DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 241257
SWODY1
SPC AC 241255

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0755 AM CDT THU MAY 24 2012

VALID 241300Z - 251200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF THE UPR MS VLY...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK
AREA...FROM THE CNTRL PLNS NEWD INTO THE UPR GRT LKS...

...SYNOPSIS...
ACTIVE...ENERGETIC UPR AIR PATTERN WILL CONTINUE OVER THE WRN AND
CNTRL U.S. THIS PERIOD AS STRONG CLOSED LOW NOW OFF THE BC CST
ADVANCES SE INTO NRN CA...AND DOWNSTREAM SHORTWAVE COMPLEX NOW
CONSOLIDATING OVER THE CNTRL RCKYS/CNTRL HI PLNS EJECTS RAPIDLY NE
TO THE UPR GRT LKS. COLD FRONT ASSOCIATED WITH THE EJECTING UPR
IMPULSE WILL SERVE AS THE MAIN FOCUS FOR STRONG TO SVR TSTMS OVER
PARTS OF THE UPR MS VLY TODAY INTO TNGT AS VERY STRONG...VERTICALLY
VEERING WIND PROFILES SPREAD NNE AHEAD OF IT.

...MID/UPR MS VLY TO UPR GRT LKS TODAY/TNGT...
SATELLITE/RADAR DATA SUGGEST THAT LEAD MEMBER OF CONSOLIDATING
SHORTWAVE COMPLEX IS OVER SW MN ATTM. THIS FEATURE SHOULD CONTINUE
SHEARING NNEWD THROUGH MUCH OF THE DAY...MAINTAINING AN AREA OF
ASCENT ALONG AND W OF STALLED FRONT NOW EXTENDING FROM WRN IA TO NW
WI. THIS...AND GRADUALLY INCREASING MOISTURE INFLOW...SHOULD
SUPPORT PERSISTENCE OF ASSOCIATED ELEVATED TSTM BAND NOW OVER NRN
IA/SE MN THROUGH AT LEAST MIDDAY.

BY EARLY TO MID AFTN...LARGE SCALE ASCENT WILL INCREASE OVER IA/SE
MN AND WRN WI WITH THE APPROACH/AMPLIFICATION OF UPSTREAM VORT MAX
NOW OVER WRN NEB. COUPLED WITH SFC HEATING AND MODEST LOW LVL
MOISTURE RETURN...THIS SHOULD FOSTER NEW STORM DEVELOPMENT ALONG THE
ERN FRINGE OF THE CONVECTIVE BAND...AND/OR STRENGTHENING OF EXISTING
STORMS FROM NRN/ERN IA NNE INTO SE MN AND WRN WI.

STRONG...VERTICALLY VEERING WIND FIELDS ALREADY PRESENT OVER THE UPR
MS VLY WILL FURTHER STRENGTHEN TODAY AS UPR IMPULSE CONSOLIDATES AND
ASSUMES A NEUTRAL TILT. ASSOCIATED DEVELOPMENT OF 70 KT SSWLY 700
MB SPEED MAX ON E SIDE OF SYSTEM /I.E. OVER WRN AND CNTRL WI/ WILL
BE FAVORABLE FOR SUSTAINED STORMS AND SUPERCELLS DESPITE SOMEWHAT
MODEST BOUNDARY LAYER MOISTURE /SFC DEWPOINTS IN THE UPR 50S TO LWR
60S/.

QUESTIONS REMAIN REGARDING DOMINANT CONVECTIVE MODE. ATTM...THE SFC
DEWPOINTS ARE GREATEST IN REGION OF STORM-PROCESSED/RAIN-COOLED AIR
W OF THE AFOREMENTIONED FRONT AND BENEATH THE ELEVATED TSTMS.
ORIENTATION OF THE FRONT PARALLEL TO STRENGTHENING DEEP SSWLY
FLOW...LIKELY CONTINUED PRESENCE OF SOMEWHAT DRIER AIR TO ITS
EAST...AND WARM SECTOR EML CAP ALL SUGGEST THAT STORMS SHOULD EVOLVE
INTO A SSW-NNE SQLN...WITH STRENGTH OF SHEAR SUPPORTING NUMEROUS
EMBEDDED LEWPS. ASSOCIATED ROTATING STORMS...SUPERCELLS...AND SMALL
BOWS WILL BE CAPABLE OF SWATHS OF DMGG WIND AND TORNADOES.

THE TORNADO THREAT SHOULD DIMINISH BY EARLY EVE AS THE SQLN
ACCELERATES NEWD INTO NE WI BEYOND AXIS OF LOW LVL MOISTURE RETURN.
A CONDITIONAL THREAT FOR SPORADIC SVR WIND WILL...HOWEVER...EXTEND
NEWD ACROSS ERN UPR MI AND PERHAPS PARTS OF LWR MI INTO EARLY FRI
GIVEN LIKELY DEVELOPMENT OF A STRONG PRESSURE RISE/FALL COUPLET AND
REASONABLY BUOYANT LOW LVL AIR STREAMING NWD FROM THE OH VLY.

...CNTRL PLNS LATE TNGT/EARLY FRI...
SSWLY LLJ WILL STRENGTHEN OVER MUCH OF KS AND WRN MO LATE TNGT AND
EARLY FRI IN RESPONSE TO DIURNAL INFLUENCES AND TO THE CONTINUED ESE
ADVANCE OF UPR LOW INTO NRN CA AND THE NRN GRT BASIN. THIS
STRENGTHENING WILL OCCUR ATOP TRAILING...SW END OF SAME FRONTAL ZONE
THAT WILL CROSS THE UPR MS VLY LATER TODAY. COUPLED WITH THE
ARRIVAL OF FAIRLY SUBSTANTIAL MOISTURE RETURN /P.W. AOA 1.25 INCHES/
AND WITH THE CONTINUED PRESENCE OF 40-50 KT WSWLY SHEAR ABOVE THE
FRONTAL SFC...SETUP MAY SUPPORT SCTD ELEVATED TSTMS WITH HAIL AND
PERHAPS LOCALLY DMG WIND. TEMPORAL STRENGTHENING OF EML CAP
/ASSOCIATED WITH ONSET OF LARGE SCALE RIDGING AHEAD OF CA-GRT BASIN
LOW/ SUGGESTS THAT AREA OF STORM DEVELOPMENT SHOULD ADVANCE NWD WITH
TIME.

...CNTRL/S FL TODAY...
SCTD TSTMS EXPECTED THIS AFTN IN ZONE OF STRONG HEATING...HIGH
PW...AND UPR DIVERGENCE BENEATH SWLY HIGH LVL JET STREAK. THESE MAY
YIELD A FEW INSTANCES OF SVR WIND/HAIL...MAINLY ALONG SEA BREEZE
BOUNDARY INTERSECTIONS.

...MID ATLANTIC TODAY...
TROPICAL MOISTURE SPREADING NWD/CONVERGING BENEATH RESIDUAL AXIS OF
RELATIVELY COOL MID LVL TEMPS MAY SUPPORT A FEW DIURNAL STORMS/STORM
CLUSTERS WITH LOCALLY SVR WIND/MARGINALLY SVR HAIL.

..CORFIDI/COHEN.. 05/24/2012

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