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SPC Feb 6, 2025 1730 UTC Day 2 Convective Outlook

5 months 1 week ago

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CST Thu Feb 06 2025 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Aside from some potential for a couple of weak thunderstorms across parts of the northern Rockies vicinity, the risk for thunderstorms appears negligible across much of the U.S., Friday through Friday night. ...Discussion... Models indicate that broad mid/upper ridging will be maintained across the subtropical latitudes, from northern Mexico through the western Atlantic, and a prominent influence across the southern into central tier of the U.S. through this period, downstream of persistent ridging in the northern mid-latitudes, and troughing in the southern mid- to subtropic latitudes, of the eastern Pacific. To the east of the northeastern Pacific ridging, broad mean troughing, with more progressive embedded smaller-scale perturbations, is forecast to linger across British Columbia and the Pacific Northwest, while developing eastward across the Canadian Prairies, northern U.S. Rockies and Great Plains. Beneath this regime, guidance indicates potential for modest surface cyclogenesis across eastern Colorado through areas near/south of the Kansas/Oklahoma border vicinity. There appears better consensus among the models, particularly the ECENS/ECMWF and GEFS/GFS. But this output may still be having issues handling ongoing reinforcing cold intrusions to the lee of Rockies. The NAM and Rapid Refresh remain slower to erode the colder boundary-layer across the Texas South Plains into central Oklahoma vicinity, and are slower and weaker with the evolving surface wave. Otherwise, a gradual erosion, from south to north, of the shallow leading edge of the entrenched cold air mass is possible, beneath a continuing southerly to westerly return flow across parts of the southeastern Great Plains into southern Mid Atlantic. However, it appears that associated moisture emanating from a modifying western Gulf boundary layer will not become supportive of more than weak destabilization, or an appreciable risk for thunderstorms, due to negligible forcing for ascent and warm, capping layers aloft. ...Pacific Northwest into northern Great Plains... Models do indicate that forcing for ascent and cooling mid-levels may contribute to pockets of weak destabilization across parts of the Pacific Northwest into northern Great Plains during this period. However, based on the latest NAM and Rapid Refresh forecast soundings, the calibrated High Resolution Ensemble Forecast guidance might be too aggressive with probabilities for thunderstorms across the eastern Great Basin into northern Rockies vicinity for Friday afternoon and evening. Instability will probably be sufficient to support scattered to numerous snow and rain showers. However, whether the boundary layer in higher elevations warms enough, or convection initiating in lower elevations deepens through sufficiently cold layers aloft, to support an appreciable risk for lightning remains a bit unclear. ..Kerr.. 02/06/2025 Read more