Saturday, April 28, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 281250
SWODY1
SPC AC 281248

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0748 AM CDT SAT APR 28 2007

VALID 281300Z - 291200Z

..THERE IS A SLGT RISK OF SVR TSTMS OVER FAR SRN NM INTO SWRN TX...

..SYNOPSIS...
HIGH OVER LOW BLOCK IN PLACE OVER THE WRN HALF OF THE U.S THIS
MORNING WILL SHIFT EWD OVER MUCH OF THE CENTRAL CONUS...WHILE BROAD
TROUGHS SHIFT EWD OFF THE EAST COAST AND INTO THE PAC NW BY THE END
OF THE PERIOD. AT THE SURFACE...PATTERN WILL REMAIN DOMINATED BY
LARGE ANTICYCLONE EXTENDING FROM THE CENTRAL ROCKIES/SRN PLAINS
ACROSS THE CENTRAL GULF COAST. THIS WILL EFFECTIVELY TRAP RICHER
BOUNDARY LAYER MOISTURE ALONG A SMALL PART OF SRN TX THROUGH THE
PERIOD.

..SRN ROCKIES INTO SWRN TX...
STEEP LAPSE RATES THROUGH THE MID LEVELS WILL REMAIN IN PLACE OVER
THIS REGION TODAY AHEAD OF SL0W MOVING UPPER LOW EXPECTED TO SHIFT
SLOWLY ENEWD TOWARDS FAR SWRN TX/SRN NM BY TONIGHT. A BROAD AREA OF
DIFFLUENT MID AND UPPER LEVEL FLOW WILL LIKEWISE OVERSPREAD MUCH OF
THIS REGION...INCREASING DEEP ASCENT AND THE POTENTIAL FOR SCATTERED
THUNDERSTORMS THROUGH THE PERIOD. MORNING SOUNDINGS...ESPECIALLY AT
TUS...INDICATE DEEP BOUNDARY LAYER IN PLACE WITH LARGE INVERTED-V
SOUNDINGS EXPECTED OVER MUCH OF THIS AREA. THUS...STRONGER GUSTS
SHOULD ACCOMPANY STORMS.

APPEARS FAR SWRN TX MAY REMAIN ON WRN FRINGE OF RICHER GULF MOISTURE
RETURN AS EVIDENCED BY MORNING DRT SOUNDING. THIS COMBINED WITH
MODEST SWLY MID/UPPER LEVEL FLOW SUGGESTS THE POTENTIAL FOR STRONGER
STORMS OVER THIS AREA SPREADING INTO FAR SRN NM LATER TODAY AND
TONIGHT. FORECAST SOUNDINGS INDICATE MLCAPE MAY APPROACH 1500 J/KG
NEAR MRF LATER THIS AFTERNOON...ALONG WITH EFFECTIVE BULK SHEAR
AROUND 40 KT WITHIN NELY UPSLOPE LOW LEVEL FLOW. THIS SHOULD
SUPPORT A THREAT OF MORE ORGANIZED STORMS...INCLUDING
SUPERCELLS...MOVING SLOWLY NNEWD. LARGE HAIL AND ISOLATED DAMAGING
WINDS SHOULD BE PRIMARY THREATS WITH THIS ACTIVITY.

..TX COASTAL PLAIN INTO FAR SRN TX...
RICH BOUNDARY LAYER MOISTURE AND DIURNAL HEATING INTO THE LOWER 80S
SHOULD BE SUFFICIENT FOR SCATTERED THUNDERSTORM DEVELOPMENT BY THE
EARLY TO MID AFTERNOON OVER THIS REGION TODAY. SHEAR WILL REMAIN
MODEST...THOUGH STRONG INSTABILITY MAY SUPPORT A FEW SHORT-LIVED
STRONG TO SEVERE THUNDERSTORMS PRODUCING DAMAGING WINDS AND HAIL.
ACTIVITY WILL LIKELY BE SLOW MOVING...THOUGH STRONG UPPER LEVEL WLYS
MAY SUSTAIN SOME ORGANIZATION TO THE STRONGER CELLS.

.EVANS.. 04/28/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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: