re: Tornado! Multi State Outbreak - New Tri-State Tornado

New tornado watch coming for N. TX, OK, and Arky:



Mesoscale Discussion 0230
NWS Storm Prediction Center Norman OK
1046 PM CST Tue Feb 28 2017

Areas affected...Eastern Oklahoma into western Arkansas

Concerning...Severe potential...Tornado Watch likely

Valid 010446Z - 010645Z

Probability of Watch Issuance...80 percent

SUMMARY...Isolated to scattered severe thunderstorms may develop in
the next few hours over eastern Oklahoma into western Arkansas.
Tornadoes and very large hail are possible.

DISCUSSION...Showers appear to be deepening across parts of eastern
Oklahoma, in advance of strong cooling aloft and approaching the
surface moist axis where dewpoints are in the lower 60s. Due to
strong winds and mixing, the boundary layer remains warm with
temperatures in the 70s and relatively weak CIN. Given extreme
cooling aloft, lapse rates are very steep, with MLCAPE to around
2000 J/kg. Shear is more impressive, with area VWPs indicating 0-1
SRH in excess of 500 to 600 m2/s2. Clearly, the environment favors
tornadic supercells, conditional on storms forming. Several CAM
solutions indicate storms in this area. A tornado watch is likely to
be needed soon.

..Jewell/Edwards.. 03/01/2017