DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 271624
SWODY1
SPC AC 271621

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1121 AM CDT SUN MAY 27 2007

VALID 271630Z - 281200Z

..THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF OH...PA...AND
NY...

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CENTRAL
HIGH PLAINS...

..THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF MT...

MORNING VISIBLE SATELLITE IMAGERY SHOWS STRONG SHORTWAVE TROUGH
MOVING EASTWARD ACROSS LAKE SUPERIOR...AND BAND OF STRONG MID/UPPER
LEVEL WINDS IN BASE OF TROUGH OVER THE UPPER MIDWEST. THIS FEATURE
IS FORECAST TO MOVE EASTWARD ACROSS THE GREAT LAKES REGION TODAY AND
INTO THE NORTHEAST TONIGHT. SURFACE COLD FRONT EXTENDS FROM LOWER
MI INTO IL WITH INCREASINGLY MOIST AND MODERATELY UNSTABLE AIR MASS
TO THE EAST OF BOUNDARY. BAND OF CLOUDS IS INHIBITING
HEATING/DESTABILIZATION AHEAD OF FRONT FROM NORTHERN IND/OH INTO
PARTS OF NY. HOWEVER...SOUTH AND EAST OF CLOUDS WILL SEE STRONG
SUNSHINE AND SCATTERED AFTERNOON THUNDERSTORMS.

..NY/VT...
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP EARLY THIS AFTERNOON
IN REGION OF STRONGER DAYTIME HEATING AND MODERATE INSTABILITY OVER
CENTRAL NY. THESE STORMS WILL MOVE EASTWARD THROUGH THE AFTERNOON
INTO EASTERN NY AND WESTERN VT. BACK DOOR COLD FRONT EXTENDS
ROUGHLY FROM UCA - NYC AND WILL BE SLOW TO RETREAT NORTHEASTWARD.
THIS WILL LIKELY RESULT IN A RATHER NARROW ZONE OF STRONGER
INSTABILITY AND RISK OF MORE INTENSE UPDRAFTS OVER CENTRAL/EASTERN
NY. VERTICAL SHEAR PROFILES ACROSS THIS AREA WILL PROMOTE ORGANIZED
MULTICELL STORMS CAPABLE OF DAMAGING WINDS AND PERHAPS HAIL.

..PA/OH/MD/VA...
OTHER MORE ISOLATED STORMS ARE POSSIBLE FROM NORTHERN/CENTRAL PA
INTO EASTERN OH WHERE FULL SUNSHINE AND STRONGER INSTABILITY ARE
EXPECTED TODAY. OTHER STORMS MAY DEVELOP OVER THE HIGHER TERRAIN
OVER MD/VA AND SPREAD EASTWARD THIS AFTERNOON. THIS REGION IS SOUTH
OF STRONGER LARGE SCALE FORCING AND WILL HAVE WEAKER WINDS ALOFT.
NEVERTHELESS...ISOLATED STORMS IN THIS REGION COULD POSE A THREAT OF
LOCALLY DAMAGING WINDS AND HAIL.

..NEB/CO/KS...
WEAK SHORTWAVE TROUGH IS EVIDENT IN SATELLITE IMAGERY MOVING ACROSS
NORTHERN CO. THIS FEATURE WILL SPREAD INTO THE HIGH PLAINS THIS
AFTERNOON. WEAK SURFACE BOUNDARY IS PRESENT FROM THE NEB PANHANDLE
SOUTHEASTWARD INTO NORTHERN KS. BACKED LOW LEVEL WINDS AND MORE
SUBSTANTIAL MOISTURE ALONG AND EAST OF BOUNDARY MAY AID IN THE
DEVELOPMENT OF ISOLATED THUNDERSTORMS THIS AFTERNOON. VEERING WINDS
WITH HEIGHT AND STEEP MID LEVEL LAPSE RATES WOULD INDICATE A RISK OF
SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS...ALTHOUGH
CONVECTION WILL LIKELY REMAIN RATHER ISOLATED.

..MT...
WELL-DEFINED UPPER SYSTEM IS MOVING ACROSS WA/ORE THIS
MORNING...WITH STRONGER UPPER FORCING SPREADING INTO ID AND WESTERN
MT. AIR MASS IS QUITE DRY IN THIS REGION AND WILL ONLY BECOME
MARGINALLY UNSTABLE THIS AFTERNOON ACROSS WESTERN AND SOUTH CENTRAL
MT. HOWEVER...STRONG WINDS JUST ABOVE THE SURFACE AND STEEP LOW/MID
LEVEL LAPSE RATES MAY BE SUFFICIENT FOR A FEW SEVERE STORMS CAPABLE
OF DAMAGING WINDS AND LARGE HAIL. TIMING OF UPPER FEATURE SUGGESTS
PRIMARY THREAT MAY BE THIS EVENING.

.HART.. 05/27/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.