Rare Southern U.S. Winter Storm; Dangerous Cold Weather For Much of the Eastern U.S.; Critical Fire Weather for Southern California

Day 4-8 Outlook Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0351 AM CDT Wed Apr 16 2025 Valid 191200Z - 241200Z ...DISCUSSION... Severe potential remains apparent into the weekend, but predictability wanes substantially by D5/Sunday. ...D4/Saturday... The persistent longwave trough is expected to breakdown as an embedded northern-stream shortwave impulse accelerates east across ON/QC and the basal shortwave impulse moves more gradually east into the southern High Plains. Through Saturday afternoon, an expansive swath of strong mid-level flow will persist from the central Appalachians southwestward into the southern Great Plains. The nearly stalled baroclinic zone from TX/OK