SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Tue Jul 04 2023 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL/SOUTHERN HIGH PLAINS AREA NORTHEASTWARD TO THE MID-MISSISSIPPI AND LOWER OHIO VALLEYS AND SOUTHERN UPPER GREAT LAKES AREA... ...SUMMARY... Strong/severe storms are forecast to be most widespread Wednesday from the central High Plains eastward into the Midwest. ...Central High Plains to the Illinois/Indiana area... A cold front will continue to advance southeastward/southward across central portions of the country, as the southern extent of mid-level troughing crossing central Canada moves eastward across the northern and central Plains, toward the Mississippi Valley/Upper Great Lakes. Daytime heating of the very moist pre-frontal boundary layer from the central Plains northeastward, will result in a zone of moderate instability in the vicinity of the front. As a result, expect development of scattered thunderstorms during the afternoon across this portion of the area. While shear will remain somewhat modest, roughly 30 kt mid-level flow atop the frontal zone will support locally stronger/multicell storms -- capable of producing locally damaging wind gusts and possibly marginal hail. Storms should gradually diminish in coverage, and eventually intensity, through the evening. Farther west into the High Plains, weaker instability is expected due to more limited boundary-layer moisture. However, stronger mid-level flow near and to the cool side of the trailing, west-to-east segment of the front, atop low-level easterly/southeasterly flow, will result in deep-layer shear sufficient to support supercells. During the afternoon, isolated High-Plains storms should develop -- with attendant risks for large hail and damaging winds locally, and possibly a tornado. Storms appear likely expand in coverage and shift out of the High Plains across parts of Kansas and Oklahoma overnight, as a modest, nocturnal increase in southeasterly low-level flow is expected. Some accompanying risk for damaging winds and hail may persist across the Kansas/Oklahoma vicinity -- initially with frontal convection, but later with storms moving east-southeastward off the higher terrain to the west. ...The Southeast... Afternoon heating/destabilization along a weak/remnant baroclinic zone lying across the Southeast will again promote scattered thunderstorm development. Though limited shear expected across the area suggests largely disorganized storms, moderate mid-level westerly flow could support a couple of semi-organized, eastward-moving clusters, with attendant risk for locally damaging wind gusts, and marginal hail. ..Goss.. 07/04/2023
