VORTEX STATUS MESSAGE AND FORECAST DISCUSSION NATIONAL SEVERE STORMS LABORATORY 1130 AM CDT SUN APRIL 16 1995 OPERATIONAL STATUS AT 1100 CDT: GO TARGET AREA: NW/NCNTRL OK BTWN CSM AND END SUPPLEMENTAL SOUNDING/ARCHIVE II REQUESTS: CLASS SNDGS BUT NO SUPPLEMENTAL NWS SNDGS. ARCHIVE II REQUESTED FM ALL 88D SITES VCNTY NRN OK SRN KS. DAILY FORECAST DISCUSSION: LL WINDS VEERING ACRS SCNTRL KS, REDUCING CONVGC AND DIR SHEAR INVOF BNDRY ACRS SRN/SERN KS. 12Z NGM/ETA AND LTST SFC ANAL INDC FNT SAGGING SWD INTO NRN/WRN OK THIS AFTN, WHILE LTST RUC HINTS AT BACKING OF LL FLOW AHD OF FNT AND RESULTANT POOLING OF LL MSTR IN NW OK. PERSISTENT CI WL INHIBIT DIURNAL HTG, BUT CAP FCST TO BE WKR FRTHR N WHICH FAVORS A MORE NRN TARGET AREA. FRTHR SW, DRYLN EXPCD TO MAKE ONLY SLGT EWD PROGRESS THIS AFTN ACRS SWRN OK AND WRN TX DUE TO DEPTH OF MOIST LYR. STGR AND MORE BACKED SLY FLOW AHD OF DRYLN ACRS WRN/ CNTRL TX IMPLIES POTL FOR MSTR CONVGC TO FOCUS ALG DRYLN IN CDS-ABI-LBB AREA DURG AFTN, ESPLY IF STGR WLY LL FLOW DVLPS BHD DRYLN. THIS AREA ALSO EXPCD TO BE ON NRN EDGE OF STGR CAP, AND THUS CUD BE HELD DOWN BY CI WHICH WL CONT TO REDUCE AFTN HTG. POWERHOUSE TROF RIPS NEWD INTO HI PLAINS ON MON SETTING UP POTL SGFNT SVR EPISODE. ATTM WE FEEL THAT MDLS ARE TOO FAST AT DRIVING THE DRYLN EWD THRU OK. EXPC DRYLN TO RETREAT WELL INTO W TX TNGT IN RESPONSE TO PRES/WND ADJUSTMENTS TO APCHG UPR SYS. SFC LOW EXPCD TO ORGANIZE OVR SERN CO LATE TNGT AND INTSFY OVR WRN KS MON, WITH DRYLN PUNCHING STGLY THRU SWRN KS AND WRN HLF OK /RATHER THAN ENTIRE STATE/ DURG DAY. STRENGTH OF DYNAMICS IMPLIES THAT TIMING AGN WL BE CRITICAL. SQLN DVLPMT MAY PVL VS ISOLD SUPERCELLS, AND THE USUAL RISK OF CONTAMINATION FM OVNGT CONVCTN LOOMS. WHATEVER DVLPS ON MON WL MOVE RPDLY AND LKLY WL MAKE IT TUFF FOR FIELD TEAMS TO STAY WTH. BRANICK/MCCAMMON PROBABILITIES OF OCCURRENCE IN VORTEX OPS AREA THRU 04Z (DAY1) AND 12-04Z (DAY2)... DAY1 DAY2 LIGHTNING 90 100 SEVERE 80 95 TORNADOES 20 50 TARGETABLE STORM 30 60 FCST STORM MOTION - TARGETABLE STORMS ONLY PRE-SUPERCELL 23038 23052 SUPERCELL 26030 25042 FCST INITIATION TIMES (LT) - TARGETABLE STORMS ONLY LIGHTNING 1500L 1200L 1ST SEVERE RPT 1545L 1230L 1ST TORNADO 1630L 1330L