VORTEX STATUS MESSAGE AND FORECAST DISCUSSION
NATIONAL SEVERE STORMS LABORATORY
1130 AM CDT APRIL 29 1995


OPERATIONAL STATUS AT 1130 CDT:  GO
TARGET AREA:  SErn OK and NErn TX
SUPPLEMENTAL SOUNDING/ARCHIVE II REQUESTS:  18Z and 21Z spe-
cial soundings at MAF and FWD, Level II archive at KTLX, FWD
and KFDR  

DAILY FORECAST DISCUSSION:

Situation as analyzed here looks pretty much as described in
the morning SELS AC.  A shortwave trough moving through the
basically zonal flow has produced an MCS overnight with an
associated outflow boundary that has been moving southward
across OK this morning.  That movement has been slowing down
and the boundary will end up in southern and southeastern OK
this afternoon.  A cold front has moved into northwestern OK
this morning and a dryline trails south-southwestward from
the surface low in southwestern OK.  Enough cold advection
is seen to expect the cold front to continue to advance to 
the southeast today, but it should slow down.  High mid-tro-
pospheric lapse rates and sufficient moisture are present to
yield CAPES in excess of 2500 J kg-1.  Strong turning of the
hodograph, even with the decay of the nocturnal "jet" should
give helicities of at least 300 J kg-1, so supercells are a
reasonable bet.  700 flow is increasing, at least according
to the 12Z RUC H700 height gradient.  Big question is the 
speed of the flow in the upper troposphere.  It appears that
by this evening, there should be 55-65 kts at H300 somewhere
in the vicinity of the Red River, which ought to be just
enough to prevent storms from being excessively outflow dom-
inated.  Storms should develop near the surface low in the
vicinity of the cold front-dryline-outflow boundary inter-
section and move relatively slowly for April.

Tomorrow looks promising as well.  The NGM and ETA differ 
as to the details ... which often are critical ... but it
appears that the surface low and associated boundaries is 
not going very far from today's positions and the H500 progs
show an increase in the flow and a significant shortwave 
trough affecting the area tomorrow.  As always, a big ques-
tion are mesoscale boundaries associated with today's action
but will have to wait and see about those, of course.

	Doswell/Crisp

PROBABILITIES OF OCCURRENCE IN VORTEX OPS AREA THRU 04Z (DAY1) 
AND 12-04Z (DAY2)...
                           DAY1    DAY2
LIGHTNING                   95      80
SEVERE                      80      70
TORNADOES                   40      30
TARGETABLE STORM            70      60

FCST STORM MOTION - TARGETABLE STORMS ONLY
PRE-SUPERCELL             270/25  270/30
SUPERCELL                 315/15  300/20

FCST INITIATION TIMES (LT) - TARGETABLE STORMS ONLY 
LIGHTNING                 1545    1600 
1ST SEVERE RPT            1630    1645
1ST TORNADO               1645    1715