[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 211653
SWODY1
SPC AC 211652

DAY 1 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
1152 AM CDT WED JUN 21 2006

VALID 211630Z - 221200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM SERN IA INTO NRN AND
CENTRAL IL...NRN INDIANA AND THE SRN HALF OF LOWER MI INTO NRN
OHIO....

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDS THE MDT RISK AREA
FROM THE GREAT LAKES AND OHIO VALLEY INTO THE CENTRAL HIGH
PLAINS....

CORRECTED FOR SWRN TO SERN IA...

...SYNOPSIS...
MAIN BAND OF WESTERLIES EXTENDS FROM THE PACIFIC NORTHWEST ESEWD
OVER THE SRN PARTS OF THE NRN PLAINS AND THE SRN GREAT LAKES ACROSS
SRN NEW ENGLAND.  MAIN FEATURES TO MONITOR TODAY WILL BE THE
EMBEDDED SHORT WAVE THAT WILL BE MOVING FROM IA INTO THE ERN GREAT
LAKES...THE MID/UPPER LEVEL TROUGH THAT WILL SWING EWD ACROSS THE
UPPER GREAT LAKES AND THE MID LEVEL SHORT WAVE TROUGH THAT DEVELOPS
OVER THE CENTRAL HIGH PLAINS LATER THIS AFTERNOON AND TONIGHT. AT
THE SURFACE...A COLD FRONT EXTENDS FROM CENTRAL MN SWD THROUGH NWRN
IA INTO NWRN KS...AND A WEAK TROUGH/FRONT THAT TRAILS SWWD INTO S
CENTRAL NM.  AHEAD OF THE UPPER MS VALLEY PORTION OF THE FRONT THERE
ARE SEVERAL CONVECTIVE BOUNDARIES THAT EXTEND EWD ACROSS NRN IA TO A
WARM FRONT THAT EXTENDS SEWD THROUGH SWRN OH.

...NRN HALF OF IL ENEWD THRU NRN OH...

FIRST EMBEDDED WAVE IS FORECAST TO MOVE EWD ACROSS SRN LOWER MI THRU
TONIGHT AND IS EXPECTED TO ENHANCE FORCING ALONG CONVECTIVE BOUNDARY
DURING THE PERIOD.  LOW LEVEL FLOW OF 35-45 KT IS EXPECTED  FROM THE
SRN HIGH PLAINS NWD AND NEWD OVER THE LOWER MO VALLEY THEN EWD
ACROSS THE LOWER GREAT LAKES BY TONIGHT.  THIS WILL INITIALLY
PROVIDE LOW LEVEL WARM AIR AND MOISTURE ADVECTION INTO THE REGION IN
THE VICINITY OF THESE BOUNDARIES.  AIR MASS IS PLENTY MOIST NOW WITH
SURFACE DEW POINTS IN THE MID 60S TO LOWER 70S...AND WITH ADDED
DAYTIME HEATING WILL CONTINUE TO DESTABILIZE THE AIR MASS.  ANALYSIS
OF RUC/NAM POINT FORECAST SOUNDINGS SHOW THAT MLCAPES WILL  BE
BETWEEN 2500 AND 3100 J/KG BY LATE THIS AFTERNOON ACROSS SRN LOWER
MI...NRN INDIANA AND NRN OH WITH 850/700 MB LAPSE RATES BETWEEN
7.5/8.0 C/KM.  THUS...EXPECT AREA OF STRONG/SEVERE THUNDERSTORMS
ALONG AND S OF THE BOUNDARY THROUGH TONIGHT WITH MAIN THREATS BEING
HAIL AND DAMAGING WINDS.  GIVEN THE BOUNDARY INTERACTIONS...THE
PRESENCE OF SOME SPEED SHEAR AND AMOUNT OF INSTABILITY...WOULD NOT
RULE OUT THE POSSIBILITY OF A FEW TORNADOES LATE THIS AFTERNOON FROM
CENTRAL IL INTO NRN OH.

...UPPER GREAT LAKES...

LATEST SURFACE ANALYSIS INDICATES LOW/MID 60S DEW POINTS IN PLACE
AHEAD OF THE COLD FRONT WHICH IS EXPECTED TO SWEEP EASTWARD
ACCOMPANIED BY VIGOROUS SHORT WAVE TROUGH NOW MOVING THROUGH NWRN
MN.  THUNDERSTORMS HAVE ALREADY DEVELOPED OVER NERN MN AND WILL
CONTINUE TO DO SO SWWD AS THE TROUGH MOVES INTO WRN UPPER MI AND
NWRN WI.  MODELS INDICATE STRONG VERTICAL ASCENT ENHANCED BY UPPER
LEVEL DIVERGENCE AND STRONG MID LEVEL DRYING ACROSS THIS AREA
THROUGH EARLY TONIGHT. AIR MASS THROUGH CENTRAL WI INTO WRN UPPER
MI IS ALREADY MODERATELY UNSTABLE WITH MLCAPES APPROACHING 1000 J/KG
AND ARE FORECAST TO BE BETWEEN 1500 AND 1800 J/KG AHEAD OF THE FRONT
THIS AFTERNOON.  THUS...POTENTIAL IS THERE FOR HAIL AND DAMAGING
WINDS AS A LINE OF STRONG TO SEVERE THUNDERSTORMS MOVE THROUGH THE
REGION THROUGH EARLY TONIGHT.

...CENTRAL HIGH PLAINS INTO PARTS CENTRAL NEB AND CENTRAL KS...

MODELS GENERATE MID/UPPER LEVEL SHORTWAVE TROUGH OVER THE CENTRAL
HIGH PLAINS OF CO EARLY THIS EVENING.  SURFACE LOW IS DEVELOPING
ALONG QUASISTATIONARY BOUNDARY FROM EXTREME NWRN MO INTO THE WRN OK
PANHANDLE AND WILL ENHANCE ELY/UPSLOPE FLOW INTO THE AREA TO ENHANCE
LOW LEVEL CONVERGENCE. AIR MASS WILL BECOME INCREASINGLY  MOIST
WITH DEW POINTS IN THE LOW/MID 60S LEADING TO INSTABILITY BETWEEN
1800 AND 2500 J/KG LATER THIS AFTERNOON PRIOR TO THE DEVELOPMENT OF
STRONG/SEVERE THUNDERSTORMS.  THIS ACTIVITY WILL DEVELOP INTO
CLUSTER/MCS TONIGHT WITH THE MAIN THREAT BEING DAMAGING WINDS AND
SOME HAIL INTO CENTRAL KS/PARTS OF CENTRAL NEB TONIGHT.

..MCCARTHY.. 06/21/2006