SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Wed Oct 08 2025 Valid 081300Z - 091200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for organized severe thunderstorms is low today and tonight. ...Synopsis and Discussion... Early morning satellite imagery depicts extensive upper ridging from the southern Plains into the Canadian Prairies, with a pair of shortwave troughs flanking this ridging. The eastern shortwave trough extends from the Hudson Bay southwestward through the OH Valley while the western shortwave extends from central British Columbia to off the Pacific Northwest coast. The eastern trough will remain progressive today, taking it off the Northeast coast by this evening. The western trough will deepen into a notable upper low while remaining just off the Pacific Northwest Coast. The upper ridging between these two systems will expand northward/northeastward and cover much of the CONUS by early Thursday morning. Recent surface analysis placed an extensive cold front from central ME southwestward into central MS before arcing more westward into southwest TX and then back northwestward through central NM. Eastern portion of this front will remain progressive today, moving quickly off the Northeast coast over the next few hours. The central portion of the front will also make steady southeastward/southward progress into more of the Mid-Atlantic and Southeast states. Modest buoyancy ahead of the front will support isolated to widely scattered thunderstorms across the Southeast. Meager buoyancy should keep the severe threat low, although some lingering mid-level flow could allow for a few transient multicells capable of strong outflow gusts. A few isolated thunderstorms are possible for the Lower MS Valley into South TX but limited convergence along the front and warm mid-level temperatures should keep coverage low. Higher thunderstorm chances exist farther west into NM/AZ, where another day of low-level upslope flow is anticipated on the western periphery of the stalled cold front. Strong heating will destabilize the airmass, with isolated to scattered thunderstorm expected this afternoon. Modest vertical shear (20-30kt) may support a few more robust multicell storms capable of occasional damaging gusts and small hail given steeper low and-level lapse rates and around 1000 J/kg of MUCAPE. ..Mosier/Bentley.. 10/08/2025
