Monday, July 23, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 231301
SWODY1
SPC AC 231258

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0758 AM CDT MON JUL 23 2007

VALID 231300Z - 241200Z

..THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID/LWR MO VLY INTO
THE CNTRL PLNS...

..SYNOPSIS...
BROAD UPR RIDGE CENTERED OVER THE NRN PLNS WILL REMAIN THE DOMINANT
WEATHER FEATURE OVER THE LWR 48 THIS PERIOD AS ERN LOW RETROGRESSES
SLIGHTLY NW. WEAK IMPULSES ROTATING AROUND PERIPHERY OF THE PLNS
RIDGE LIKELY WILL CONTINUE TO SERVE AS FOCI FOR LOCALLY
CONCENTRATED TSTM DEVELOPMENT.

FEATURES AT THE SFC WILL REMAIN FAIRLY WEAK. A COLD FRONT
ASSOCIATED WITH A SHORTWAVE TROUGH MOVING NE AROUND UPR LOW OFF THE
BC CST WILL MOVE E ACROSS THE PAC NW ACROSS MUCH OF WA AND ORE BY
12Z TUESDAY...AND A DIFFUSE FRONTAL ZONE WILL REMAIN NEARLY
STATIONARY FROM THE UPR MS VLY TO THE CNTRL PLNS.

..MID/LWR MO VLY SW TO THE TX PANHANDLE/WRN OK...
SCTD STORMS SHOULD CONTINUE MOVING/DEVELOPING SW ACROSS THE MID/LWR
MO VLY INTO THE CNTRL PLNS...AHEAD OF WEAK SW-MOVING UPR IMPULSE.
WHILE A LIMITED THREAT FOR LOCALLY SVR WIND/HAIL MAY EXIST THROUGH
THE MORNING...A MORE SUBSTANTIAL POTENTIAL MAY DEVELOP WITH SFC
HEATING THIS AFTERNOON AS SBCAPE INCREASES TO AROUND 2000 J/KG.

MODERATE NNELY MID/UPR LVL FLOW WITH CONSIDERABLE DEEP VEERING WILL
YIELD PROFILES FAVORABLE FOR SUSTAINED/ORGANIZED STORMS...INCLUDING
SW OR WSW-MOVING SUPERCELLS WITH HIGH WIND/HAIL AND POSSIBLY A
COUPLE TORNADOES. THIS ACTIVITY APPEARS MOST LIKELY FROM WRN IA AND
PERHAPS SE SD SWD INTO CNTRL/ERN NEB TO NRN KS. WITH TIME THE
STORMS SHOULD MERGE INTO SEVERAL SW-MOVING CLUSTERS OF STRONG TO SVR
STORMS. OTHER STORMS/CLUSTERS LIKELY WILL IN SOMEWHAT LESS
STRONGLY-SHEARED ENVIRONMENT EXTENDING S INTO CNTRL/WRN OK AND THE
TX PANHANDLE.

NOCTURNAL STRENGTHENING OF SSWLY LLJ OVER WRN PORTIONS OF THE CNTRL
AND SRN PLNS THIS EVENING SUGGESTS THAT ADDITIONAL STORMS/CLUSTERS
MAY REMAIN ACTIVE OVER PARTS OF KS/OK...AND MOVE/DEVELOP INTO WRN
AND PERHAPS SW TX TONIGHT/EARLY TUESDAY.

..WRN/CNTRL MT AND ADJACENT AREAS OF ID...
WEAK SHORT-WAVE DISTURBANCES MOVING NE ACROSS ID AND WRN/CNTRL MT ON
WRN FRINGE OF UPR RIDGE EXPECTED TO MODULATE DIURNALLY ENHANCED
STORM DEVELOPMENT ACROSS THIS REGION. STRONGER FLOW ALOFT WILL...
HOWEVER...FARTHER NW ACROSS WA/BC. COUPLED WITH RELATIVELY WARM MID
LVL TEMPERATURES ON W SIDE OF UPR RIDGE...ANY SVR THREAT SHOULD
REMAIN FAIRLY BRIEF AND/OR ISOLATED...MAINLY IN THE FORM OF LOCALLY
DAMAGING WIND.

..CNTRL/SRN FL...
MORNING RAOBS AND SATELLITE DATA SUGGEST THAT MID LVL LAPSE RATES
WILL REMAIN FAIRLY WEAK OVER MUCH OF FL TODAY...WITH THE STEEPEST
LAPSE RATES /AROUND 6.5 DEG C PER KM/ EXPECTED IN THE SOUTHEAST PART
OF THE STATE. NEVERTHELESS...SLIGHTLY-ENHANCED WLY MID LVL FLOW ON
SRN EDGE OF ERN U.S. UPR LOW MAY ENHANCE STORM
ORGANIZATION/SUSTENANCE OVER PARTS OF SRN AND CNTRL FL GIVEN ELY
ONSHORE FLOW NEAR THE SFC.

.CORFIDI/GUYER.. 07/23/2007

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