Subj : MESO: Mesoscale Discussion 2229 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Nov 18 2024 08:03:05 ACUS11 KWNS 180803 SWOMCD SPC MCD 180802 COR OKZ000-TXZ000-180930- Mesoscale Discussion 2229 NWS Storm Prediction Center Norman OK 0202 AM CST Mon Nov 18 2024 Areas affected...much of northwestern Texas into southwestern Oklahoma Concerning...Severe potential...Watch likely=20 Valid 180802Z - 180930Z CORRECTED FOR TIME REFERENCE TO CST 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 CST. 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.=20=20 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. =20 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 https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!-l_NNB_qckDrSPg-oIPr3-9-HAPwUtEioGtsKWpIH9Nsx-ReqWpcMoCrk1yaTCXBexsGsnbx5= ngyec87TEUJgfr9guI$ for graphic product... ATTN...WFO...FWD...OUN...SJT...LUB...AMA...MAF... LAT...LON 33610035 34130064 35169968 35239810 34159800 32049873 31479966 31470050 32160084 33610035=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .