[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 120522
SWODY1
SPC AC 120520

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1220 AM CDT WED APR 12 2006

VALID 121200Z - 131200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

WELL-DEFINED SHORT WAVE TROUGH CURRENTLY MOVING THROUGH THE MIDWEST
WILL CONTINUE ENEWD THROUGH THE GREAT LAKES AND OH VALLEY
TODAY...EVENTUALLY PHASING WITH FASTER NRN STREAM DISTURBANCE OVER
THE NERN STATES TONIGHT.  IN THE LOW-LEVELS...SURFACE LOW INITIALLY
OVER THE UP OF MI WILL RAPIDLY DEVELOP NEWD INTO QUEBEC WHILE
ASSOCIATED COLD FRONT PUSHES EWD THROUGH THE UPPER OH VALLEY INTO
WRN NEW ENGLAND.  THE TRAILING PORTION OF THIS FRONT WILL MOVE MORE
SLOWLY SEWD PRIOR TO STALLING AND UNDERGOING FRONTOLYSIS S OF THE OH
RIVER. THIS BOUNDARY WILL ALSO BECOME PROGRESSIVELY ILL-DEFINED
WITH TIME OVER THE CNTRL AND SRN PLAINS WITH THE MAIN BAROCLINIC
ZONE BECOMING RE-ESTABLISHED FARTHER TO THE N OWING TO STRENGTHENING
LEE TROUGH OVER THE NRN HIGH PLAINS.

...OH VALLEY...

12/00Z REGIONAL SOUNDINGS CONTINUE TO INDICATE THAT LOW-LEVEL
MOISTURE REMAINS LIMITED ACROSS THE ERN PLAINS AND MS VALLEY WITH
UPSTREAM...MEAN MIXING RATIOS COMMONLY BETWEEN 7-9 G/KG. 
MOREOVER...ONGOING TSTMS OVER IA HAVE LIKELY PROCESSED THE PLUME OF
STEEP MID-LEVEL LAPSE RATES WHICH PRECEEDED THE SHORT WAVE TROUGH
INTO THE PLAINS.  THIS MODEST LOW-LEVEL MOISTURE COUPLED WITH A
TENDENCY FOR WEAKER MID-LEVEL LAPSE RATES WILL LIKELY LIMIT A MORE
ORGANIZED SEVERE THREAT LATER TODAY ACROSS REGION.

A PRE-FRONTAL CLUSTER OF TSTMS SHOULD BE ONGOING AT THE START OF THE
FORECAST PERIOD OVER THE MIDWEST...WITH ACTIVITY CONTINUING EWD
THROUGH THE SRN GREAT LAKES AND OH VALLEY TODAY.  NO SEVERE WEATHER
IS EXPECTED WITH THESE STORMS OWING TO THE WEAK INSTABILITY.  MORE
VIGOROUS TSTM DEVELOPMENT IS ANTICIPATED BY MID TO LATE AFTERNOON
ALONG FRONT OVER ERN IND OR OH WITHIN MARGINALLY UNSTABLE
ENVIRONMENT CHARACTERIZED BY SBCAPES OF AROUND 500 J/KG.  SUBSEQUENT
STORM DEVELOPMENT WILL BE POSSIBLE SWWD ALONG FRONT NEAR OR S OF THE
OH RIVER FROM LATE AFTERNOON INTO EARLY EVENING.

FORECAST SHEAR PROFILES ARE EXPECTED TO BE QUITE SUPPORTIVE OF
ORGANIZED/ROTATING STORMS WITH SWLY SURFACE WINDS VEERING TO WNWLY
AT 50 KTS IN THE MID-LEVELS.  WHILE THE MOST INTENSE STORMS WILL BE
CAPABLE OF LOCALLY STRONG WIND GUSTS AND SOME MARGINALLY SEVERE
HAIL...A MORE SUBSTANTIAL SEVERE WEATHER THREAT WILL LIKELY BE
LIMITED BY THE WEAK INSTABILITY.

..MEAD/TAYLOR.. 04/12/2006