CATEGORICAL OUTLOOK
PROBABILISTIC OUTLOOK
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT SAT JUN 30 2012 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF ERN MT INTO NWRN ND... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY INTO THE CAROLINAS... ...SYNOPSIS... THE BLOCKING PATTERN WILL PERSIST SUNDAY WITH UPPER RIDGE ANCHORED OVER THE CNTRL U.S. FLANKED BY UPPER TROUGHS OVER THE ERN AND WRN STATES. SEVERAL IMPULSES WILL MOVE THROUGH THE LARGER SCALE TROUGHS INCLUDING SIGNIFICANT SHORTWAVE TROUGH FORECAST TO EJECT THROUGH THE NRN ROCKY MOUNTAIN REGION. AT THE SFC...WARM FRONT WILL LIFT NWD INTO THE NRN HIGH PLAINS AS SLY LOW LEVEL FLOW INCREASES EAST OF DEVELOPING LEE LOW. THIS FRONT WILL EXTEND SEWD THROUGH THE UPPER MS VALLEY...OH VALLEY AND VA AS A QUASI-STATIONARY BOUNDARY. LEE TROUGH WILL DEVELOP EAST OF CNTRL AND SRN APPALACHIANS. COLD FRONT WILL ACCOMPANY THE EJECTING NRN STREAM SHORTWAVE TROUGH AND ADVANCE THROUGH CNTRL AND ERN MT DURING THE DAY. ...CNTRL/ERN MT INTO WRN ND... RICHER MOISTURE NOW RESIDING OVER THE CNTRL PLAINS WILL BEGIN TO RETURN NWWD INTO THE NRN HIGH PLAINS WITH MID-UPPER 50S DEWPOINTS LIKELY ADVECTING INTO PRE-FRONTAL WARM SECTOR OF CNTRL AND ERN MT BENEATH STEEP LAPSE RATES. THIS PROCESS WILL RESULT IN MODERATE SFC BASED INSTABILITY AS THE BOUNDARY LAYER WARMS DURING THE AFTERNOON. STORMS SHOULD DEVELOP WITHIN ZONE OF DEEPER ASCENT ALONG THE FRONT INITIALLY OVER CNTRL MT THEN ADVANCING NEWD INTO PARTS OF ERN MT. ORGANIZED STORMS INCLUDING SUPERCELLS AND BOWING SEGMENTS WILL BE SUPPORTED BY EFFECTIVE SHEAR INCREASING TO 40+ KT. ACTIVITY SHOULD EXPAND INTO WRN ND SUNDAY EVENING SUPPORTED BY INCREASING WARM ADVECTION AND ISENTROPIC ASCENT NORTH OF WARM FRONT. ...UPPER MS VALLEY...OH VALLEY AND MID ATLANTIC REGION... ATMOSPHERE IS EXPECTED TO BECOME MODERATELY TO STRONGLY UNSTABLE ALONG MOIST AXIS IN VICINITY OF NW-SE ORIENTED BOUNDARY FROM THE UPPER MS VALLEY SEWD THROUGH THE OH VALLEY...AS WELL AS EAST OF LEE TROUGH OVER THE ERN CAROLINAS AND VA. THIS REGION WILL EXIST ALONG NRN FRINGE OF STEEPER LAPSE RATES ASSOCIATED WITH EML. SFC HEATING AND VORTICITY MAXIMA EMBEDDED WITHIN THE NWLY FLOW REGIME WILL LIKELY SUPPORT THUNDERSTORM DEVELOPMENT IN VICINITY OF THE FRONT AND ALONG AND EAST OF LEE TROUGH. NWLY UPPER FLOW WITHIN BASE OF UPPER TROUGH WILL SUPPORT 30-40 KT EFFECTIVE SHEAR. CLUSTERS OF STORMS DEVELOPING WITHIN THIS ENVIRONMENT WILL POSE A THREAT FOR ISOLATED LARGE HAIL AND DAMAGING WIND THROUGH MID EVENING. ...SERN STATES... RICH LOW LEVEL MOISTURE...AMPLE DIABATIC HEATING AND STEEP LAPSE RATES WILL PROMOTE STRONG INSTABILITY DURING THE AFTERNOON OVER MUCH OF THE SERN STATES. SUBSIDENCE ASSOCIATED WITH UPPER RIDGE AND CAPPING WITH REMNANT EML WILL HAVE THE POTENTIAL TO SUPPRESS CONVECTION OVER MUCH OF THIS REGION. HOWEVER...EXPECT AT LEAST ISOLATED STORMS TO DEVELOP...AND WHERE STORMS INITIATE A THREAT WILL EXIST FOR ISOLATED DAMAGING WIND AND HAIL THROUGH EARLY EVENING. ...UPPER MS VALLEY REGION... POTENTIAL WILL EXIST FOR STORMS TO DEVELOP WITHIN ZONE OF ISENTROPIC ASCENT NORTH OF STATIONARY FRONT OVER THE UPPER MS VALLEY AND GREAT LAKES REGION WHERE THE ATMOSPHERE WILL BECOME MODERATELY UNSTABLE AND WHERE SHEAR WILL BE SUFFICIENT FOR ORGANIZED CONVECTION. HOWEVER...HEIGHT RISES WITH BUILDING RIDGE AND GENERAL WEAK DEEP LAYER FORCING LOWERS CONFIDENCE IN STORM COVERAGE. THIS AREA WILL CONTINUE TO BE MONITORED FOR A POSSIBLE SLIGHT RISK IN LATER OUTLOOKS. ..DIAL.. 06/30/2012 NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z CURRENT UTC TIME: 1338Z (8:38AM), RELOAD THIS PAGE TO UPDATE THE TIME 
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