SWODY1
SPC AC 171241
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0741 AM CDT THU MAY 17 2007
VALID 171300Z - 181200Z
..NO SVR TSTM AREAS FORECAST...
..SYNOPSIS...
UPR TROUGH EXPECTED TO FURTHER AMPLIFY OVER THE UPR OH VLY/LWR GRT
LKS THIS PERIOD AS LOW AMPLITUDE RIDGE BUILDS E FROM THE RCKYS INTO
THE PLNS. AMPLIFICATION OF ERN SYSTEM WILL BE DUE LARGELY TO VORT
MAX/JET STREAK NOW CROSSING MO. THIS FEATURE SHOULD REACH THE TN
VLY/SRN APLCNS TONIGHT/EARLY FRIDAY AS UPR LOW CLOSES OFF OVER
OH/WV.
SATELLITE LOOPS SHOW SEVERAL DISTURBANCES UNDERCUTTING WRN RIDGE...
THE STRONGEST OF WHICH APPEARS TO BE NEGATIVELY-TILTED FROM SRN AZ
TO NRN CHIHUAHUA. IN THE NORTHWEST...MAIN SHORTWAVE TROUGH NOW
APPROACHING THE WA CST IS PRECEDED BY A WEAKER IMPULSE IN WRN ORE
THAT SHOULD REACH THE NRN RCKYS BY EVENING.
INCREASING WSW FLOW SHOULD STRENGTHEN LEE LOW/TROUGH OVER MT...AND
LARGE/COOL ANTICYCLONE WILL BUILD S THROUGH THE MS VLY. OTHERWISE
..SFC FEATURES WILL REMAIN WEAK.
..NRN RCKYS...
STRONG HEATING WILL OCCUR OVER THE NRN RCKYS AND ADJACENT HI PLNS OF
ID/MT AHEAD OF ORE UPR IMPULSE. BOUNDARY LAYER MOISTURE WILL BE
LIMITED...WITH SFC DEWPOINTS LIKELY MIXING INTO THE UPR 30S OR LOW
40S. BUT PRESENCE OF STEEP MID LEVEL LAPSE RATES AND DEEPLY MIXED
ENVIRONMENT SHOULD SUPPORT MLCAPE OF 500 J/KG. COUPLED WITH
FAVORABLY-TIMED UPR DISTURBANCE AND ASSOCIATED MID LEVEL
MOISTURE/ASCENT...THIS SHOULD FOSTER DEVELOPMENT OF WIDELY SCTD
STORMS OVER THE HIGHER TERRAIN. DEEP UNIDIRECTIONAL WSWLY FLOW
INCREASING TO AROUND 30 KTS WILL FAVOR ORGANIZATION OF ACTIVITY INTO
SHORT LINES...AND EXPECTED THERMODYNAMIC ENVIRONMENT APPEARS
SUPPORTIVE OF MICROBURSTS. THUS...A FEW STORMS MAY YIELD DAMAGING
WIND GUSTS BEFORE WEAKENING WITH SUNSET.
..CNTRL/NRN HI PLNS...
SCTD HIGH-BASED STORMS SHOULD DEVELOP WITH AFTERNOON HEATING OVER
THE HIGHER TERRAIN OF CO/WY AND POSSIBLY WRN SD. DEEPLY MIXED
ENVIRONMENT WITH SPARSE MOISTURE /DEWPOINTS IN THE 40S/ WILL KEEP
MLCAPE AOA 1000 J/KG. BUT 20-25 KT MID LEVEL WNWLY FLOW WILL BE
SUFFICIENT TO SUPPORT ORGANIZATION INTO SMALL CLUSTERS/BANDS.
COUPLED WITH GIVEN THERMODYNAMIC SETUP...A THREAT WILL EXIST FOR
ISOLATED STRONG WIND GUSTS AND POSSIBLY SVR HAIL BEFORE STORMS
WEAKEN THIS EVENING.
..SWRN U.S....
A SEASONABLY MOIST BOUNDARY LAYER IS IN PLACE FROM FAR W TX/NM INTO
CNTRL AZ AND THE FOUR CORNERS REGION. SFC HEATING AND OROGRAPHIC
UPLIFT LIKELY WILL SUPPORT ANOTHER ROUND OF DIURNAL STORMS...WITH
ACTIVITY PERHAPS MOST CONCENTRATED JUST DOWNSTREAM FROM PREVIOUSLY
MENTIONED SHORTWAVE TROUGH. WIND PROFILES WILL FOR THE MOST PART BE
QUITE WEAK...WITH MODEST /25+ KT/ DEEP WLY SHEAR BEING CONFINED TO
SRN NM/FAR W TX. WHILE A FEW SUSTAINED STORMS/MARGINAL ROTATING
STRUCTURES MAY EVOLVE IN THAT REGION ...OVERALL SETUP APPEARS MORE
SUPPORTIVE OF MULTICELL CLUSTERS. A FEW STORMS...ESPECIALLY DURING
THEIR EARLY STAGES OF GROWTH...MAY YIELD SVR WIND/HAIL BEFORE
TRANSITIONING INTO HEAVY RAIN PRODUCERS THIS EVENING.
..OH/WV/KY...
SFC HEATING AND PRESENCE OF MID LEVEL COLD POCKET /-22C TO -26C AT
500 MB/ WITH DEVELOPING UPR LOW WILL RESULT IN MODERATE
DESTABILIZATION OVER PARTS OF OH/WV AND KY. HOWEVER...LIMITED
BOUNDARY LAYER MOISTURE SHOULD KEEP SBCAPE AOB 500 J/KG. NUMEROUS
LOW-TOPPED STORMS LIKELY WILL FORM EARLY THIS AFTERNOON...AND SOME
MAY PRODUCE MARGINALLY SVR HAIL/STRONG SFC WINDS. HOWEVER... SPARSE
MOISTURE SUPPLY AND DESTRUCTIVE INTERFERENCE BETWEEN UPDRAFTS
SUGGEST THAT PROBABILITY FOR SUSTAINED SVR ACTIVITY WILL REMAIN LOW
.CORFIDI/CROSBIE.. 05/17/2007
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