SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 AM CDT Thu Jun 05 2025 Valid 051300Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM FAR SOUTHEAST NM INTO THE TX SOUTH PLAINS...AND FROM FAR SOUTHEAST CO INTO SOUTHWEST KS AND THE OK PANHANDLE.... ...SUMMARY... Scattered severe thunderstorms are expected across the High Plains from southwestern Kansas into west Texas. A few tornadoes, large to isolated very large hail, and severe gusts are possible. ...Southern High Plains... A modest MCS has persisted through the early morning, moving from the TX Panhandle into northwest TX. This MCS will likely continue southeastward into more of north TX over the next several hours. The downstream airmass is forecast to become increasingly unstable amid daytime heating, suggesting there is some potential for this system to strengthen once heating commences in earnest. However, vertical shear will remain modest, likely limiting the overall organization and intensity of this system and keeping the severe potential low. A greater severe potential is anticipated in the vicinity of the outflow associated with this early morning MCS. This outflow currently extends from the MCS westward across the TX South Plains into southeast NM. Some continued southward progress of this boundary is likely over the next few hours before it stalls. There is some potential for this boundary to then move back northward as an effective warm front during the late afternoon, but this depends on the coverage of any morning/early afternoon storms to its north. Given the mesoscale nature of that evolution, uncertainty is high on where this boundary will be by this afternoon. Even so, the general expectation is that this outflow will likely serve as the focus for robust convection later this afternoon as temperatures warm into the mid 80s-lower 90s, west and south of the outflow. Strong buoyancy is anticipated across much of this region, particularly south of the outflow boundary where the highest temperatures and dewpoints are anticipated. Southeasterly low-level flow beneath the enhanced westerlies aloft will result in long hodographs with moderate to strong low-level veering. These environmental conditions will be very supportive of discrete supercells capable of all severe hazards, including very large hail, severe wind gusts, and tornadoes. Hail probabilities were increased across far southeast NM into the TX South Plains where the highest supercell coverage is anticipated. There could be a corridor of higher tornado potential along the outflow boundary, but uncertainty on its location precludes introducing any high probabilities with this outlook. A discrete cell or two could also develop north of the outflow along a sharpening lee trough over eastern NM. Buoyancy will be slightly lower than areas farther south, but similar kinematic profiles will still support supercells capable of all severe hazards. ...Central High Plains into KS and OK... A second severe area is possible today from the central High Plains downstream into KS and OK. A subtle shortwave trough is expected to move within the southwesterly flow aloft, contributing to thunderstorm development across the high terrain and its movement off the terrain during the early evening. Northward-advecting low-level moisture will result in a east-west oriented warm front from southeast CO into southern KS. The storms coming off the terrain will likely interact with this boundary, with in-situ development likely along this boundary as well. Environmental conditions favor supercells along this boundary, with the interactions contributing to upscale growth into a larger complex of storms that spreads downstream along the KS/OK. Very large hail and tornadoes are possible with any early, more discrete storms before upscale growth and a transition to damaging gusts as the primary hazard. ...Mid MS Valley through the OH Valley into the Northeast... High-PW airmass currently stretches from the Mid MS Valley through the OH Valley into the lower Great Lakes/southeast Canada. Scattered convection will readily develop along this corridor, juxtaposed along a weak frontal zone. Poor lapse rates should limit updraft strength and vertical shear will be weak, but some risk for isolated water-loaded downbursts capable of damaging gusts does exist. ..Mosier/Broyles.. 06/05/2025