DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 130039
SWODY1
SPC AC 130037

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0737 PM CDT SUN AUG 12 2007

VALID 130100Z - 131200Z

..THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID MS VALLEY...

..MID MS VALLEY...

WELL ORGANIZED MCS IS PROGRESSING ESEWD ACROSS SRN IA AT ROUGHLY
35-40KT. THIS SYSTEM HAS YET TO TURN SIGNIFICANTLY SE BUT SHOULD DO
SO AS IT APPROACHES THE MS RIVER ALONG AXIS OF GREATEST INSTABILITY.
00Z SOUNDING FROM ILX OVER CNTRL IL IS QUITE UNSTABLE ON THE COOL
SIDE OF THE BOUNDARY WITH STEEP LAPSE RATES AND MORE THAN SUFFICIENT
CAPE FOR SUSTAINING AN ORGANIZED MCS. IT REMAINS TO BE SEEN WHETHER
THIS COMPLEX OF STORMS WILL REMAIN SEVERE INTO IL...ALTHOUGH CURRENT
SPEED/MOVEMENT SUGGESTS LEADING EDGE WILL APPROACH THE UIN AREA BY
04Z. GIVEN THE MODEST NWLY FLOW ALOFT THAT EXTENDS ACROSS NEB/IA
INTO CNTRL IL IT APPEARS THIS ACTIVITY WILL REMAIN ORGANIZED EAST OF
THE MS RIVER BEFORE GRADUALLY WEAKENING. DAMAGING WINDS ARE THE
GREATEST SEVERE RISK.

UPSTREAM ACROSS THE CNTRL PLAINS...SCATTERED THUNDERSTORMS HAVE
DEVELOPED OVER THE HIGHER TERRAIN OF ERN CO INTO THE NEB PANHANDLE.
THIS ACTIVITY SHOULD DIMINISH LATER THIS EVENING WITH LOSS OF
DAYTIME HEATING...ALTHOUGH INCREASING WARM ADVECTION AFTER DARK MAY
ULTIMATELY RESULT IN ADDITIONAL ELEVATED THUNDERSTORMS IN THE WAKE
OF MCS ACROSS PORTIONS OF CNTRL/ERN NEB. THIS LATE NIGHT ACTIVITY
SHOULD PROVE MOSTLY SUB-SEVERE WITH ONLY LOW PROBABILITIES FOR
SEVERE HAIL.

..OH VALLEY...

UPPER SHORTWAVE TROUGH IS SHIFTING EAST OF THE OH VALLEY THIS
EVENING WITH ONLY WEAK CONVERGENCE/SUBSIDENCE IN ITS WAKE. ANY
ISOLATED THUNDERSTORMS THAT ARE ONGOING SHOULD DIE QUICKLY WITH LOSS
OF DAYTIME HEATING ACROSS SERN LOWER MI INTO NRN WV.

..SERN U.S...

WIDESPREAD SHOWERS/THUNDERSTORMS ACROSS NRN FL INTO SRN GA/AL HAVE
EFFECTIVELY OVERTURNED MUCH OF THE STRONGER INSTABILITY THAT EXISTED
THIS AFTERNOON. VARIOUS OUTFLOW BOUNDARIES AND COOLING TEMPERATURES
WILL UNDOUBTEDLY LEAD TO THE DEMISE OF ANY SEVERE STORMS ACROSS THIS
REGION. FOR THE NEXT HOUR OR SO A FEW STORMS MAY YET PRODUCE GUSTY
DOWNBURSTS.

.DARROW.. 08/13/2007

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