Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue May 09 2023 05:58:54 ACUS02 KWNS 090558 SWODY2 SPC AC 090557 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CDT Tue May 09 2023 Valid 101200Z - 111200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS CENTERED OVER THE CENTRAL HIGH PLAINS REGION... ....SUMMARY... Scattered strong to severe storms -- capable of producing damaging winds and hail, and potentially a couple of tornadoes -- are expected Wednesday afternoon and evening within an area centered over the central High Plains. ....Synopsis... As a weak mid-level disturbance moves across the southern Plains toward the lower Mississippi Valley, a more substantial low/trough is forecast to move across the West. As this trough crosses California and the Great Basin in negatively tilted fashion, low is progged to evolve within the base of the trough over the Four Corners region late in the day. Overnight, the low will reach the central High Plains. At the surface, high pressure will generally prevail over the east of the Mississippi Valley. Meanwhile, a cold front crossing the western states should reach the High Plains during the evening, merging with an existing lee trough/low. ....Southeastern Montana south to the Texas/Oklahoma Panhandles... A modestly/seasonably moist boundary layer will be maintained across the High Plains region Wednesday, southeasterly low-level flow encompasses the Plains to the east of the lee trough. Daytime heating will support afternoon destabilization, with 1000 to 2000 J/kg mixed-layer CAPE expected by mid afternoon. With a weak upslope component to the flow, and presence of the lee trough, expect scattered convective development to begin by mid afternoon across portions of eastern Wyoming and the Colorado front range, and shortly thereafter northward into southeastern Montana, and southward across the southern High Plains in a more isolated manner. As a meridional/southerly mid-level jet streak on the eastern periphery of the trough spreads across the High Plains, atop low-level southeasterlies, shear sufficient for organized/rotating updrafts will evolve. As such, initial/cellular storm mode should support large hail as the primary risk, though damaging winds will also be possible locally. A couple of tornadoes will also be possible -- particularly from the Palmer Divide of Colorado northward across eastern Wyoming where surface winds are expected to be more backed/easterly north of a weak lee low. With time, storms should grow upscale locally into more complex/banded modes, spreading northeastward off the higher terrain. This could support some increase in wind risk into the evening hours, before a gradual overnight nocturnal decrease in convective intensity commences. ...Goss.. 05/09/2023 $$ = = = 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) .