VORTEX STATUS MESSAGE AND FORECAST DISCUSSION NATIONAL SEVERE STORMS LABORATORY 1130 AM CDT APRIL 17 1995 OPERATIONAL STATUS AT 1130 CDT: GO TARGET AREA: North TX/Southwestern OK SUPPLEMENTAL SOUNDING/ARCHIVE II REQUESTS: Special 18Z and 21Z soundings from all raob sites in the VORTEX ops area and Archive II from KLTX, FWS, KFDR, AMA, LBB, DYS DAILY FORECAST DISCUSSION: potent situation dvplg this mrng as high energy short wave lifts out of long-wave trof and acrs the srn and cntrl plains. the most problematic feature is a sfc cold air pool which has moved swd to nr a muskogee-waurika-20 s sps line at 16z. the bndry was beginning to lift nwd at 16z as a stg dry punch with a pres fall/rise couplet movd newd out of se and scntrl nm. at 15z ruc helicities were showing values of 250-400 in a band from near abi to the ern pnhdl with capes nr 2500 in the abi area. as the dry punch apprchs the slower movg wrmfnt stg-svr tstms wl begin to dvlp abt 1330-1400 local time nr a lbb-25 ne abi-70 w act ln. other storms wl form nr the wrmfnt where low-lvl turning of the winds wl be maximized. combo of helicities nr 400 and capes of 3000-3500 suggests a significant threat of supercells and tornadoes acrs mainly extrm nrn n tx and srn/swrn ptns of ok. threat of tornadoes will continue into the evening acrs mainly the ern 1/2 of ok. the srn bndry of the threat area will be dictated by a stg capping inversion...whereas the nrn extent of the tornado threat area will be determined by how far the wrmfnt retreats this aftn/eve. Moller/Doswell PROBABILITIES OF OCCURRENCE IN VORTEX OPS AREA THRU 04Z (DAY1) AND 12-04Z (DAY2)... DAY1 DAY2 LIGHTNING 100 05 SEVERE 100 02 TORNADOES 60 02 TARGETABLE STORM 90 02 FCST STORM MOTION - TARGETABLE STORMS ONLY PRE-SUPERCELL 210/40 -N/A- SUPERCELL 235/30 -N/A- FCST INITIATION TIMES (LT) - TARGETABLE STORMS ONLY LIGHTNING 1330 -N/A- 1ST SEVERE RPT 1430 -N/A- 1ST TORNADO 1600 -N/A-