Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jun 19 2023 20:00:34 ACUS01 KWNS 192000 SWODY1 SPC AC 191958 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Mon Jun 19 2023 Valid 192000Z - 201200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST...NORTHERN PLAINS...AND CENTRAL TEXAS... ....SUMMARY... Severe thunderstorms are possible today over parts of the Southeast, central Texas, Arklatex, and northern Plains. ....20Z Update... The only meaningful change to the outlook has been to introduce a small Slight Risk across parts of central TX. Temperatures have soared into the low to mid 100s amid upper 60s to low 70s surface dewpoints to the east of a dryline. Recent visible satellite imagery shows convective initiation occurring east of San Angelo TX. Even though large-scale ascent will remain weak, any thunderstorms that can form and be sustained may become supercellular given 35-40 kt of deep-layer shear due to modestly enhanced mid/upper-level northwesterly winds. An associated threat for very large hail should exist given the presence of very strong instability and steep mid-level lapse rates. Severe downdraft winds may also occur. For more details, see recently issued Mesoscale Discussion 1166 and Severe Thunderstorm Watch 340. Across the Southeast, tornado potential will likely remain focused along/very near the Gulf Coast in MS/AL and the FL Panhandle. Multiple areas of low-level rotation, with occasional debris signatures, have been noted with convection occurring across these areas given favorable low-level shear noted on recent VWPs from KMOB/KEVX, etc... In the wake of earlier thunderstorms, a separate area of convection has also developed this afternoon across south-central AL. This activity may pose an isolated threat for damaging winds and hail through the rest of the afternoon into this evening as the boundary layer attempts to re-destabilize. See Mesoscale Discussion 1165 for more details on the near-term severe threat across the central Gulf Coast states. No changes have been made to the Slight Risk across parts of eastern MT into ND. ...Gleason.. 06/19/2023 ..PREV DISCUSSION... /ISSUED 1112 AM CDT Mon Jun 19 2023/ ....Southern MS/AL to FL Panhandle... A large upper trough is present today over much of the eastern states, with a corridor of 30-40 knot mid-level winds extending from AR into the central Gulf Coast region. Ample low-level moisture remains across much of the southeast, but multiple bouts of convection have pushed the main outflow boundary southward into southern MS/AL and the FL Panhandle. Strong afternoon heating will help to establish moderate to strong instability along this axis where re-development of widely scattered strong/severe storms are expected. Weak forcing mechanisms suggest limited coverage of intense storms, but sufficient deep-layer vertical shear and proximity to boundaries may result in isolated supercells capable of hail, damaging wind gusts, and perhaps a tornado. ....Southeast GA/Northeast FL... A persistent linear MCS continues to track eastward across southern GA and northern FL. Strong heating ahead of the line has resulted in moderate CAPE values and sufficient westerly flow aloft to pose a risk of locally gusty/damaging winds for a few more hours until the line moves offshore. Cooler temperatures in the wake of the line should limit the redevelopment of severe storms later today. ....MT/ND... Fast southwesterly flow aloft extends across the northern Rockies and High Plains today. A band of mid/high clouds lies from northern WY into eastern MT and western ND. A consensus of morning model solutions indicate that strong heating along and east of the eastern edge of this cloud cover will result in a corridor of steep low-level lapse rates and sufficient CAPE for scattered thunderstorm development. Fast-moving supercell and bowing structures appear likely this afternoon and evening as storms track from eastern MT into western ND. Damaging winds and hail are the main risks. ....Central TX... Hot/humid conditions along the surface dryline over central TX will pose some risk of isolated thunderstorms by mid/late afternoon. While coverage of these storms may be quite limited, any storm that forms in the extremely unstable air will pose a risk of large hail and damaging winds. $$ = = = 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) .