VORTEX STATUS MESSAGE AND FORECAST DISCUSSION
NATIONAL SEVERE STORMS LABORATORY
1130 AM CDT APRIL 27 1995


OPERATIONAL STATUS AT 1100 CDT:
TARGET AREA:  n/a  
SUPPLEMENTAL SOUNDING/ARCHIVE II REQUESTS:  

DAILY FORECAST DISCUSSION:
Air mass has stabilized across the vortex area as cold high
pressure dome moved southward into Tx and Ok overnight.
Thus no ops are planned for today.

Increasing westerlies aloft and a series of approaching 
mid-level disturbances will result in a southerly low-lvl
jet and moist isentropic lift across north Tx and Ok at the
295-300 deg. surfaces tngt.  Strong mid-lvl lapse rates in 
place across sw tx and nm will spread northeastward as large
scale lift moves into the area, setting the stage for some 
elevated thunderstorms tonight and early friday across n tx
and portions of ok. Some of these storms could produce small
hail. 

The convective focus will shift into northwest Texas, 
western Oklahoma, and southwest Kansas Friday afternoon and
evening as a dry line forms southward from a developing 
surface low in southwest Kansas.  The main question is
once again return flow.  Should 60 degree dew points advect 
all the way to the triple point (unlikely) sw Ks would bcm
a choice target.  Otherwise, an intersection between the 
dry line and returning warm front might offer an excellent 
low-level shear structure.  12Z eta suggests that the 
highest SR helicity values will be across the northeast
1/2 of Oklahoma Friday evening.  However, I think the 
mid-level wind structure (and possibly even the low-level 
jet) are underforecast (as usual) in northwest Texas, so
attm the dry line/warm front intersection appear to be a
good bet for Friday.  Apprchg difluent upr jet wl aid in
svr potential acrs the nw Tx/ Wrn Ok late Friday.       

Moller

PROBABILITIES OF OCCURRENCE IN VORTEX OPS AREA THRU 04Z (DAY1) 
AND 12-04Z (DAY2)...
                           DAY1    DAY2
LIGHTNING                   10      99
SEVERE                      01      70
TORNADOES                   00      30
TARGETABLE STORM            01      60
FCST STORM MOTION - TARGETABLE STORMS ONLY
PRE-SUPERCELL             2825    2630
SUPERCELL                  n/a    2925  

FCST INITIATION TIMES (LT) - TARGETABLE STORMS ONLY 
LIGHTNING                  n/a     1530 
1ST SEVERE RPT             n/a     1630
1ST TORNADO                n/a     1730