SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Mon Mar 24 2025 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE PACIFIC NORTHWEST... ...SUMMARY... A few strong/severe storms will be possible across portions of the Pacific Northwest on Wednesday. ...Synopsis... A slowly progressive upper pattern will persist across the U.S. Wednesday, as an eastern U.S. trough continues to advance slowly toward the Atlantic Coast. Upstream, ridging over the interior West will gradually expand into the Plains, while still farther upstream, a second upper trough over the eastern Pacific approaches the northwestern states. At the surface, the primary feature will be a cold front shifting into/across the Pacific Northwest, while the parent occluded low remains offshore through the period. ...Portions of the Northwest... As the eastern Pacific upper low nears the Pacific Northwest Coast, cold air aloft/steep mid-level lapse rates will overspread the area, atop low 50s surface dewpoints. This will combine with afternoon heating to support development of 500 to 1000 J/kg mixed-layer CAPE. Meanwhile, the approach of the upper system will also allow deep-layer south-southwesterly flow to increase across the area, allowing shear to become favorable for supporting organized updrafts -- potentially including a few rotating storms. As such, local risk for hail and/or damaging wind gusts may evolve during the afternoon and evening, spreading across parts of Washington and Oregon and possibly into western/northern Idaho by evening. While coverage of the stronger storms should remain rather sparse, the degree of risk appears to warrant introduction of 5%/MRGL risk across this area. ..Goss.. 03/24/2025