SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Oct 21 2025 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NM TO CENTRAL OK... ...SUMMARY... Isolated severe storms are possible beginning late afternoon Thursday across parts of the Southwest and continuing into Thursday night over the southern Great Plains. ...Southwest/Southern Great Plains... A compact shortwave trough over the Lower CO Valley will reach the southern Rockies by early Friday, as a separate impulse moves across northern Baja/Gulf of CA. This will reinforce a positive-tilt orientation to the broader trough and support only a weak lee surface cyclone over the southern High Plains. Another day of low-level moisture return from the TX Coastal Plain should yield a plume of moderate buoyancy reaching the Permian Basin to southwest OK by Thursday afternoon. More limited moisture is anticipated farther north/west, supporting weak buoyancy. But this will be compensated by stronger large-scale ascent accompanying the leading shortwave impulse. Scattered thunderstorms are expected over the Four Corners by mid-afternoon, with isolated storms arcing southeast to southward over central to eastern NM. Sufficient deep-layer shear will exist for a few supercells as storms mature in the late afternoon, capable of producing isolated severe hail/wind. A mesoscale corridor of more concentrated supercell potential may evolve downstream on Thursday evening as storms impinge on the aforementioned moderate buoyancy plume in west TX. Otherwise, increasingly widespread elevated convection should occur on Thursday night from west TX through much of OK. This should foster a rather messy mode, with transient supercells/semi-organized clustering relegated to the southern portion of the broader convective plume. An isolated severe threat may persist in this regime overnight. ..Grams.. 10/21/2025
