Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 02 2023 19:51:14 ACUS01 KWNS 021951 SWODY1 SPC AC 021949 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Fri Jun 02 2023 Valid 022000Z - 031200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE TX SOUTH PLAINS INTO THE EDWARDS PLATEAU... ....SUMMARY... A few tornadoes, destructive baseball to softball sized hail, and scattered severe wind gusts to around 75 mph will be possible across parts of the southern High Plains into this evening. ....20Z Update... ....Southern High Plains... Overall forecast outlined in the previous discussion (appended below) remains valid. Higher thunderstorm coverage across and more linear storm structure has materialized across the western TX Panhandle, with more discrete activity farther south across far southeast NM into west TX. A tornado has been reported with the supercells in Gaines and Pecos Counties in Texas, with large hail reported in these storms as well as the other more discrete storms across the region. A trend towards additional upscale growth is anticipated with this more discrete activity entering the TX South Plains. All severe hazards are possible before this transition occurs, with the primary threat then becoming damaging gusts. There is also some potential for the lone storm in Pecos county to eventually trend more linear and progress southeastward. Additional storm development is ongoing back farther west over the higher terrain, with at least some potential for additional hail and a strong gusts or two as it gradually moves eastward this afternoon and evening. ....Eastern MT... Recently issued MCD #922 addresses this region, where a marginal wind and hail threat is expected through the afternoon and early evening. Overall, the weak mid-level lapse rates and weak forcing for ascent (mainly terrain driven) will keep the threat localized. ....New England... As discussed in MCD #919, thunderstorms with marginal severe wind threat are possible through the afternoon. 18Z GYX sounding sampled modest buoyancy, but relatively high cloud bases and steep low-level lapse rates could still contribute to occasional damaging downbursts. ...Mosier.. 06/02/2023 ..PREV DISCUSSION... /ISSUED 1056 AM CDT Fri Jun 02 2023/ ....Southern High Plains... Large-scale ascent is already underway ahead of a shortwave trough over NM that will slowly shift into west TX through tonight. Stratus is fairly pervasive across most of west TX, outside of the Permian Basin. In this latter area, with mid 60s surface dew points and a pocket of nearly full insolation, convection will likely develop in the next couple hours. With around 8-9 C/km mid-level lapse rates and an elongated nearly straight-line hodograph, splitting discrete supercells are expected with very large to giant hail possible. A couple long-lived supercells may occur as they slowly move southeast along the Lower Pecos Valley through early evening. More widespread thunderstorm activity is expected farther north, initially beginning in southeast NM and then spreading into the South Plains and southern TX Panhandle areas. Relatively larger low-level SRH compared to farther south should support potential for at least a couple tornadoes in addition to significant severe hail, centered on the late afternoon period. Amalgamation of numerous cells should result in upscale growth into an MCS by early evening with a threat for localized significant severe wind gusts. Overall severe threat should wane after sunset into late evening as the MCS spreads deeper into southwest OK through the Big Country. ....Central High Plains to eastern MT... Isolated to scattered thunderstorms will develop along a lee trough later this afternoon in the presence of generally 50s surface dew points. Convection will probably tend to focus near a pair of slow-moving mid-level impulses across eastern CO and eastern MT. For the eastern MT regime in the mid-levels, lapse rates will be weak but compensated by a belt of 25-30 kt southeasterlies. This may be adequate to support transient weak supercell structures. In the eastern CO regime, steep mid-level lapse rates will counter weaknesses in the low to mid-level hodograph. Isolated severe hail and wind will be possible, centered on the late afternoon to early evening. ....New England... Isolated to scattered thunderstorms are expected downstream of a southward-moving shortwave trough approaching from Quebec. Nearly all enhancement to mid/upper flow will be confined to the cool side of a surface cold front pushing south-southwest. 12Z GYX sounding revealed very light winds throughout the troposphere. As such, single-digit effective bulk shear is anticipated across most of the region, with values perhaps into the teens closer to the front. Well-mixed and inverted-v thermodynamic profiles should support locally strong wind gusts in sporadic microbursts during the late afternoon to early evening. $$ = = = 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) .