Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jun 07 2023 06:02:18 ACUS02 KWNS 070602 SWODY2 SPC AC 070600 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Jun 07 2023 Valid 081200Z - 091200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS...THE SOUTHEAST...DAKOTAS...AND NORTHERN ROCKIES/HIGH PLAINS... ....SUMMARY... Isolated strong to severe thunderstorms may occur Thursday across parts of Texas, the Southeast, Dakotas, and northern Rockies/High Plains. Strong to locally damaging winds and hail should be the main threats. ....Synopsis... The upper-air pattern across the CONUS will remain generally stagnant on Thursday. Upper ridging will extend from western Canada across much of the Plains. A weak upper low over the Great Basin should drift slowly northward through the period. Large-scale upper troughing will continue across the eastern states, with some amplification of its southern extent across the Southeast. ....Texas... Neutral to slightly rising mid-level heights should occur Thursday in association with the southern portion of upper ridging across TX. Still, it appears probable that a remnant MCV from prior convection will be in place somewhere across central TX. Latest high-resolution guidance suggests that isolated to scattered convection will develop Thursday afternoon downstream of the MCV and associated outflow boundaries across parts of central into southeast/coastal TX. Heating of a moist low-level airmass will likely aid the development of moderate instability. Weak low-level winds should gradually increase with height into mid/upper levels. 20-30 kt of deep-layer shear is forecast, with multicell clusters and perhaps a marginal supercell or two possible. Isolated severe hail and wind gusts should be the main threats with any robust convection that can develop and spread east-southeastward to the Gulf Coast through Thursday evening. ....Southeast... A weak cold front is forecast to shift southward Thursday across parts of the Southeast as an embedded mid-level shortwave trough moves across the TN Valley and Carolinas. 1500-2500 J/kg of MLCAPE should develop by peak afternoon heating along/south of the front from parts of north FL into southern/central GA and vicinity. Although the stronger mid-level flow associated with the shortwave trough will likely remain displaced to the north of the surface front, sufficient deep-layer shear to support organized convection should be present in a narrow corridor along and just south of the boundary. Multicell clusters capable of producing isolated damaging winds and some hail appear possible as convection develops along the front and subsequently moves east-southeastward Thursday afternoon and evening. ....Dakotas... Modest (around 15-25 kt) northerly mid-level winds will be present over the eastern Dakotas Thursday, on the eastern side of an upper ridge. A narrow corridor of moderate to locally strong instability should also develop across this area Thursday afternoon along/west of a surface front. Weak low-level winds veering with height through mid/upper levels should foster around 20-30 kt of deep-layer shear. A mix of multicells and marginal supercell structures may develop along a weak surface trough moving southward, and possibly in association with a convectively enhanced mid-level vorticity maxima. This activity should pose an isolated threat for large hail and severe/damaging wind gusts as it spreads southward from ND into eastern SD through Thursday evening. Weak large-scale ascent aloft limits confidence in greater coverage of strong to severe convection. ....Northern Rockies/High Plains... High-based thunderstorms should develop once again Thursday afternoon across parts of the northern Rockies and adjacent High Plains, on the northern periphery of a weak upper low expected to remain over the Great Basin. Winds through the troposphere are forecast to remain fairly weak. Still, up to 20-30 kt of deep-layer shear should be enough to foster occasional convective organization and some clustering. A fairly moist low-level airmass, with surface dewpoints in the mid 50s to low 60s, is also forecast across parts of eastern WA into northern ID and MT. As low-level lapse rates steepen with diurnal heating and weak to moderate instability develops, convective downdrafts may produce isolated severe wind gusts. Occasional hail may also occur with the more robust cores, particularly where greater instability is forecast over the northern High Plains of central/eastern MT. ...Gleason.. 06/07/2023 $$ = = = 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) .