Mesoscale Discussion 1807
   NWS Storm Prediction Center Norman OK
   1231 PM CST Tue Nov 24 2020

   Areas affected...northeast TX Panhandle...northwest and
   north-central OK...far southern KS

   Concerning...Severe potential...Watch likely 

   Valid 241831Z - 242030Z

   Probability of Watch Issuance...95 percent

   SUMMARY...The potential for severe thunderstorms and possibly a
   tornado will likely begin mid-late afternoon in the northeast TX
   Panhandle and far northwest OK, and then develop eastward this
   evening towards the I-35 corridor later this evening.

   DISCUSSION...Visible-satellite imagery as of 1230pm CST shows the
   initial stages of a swelling cumulus field near a triple point
   located over the northeastern part of the TX Panhandle.  Surface
   analysis indicates a dryline extending south from the low with a
   cold front arcing from the northwest TX Panhandle east to the triple
   point and northeast into southwest KS.  Midday water-vapor imagery
   shows a dryslot wrapping into western OK in wake of elevated morning
   convection.  Furthermore, a strong mid-level shortwave trough over
   north-central NM continues to progress eastward towards the southern
   High Plains where objective analysis indicates -24 deg C 500 mb
   temperatures over central NM.

   Surface observations as of 12pm CST on the West Texas and Oklahoma
   mesonets show temperatures ranging from 70 deg F around Childress to
   the lower 60s near I-40 and the upper 50s in northwest OK. 
   Dewpoints are highest near the OK/TX border near I-40 (near 60 F)
   with mid 50s in northwest OK.

   12z HREF and recent time-lagged HRRR guidance indicates convective
   initiation will likely occur between 130-230 CST.  Given the trends
   in the swelling cumulus field, this appears to be a plausible
   scenario.  Forecast soundings this afternoon show a relatively moist
   and increasingly unstable boundary layer beneath 500 mb temperatures
   in the -18 to -20 deg C range.  Upwards of 500-1000 J/kg MLCAPE is
   likely to develop as additional cloud breaks/heating occurs through
   the mid afternoon.  The belt of stronger 700 mb flow (40-50 kt) is
   forecast to largely remain on the southern periphery of the
   discussion area near the I-40 corridor.  Nonetheless, hodographs are
   forecast to elongate over northwest OK with a moderate enlarging of
   the hodograph to the immediate north of the belt of stronger 700 mb
   flow.

   A few supercells are possible later this afternoon near the OK/TX
   border east-northeast into northwest OK.  It is within this focused
   zone where a tornado or two could develop, in addition to risk for
   large to very large hail and isolated severe gusts.  This activity
   will likely evolve into a cluster towards this evening and
   eventually into a linear band with severe gusts and possibly a hail
   risk as it moves towards the I-35 corridor.

   ..Smith/Thompson.. 11/24/2020

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...TSA...ICT...OUN...DDC...AMA...

   LAT...LON   35910097 36740046 37499867 37399716 36769640 36079627
               35409680 35039837 34839985 35070030 35610062 35910097