Subj : MESO: Mesoscale Discussion 2009 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Dec 13 2022 09:07:59 ACUS11 KWNS 130907 SWOMCD SPC MCD 130907=20 OKZ000-TXZ000-131100- Mesoscale Discussion 2009 NWS Storm Prediction Center Norman OK 0307 AM CST Tue Dec 13 2022 Areas affected...south-central Oklahoma Concerning...Severe Thunderstorm Watch 580... Valid 130907Z - 131100Z The severe weather threat for Severe Thunderstorm Watch 580 continues. SUMMARY...A new watch downstream from WW 580 is not expected at this time. Locally strong gusts may occur with a line of thunderstorms as it shifts east through early morning, but overall severe potential appears limited. DISCUSSION...Modest instability and moderate vertical shear ahead of an eastward-advancing cold front are contributing to a semi-organized line of convection early this morning over southwest OK/northwest TX within WW 580. A cell with at least transient supercell characteristics has also been noted on the southern edge of the line moving into Archer and Wichita Counties in northwest TX. The airmass downstream from WW 580 across south-central OK (south of the I-40 corridor) remains rather cool, with surface temperatures in the 53-59 F range. Surface-based instability will remain limited, with 08z mesoanalysis indicating SBCINH increasing toward the I-35 corridor. While vertical shear typically would support supercells and rotating cells within the line, poor low-level thermodynamics will continue to limit severe potential. Isolated strong gusts will be possible with more intense convection, but overall severe potential should decrease with eastward extent over the next couple of hours across south-central OK.=20 The exception may be near and just south of the Red River where temperatures and dewpoints are in the low to mid 60s, resulting in greater instability and weak CINH. The aforementioned supercell on the southern end of the convective line is occurring within this environment and may pose the greatest severe risk in the short term. Depending on trends, a very small watch could be needed near the immediate Red River vicinity. However, the overall threat appears limited by the narrow warm sector. A downstream watch is not expected at this time, but trends will continue to be monitored. ...Leitman.. 12/13/2022 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!-8oSjfUg6NnMNTONkMfBuPdiNBie0IyFUc7ZVeW9qtVVF7dXiNFXNyBQkdMhm9CixRo31IT2A= KiS80yyZxKbGHgskto$ for graphic product... ATTN...WFO...TSA...FWD...OUN... LAT...LON 35259817 35419803 35559744 35509652 35479638 35179604 34699594 34099606 33589640 33379684 33299745 33339801 33519838 33769845 34459829 35259817=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .