DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 251245
SWODY1
SPC AC 251243

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0743 AM CDT THU APR 25 2013

VALID 251300Z - 261200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
BROAD ERN U.S. TROUGH WILL PROGRESS E TO THE NEW ENG CST BY THE END
OF THE PERIOD AS LEAD SHORTWAVE IMPULSE SHEARS NNE INTO
LABRADOR...AND UPSTREAM DISTURBANCE MOVES FROM LK MI TO UPSTATE NY.
WEAK SPLIT FLOW WILL DOMINATE THE WEST...WITH NRN BAJA UPR LOW
EXPECTED TO DEAMPLIFY AND SHEAR ENE INTO CONFLUENCE ZONE OVER THE
SRN GRT BASIN...SRN RCKYS...AND SRN PLNS. FARTHER S...SUBTROPICAL
JET WILL PERSIST ACROSS NRN MEXICO AND THE NRN GULF OF MEXICO.

AT LWR LVLS...COOL SFC HIGH WILL LINGER OVER THE ERN HALF OF THE
COUNTRY AS ASSOCIATED COLD FRONT CLEARS THE CAROLINAS CST THIS
AFTN...AND SRN PART OF THE SAME BOUNDARY DISSIPATES OVER THE FL
PENINSULA. WHILE SVR WEATHER CONCERNS WILL BE MINIMAL THIS
PERIOD...SEVERAL AREAS WILL HAVE A POTENTIAL FOR TSTMS.

...CNTRL/SRN RCKYS INTO CNTRL/SRN PLNS TODAY THROUGH EARLY FRI...
SFC HEATING AND ASCENT DOWNSTREAM FROM DEAMPLIFYING UPR TROUGH
SHOULD SUPPORT SCTD DIURNAL STORMS OVER THE HIGHER TERRAIN OF CO AND
NRN MN. MORE ISOLD ACTIVITY MAY OCCUR FARTHER S ACROSS FAR W TX. THE
SHOWERS/STORMS SHOULD MOVE/DEVELOP E INTO DEVELOPING 700 MB WAA
PATTERN OVER KS AND FAR NRN OK TNGT/EARLY FRI. WHILE SOME OF THESE
MAY PRODUCE SMALL HAIL...MOISTURE LIKELY WILL REMAIN TOO LIMITED TO
SUPPORT A SUSTAINED SVR RISK.

A BIT FARTHER S..SOMEWHAT MORE SUBSTANTIAL ELEVATED WAA STORMS MAY
ARISE OVER CNTRL AND ERN OK TOWARD THE END OF THE PERIOD AS CURRENT
OF RICHER MOISTURE /PW AROUND 1 INCH/ SPREADS NWD INTO ZONE OF
STRENGTHENING DCVA/UPR DIVERGENCE AHEAD OF SRN STREAM TROUGH.
COUPLED WITH MODERATE CLOUD-LAYER SHEAR...SETUP COULD YIELD A STORM
OR TWO WITH HAIL APPROACHING OR PERHAPS EXCEEDING SVR LIMITS.

...NRN FL TO CSTL CAROLINAS THIS AFTN...
ISOLD TO WDLY SCTD TSTMS MAY FORM WITH AFTN HEATING ALONG WEAKLY
CONVERGENT COLD FRONT FROM NRN FL TO CSTL SC/NC. WEAK MID-LVL LAPSE
RATES SHOULD LIMIT STORM STRENGTH...DESPITE PRESENCE OF APPRECIABLE
MID/UPR LVL FLOW ASSOCIATED WITH SRN END OF SHORTWAVE TROUGH MOVING
INTO CANADA. WHILE A STORM OR TWO WITH LOCALLY DMGG WIND GUSTS
CANNOT ENTIRELY BE RULED OUT...AND MORE CONCENTRATED/SUSTAINED
DEVELOPMENT MAY OCCUR JUST OFFSHORE...THE SVR RISK OVER LAND APPEARS
LOW.

...LWR GRT LKS THIS AFTN/EARLY EVE...
SFC HEATING AND APPROACH OF LK MI UPR TROUGH LIKELY WILL LEAD TO
LOW-TOPPED DIURNAL CONVECTION/SCTD TSTMS OVER THE LWR GRT
LKS...DESPITE RELATIVELY COOL/DRY SFC ENVIRONMENT. LOCALLY STRONG
WIND GUSTS COULD ACCOMPANY THIS ACTIVITY GIVEN STEEP LOW-LVL LAPSE
RATES AND 25+ KT MEAN LWR TROPOSPHERIC FLOW.

...DAKOTAS THIS AFTN...
NRN STREAM IMPULSE NOW ENTERING N CNTRL MT WILL CONTINUE ESE INTO
WRN ND BY EVE. SHOWERS AND ISOLD TSTMS MAY FORM WITH SFC HEATING IN
DEEPLY MIXED ENVIRONMENT DOWNSTREAM ACROSS PARTS OF THE
DAKOTAS...WHERE A WEAK WAA PATTERN WILL EVOLVE. WHILE GUSTY SFC
WINDS AND SMALL HAIL MAY ACCOMPANY ANY STRONGER STORMS...MEAGER
MOISTURE /SFC DEWPOINTS IN THE 20 AND 30S F/ WILL LIMIT UPDRAFT
STRENGTH/LONGEVITY.

...NWRN GULF/CSTL TX TODAY...
THE STRONGEST ELEVATED TSTMS FORMING IN ASSOCIATION WITH A PASSING
IMPULSE IN THE SUBTROPICAL JET...AND THOSE THAT COULD CONTAIN SVR
HAIL...SHOULD REMAIN OFFSHORE TODAY.

..CORFIDI/DEAN.. 04/25/2013

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.