BBS: TELESC.NET.BR Assunto: DAY1SVR: Day 1 Convective Outlook De: COD Weather Processor Data: Tue, 5 May 2026 05:37:51 +0000 ----------------------------------------------------------- ACUS01 KWNS 050537 SWODY1 SPC AC 050536 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1236 AM CDT Tue May 05 2026 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS CENTERED OVER ARKANSAS AND EXTENDING FROM NORTHEAST TEXAS INTO WESTERN TENNESSEE... ...SUMMARY... Widely scattered severe storms are possible Tuesday afternoon into Tuesday night from northeast Texas into western Tennessee, with the main threat centered over Arkansas. The strongest storms will be capable of large hail, damaging winds, and a few tornadoes. More isolated, strong to severe storms are possible across parts of the Northeast. ...Synopsis... A vigorous, mid-level low over Ontario this evening is forecast to evolve into an open wave while translating east into Quebec on Tuesday. An accompanying belt of strong, mid/upper-level winds will overspread the lower Great Lakes and northern New England in tandem with modest height falls related to a vorticity maximum pivoting through the base of the parent system. Elsewhere, a mid-level low currently along the CA coast is expected to weaken while shifting through the lower-CO Valley to the vicinity of the Four Corners region. A belt of 50-70 kt winds at 500 mb are forecast downstream from that feature, extending from the southern Plains into the Mid South on Tuesday afternoon into evening. In the low levels, a cold front is expected to extend from southeast Quebec through the OH and mid-MS Valleys to low pressure over OK Tuesday morning. The northern extension of the boundary will move into the lower Great Lakes and northern New England during the peak of the diurnal heating cycle. The segment of the front across the Ozarks and Ozark Plateau may be temporarily displaced to the south Tuesday morning due to overnight thunderstorm activity. However by afternoon, the front is expected to refocus in the vicinity of the MO-AR border, ahead of a weakening surface low moving through eastern OK into western AR. The western extension of the cold front trailing the surface low is expected to advance southeast through the Red River Valley. ...Northeast Texas into the southern Missouri and western Tennessee... As mentioned in the synopsis, a complex of thunderstorms may be ongoing at the start of the forecast period across portions of MO into northern AR. That activity is expected to shift east of the area by late morning or early afternoon, with some lingering shower and thunderstorm development occurring to the north of the front in central MO. In the wake of the early-day convection, HREF cloud forecasts indicate the potential for considerable high-level clouds and pockets of thicker low-cloudiness, which could limit the potential for stronger diabatic warming within the pre-frontal air mass. Nonetheless, the presence of boundary-layer dewpoints in the 60s in conjunction with an elevated-mixed layer (EML) plume will support a moderately unstable air mass by afternoon with MLCAPE of 1000-2000 J/kg. Neutral to slight height rises are forecast in the mid levels during the peak of the diurnal heating cycle with model forecast soundings indicating considerable capping at the base of the EML. As such, eventual storm coverage remains uncertain. The 00z high-resolution models suggest that isolated to widely scattered thunderstorms will become increasingly likely by late afternoon or early evening along the frontal segment along the MO-AR border, immediately east/northeast of the surface low. Additional, isolated storm development also appears possible from the vicinity of the surface low southwest along the cold front into northeast TX, mainly during the evening hours. The favorable overlap of moderate instability and strong deep-layer shear will favor supercell storm modes, especially given the anticipated weak forcing for ascent. Large hail will be the predominant severe-weather hazard initially. A few tornadoes appear possible across portions of northern AR, potentially into western TN from late afternoon through the evening association with any sustained supercells. Here, the presence of a 35-40 kt low-level jet will yield effective SRH of 200-300 m2/s2 amidst a moist/low-LCL environment. Storms may eventually grow upscale into clusters, at which point damaging winds would become a growing concern. ...Lower Great Lakes into northern New England... Moisture advection occurring along a southwesterly low-level jet will allow dewpoints to rise into the 50s within the pre-frontal warm sector on Tuesday. And while mid-level lapse rates are not expected to be particularly steep, the moisture increase combined with daytime heating and the resultant steepening of low-level lapse rates will result in MLCAPE of 500 to perhaps 1000 J/kg. Increasing height falls aloft and convergence/lift along the cold front are expected to support surface-based storm development by early afternoon within the destabilizing air mass across portions of upstate NY. The storms will quickly overspread northern portions of VT, NH, and ME during the afternoon into early evening. The 00z high-resolution models indicate the potential for transient supercell and bowing structures, which appears reasonable given the presence of a relatively strong, deep-layer wind field. In that scenario, isolated occurrences of damaging winds and perhaps some marginally severe hail appear possible. The tornado threat will be conditional on sufficient instability to support more sustained supercell structures. A level 1/Marginal Risk will be maintained; however, if it becomes apparent that stronger instability will develop than is currently anticipated, an upgraded to level 2/Slight Risk may become necessary. ..Mead/Lyons.. 05/05/2026 $$ = = = 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]