VORTEX STATUS MESSAGE AND FORECAST DISCUSSION
NATIONAL SEVERE STORMS LABORATORY
1130 AM CDT APRIL 18 1995


OPERATIONAL STATUS AT 1130 CDT:  NO GO (Survey day)
TARGET AREA:  NONE  
SUPPLEMENTAL SOUNDING/ARCHIVE II REQUESTS:  NONE ... VORTEX
NWS raob sites have been put on alert for tomorrow. 

DAILY FORECAST DISCUSSION:

With major cyclogenesis having occurred overnight, the
surface moisture has been carred well out of the VORTEX ops
area today.  An interesting feature is the persistence of a
thermal boundary this morning across OK and into west TX
just south of the panhandle.  The surface winds over most of
TX are weak and the thermal gradient there this morning is 
probably not going to survive the daytime heating, so it ap-
pears that the surface thermal boundary will end up some-
where in north TX by the end of the day.  Although today is
a dead duck, there is a real chance for an interesting situ-
ation tomorrow.

As noted in the early Day2 by SELS, the models are bringing
another in the series of vigorous systems out across the 
plains, this time further south.  Given that the drive that 
is pushing the low-level moisture away has weakened consid-
erably and that another strong system is approaching, we 
could be developing a moisture return by evening, to be en-
hanced by the nocturnal jet.  This is supported in the 12Z
RUC and ETA, with the ETA timing looking pretty favorable
for severe in southeastern OK and northeastern TX, within
the VORTEX ops area.  The surfave boundary will be a focus
and it appears it will be somewhere near the Red River by
morning.  A day of heating should bring back strong delta-t
values over the high terrain, to be swept eastward into the
threat area   The 12Z ETA indicates strong H700 flow and the
UVV moving across the area by 18Z, so the show might be an
early one.  As always, the timing will be tough to predict.
It also appears that a supercell-favorable hodograph will be
in place by tomorrow.

	Doswell 

PROBABILITIES OF OCCURRENCE IN VORTEX OPS AREA THRU 04Z (DAY1) 
AND 12-04Z (DAY2)...
                           DAY1    DAY2
LIGHTNING                   10      70
SEVERE                      02      50
TORNADOES                   00      30
TARGETABLE STORM            00      40

FCST STORM MOTION - TARGETABLE STORMS ONLY
PRE-SUPERCELL             -N/A-   240/35
SUPERCELL                 -N/A-   270/25

FCST INITIATION TIMES (LT) - TARGETABLE STORMS ONLY 
LIGHTNING                 -N/A-   1330 
1ST SEVERE RPT            -N/A-   1415
1ST TORNADO               -N/A-   1445