLS.

...OK/TX...
SURFACE DRYLINE IS EXPECTED TO BECOME ESTABLISHED THIS AFTERNOON
FROM THE EASTERN TX PANHANDLE INTO THE TRANSPECOS AREA.  WEAK FLOW
ALOFT...COMBINED WITH RELATIVELY STRONG INSTABILITY...WILL ONCE
AGAIN RESULT IN ISOLATED STRONG/SEVERE STORMS. HIGH-BASED CELLS
WILL BE CAPABLE OF DAMAGING WINDS AND HAIL FOR A FEW HOURS THIS
EVENING BEFORE WEAKENING.

...NORTHEAST STATES...
WATER VAPOR IMAGERY SHOWS WELL-DEFINED SHORTWAVE TROUGH TRACKING
SOUTHEASTWARD ACROSS NY.  WEAK FORCING FOR UPWARD VERTICAL MOTION
ALONG THE SOUTHERN PERIPHERY OF THIS FEATURE WILL LIKELY AID IN THE
DEVELOPMENT OF ISOLATED AFTERNOON THUNDERSTORMS FROM EASTERN NY/PA
SOUTHWARD INTO THE DELMARVA REGION.  AIR MASS IN THIS REGION IS
MODERATELY UNSTABLE WITH MLCAPE VALUES UP TO 1500 J/KG...ALONG WITH
SUFFICIENT NORTHERLY FLOW ALOFT FOR SOME CONVECTIVE ORGANIZATION. 
AREAL COVERAGE OF STRONGER CELLS REMAINS IN QUESTION DUE TO WEAK
FORCING...SO WILL MAINTAIN ONLY LOW SEVERE PROBABILITIES AT THIS
TIME.

...MID MS AND TN VALLEYS INTO FL...
WATER VAPOR IMAGERY SHOWS AXIS OF MID LEVEL MOISTURE EXTENDING FROM
PARTS OF IL/IND ACROSS TN/AL INTO SOUTH FL.  THIS IS THE SAME AXIS
IN WHICH SCATTERED INTENSE STORMS DEVELOPED YESTERDAY. STRONG
DAYTIME HEATING IN THIS ZONE...COUPLED WITH DEWPOINTS NEAR 70F MAY
AGAIN PROVE SUFFICIENT FOR WEAKLY ORGANIZED MULTICELL STORMS CAPABLE
OF WET MICROBURSTS AND HAIL.  SEA-BREEZE INTERACTIONS MAY ALSO
ENHANCE STORMS OVER THE WESTERN COAST OF THE FL PENINSULA.

..HART/LEVIT.. 05/29/2006