SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Wed Aug 04 2021 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL NORTH CAROLINA AND WESTERN MONTANA... ...SUMMARY... Gusty winds may accompany afternoon storms over the northern Rockies. A severe storm capable of a tornado will be possible over coastal North Carolina mainly this morning. ...Coastal North Carolina... Eastern US upper trough is forecast to gradually shift into the central/southern Appalachians by the end of the day1 period. Latest satellite imagery suggests a plume of high-PW air extends across the eastern Gulf Basin-FL-coastal Carolinas. A few weak disturbances are embedded along this corridor with one notable feature ejecting across SC at this time. An expansive shield of precipitation extends ahead of the short wave but the primary surface boundary appears to be holding near/just offshore. This boundary will struggle to advance inland, thus buoyancy will remain limited across interior portions of the Carolinas. The greatest risk for destabilization appears to be across the Outer Banks region where onshore flow may persist through late morning. While buoyancy should remain meager in this weak-lapse-rate environment, sufficient deep-layer flow likely exists for a few weakly rotating storms. A brief tornado can not be ruled out in this regime. ...Northern Rockies... Western WA short-wave trough is forecast to eject into southeast BC/northern ID by 18z, then into northwestern MT where mid-level heights should be suppressed a bit by afternoon. Eastern WA is notably more moist than western MT at this time but westerly trajectories should allow for some moistening into western MT prior to peak heating. Latest guidance suggest PW values could approach one inch over the MRGL Risk area, and forecast soundings at MSO and GPI suggest this activity would be based near 3km AGL with substantial sub-cloud drying. With large-scale forcing for ascent expected to aid this high-based activity, some organization could occur, and gusty winds are the primary threat. ..Darrow/Moore.. 08/04/2021 Read more LIVE: spc.noaa.gov
http://dlvr.it/S50fYF
