CATEGORICAL OUTLOOK
PROBABILISTIC OUTLOOK
SPC AC 041644 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 AM CDT MON JUN 04 2012 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF CNTRL MT... ...THERE IS A SLGT RISK OF SVR TSTMS FOR PORTIONS OF SRN GA/SERN AL/NRN FL... ...SYNOPSIS... AN OMEGA-BLOCKING PATTERN WILL PERSIST THROUGH THE DAY TWO PERIOD...FEATURING A HIGH-AMPLITUDE RIDGE OVER THE GREAT PLAINS WHICH WILL BE BRACKETED BY TROUGHS OVER THE INTERMOUNTAIN WEST AND ERN THIRD OF THE NATION. WITHIN THIS BROADER-SCALE PATTERN...AN INTENSE VORTICITY MAXIMUM AND ASSOCIATED 60-70 KT MIDLEVEL JET STREAK INITIALLY OVER THE SIERRA NEVADAS INTO GREAT BASIN WILL PROGRESS NEWD INTO THE NRN HIGH PLAINS WITH A CORRIDOR OF 50-100 M/12-HR HEIGHT FALLS AT 500 MB FORECAST ALONG SYSTEM TRACK. ELSEWHERE...A SERIES OF LOW-AMPLITUDE PERTURBATIONS WILL EXIST ALONG CYCLONIC SIDE OF 40-50 KT MIDLEVEL JET CORE SETTLING SWD THROUGH THE TN VALLEY AND SERN STATES. AT THE SURFACE...LEE CYCLOGENESIS WILL OCCUR TUESDAY OVER CNTRL MT IN RESPONSE TO LOWERING MIDLEVEL HEIGHTS/DCVA PRECEDING THE GREAT BASIN SYSTEM MENTIONED ABOVE. AT THE SAME TIME...A STRENGTHENING PACIFIC FRONT WILL ADVANCE EWD THROUGH THE NRN INTERMOUNTAIN REGION...EVENTUALLY LINKING WITH THE SURFACE LOW OVER THE NRN HIGH PLAINS TUESDAY NIGHT. THE SRN EXTENSION OF THE PACIFIC FRONT WILL MAKE STEADY SEWD PROGRESS INTO THE CNTRL ROCKIES AND LOWER CO VALLEY. FARTHER E...A COLD FRONT INITIALLY FROM THE LOWER SAVANNAH RIVER VALLEY WWD THROUGH THE LOWER MS VALLEY INTO SRN PLAINS WILL MOVE SWD/SWWD ACROSS THE GULF COAST STATES. ...NRN HIGH PLAINS... LOW-LEVEL MASS RESPONSE TO APPROACHING VORTICITY MAXIMUM --MANIFEST AS A 30-40 KT SSELY LLJ AND SURFACE LEE CYCLOGENESIS-- WILL MAINTAIN A MOIST UPSLOPE FLOW COMPONENT BENEATH STEEPENING MIDLEVEL LAPSE RATE PLUME PRECEDING UPPER SYSTEM. LATEST MODEL GUIDANCE INDICATES THAT DEEPER PBL MIXING WILL RESULT IN A DECREASE IN LOW-LEVEL MOISTURE THROUGH THE AFTERNOON OVER S-CNTRL MT...WITH THE STRONGEST DESTABILIZATION /I.E. MLCAPE OF 1500-2500 J PER KG/ FORECAST FROM THE WRN DAKOTAS/FAR ERN MT NWWD INTO N-CNTRL MT. MULTI-MODEL CONSENSUS IS SUGGESTIVE THAT THE HIGHEST LIKELIHOOD FOR STORM INITIATION AND SUSTENANCE WILL BE LATE TUESDAY AFTERNOON INTO EVENING WITHIN IMMEDIATE POST-FRONTAL ENVIRONMENT W/NW OF SURFACE LOW WHERE THE CAP WILL BE THE WEAKEST. HERE...THE WRN EXTENSION OF LOW-LEVEL INSTABILITY AXIS WILL COINCIDE WITH MODERATELY STRONG DEEP-LAYER SHEAR WITH THE POTENTIAL FOR ORGANIZED STORM MODES --INCLUDING SUPERCELLS-- WITH A RISK FOR DAMAGING WINDS AND LARGE HAIL. ...SERN U.S... CONVECTIVE EVOLUTION AND RESULTANT SEVERE THREAT WILL BE MODULATED TO SOME DEGREE BY ANTECEDENT TSTM ACTIVITY DURING THE DAY ONE PERIOD. STILL...IT APPEARS THAT DIURNALLY ENHANCED STORM DEVELOPMENT WILL BE FAVORED ALONG COLD FRONT AND PRE-EXISTING CONVECTIVE OUTFLOW BOUNDARIES SAGGING SWD. THE MOST INTENSE STORMS MAY BE FOCUSED ACROSS PARTS OF GA INTO NRN FL WHERE DEEP-LAYER SHEAR AND FORCING FOR ASCENT WILL BE ENHANCED BY A VORTICITY MAXIMUM PROGRESSING SEWD THROUGH THE SRN APPALACHIANS. GIVEN THE PRESENCE OF A MOIST...MODERATELY UNSTABLE WARM SECTOR /I.E. MLCAPE OF 1500-3000 J PER KG/...SETUP WILL FAVOR ORGANIZED STORM CLUSTERS WITH A RISK FOR DAMAGING WINDS AND HAIL. ...LOWER MS VALLEY INTO SRN PLAINS... SCATTERED TSTMS APPEAR LIKELY ALONG COLD FRONT TUESDAY AFTERNOON/EVENING WITHIN A MODERATELY UNSTABLE BUT GENERALLY WEAKLY SHEARED ENVIRONMENT. WHILE ISOLATED OCCURRENCES OF DAMAGING WINDS AND HAIL WILL BE POSSIBLE...WEAK SHEAR AND FORCING FOR ASCENT WILL PRECLUDE A MORE ORGANIZED SEVERE WEATHER THREAT. ...CNTRL HIGH PLAINS... ISOLATED-WIDELY SCATTERED TSTMS WILL BE POSSIBLE TUESDAY AFTERNOON/EVENING ALONG LEE TROUGH WITHIN A STEEP LAPSE RATE ENVIRONMENT. MARGINAL BOUNDARY LAYER MOISTURE CONTENT /AND RESULTANT INSTABILITY/ AND WEAK VERTICAL SHEAR WILL LIMIT UPDRAFT STRENGTH/LONGEVITY. STILL...A FEW MARGINALLY SEVERE STORMS WILL BE POSSIBLE WITH A RISK FOR GUSTY WINDS AND SOME HAIL. ..MEAD.. 06/04/2012 NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z CURRENT UTC TIME: 1753Z (12:53PM), RELOAD THIS PAGE TO UPDATE THE TIME 
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