DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 151241
SWODY1
SPC AC 151239

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0739 AM CDT FRI MAR 15 2013

VALID 151300Z - 161200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
THE UPPER FLOW REGIME WILL BECOME INCREASINGLY QUASI-ZONAL AS A
TROUGH MOVES OFFSHORE THE SERN ATLANTIC COAST AND A RIDGE DAMPENS
OVER THE WRN CONUS. A LOW-AMPLITUDE SHORTWAVE UPPER TROUGH CURRENTLY
OVER THE NRN ROCKIES IS FORECAST TO REACH THE GREAT LAKES BY EARLY
SAT MORNING. AN ACCOMPANYING INCREASE IN LOW-LEVEL FLOW AND ENEWD
THETA-E ADVECTION OVER THE OH VALLEY WILL AID IN THUNDERSTORM
DEVELOPMENT LATE IN THE PERIOD.

...OH VALLEY...
MODEST ADVECTION OF MOISTURE NEWD WILL OCCUR TODAY ACROSS THE OH
VALLEY...AS THIS AREA IS DOWNSTREAM FROM A RESERVOIR OF MID-40S F
DEWPOINTS OVER THE SRN PLAINS/MID-SOUTH. A PLUME OF STEEP MIDLEVEL
LAPSE RATES WILL SPREAD EWD OUT OF THE CNTRL PLAINS IN ASSOCIATION
WITH THE AFOREMENTIONED SHORTWAVE UPPER TROUGH. ALTHOUGH SOME MODEL
FORECAST SOUNDINGS APPEAR TO BE TOO AGGRESSIVE IN LOW-LEVEL
MOISTENING THIS AFTERNOON /E.G. 06Z NAM/ DEPICTING WIDESPREAD
MID-50S DEWPOINTS OVER THE LOWER OH VALLEY...CONSENSUS SUGGESTS
MUCAPE VALUES OF 200-600 J/KG WILL BECOME COMMON AFTER
16/01Z...SUPPORTIVE FOR THUNDERSTORM DEVELOPMENT WITHIN A WEAK
LOW-LEVEL WAA REGIME. MODERATELY STRONG DEEP-LAYER SHEAR COULD
SUPPORT ORGANIZED ELEVATED THUNDERSTORMS WITH THE POTENTIAL TO
PRODUCE MARGINALLY SVR HAIL...BUT A MORE SIGNIFICANT/WIDESPREAD
THREAT APPEARS TO BE LIMITED BY WEAK INSTABILITY.

..ROGERS/EDWARDS.. 03/15/2013

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