Subj : MESO: Mesoscale Discussion 2110 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Sep 08 2023 18:47:17 ACUS11 KWNS 081847 SWOMCD SPC MCD 081846=20 MEZ000-MAZ000-NHZ000-RIZ000-CTZ000-NYZ000-VTZ000-NJZ000-PAZ000-DEZ000-MDZ00= 0-DCZ000-VAZ000-WVZ000-082045- Mesoscale Discussion 2110 NWS Storm Prediction Center Norman OK 0146 PM CDT Fri Sep 08 2023 Areas affected...Portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Severe Thunderstorm Watch likely=20 Valid 081846Z - 082045Z Probability of Watch Issuance...80 percent SUMMARY...The threat for scattered damaging winds and isolated large hail will likely increase this afternoon and warrant Severe Thunderstorm Watch issuance. DISCUSSION...In addition to widely spaced convection which has developed across the coastal Mid-Atlantic and southern New England along a marine warm front/sea breeze, a gradual increase in thunderstorm coverage and intensity is expected to occur this afternoon from parts of VA northeastward into New England as modest ascent preceding a weak upper trough aids parcels in reaching their LFC. Initial development over the higher terrain of the Appalachians and Blue Ridge should move northeastward with time given a fairly unidirectional southwesterly flow at mid/upper levels. A fairy tight gradient of instability if present from the southern Mid-Atlantic to the Northeast, with 1500-2500+ J/kg of MLCPAE present where strong daytime heating of a rather moist low-level airmass has occurred. Various VWPs from area radars show weak low-level flow gradually strengthening to around 25-35 kt, with around 20-30 kt of deep-layer shear. Multicells should be the dominant convective mode, with marginal supercells possibly posing an isolated threat for large hail initially. With time, damaging winds around 50-60 mph will likely become the main concern as multiple clusters form and subsequently spread northeastward through the evening. The greatest threat for damaging winds will probably be focused in a fairly narrow corridor where low-level lapse rates have become steepened along/near the instability gradient/weak front that extends from southwest to northeast across the Mid-Atlantic into New England. Given the ongoing coastal convection, which has already produced some hail/damaging wind reports, and expectations for increasing thunderstorm coverage this afternoon, one or more Severe Thunderstorm Watches will likely be needed. ...Gleason/Guyer.. 09/08/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!9xODJfKAh3UxGocGAaP5VSQeaEdqSmVjHZc70fpPCZs6Lkii-lpBXqtZhPSGhRI6EVUuqTzax= L1bLYwA4IiCoP__TKE$ for graphic product... ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...CTP... LWX... LAT...LON 38217935 39907873 42337506 43517257 44087095 43467032 42347128 40917331 40177413 38927548 38157822 38217935=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) .