Subj : MESO: Mesoscale Discussion 0689 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat May 06 2023 20:09:00 ACUS11 KWNS 062008 SWOMCD SPC MCD 062008=20 TXZ000-OKZ000-062215- Mesoscale Discussion 0689 NWS Storm Prediction Center Norman OK 0308 PM CDT Sat May 06 2023 Areas affected...portions of central/northern TX into south-central OK Concerning...Severe potential...Watch likely=20 Valid 062008Z - 062215Z Probability of Watch Issuance...80 percent SUMMARY...Vigorous thunderstorm development is expected by 21-23z/4-6pm CDT. Very large hail and scattered damaging gusts will be the main hazards associated with these storms through this evening. A severe thunderstorm watch will likely be needed in the next couple of hours. DISCUSSION...An expanding cumulus field from near San Angelo TX northeast toward Wichita Falls TX is becoming increasingly agitated this afternoon. Strong heating along a dryline has resulted in temperatures from the upper 80s to low 90s. To the east of the dryline, surface dewpoints from the upper 60s to low 70s F beneath very steep midlevel lapse rates (greater than 8 C/km) are contributing to MLCAPE values around 2500-3000 J/kg. 19z objective analysis indicated capping is also rapidly eroding. Thunderstorms are expected to develop close to the dryline by 22z/5 pm CDT. Given strong instability and favorable lapse rates, intensification may occur fairly rapidly. Deep-layer flow is relatively modest, but vertically veering wind profiles with some increase in midlevel southwesterly flow by 23-00z will result in effective shear magnitudes around 25-30 kt.=20 Very large hail (to around 3 inch diameter) will be possible, especially early in storm evolution. Steep low-level lapse rates also may promote strong downburst winds. Wind potential also may increase with time/eastward extent if some upscale development into forward-propagating clusters/bowing segments occurs, as some some short term hi-res guidance suggests. ...Leitman/Hart.. 05/06/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5mVzGNFlA6RJHf3JAAtcu7SNAbKo7W4zl-O9XYjFp9Yk7bvQ1-r3gqzbi_oFknR4LUikfhXbw= 5LERdMUrMVssS1qoiQ$ for graphic product... ATTN...WFO...FWD...OUN...SJT...LUB... LAT...LON 31349948 31379990 31510025 31630048 31880061 32240065 32600044 33849920 34599830 34799790 34859744 34779708 34619683 34389674 34089672 33929676 32839740 32559755 32009798 31469882 31349936 31349948=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) .