939
ACUS1 KMKC 121453
SWODY1
-MKC AC 121453

CONVECTIVE OUTLOOK...REF AFOS NMCGPH94O.

VALID 121500Z - 131200Z

REF WW NUMBER 360...VALID TIL 1600Z

THERE IS A HIGH RISK OF SVR TSTMS OVR MUCH OF KS...SRN NEB...WRN MO...NWRN AR...AND NRN AND CNTRL OK. THE HIGH RISK AREA IS TO THE RIGHT OF A LINE FROM 20 W MLC 35 W OKC DDC IML BBW 20 W OLU OMA SZL SGF FSM 20 W MLC.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM PSX ABI 10 NE CDS LBL AKO 40 W CDR PIR OTG OTM JEF MLU 15 S SSI...CONT... VRB SRQ.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 E CRP DRT HOB FMN P38 U31 WMC BOI JAC SHR 45 N ISN ...CONT... 20 WSW CMX MTW LAF BNA GAD AGS 15 NE ECG.

...SEVERE THUNDERSTORM FORECAST DISCUSSION...

12Z UPR AIR DATA CONFIRM TRENDS FM 00Z MODEL RUNS SUGG CONTD PTNL FOR SGFNT OUTBREAK OF SVR WX OVR PTNS OF THE PLAINS LTR THIS AFTN AND TNGT. STLT IMAGERY INDCS SERIES OF UPR SHRTWV TROFS MOVG EWD FM THE PAC CST INTO THE CNTRL PLAINS AS VERY STG ZONAL MID/UPR LVL JET SURGES EWD FM CA ACRS THE ROCKIES. DEEP SFC LOW HAS ALREADY DVLPD IN LEE TROF OVR ERN CO IN RESPONSE TO THE OROGRAPHIC AND DYNAMIC FORCING. MODELS INDC SFC LOW WILL CONT TO DEEPEN AS IT MOVES SLOLY NEWD INTO NEB BY THE END OF THE PD. 12Z UPR AIR DATA AND PROFILERS INDC 40-50 KT SLY WINDS HAVE ALREADY DVLPD ABV THE SFC...AND THIS IS RESULTING IN THE NWD RTRN OF MSTR FM TX INTO THE HI PLAINS RGN ATTM. MSTR IS EXPCD TO CONT TO SPRD NWD THRU THE PLAINS WITH SFC DEW POINTS OF 60-65F ANTICIPATED INTO PTNS OF KS AND MO BY THIS EVE. THIS WILL CONTRIBUTE TO SUBSTANTIAL DESTABILIZATION IN THE WARM SECTOR WITH LIFTED INDEX OF MINUS 5 TO MINUS 8 AND CAPE VALUES OF 2500-3500 J/KG EXPCD.

TSTM ACTVTY IS EXPCD TO RDVLP DURG THE MID/LATE AFTN FM NERN CO SWD INTO WRN KS AS CDFNT/DRYLN MOVES EWD INTO INCRGLY MOIST AND UNSTBL AMS. ACTVTY IS LIKELY TO CONT DVLPG SWD ALG DRYLN INTO WRN OK BY THIS EVE. SVR THREAT IS EXPCD TO INCR SGFNTLY LATE THIS AFTN INTO TNGT AS NOSE OF STG MID/UPR LVL JTSTR MOVES EWD ACRS NRN OK/SRN KS RGN AND CDFNT/DRYLN SURGES EWD DURG THE NIGHT. INCRGLY STG WIND FIELDS ALF /60 KT AT 850 MB AND 90 KT AT 500 MB/ THAT VEER STGLY WITH HGT WILL CREATE A VERY FVRBL SHEAR/HELICITY ENVIRONMENT SUPPORTIVE OF SVR TSTMS AND SUPERCELL DVLPMT. FVRBL VERT STORM-RELATIVE WINDS ALSO SUG STG PTNL FOR TORNADO DVLPMT IN THE HIGH RISK AREA...WITH THE GREATEST THREAT SPRDG EWD FM THE HI PLAINS LATE THIS AFTN ACRS THE CNTRL PLAINS AREA TNGT. STRENGTH OF THE DYNAMIC FORCING INDCS SVR PTNL WILL CONT THRUT THE NIGHT.

12Z SNDGS INDC VERY MOIST AND UNSTBL AMS PERSISTS ALG THE GULF CST RGN TDA WITH LIFTED INDEX TO MINUS 8 AND CAPE VALUES TO 3500 J/KG. MDTLY STG WLY FLOW OF 40-50 KT AT 500 MB WILL MAINTAIN SUFF VERT SHEAR ACRS THE AREA TO ENHANCE CONTD PTNL FOR SVR TSTMS FM THE GULF CST INTO NRN/CNTRL PTNS OF FL.

A PUBLIC SEVERE WEATHER OUTLOOK /AFOS MKCPWOMKC/ WILL BE ISSUED AROUND 11 AM CDT.

..WEISS.. 05/12/95

...GENERAL THUNDERSTORM FORECAST DISCUSSION...

SAT IMAGERY SHOWS UPR LVL SHRTWV TROF MOVG EWD INTO WRN PTNS OF UT THIS MRNG. COLD MID LVL TEMPS (500MB LESS THAN -20 DEG) EXIST N OF THE MAIN JET AXIS WHICH EXTDS FM CNTRL PTNS OF CA INTO THE SRN RCKYS. AS INSOLATION INCRS EXPC LAPSE RATES TO STEEPEN ACRS MUCH OF THE CNTRL RCKYS RGN AHD OF APCHG UPR LVL SYS. NEG LI/S ARE EXPCD TO REMAIN WK BUT QUITE COLD MID LVL TEMPS (LOW WBZ LVLS) MAYBE SUF FOR ISOLD TSTMS TO PRODUCE SMALL HAIL.

..DARROW.. 05/12/95