SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 PM CST Mon Jan 18 2021 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms may occur today across parts of Texas as well as near the coast of southern California into the lower Colorado River Valley. Severe thunderstorms are not expected. ...Texas... Shortwave ridging should build over the southern Plains today as a surface cold front slowly moves southward over parts of central/east TX. Partially modified low-level moisture, with surface dewpoints generally in the low 60s, will reside to the south of the cold front. Scattered, low-topped showers should be ongoing at the start of the period along/near the front across parts of central/east TX. Some of this convection may become deep enough through the day to support isolated lightning flashes, even though the presence of an inversion centered around 700 mb should generally limit boundary-layer instability. A minor mid-level perturbation approaching the southern Plains from northern Mexico may also encourage continued convective development along the front through the evening and overnight hours. Weak forecast instability and poor lapse rates are expected to preclude an organized severe threat. ...Channel Islands/Southern California into the Lower Colorado River Valley... A closed upper low over the western CONUS will develop southward off the coast of southern CA and the northern Baja Peninsula by tonight. Cool mid-level temperatures will promote steepened mid-level lapse rates beneath the upper low. Lift associated with multiple vorticity maxima should support shallow convection. The deepest cores could reach sufficient height to induce charge separation and isolated lightning flashes. The best potential for thunderstorms will likely remain just off the CA Coast and over the Channel Islands. Other isolated thunderstorms may also occur in the mid-level moisture plume over parts of the lower CO River Valley, but instability should remain rather weak across this region. ..Gleason/Moore.. 01/19/2021
There’s more click here.