SWODY1
SPC AC 041626
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1126 AM CDT FRI MAY 04 2007
VALID 041630Z - 051200Z
..THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EARLY TONIGHT
OVER PARTS OF EASTERN CO...WESTERN AND CENTRAL KS...NORTHWEST OK AND
SOUTHWEST NEB...
..THERE IS A SLGT RISK OF SVR TSTMS FROM SOUTHWEST TX INTO SD...
..THERE IS A SLGT RISK OF SVR TSTMS PARTS OF LOWER MS VALLEY...
..CENTRAL/SRN HIGH PLAINS...
MAJOR COLD TROUGH CONTINUES TO DIG INTO INTERIOR OF THE WESTERN U.S.
LEADING TO CLOSED UPPER LOW VICINITY 4-CORNERS BY 12Z SAT. BAND OF
VERY STRONG WINDS ON BACK SIDE OF TROUGH INITIALLY WILL ROTATE
ACROSS SRN ROCKIES THIS AFTERNOON/EVENING. THIS LEADS TO INCREASING
UPPER DIFFLUENCE SPREADING ACROSS HIGH PLAINS BEGINNING LATE THIS
AFTERNOON.
COLD FRONT HAS PUSHED EWD ACROSS DAKOTAS...WRN NEB EXTENDING SWWD
INTO SERN CO. SURFACE LOW SWRN CORNER OF KS WITH DRY LINE EXTENDING
THRU ERN TX PANHANDLE TO SWRN TX. SURFACE PRESSURE/UPPER HEIGHT
FALLS IN ADVANCE OF WRN TROUGH WILL RESULT IN DEEPENING OF SURFACE
LOW ALONG SERN CO/KS BORDER DURING AFTERNOON...THEN MOVING SLOWLY
NWD TONIGHT.
INCREASING SLY FLOW E OF DRY LINE IS RAPIDLY INCREASING LOW LEVEL
MOISTURE NWD INTO CENTRAL PLAINS LEADING TO A VERY UNSTABLE AIR MASS
BY MID AFTERNOON FROM WRN TX TO WRN KS. MLCAPES AOA 4000 J/KG WILL
BE IN PLACE BY LATER THIS AFTERNOON E OF DRY LINE NWD INTO WRN KS.
50-60KT OF DEEP LAYER SHEAR COUPLED WITH ELY LOW LEVEL FLOW N OF
SURFACE LOW SUPPORTS RAPID DEVELOPMENT OF SUPERCELLS IN UPSLOPE AREA
OF ERN CO BY MID AFTERNOON. MORE LIMITED INSTABILITY THIS AREA THAN
E OF DRY LINE...HOWEVER GIVEN SHEAR AND STEEP LAPSE RATES...LARGE
HAIL AND A FEW TORNADOES EXPECTED AS STORMS MOVE/DEVELOP NEWD TOWARD
CO/KS BORDER THIS EVENING.
THE INTERSECTION OF DRY LINE/COLD FRONT OVER WRN KS FOCUSES ANOTHER
AREA OF ENHANCED CONVERGENCE AND CONVECTIVE INITIATION BY MID/LATE
AFTERNOON. WITH THE HIGH INSTABILITY AND ENHANCED VEERING SHEAR
PROFILES VICINITY FRONTAL ZONE/DRY LINE...SUPERCELLS WOULD RAPIDLY
BECOME SEVERE WITH VERY LARGE HAIL AND TORNADO POTENTIAL. STRONG
TORNADOES CERTAINLY A POSSIBILITY IN WRN KS GIVEN THE HIGH
CAPE/SHEAR ENVIRONMENT EXPECTED TO BE IN PLACE BY LATE AFTERNOON.
FURTHER SOUTH ALONG DRY LINE FROM SRN KS ALONG TX/OK BORDER INTO
SWRN TX...THE THREAT OF STORM INITIATION WILL BE BOTH MORE
CONDITIONAL AND LATER. BY EVENING WITH CAP WEAKENING AND INCREASING
UPPER DIFFLUENCE AHEAD OF APPROACHING WIND MAX...AT LEAST ISOLATED
INITIATION IS LIKELY VICINITY/JUST E OF DRY LINE. WITH MLCAPES AOA
4000 J/KG...STORMS THAT AREA ABLE TO FORM WILL QUICKLY BECOME
SEVERE/SUPERCELLS WITH LARGE HAIL AND TORNADO THREAT.
AFTER 00Z SEVERE THUNDERSTORMS WILL LIKELY CONTINUE AND BECOME MORE
WIDESPREAD AS THEY SPREAD NEWD ACROSS CENTRAL PLAINS AS FAR N AS SRN
SD. THIS SUPPORTED BY CONTINUED DEEPENING OF SURFACE LOW NEWD THRU
CENTRAL HIGH PLAINS AS S/WV IMPULSE ROTATES NEWD FROM SRN ROCKIES.
..LOWER MS VALLEY...
SCATTERED STRONG/ISOLATED SEVERE THUNDERSTORMS ARE ONGOING OVER SRN
LA/MS. THESE STORMS ARE OCCURRING IN A VERY MOIST/MODERATELY
UNSTABLE AND WEAKLY CAPPED ENVIRONMENT. DURING AFTERNOON SHEAR
WEAKENS AS UPPER TROUGH LWR MS VALLEY ROTATES NEWD AWAY FROM AREA.
THIS SHOULD LIMIT SEVERE THREAT TO BRIEF WET DOWNBURSTS AND ISOLATED
LARGE HAIL...DIMINISHING BY EVENING.
.HALES/GUYER.. 05/04/2007
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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