DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 290027
SWODY1
SPC AC 290025

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0725 PM CDT FRI SEP 28 2007

VALID 290100Z - 291200Z

..THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE CNTRL
HIGH PLAINS...

..CNTRL HIGH PLAINS...

STORMS THAT DEVELOPED OVER THE HIGH PLAINS OF ERN CO...WRN KS AND
SWRN NEB HAVE SHIFTED EAST AND ARE CURRENTLY MOVING THROUGH NARROW
INSTABILITY AXIS WITH MLCAPE AROUND 1500 J/KG AND 7-7.5 C/KM 3-6 KM
LAPSE RATES. EFFECTIVE SHEAR OF 40 TO 45 KT IN THIS REGION IS
SUPPORTING SUPERCELL STRUCTURES WITH LARGE HAIL THE MAIN THREAT.
SURFACE TO 1 KM HODOGRAPHS WILL INCREASE INTO THE EVENING AS THE LOW
LEVEL JET STRENGTHENS TO 60+ KT...BUT THE BOUNDARY LAYER WILL
GRADUALLY DECOUPLE AS NOCTURNAL COOLING COMMENCES. INCREASING
CONVECTIVE INHIBITION WITH RESPECT TO SURFACE BASED PARCELS SUGGESTS
STORMS SHOULD BEGIN TO UNDERGO A GRADUAL WEAKENING TREND BY MID
EVENING.

..CNTRL AND ERN NM...

SURFACE HEATING AND AN INCREASE IN DEEP MOISTURE HAVE RESULTED IN
DESTABILIZATION ACROSS NM TODAY WITH MLCAPE RANGING FROM 500 J/KG
OVER NRN PARTS OF THE STATE TO 1500 J/KG OVER SRN NM WHERE RICHER
LOW LEVEL MOISTURE EXISTS AND STRONGER SURFACE HEATING OCCURRED.
WEAK CAP AND OROGRAPHIC FORCING HAVE CONTRIBUTED TO THUNDERSTORMS
DEVELOPING ACROSS CNTRL AND ERN PARTS OF NM. MID-UPPER SWLY FLOW HAS
INCREASED DOWNSTREAM FROM UPPER TROUGH AMPLIFYING OVER THE WRN U.S.
WITH DEEP SHEAR OF 35 TO 40 KT SUPPORTIVE OF SUPERCELLS. LARGE HAIL
WILL REMAIN THE PRIMARY THREAT...THOUGH A GRADUAL DECREASE IN
INTENSITY IS EXPECTED TONIGHT WITH THE ONSET OF NOCTURNAL COOLING.

..UPPER MS VALLEY...

ELEVATED STORMS ROOTED AROUND 700 MB CURRENTLY DEVELOPING OVER NRN
MN MAY POSE A THREAT FOR MARGINALLY SEVERE HAIL.

LATER TONIGHT LOW LEVEL THETA-E ADVECTION ATTENDING THE DEVELOPING
LOW LEVEL JET BENEATH EWD TRANSPORT OF STEEPER 2-8 KM LAPSE RATES
WILL CONTRIBUTE TO NWD DESTABILIZATION ALONG WITH INCREASING WARM
ADVECTION AND LIFT ACROSS PARTS OF THE UPPER MS VALLEY. MUCAPE FROM
1500 TO 2000 J/KG WILL BE POSSIBLE IN THIS REGION. ELEVATED STORMS
MAY DEVELOP OR SPREAD INTO THE ERN DAKOTAS AND PARTS OF MN LATE
TONIGHT WITH A THREAT FOR MAINLY HAIL.

.DIAL.. 09/29/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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 cnovy@cox.net.