SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0149 AM CST Fri Jan 22 2021 Valid 241200Z - 251200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the U.S. on Sunday. ...Synopsis... Mean long-wave upper troughing is forecast to remain over the western U.S. this period, as smaller-scale/short-wave troughs rotate through the broader cyclonic flow field. The first of these -- initially lying across southern California and northern Baja, is expected to shift eastward across the Desert Southwest and southern Rockies, and then reach the southern High Plains region as a negatively tilted, deamplifying impulse late in the period. Meanwhile, the second short-wave feature will lie just off the western Canada coast initially, with an associated/elongated north-south lobe of vorticity extending from Alaska to just off the Pacific Northwest coast. With time, the short-wave energy will dig southward along the West Coast, to a position just inland by the end of the period -- thus reinforcing the pre-existing long-wave trough. At the surface, a cold front associated with the initial short-wave trough ejecting across the Southwest will move across New Mexico and later Texas. East of this system, a west-to-east baroclinic zone will become established across the Mid Mississippi and Tennessee Valleys through the end of the period. With much of the CONUS remaining cool and stable through the period, deep convective potential will be limited to the southwestern and south-central portions of the country. Cold air/steep lapse rates aloft accompanying the upper system will support potential for sporadic lightning flashes across portions of the Four Corners states. Later, as downstream warm advection increases across the south-central U.S., elevated convection -- including scattered thunderstorms -- will likely evolve during the second half of the period. Muted instability, however, precludes appreciable risk for severe storms. ..Goss.. 01/22/2021
There’s more click here.