SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sat Jun 03 2023 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS...AND PARTS OF THE CENTRAL APPALACHIANS REGION... ...SUMMARY... Isolated strong to severe thunderstorms may occur Saturday across parts of the southern Plains. ...Synopsis... Large-scale northern-stream ridging/anticyclonic flow is forecast to prevail across the Canadian Prairie and into the northern and central Plains states, today. Meanwhile, several weak disturbances/short-wave troughs within the southern stream will continue to undercut the ridge, affecting roughly the southern half of the country. One of these disturbances is forecast to linger across the southern Plains region, and will contribute to another day of diurnally maximized convective development, along with associated potential for a few severe storms across this region. A few stronger storms are also expected over the central Appalachians during the afternoon and early evening, where low-end severe-weather risk may evolve. Elsewhere across the U.S., scattered thunderstorms will occur across a large portion of the country. ...Southern Plains... A complex convective scenario is anticipated from eastern New Mexico across the southern Plains today, as clusters of ongoing/overnight convection continue to alter the environment. Remnant convection/cloud cover early in the day will modulate heating/destabilization in some areas, though the higher terrain of eastern New Mexico likely to be a favored area for diurnal storm development. Though shear will not be particularly strong across the area due to rather weak westerlies aloft, a couple of stronger storms will likely become capable of producing marginal hail/wind. Farther east, convective redevelopment is expected near remnant outflows/MCVs, as the moist airmass moderately destabilizes away from areas most substantially overturned. Overall however, shear will remain relatively weak, with the strongest flow aloft confined to Deep South Texas, and adjacent northern Mexico. As such, overall severe risk should remain low in most areas, with only the strongest storms briefly capable of producing hail/wind. With time, as effects from prior convection become more clear, a more concentrated area for risk may become apparent, permitting consideration for locally higher areal probability. At this time however, will maintain a broad MRGL risk across the region. ...Parts of the central Appalachians/Upper Ohio Valley... As a very subtle backdoor-like cold front shifts southwestward across the central Appalachians region, daytime heating ahead of this surge of cooler low-level air will result in ample afternoon destabilization to allow development of scattered to numerous thunderstorms. While deep-layer shear will remain weak, quasi-unidirectional northeasterly flow aloft will likely contribute to a few clusters of semi-organized, southwestward-moving storms, capable of producing small hail and gusty winds. With potential that a few of the strongest storms may become briefly severe, will introduce 5% hail/wind -- i.e. MRGL risk -- across this area through the afternoon, with storms expected to weaken during the evening hours. ..Goss.. 06/03/2023
