MD 2229 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR MUCH OF NORTHWESTERN TEXAS INTO SOUTHWESTERN OKLAHOMA
Mesoscale Discussion 2229
NWS Storm Prediction Center Norman OK
0125 AM CST Mon Nov 18 2024
Areas affected...much of northwestern Texas into southwestern
Oklahoma
Concerning...Severe potential...Watch likely
Valid 180725Z - 180930Z
Probability of Watch Issuance...80 percent
SUMMARY...Potential for damaging wind gusts and perhaps a few
tornadoes may begin to increase with an evolving squall line
accelerating northeast of the Texas South Plains through much of
northwestern Texas and southwestern Oklahoma by 3-5 AM CDT.
DISCUSSION...Downstream of a 90+ kt 500 mb jet streak beginning to
nose northeast of the Texas Big Bend into the Pecos Valley, strong
forcing for ascent continues to aid the evolution of a squall line
in advance of a deepening surface low now near/southwest of Lubbock.
Instability is still rather weak in the presence of thermodynamic
profiles characterized by modest mid-level lapse rates, but weak
low-level lapse rates and modest moisture. However, low-level and
deep-layer shear is strong, and an ill-defined meso-beta scale
mid-level cyclonic circulation is now progressing northeast of
Lubbock.
A number of better defined meso-gamma scale cyclonic circulations
are evident along the line, which has been surging northeastward
around 30 kt, to the northeast of the mid-level circulation. This
appears likely to propagate into the Altus OK vicinity through
09-11Z, with the southern flank of the line progressing across the
Abilene TX vicinity.
In response to the deepening surface troughing, a gradual
north-northwestward advection of mid 60s to near 70F surface dew
points toward the upstream squall line will gradually contribute to
somewhat more unstable updraft inflow. This may also contribute to
a boundary-layer at least marginally more supportive of downward
momentum transfer to the surface and potential for tornadoes, as
low-level shear intensifies beneath an 850 mb jet forecast to
strengthen in excess of 50 kt.
..Kerr/Gleason.. 11/18/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...OUN...SJT...LUB...AMA...MAF...
LAT...LON 33610035 34130064 35169968 35239810 34159800 32049873
31479966 31470050 32160084 33610035
