Monday, July 2, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 022001
SWODY1
SPC AC 021959

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0259 PM CDT MON JUL 02 2007

VALID 022000Z - 031200Z

..THERE IS A SLGT RISK OF SVR TSTMS FROM MT EWD INTO MN AND SEWD
INTO NWRN NEB...

..THERE IS A SLGT RISK OF SVR TSTMS FROM LA EWD INTO THE WRN FL
PANHANDLE...

..CNTRL/ERN MT INTO THE DAKOTAS AND NWRN NEB...
SCATTERED ELEVATED THUNDERSTORMS WERE OCCURRING IN ERN MT AT MID
AFTERNOON...MAINLY EAST OF A WEAK N-S ORIENTED FRONT/BOUNDARY IN
CENTRAL MT. ELY BOUNDARY LAYER WINDS ON THE EAST SIDE OF THE FRONT
WAS MAINTAINING UPPER 50/LOWER 60 DEWPOINTS. THESE DEWPOINTS COUPLED
WITH STEEP MID LEVEL LAPSE RATES WERE YIELDING MLCAPE VALUES IN
EXCESS OF 2000 J/KG. SUFFICIENT SHEAR/INSTABILITY EXISTS FOR SOME OF
THESE STORMS TO BECOME SEVERE. HOWEVER...MORE INTENSE STORMS ARE
LIKELY LATER TODAY AND TONIGHT ACROSS THE ERN HALF OF MT AS LARGE
SCALE ASCENT INCREASES AHEAD OF SHORTWAVE TROUGH... CURRENTLY MOVING
THROUGH ID. THESE STORMS WILL BE EMBEDDED WITHIN A STRONGLY SHEARED
ENVIRONMENT...0-6 KM SHEAR NEAR 50 KT...SO ONCE STORMS BECOME ROOTED
IN THE BOUNDARY LAYER...SUPERCELLS ARE LIKELY. THE RELATIVELY MOIST
BOUNDARY LAYER AND 1 KM SHEAR NEAR 20 KT MIGHT BE SUPPORTIVE OF A
TORNADO OR TWO INITIALLY WITH THE STORMS. HOWEVER...THE STORMS
SHOULD CONSOLIDATE INTO AN MCS THIS EVENING AS STORM OUTFLOWS
CONGEAL AND LOW LEVEL JET STRENGTHENS ACROSS THE WRN DAKOTAS. ONCE
THE STORMS ORGANIZE INTO AN MCS... WIND DAMAGE SHOULD BECOME THE
PRIMARY THREAT. THE STORMS ARE EXPECTED TO GRADUALLY WEAKEN ACROSS
THE DAKOTAS LATE TONIGHT AS THE STORMS SPREAD EWD INTO A LESS
UNSTABLE ENVIRONMENT.

..ERN SD/ND AND MN...
WEAK OUTFLOW BOUNDARY/FRONT EXTENDED FROM NWRN MN SWWD INTO CENTRAL
SD. LATEST WV IMAGERY SUGGESTS A SHORTWAVE TROUGH WAS LOCATED IN WRN
SD AND MAY PROVIDE ENOUGH CONVERGENCE ALONG BOUNDARY FOR CONVECTIVE
DEVELOPMENT LATER TODAY. HOWEVER...CLOUDS FROM EARLIER
CONVECTION...HAVE SLOWED DIURNAL HEATING...AND DO PROVIDE SOME
UNCERTAINTY IF THE CONVERGENCE WILL BE STRONG ENOUGH TO BREAK
CAPPING INVERSION. IF STORMS DEVELOP...SUFFICIENT INSTABILITY AND
SHEAR EXISTS FOR SEVERE STORMS...WITH HIGH WINDS AND HAIL THE MAIN
THREATS.

..LA EWD TO THE FL PENINSULA...
VERY MOIST AIR REMAINS ACROSS THE GULF COASTAL STATES IN WEAKLY
SHEARED REGIME ALONG/SOUTH OF WEAK FRONT. IN AREAS WHERE
TEMPERATURES CLIMB INTO THE 90S...THE MODERATE INSTABILITY AND HIGH
PW VALUES WOULD BE FAVORABLE FOR A FEW WET MICROBURSTS THROUGHOUT
THE AFTERNOON.

..CENTRAL/SRN ROCKIES...
WIDELY SCATTERED STORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN AND
WEAK NLY FLOW ALOFT SHOULD AID IN STORMS MOVING MOSTLY SWD...
DESPITE STRONGER INSTABILITY LOCATED JUST EAST OF THE FOOTHILLS. THE
DEEPLY MIXED AND DRY SUB CLOUD LAYER WILL BE FAVORABLE FOR A FEW
STORMS WITH STRONG WIND GUSTS.

..SWRN TX...
SWWD MOVING MCS...NW OF SJT...HAS WELL DEVELOPED COLD POOL
ASSOCIATED WITH IT. THE STRONGEST CONVECTION IS EXPECTED TO REMAIN
ALONG THE SW FLANK/LEADING EDGE OF THE CLUSTER...AS TEMPERATURES
NEAR 90 ARE SUPPORTING MODERATE INSTABILITY AND STEEPER LOW LEVEL
LAPSE RATES. NLY DEEP LAYER SHEAR AT 20-30 KT AND COLD POOL SHOULD
MAINTAIN CONVECTION THROUGH THE AFTERNOON. THE WARM TEMPERATURES AND
STEEP LOW LEVEL LAPSE RATES WILL BE SUPPORTIVE OF ISOLATED
STRONG/DAMAGING WIND GUSTS.

.IMY.. 07/02/2007

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