[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 140551
SWODY1
SPC AC 140549

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CDT FRI JUL 14 2006

VALID 141200Z - 151200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN/EARLY EVE ACROSS
PARTS OF THE UPPER GREAT LAKES/LOWER OHIO VALLEY....

SOUTHWESTERN STATES SUBTROPICAL RIDGE REMAINS STRONG...AND IS
ALREADY BUILDING NORTHEASTWARD THROUGH THE CENTRAL ROCKIES AND PARTS
OF THE NORTHERN HIGH PLAINS.  FURTHER EXPANSION EASTWARD ACROSS THE
CENTRAL/NORTHERN PLAINS THROUGH THE UPPER HALF OF THE MISSISSIPPI
VALLEY IS PROGGED TO OCCUR TODAY...AS A SEASONABLY STRONG MID/UPPER
JET...EMANATING FROM THE NORTHEAST PACIFIC... NOSES EASTWARD
ALONG/JUST NORTH OF THE CANADIAN/U.S. BORDER.  THIS IS EXPECTED TO
SUPPORT THE EASTWARD PROGRESSION OF A WEAKENING UPPER TROUGH ACROSS
THE GREAT LAKES/LOWER OHIO VALLEY REGION...TO THE SOUTH OF A
SOMEWHAT STRONGER BELT OF WESTERLIES ACROSS EASTERN CANADA.

...MISSISSIPPI RIVER EASTWARD...
DRYING IN THE WAKE OF UPPER TROUGH MIGRATING OFF THE NORTH ATLANTIC
COAST SEEMS LIKELY TO LIMIT CONVECTIVE POTENTIAL ACROSS MUCH OF THE
NORTHEAST DURING THIS FORECAST PERIOD. HOWEVER...MOST OTHER AREAS
WILL REMAIN VERY MOIST...REFLECTED BY SURFACE DEW POINTS IN THE
UPPER 60S/LOWER 70S.  NORTH OF FLAT UPPER RIDGE ACROSS THE GULF
STATES...CAPPING WILL BE WEAK...LIKELY ALLOWING WIDESPREAD
CONVECTIVE DEVELOPMENT WITH DAYTIME HEATING.

GUSTY WINDS AND MARGINALLY SEVERE HAIL WILL BE POSSIBLE IN STRONGER
UPDRAFT PULSES WHERE CONVECTION FORMS. HOWEVER...SEVERE THREAT MAY
BECOME MOST CONCENTRATED FROM PARTS OF THE UPPER MIDWEST INTO THE
LOWER OHIO VALLEY.  THIS IS WHERE MODELS SUGGEST STRONGEST
DESTABILIZATION WILL OCCUR TODAY...WITH MIXED LAYER CAPE UP TO
AROUND 3000 J/KG POSSIBLE BY PEAK HEATING...BENEATH REMNANT
MID-LEVEL COLD POOL ASSOCIATED WITH WEAKENING UPPER TROUGH. 
POTENTIAL FOR A LARGE ORGANIZED CONVECTIVE CLUSTER SEEMS LOW...BUT
NORTHWESTERLY MID/UPPER FLOW ON WESTERN/SOUTHERN PERIPHERY OF UPPER
THERMAL TROUGH MAY CONTRIBUTE TO DEEP LAYER SHEAR AS STRONG AS
25-30KT.  THIS WOULD ENHANCE RISK FOR LARGE HAIL IN SCATTERED STORMS
ACROSS PARTS OF WISCONSIN/ILLINOIS INTO LOWER MICHIGAN/INDIANA
DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.

...SOUTHERN PLAINS INTO OZARK PLATEAU...
CONVECTIVE OUTFLOW BOUNDARY FROM ONGOING CONVECTION IS EXPECTED TO
STALL ACROSS PARTS OF NORTHERN ARKANSAS/OKLAHOMA EARLY TODAY.  SOUTH
OF THIS BOUNDARY...LOW-LEVEL THERMAL RIDGE AXIS IS EXPECTED TO
BECOME A POSSIBLE FOCUS FOR SCATTERED NEW AFTERNOON
THUNDERSTORMS...MOSTLY IN RESPONSE TO STRONG SURFACE HEATING. 
LATENT INSTABILITY MAY NOT BECOME PARTICULARLY LARGE DUE TO WARM
MID-LEVEL ENVIRONMENT...BUT HOT DEEP MIXED BOUNDARY LAYER WITH 30-40
DEGREE TEMPERATURE/DEW POINT SPREADS WILL BE FAVORABLE FOR LOCALIZED
DOWNBURSTS.

..KERR.. 07/14/2006