BBS: TELESC.NET.BR Assunto: DAY1SVR: Day 1 Convective Outlook De: COD Weather Processor Data: Mon, 18 May 2026 05:56:49 +0000 ----------------------------------------------------------- ACUS01 KWNS 180556 SWODY1 SPC AC 180555 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Mon May 18 2026 Valid 181200Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN/SOUTH-CENTRAL KANSAS AND SOUTHEAST NEBRASKA/FAR NORTHWEST MISSOURI... ...SUMMARY... Numerous severe thunderstorms are expected this afternoon and evening across the south-central Plains and Middle Missouri Valley. Supercells capable of very large hail and strong to intense tornadoes are most likely from central Kansas and southeast Nebraska into Iowa and northwest Missouri. ...Central Plains and Midwest... A regional outbreak of severe storms, potentially including strong/intense tornadoes (EF2/EF3+), is expected across the central Plains during the late afternoon and evening, although some uncertainties persist regarding the upper-end magnitude/spatial details of the heightened tornado potential. An extensive MCS exists early in the overnight from eastern/central Iowa southwestward into northeast/central Kansas, where regenerative/repetitive storms persist. This MCS should weaken/lose integrity through the early morning, although convection may regenerate and intensify again along composite outflow, eastward across the middle Mississippi Valley and lower Ohio Valley and potentially parts of the Great Lakes within a destabilizing air mass this afternoon. Damaging winds should be the most probable risk, although some tornado and hail potential will exist as well. The western fringe of this remnant cold pool will modify early today with a steady northward flux of low-level moisture, with a very unstable environment unfolding by mid/late afternoon across south-central/eastern Kansas into far west/northwest Missouri and Iowa/far southeast Nebraska. As a shortwave trough/speed max emerges from the central Rockies, deep convective development is expected along the initially stalled or slow-moving northeast/southwest-oriented front across central/northeast Kansas and southeast Nebraska and western Iowa by late afternoon. This increasingly rich low-level moisture will reside beneath an elevated mixed layer characterized by 8-9 C/km mid-level lapse rates, resulting in MLCAPE 3000-4000 J/kg. Mass response to the ejecting wave, along with a northeastward-translating 60-70 kt mid-level jet, and a significantly strengthening low-level jet by sunset, will yield increasingly favorable wind profiles for intense supercells capable of very large hail and tornadoes. This may includes strong and potentially intense tornadoes (EF2/EF3+). That said, the duration of a semi-discrete storm mode remains a key question, given the parallel orientation of the stalled front and the deep-layer shear vectors, and that the front will trend more southeastward-progressive during the evening. Thus, the strong/potentially intense tornado threat will peak prior to upscale growth into line segments along the front, with severe outflow gusts and embedded circulations becoming the main concerns over time tonight as storms progress east-southeastward across the Lower Missouri Valley and middle Mississippi Valley. ...Oklahoma and western North Texas... Storm development along the dryline across western Oklahoma into western North Texas/Lower Rolling Plains is more uncertain given more limited forcing for ascent. If/where storms do form, there is the potential for very large hail and a conditional risk for tornadoes. A consistently forecast flow weakness above 400 mb by late afternoon/evening does not appear favorable for particularly long-lived storms if they do form. ...Mid-Atlantic/Northeast States... Influenced by terrain and a surface trough, isolated strong to locally severe storms capable of wind damage could occur this afternoon within a moderately unstable environment. ..Guyer/Squitieri.. 05/18/2026 $$ = = = 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]