SWODY1
SPC AC 231628
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1128 AM CDT MON JUL 23 2007
VALID 231630Z - 241200Z
..THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CENTRAL
PLAINS...
..CENTRAL PLAINS...
EXPANSIVE UPPER RIDGE REMAINS OVER THE ROCKIES AND PLAINS STATES
TODAY...WITH SEVERAL SMALL SCALE UPPER FEATURES ROTATING ATOP RIDGE
AND TRACKING SOUTHWARD INTO PARTS OF NEB/IA/KS/MO/OK. AMPLE
INSTABILITY AND SUFFICIENT VERTICAL SHEAR SUGGEST POTENTIAL FOR
SCATTERED SEVERE STORMS OVER THIS REGION TODAY. HOWEVER...
CONSIDERABLE UNCERTAINTY EXISTS REGARDING THE EVOLUTION OF
CONVECTION.
BAND OF ONGOING STORMS EXTENDS FROM SOUTHWEST IA...ACROSS EASTERN
KS...INTO CENTRAL OK. THESE STORMS ARE DRIFTING SLOWLY
SOUTHWESTWARD INTO AN INCREASINGLY WARM/UNSTABLE AIR MASS /MLCAPE
VALUES LIKELY TO EXCEED 3000 J/KG THIS AFTERNOON/. WEAK OUTFLOWS
ASSOCIATED WITH THIS MORNINGS CONVECTION WILL LIKELY HELP INITIATE
NEW STORMS FROM EASTERN NEB INTO WESTERN OK THIS AFTERNOON.
FORECAST SOUNDINGS THROUGHOUT THIS AREA SHOW STEEP MID LEVEL LAPSE
RATES AND EFFECTIVE VERTICAL SHEAR OF 25-35 KNOTS. COMBINED WITH A
VERY UNSTABLE AIR MASS...THESE PARAMETERS SUGGEST THE POTENTIAL FOR
SCATTERED MULTICELL AND ISOLATED SUPERCELL STORMS CAPABLE OF LARGE
HAIL AND DAMAGING WINDS. STORMS MAY SPREAD WESTWARD THIS EVENING
INTO MORE DEEPLY MIXED AIR MASS OVER WESTERN KS AND THE EASTERN TX
PANHANDLE...WITH A CONTINUED THREAT OF DAMAGING WINDS.
..MT...
WATER VAPOR IMAGERY SHOWS COMPACT SHORTWAVE TROUGH ALONG THE ID/MT
BORDER. THIS FEATURE WILL RESULT IN LARGE SCALE FORCING FOR ASCENT
OVER WESTERN AND CENTRAL MT THIS AFTERNOON AND EVENING. FULL
SUNSHINE OVER THIS REGION WILL YIELD STEEP LOW LEVEL LAPSE RATES AND
INVERTED-V THERMODYNAMIC PROFILES. SCATTERED THUNDERSTORMS ARE
EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF WESTERN MT THIS
AFTERNOON AND SPREAD EASTWARD THIS EVENING. DAMAGING WINDS AND HAIL
ARE POSSIBLE IN THE STRONGER CELLS.
..ND...
ANOTHER SHORTWAVE TROUGH IS INDICATED OVER EASTERN MT NEAR GGW.
THIS FEATURE WILL MOVE SLOWLY EASTWARD AND MAINTAIN WEAK ASCENT
ACROSS WESTERN ND TODAY. TEMPERATURES ARE FORECAST TO WARM INTO THE
LOWER 100S IN THIS AREA...WITH DEWPOINTS REMAINING NEAR 70F. THIS
EXTREMELY UNSTABLE AIR MASS /MLCAPE VALUES OVER 4000 J/KG/ WILL BE
CONDUCIVE TO DAMAGING WINDS AND HAIL IF ANY THUNDERSTORMS CAN FORM.
12Z NAM...09Z SREF...AND 00Z 4KM WRF DO INITIATE THUNDERSTORMS OVER
THIS AREA THIS EVENING...SO HAVE ADDED LOW PROBABILITIES OF SEVERE
STORMS.
..FL...
MORNING SOUNDINGS ARE SLIGHTLY WARMER ALOFT THIS MORNING OVER THE FL
PENINSULA...ALONG WITH SCATTERED CLOUDS THAT MAY HINDER DAYTIME
HEATING AND DESTABILIZATION. THESE CHANGES OVER YESTERDAY SUGGEST
THE THREAT HAS DIMINISHED SOMEWHAT COMPARED TO THE LAST FEW DAYS.
NEVERTHELESS...MLCAPE VALUES OVER 1500 J/KG AND SOUTHWESTERLY FLOW
ALOFT MAY RESULT IN LOCALLY DAMAGING WINDS AS STORMS FORM ALONG EAST
COAST SEA BREEZE.
.HART/TAYLOR.. 07/23/2007
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.
No comments:
Post a Comment