BBS: TELESC.NET.BR Assunto: DAY1SVR: Day 1 Convective Outlook De: COD Weather Processor Data: Wed, 27 May 2026 16:22:26 +0000 ----------------------------------------------------------- ACUS01 KWNS 271622 SWODY1 SPC AC 271620 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Wed May 27 2026 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY INTO THE MID-ATLANTIC... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Ohio Valley and Mid-Atlantic this afternoon and evening. Strong to severe gusts capable of producing wind damage should be the primary hazard, but isolated hail may also occur. ...Ohio Valley/Mid-Atlantic... 30-40 kt of mid-level westerly flow will be present today across parts of the OH Valley and Mid-Atlantic, sandwiched between an upper trough over Ontario/Quebec and a mid-level anticyclone centered over the western Atlantic. A west-east oriented front, modulated by ongoing convection, will serve as a focus and northern limit for severe potential. Latest surface observations show a rather moist low-level airmass present along/south of this boundary (also reference the 12Z observed soundings from IAD/RNK), with surface dewpoints generally in the mid 60s to low 70s. Lapse rates aloft are expected to remain poor, and persistent cloud cover will slow daytime heating. Still, weak to moderate instability (MLCAPE 500-1500 J/kg) coupled with 30-40 kt of westerly deep-layer shear will support organized thunderstorms this afternoon and early evening as a weak mid-level shortwave trough moves eastward across the OH Valley/Mid-Atlantic. A mix of multicells and marginal supercell structures is anticipated along/south of the front, with scattered damaging winds the main severe risk. Some hail could also occur with the strongest cores. The Slight Risk for severe/damaging winds has been expanded westward into parts of WV and vicinity, where a favorable environment/convective evolution should occur, similar to locations farther east in VA/MD along/south of ongoing precipitation. ...Pacific Northwest/Northern Rockies... A closed mid/upper-level low is not expected to move much over CA/NV today. Enhanced east-southeasterly mid-level flow and modest large-scale ascent to the north of this cyclone will likely support isolated to widely scattered thunderstorms this afternoon and evening across parts of OR/ID and western MT. Cool temperatures aloft and adequate low-level moisture should support at least weak instability as filtered daytime heating occurs. As low-level lapse rates steepen with the well-mixed boundary layer, isolated severe gusts appear possible with the high-based convection that develops and spreads west-northwestward through the afternoon/evening. Some gusts may reach up to 70-75 mph on a localized basis, but confidence in a more focused corridor of severe winds remains too low to include greater probabilities at this time. Isolated hail may also occur. ...Coastal Texas to the ArklaTex... An expansive MCS has moved offshore from coastal TX into the western Gulf late this morning. A leading MCS/outflow is also present across parts of southern/central LA. Current expectations are for limited redevelopment and severe risk through the period in the wake of this ongoing activity across coastal TX/southern LA. However, there may be an opportunity for modest destabilization near an MCV across the ArkLaTex vicinity this afternoon. Favorable/veering wind profiles with height through mid levels and related deep-layer shear (see recent VWPs from KSHV) would conditionally support organized thunderstorms this afternoon, assuming sufficient instability can develop amid widespread cloud cover. Have opted to add a focused Marginal Risk across portions of the ArkLaTex and vicinity for this potential, with both occasional damaging winds and a tornado or two possible with the stronger cells that develop. ...Upper Midwest/Western Great Lakes... Modest north-northwesterly mid-level flow should exist today across the Upper Midwest and western Great Lakes. With continued daytime heating, moderate instability should develop along/south of a weak surface front. Thunderstorms that initiate along/near the front this afternoon could pose an isolated threat for severe hail and damaging winds, particularly across parts of WI where the best convective signal exists in various short-term model guidance. However, overall convective coverage is uncertain, as large-scale ascent should remain fairly weak. ...Southern High Plains... Cool temperatures aloft in association with a weak mid-level trough over the southern High Plains should aid at least weak destabilization this afternoon across parts of northwest TX into the TX Panhandle and far western OK. While low-level moisture will remain fairly muted and deep-layer shear rather modest, a few stronger thunderstorms capable of producing isolated hail/gusty winds and perhaps a landspout may occur. ..Gleason/Lyons.. 05/27/2026 $$ = = = 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 3.28-Linux * Origin: Capitol City Online (1:2320/107) ----------------------------------------------------------- [Voltar]