SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 PM CDT Sun May 21 2023 Valid 220100Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE INTERIOR NORTHWEST INTO WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms remain possible across portions of the interior Northwest this evening. Large hail and isolated damaging gusts will be the primary hazards. ...01z Update... Early-evening water-vapor imagery depicts a notable short-wave trough advancing inland along the WA/OR Coast. Leading edge of large-scale ascent appears to be spreading across eastern WA/OR at this time. Two main corridors of organized convection have evolved ahead of the short wave. The northern-most area extends from northeast WA/northern ID into southeast BC. The second extends from southeast OR into central ID. Strongest buoyancy arcs from southeast BC into central ID, with weaker instability observed into the northern Great Basin due to poorer low-level moisture. 00z soundings from OTX and BOI/LKN exemplify this CAPE field, but steep lapse rates are noted across most of the interior northwest. As height falls spread inland, and 500mb flow strengthens into the northern Rockies, this activity should propagate toward western MT later this evening. Hail/gusty winds remain the dominant threats. ..Darrow.. 05/22/2023
