VORTEX STATUS MESSAGE AND FORECAST DISCUSSION
NATIONAL SEVERE STORMS LABORATORY
1130 AM CDT SUN APRIL 9 1995


OPERATIONAL STATUS AT 1100 CDT: GO
TARGET AREA:  SW OK, N CNTRL TX
SUPPLEMENTAL SOUNDING/ARCHIVE II REQUESTS: 18/21Z SNDGS 
REQUESTED FM ALL VORTEX RAOB SITES TDA; ALL SITES ALSO
ON STANDBY FOR SUPPLEMENTAL SNDGS MON. WE REQUEST AVBL 
ARCHIVE II BE ACTIVATED AT ALL 88D SITES INVOF TARGET AREA. 

DAILY FORECAST DISCUSSION:
NOT AN EASY ONE. CDFNT CONTS DRIVING S THRU CNTRL OK INTO
N CNTRL TX WITH DRYLN TRPL PT VCNTY RED RVR W OF SPS. EXPC
FNT TO SLOW THIS AFTN AS LEAD SFC WAVE CRNTLY SERN KS WKNS 
AND PRES FALLS DVLP FRTHR W IN RESPONSE TO DIGG SYS OVR 
RCKYS. 12Z UA DATA AND LTST RUC SUGGEST SYS WL DIG MORE
STGLY THAN INDCD BY PROGS. THIS COMPLICATES TIMING ISSUE
FOR TDA, AS PRES FALLS MAY BE SLOWER TO SPRD EWD INTO HI
PLAINS. WE EXPC PRES FALLS TO BEGIN BACKING LL FLOW BY LATE
AFTN, HOWVR, WITH DRYLN AND ASSOCD TRPL PT RMNG IN SAME GENL 
AREA THRU EARLY EVE. TWO MESOSCALE SCENARIOS BEING CONSDRD.
ONE IS DVLPMT NR TRPL PT AS DIURNAL HTG WKNS STG CAP ENUF 
FOR LL CONVGC TO INITIATE CONVCTN. AVBL CAPE NR 3000 BY MAX
HTG INDCS POTL FOR RPD DVLPMT IF CAP BRKS, WITH STMS MOVG/
DVLPG NEWD ALG QSTNRY FNT. ADDL DVLPMT ALSO PSBL SWD ALG 
DRYLN INTO NRN TX. OTR SCENARIO IS DVLPMT ALG FNT 
FRTHR W OVR SRN TX PNHDL OR S PLAINS AREA. MSTR WL BE NEG
FACTOR THERE, BUT WE CUD SEE ENUF LL MSTR BHD FNT TO 
DESTBLZ AMS IN REGION WHERE CAP WL BE WKR.  ARMADA WL HEAD 
TWD RED RVR AREA OF SW OK NRN TX INITIALLY TO BE IN POSN
FOR ANY OF THESE SCENARIOS. DUE TO DELAY OF UPR DYNAMICS
AND MID-LVL COOLING, WE EXPC A LATE SHOW.

LTL TIME TO EXAMINE DAY2 CLOSELY, BUT WITH WRN TROF EXPCD TO 
DIG STGR THAN PROGGED, DYNAMIC FORCING MAY CONT INTO MON AND 
MAINTAIN A RISK OF SVR FRTHR W THAN EARLIER EXPCD, INCLDG
ERN PTNS OF VORTEX AREA. BUT SNC IT ALSO INCRSS POTL FOR 
DVLPMT OVNGT, DAY2 MAY BE GUNGED IF WDSPRD CONVCTN FIRES OVR 
AREA TNGT.  BRANICK/BURGESS

PROBABILITIES OF OCCURRENCE IN VORTEX OPS AREA THRU 04Z (DAY1) 
AND 12-04Z (DAY2)...
                           DAY1    DAY2
LIGHTNING                   70      90
SEVERE                      60      60
TORNADOES                   30      30
TARGETABLE STORM            40      30

FCST STORM MOTION - TARGETABLE STORMS ONLY
PRE-SUPERCELL             23035   22045
SUPERCELL                 26025   25035

FCST INITIATION TIMES (LT) - TARGETABLE STORMS ONLY 
LIGHTNING                 1800L   1300L 
1ST SEVERE RPT            1845L   1330L
1ST TORNADO               1930L   1415L