SPC AC 220530 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Tue Sep 22 2020 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND FAR NORTHWESTERN WISCONSIN... ...SUMMARY... Isolated strong to severe storms may occur Wednesday afternoon and evening across parts of northern Minnesota and far northwestern Wisconsin. Large hail and damaging wind gusts should be the main threats. ...Upper Midwest... A low-amplitude shortwave trough embedded within quasi-zonal mid-level westerly flow should advance east-southeastward from the northern Plains to the Upper Midwest through the period. Elevated thunderstorms that may be ongoing Wednesday morning across parts of ND should weaken through the day. Additional convection may form along a weak surface front across parts of northern MN into far northwestern WI by late Wednesday afternoon into the evening. Although low-level moisture is forecast to remain somewhat limited along/south of the front (mid 50s to low 60s surface dewpoints), it should still support 1000-2000 J/kg of MLCAPE given the presence of steep mid-level lapse rates. Strong effective bulk shear of 40-50 kt will likely foster storm organization, with isolated supercells possible with the initial development along the front. Large hail and damaging wind gusts should be the main threats as storms move east-southeastward across northern MN and into far northwestern WI through Wednesday evening. ...Lower Mississippi Valley... Beta is forecast by the National Hurricane Center to weaken to a Tropical Depression on Wednesday as it moves slowly northeastward along/near the TX/LA Coast. There are still differences between global and convection-allowing guidance regarding Beta's location by Wednesday evening. A more northward position into southern LA would allow for a moist low-level airmass to move inland across this area through the day, with at least weak destabilization occurring. Even so, most guidance suggests that modestly enhanced low-level south-southeasterly winds should remain generally displaced to the north of the surface-based instability through the period, which would limit both effective bulk shear and storm organization. At this point, the potential for severe storms appears too limited to include any severe probabilities across southern LA/MS. ...Pacific Northwest... A large-scale upper trough with strong mid-level jet should move eastward across parts of the Pacific Northwest on Wednesday. Strong deep-layer shear should be present, but instability is forecast to remain meager at best. While isolated thunderstorms appear possible, the overall severe threat should remain low owing to the limited instability. ..Gleason.. 09/22/2020 NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z