SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Sun May 04 2025 Valid 050100Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO RIVER VALLEY...PARTS OF THE MID-ATLANTIC...AND SOUTHEAST NEW MEXICO AND FAR WESTERN TEXAS.... ...SUMMARY... Isolated to scattered severe thunderstorms will remain possible through the late evening hours across parts of southeast New Mexico and western Texas as well as across parts of the central Appalachians and parts of the Carolinas and southeast Virginia. ...Synopsis... An omega blocking pattern will continue to become established aloft across the country as a pair of upper lows linger over the OH River Valley and Southwest. Broad scale ascent ahead of both of these low will continue to promote thunderstorm chances across the eastern U.S. and the Intermountain West through early Monday morning. ...Upper Ohio River Valley... As of 00 UTC, a lobe of mid-level vorticity pivoting into the upper OH River Valley, coupled with weak mid-level warm advection, continues to promote widely scattered strong/severe thunderstorms. A recent 00 UTC sounding from Pittsburg, PA sampled limited mixed-layer buoyancy, but recent high-res guidance and mesoanalysis estimates suggests a corridor of somewhat higher buoyancy (500-750 J/kg MLCAPE) resides from northern WV into western PA. Additionally, 30-40 knot mid-level flow sampled by the recent RAOB is adequate to support supercells. The thermodynamic environment should continue to wane heading into the overnight hours, and stronger forcing for ascent will increasingly overspread a less buoyant air mass to the north, though a severe hail threat may persist for the next couple of hours. ...Coastal Carolinas into southeast Virginia... Thunderstorms continue to develop and propagate along a weakly confluent marine boundary draped from south-central VA into the eastern Carolinas. Dewpoints in the mid to upper 60s continue to contribute to around 1000 J/kg MLCAPE (perhaps best sampled by the 00 UTC CHS sounding). A localized hail/wind threat should persist with ongoing convection given adequate buoyancy and deep-layer shear, but nocturnal cooling should increase low-level stability and limit thunderstorm coverage and intensity through the overnight hours. Latest guidance hints that an early-morning (10-12 UTC) round of thunderstorms is possible across north-central NC into southeast VA. Strong mid-level flow should remain over the region and may support organized cells with an attendant hail/wind threat. ...New Mexico into western Texas... Long-lived supercells continue to migrate across far southeast NM into western TX as of 00 UTC. A strengthening low-level jet will help elongate low to mid-level hodographs as well as maintain moisture advection from the southeast. As a result, supercell maintenance is likely for the next few hours before cells drift further east into TX and out of the primary low-level jet/moist advection axis. Persistent lift across the region in the vicinity of the terminus of the low-level jet and within the left-exit region of an approaching upper jet may support additional strong/severe storms later tonight. However, more limited buoyancy/increased inhibition should limit storm coverage. Therefore, opted to remove Slight-risk caliber risk probabilities, but maintain low-end probabilities to address the severe potential for additional overnight storms. ..Moore.. 05/05/2025