SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Wed Nov 25 2020 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF COASTAL/EAST TEXAS INTO LOUISIANA... ...SUMMARY... Isolated large hail may occur with thunderstorms that develop across parts of east Texas and Louisiana, mainly from Thursday night into early Friday morning. ...Coastal/East Texas into Louisiana... A positively tilted upper trough is forecast to move southeastward over the western/central CONUS, with the southern portion of this system closing off over the Southwest late Thursday. Ahead of this feature, low-level moisture return should occur across parts of coastal/east TX and the lower MS Valley through the period. 700-500 mb lapse rates around 7-7.5 C/km emanating from the higher terrain of west TX and northern Mexico may overspread this region late Thursday into early Friday morning. Latest guidance suggests MUCAPE around 1000-1500 J/kg may develop along/north of a warm front, with strengthening west-southwesterly mid/upper-level flow with height that should support 40-50 kt of deep-layer shear. Confidence has increased that mainly elevated storms may form by late Thursday evening in a modestly strengthening low-level warm advection regime over parts of east TX into LA, generally to the north of the warm front. The forecast combination of sufficient instability, steep mid-level lapse rates, and strong speed shear in the mid/upper levels suggest that isolated large hail may occur with any elevated supercells that can develop. The potential for surface-based storms along the immediate upper TX Coast and southwestern LA remains too uncertain to include any probabilities for strong/gusty winds at this time. ...East Coast... A de-amplifying shortwave trough should move across the Mid-Atlantic and southern New England on Thursday. A weak surface low associated with this feature is forecast to fill further through the day. An eastward-moving cold front should extend from the Mid-Atlantic southwestward along parts of the East Coast and into the Southeast. The stronger mid-level flow attendant to the shortwave trough should remain displaced to the north of greater low-level moisture across the Carolinas and Southeast. Although enough weak instability may develop across eastern portions of the Mid-Atlantic and southern New England to support isolated thunderstorms Thursday afternoon, truly surface-based convection still appears unlikely. From the Carolinas into the Southeast, additional storms may occur through the day along/ahead of the cold front. These areas will remain generally to the south of stronger forcing for ascent tied to the previously mentioned shortwave trough, with overall storm coverage expected to remain fairly low. ..Gleason.. 11/25/2020
There’s more click here.