SPC AC 162018 COR      STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK    DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.      VALID 162000Z - 171200Z    THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF MN AND PORTIONS FAR    WRN WI...TO THE RIGHT OF A LINE FROM 30 E INL DLH 40 WNW EAU RST 20    ESE FRM 25 WSW OTG 30 NE BKX 75 N GFK.    THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE TO THE RIGHT OF A LINE    FROM 20 NNE ELO 20 NNW IWD 20 SSW RHI CWA LNR DBQ P35 TOP MHK CNK    HSI GRI YKN ATY 65 NNW DVL.    THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM SJT    GAG 40 SSE DDC 25 SSW ICT DUA 30 E DAL 25 ESE ACT TPL SJT.    GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SSE TLH AUO ANB    40 WNW CHA LEX LUK 35 NW LUK 50 E BMG OWB SHV 20 NW LFK CLL AUS    JCT 55 N DRT 70 SW SJT 55 NE BGS CDS 25 SSE DDC 40 SW HLC GLD AKO    30 NW SNY AIA PIR MBG BIS P24 70 NNE ISN.      --- SYNOPSIS ---    DOMINANT LONGWAVE FEATURE REMAINS WRN CONUS TROUGH...WITH THREE    PRIMARY SHORTWAVES OF INTEREST. STRONGEST IS EVIDENT ON MOISTURE    CHANNEL IMAGERY ATTM OVER CENTRAL ROCKIES...FORECAST TO LIFT ACROSS    NRN PLAINS THROUGH REMAINDER PERIOD. SRN STREAM TROUGH NOW MOVING    ACROSS PORTIONS TX/OK HAS CONTRIBUTED TO AREA OF CLOUDS/PRECIP AND    SHOULD EJECT NEWD OVER MO THIS EVE/TONIGHT...NEARLY IN PHASE WITH    CENTRAL ROCKIES PERTURBATION. WEAK SRN STREAM TROUGH FOLLOWS    IMMEDIATELY BEHIND -- EVIDENT IN MOISTURE CHANNEL IMAGERY AND    PROFILER LOOPS ATTM INVOF TX/NM BORDER.      AT SURFACE...INTENSE CYCLONE NOW ANALYZED OVER SERN ND SHOULD MOVE    NEWD ACROSS EXTREME NWRN MN THIS EVENING...WITH WARM FRONT NOW IN    LATTER AREA LIFTING NWD INTO NWRN ONT. COLD FRONT OVER ERN    SD/CENTRAL NEB WILL SWEEP EWD OVER REMAINDER OF THOSE STATES AND    OVER MUCH OF MN/IA BY END OF PERIOD. DRYLINE -- NOW ANALYZED FROM    CENTRAL NEB SSWWD ACROSS EXTREME WRN OK TO RIO GRANDE NEAR DRT --    WILL MOVE SLOWLY EWD OVER KS/OK/NW TX REMAINDER AFTERNOON.      --- UPPER MIDWEST ---    SEVERAL CAVEATS EVIDENT WHICH COMPEL DOWNGRADE IN BOTH SEVERE    COVERAGE PROBABILITIES AND CATEGORICAL OUTLOOK RISK. HOWEVER...    POSSIBILITY REMAINS FOR INITIATION IN AN ARC ALONG COLD    FRONT/DRYLINE OVER ERN SD/ERN NEB/WRN MN...WHICH WOULD POSE THREAT    OF WIND DAMAGE AND LARGE HAIL GIVEN VERY STEEP MID LEVEL LAPSE    RATES AND MODERATE-STRONG BUT ALMOST UNIDIRECTIONAL VERTICAL WIND    PROFILES PER LATEST VWP/PROFILER/RAOBS. REGIONAL 18Z SOUNDINGS    SHOW VERY STRONG CAPPING REMAINING OVER THIS REGION AT BASE OF    ELEVATED/MIXED-LAYER AIR MASS...WITH SOME MID LEVEL LAPSE RATES    EXCEEDING 9 DEG C/KM. SOME TCU EVIDENT ATTM ALONG ERN NEB DRYLINE.    STRONG LARGE-SCALE ASCENT IN MIDLEVELS EVIDENT UPSTREAM IN FORM OF    DEEP ACCAS PLUME OVER ERN CO/WRN KS/SW NEB. MAIN CONCERN IS OVER    SUFFICIENCY AND EXTENT OF FRONTAL LIFT STRONG ENOUGH TO BREAK CAP    -- ESPECIALLY GIVEN LACK OF SUBSTANTIAL PRESSURE FALLS AHEAD OF    FRONT TO AID IN CONVERGENCE VIA ISALLOBARIC FORCING IN WARM SECTOR.    PRIND MOST PROBABLE CORRIDOR FOR CONCENTRATED SEVERE EVENT REMAINS    FROM FSD/SUX REGION NNEWD...WITH DEVELOPMENT MORE CONDITIONAL    FARTHER S AND E.      --- SRN PLAINS ---    DRYLINE CONVECTIVE INITIATION APPEARS PROBABLE NEXT FEW HOURS...    WITH VERY STEEP LAPSE RATES BEING MAINTAINED AHEAD OF TX/NM BORDER    UPPER TROUGH...AND CUMULIFORM CLOUD DEVELOPMENT ON VIS IMAGERY    BETWEEN DRYLINE AND CAPROCK OVER PORTIONS W-CENTRAL/NW TX AND NW    OK. MOST DENSE CU DEVELOPMENT ATTM IS JUST DOWNSTREAM FROM AND    ASSOCIATED WITH CONFLUENCE LINE WELL-EVIDENT IN STREAMLINE ANALYSIS    OVER SWRN OK...AND ATTM NEARBY PORTIONS DRYLINE APPEARS TO BE MOST    FAVORED AREA FOR INITIATION. CURRENT VWP/PROFILER AVAILABLE DATA    AND NOWCAST VERTICAL SHEAR PROFILES SUPPORT STORM ROTATION...WITH    FORECAST SOUNDING DATA SHOWING NARROW PLUME OF 2000-3000 J/KG    MLCAPE AVAILABLE TO ANY CONVECTION THAT FORMS OVER NW TX/WRN OK.    LARGE HAIL WILL BE MAIN THREAT...DAMAGING WIND POSSIBLE...TORNADO    POTENTIAL APPEARING BRIEF/MARGINAL ATTM WITH SOMEWHAT HIGH LFC AND    COLD DOWNDRAFT POTENTIAL.      ISOLATED TCU/CB DEVELOPING IN REGION WELL AHEAD OF DRYLINE...WITH    WEAK TO NO CONVERGENCE BUT ALSO WEAK CAPPING...ALSO MLCAPE AOA 3000    J/KG AND LARGE BOUNDARY11 LAYER HODOGRAPHS OVER PORTIONS CENTRAL/N-    CENTRAL TX. REF SPC MESOSCALE DISCUSSION 380 FOR DETAILS.    ..EDWARDS.. 04/16/02       NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 0100Z