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SPC Jun 27, 2024 0100 UTC Day 1 Convective Outlook

1 year 2 months ago

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0809 PM CDT Wed Jun 26 2024 Valid 270100Z - 271200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY...NORTHEAST...RED RIVER VALLEY...AND FRONT RANGE... ...SUMMARY... Clusters of thunderstorms accompanied by potentially damaging wind gusts and sporadic hail are possible into tonight from the Ohio Valley into the northern Mid Atlantic, the Red River Vicinity, and to the lee of the Front Range and Sangre de Cristo Mountains. ...01z Update Western US... An upper trough over the Western US will continue to deepen as it emerges over the Great Basin and southern Rockies while a strong ridge builds over the western High Plains. Ongoing isolated storms over parts of the eastern Great Basin have shown steady organization with a few supercell structures noted. Sufficient buoyancy and moderate deep-layer shear will be accompanied by intensifying upper-level support from the trough approaching this evening. With fairly sustained support into the early overnight period, the risk for damaging gusts and sporadic hail may continue for several more hours tonight, even as instability wanes. MRGL level-1 risk has been expanded over parts of ID, WY, UT and NV. ...Red River Valley Vicinity... Vigorous thunderstorm development has been noted along a remnant outflow boundary stretching from the TX Panhandle through the Red River Valley. South of this boundary, an oppressively warm and moist air mass is supporting large buoyancy (MLCAPE of 2500-3000 J/kg) beneath enhanced northerly flow aloft. Sufficient for supercells and organized multicell clusters, (30-35 kt EBWD) additional storm development/organization appears probable this evening despite relatively warm mid-level temperatures. Damaging winds appear to be the most likely threat, given 20+ degree temperature/dewpoint spreads and dry mid-level air. However, severe hail will also be possible with the stronger updrafts, especially any sustained rotating ones. Some upscale growth into a southward moving cluster is also possible later this evening with a risk for damaging winds into north TX. The level-2 SLGT risk area was expanded west along the Red River Valley to better encompass the threat this evening. ...Southeast US into the Northeast... Several clusters of severe thunderstorms are ongoing over parts of the Southeast, OH Valley and into the Northeast CONUS. So far this evening, these clusters have shown organization with self propagating cold pools and linear structures owing to modest, but increasing deep-layer shear beneath a broad trough over the Great Lakes. Several of these more organized clusters are ongoing near the KY/TN border, western PA southern New England. Despite the loss of diurnal heating, residual buoyancy and sufficient deep-layer shear should remain supportive of strong to severe storms this evening. Damaging gusts appear likely to remain a threat for a few more hours, though sporadic hail and a tornado or two are also possible. ...Front Range... Widely scattered clusters of strong to severe storms are ongoing from southern WY to southern CO this evening. Weak forcing for ascent from a subtle impulse rounding the top of a building ridge will gradually decrease in strength this evening. Still, relatively moist surface conditions, dewpoints in the mid to upper 50s, will likely support isolated thunderstorms into tonight. Damaging winds and isolated hail are the most likely threat, especially with any more persistent clusters. ..Lyons.. 06/27/2024 Read more