SPC AC 021230 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Tue May 02 2023 Valid 021300Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TEXAS SOUTH PLAINS INTO THE PERMIAN BASIN... ...SUMMARY... Strong to severe thunderstorms may impact parts of eastern New Mexico into west Texas this afternoon and evening, accompanied by at least some risk for severe hail and wind. ...Synopsis... An expansive mid-latitude cyclone currently covers the eastern CONUS, with enhanced mid-level flow extended through its southern periphery. The center of this cyclone is expected to gradually shift southeastward from its current position over southeast Ontario across the Lower Great Lakes and into western NY and PA. As it does, several shortwave troughs will move quickly through its base, with both waves tracking from the Mid MS Valley across the TN Valley and off the Mid-Atlantic Coast. This pattern evolution will act to reinforce the already stable conditions across much of the central and eastern CONUS. Another cyclone exists farther west, with recent satellite imagery placing its center near San Francisco Bay. This cyclone is expected to gradually drift southwestward as a shortwave rotates through its western and southern peripheries, approaching the southern CA Coast early tomorrow morning. Cold mid-level temperatures and persistent forcing for ascent will contribute to isolated thunderstorms from the San Francisco Bay vicinity into the Sacramento Valley this afternoon and evening. Extensive ridging exists between these two cyclones, stretching from TX through MT. However, recent satellite imagery shows a weak shortwave trough moving across northern Mexico towards the southern High Plains. Increasing mid-level moisture and ascent attendant to this shortwave will interact with a deeply mixed boundary layer over the southern High Plains, fostering thunderstorm development. ...Southern High Plains... The airmass across the southern High Plains is quite dry, with morning soundings sampling PW values 0.5 to 0.6 inches. Even so, influence of the approaching shortwave can already be seen, with moist profiles already in place above about 600 mb. The drier low-levels are expected to mix quickly, likely resulting in a boundary layer mixed to around 600 mb by the late afternoon. The mid-levels will remain moist, contributing to inverted-v soundings with little to no convective inhibition. Scattered thunderstorms development is anticipated during the afternoon, beginning across northern and eastern NM, as the shortwave trough moves through. Deep-layer shear will be weak, particularly west of the lee trough, contributing to a largely outflow-dominant, multicellular storm mode. Southeasterly low-level flow east of the lee trough will help increase deep-layer shear somewhat, with higher dewpoints supporting greater buoyancy as well. This should result in stronger storms and higher likelihood for damaging gusts. Highest storm coverage is anticipated from east-central NM into the TX South Plains. Given this higher coverage, a greater likelihood of cold pool amalgamation exists, with some potential for a forward-propagating cluster. ..Mosier/Wendt.. 05/02/2023 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z CURRENT UTC TIME: 1330Z (9:30AM), RELOAD THIS PAGE TO UPDATE THE TIME
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