


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
121 ACUS02 KWNS 010557 SWODY2 SPC AC 010556 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OREGON TO NORTHERN MONTANA AND FAR NORTHWEST NORTH DAKOTA AND FROM THE UPPER MIDWEST TO THE CENTRAL GREAT LAKES.... ...SUMMARY... At least scattered storms are possible across a large portion of the continental U.S. on Wednesday. A couple of severe gusts may accompany the stronger storms over portions of the Northern Rockies and the Upper Midwest to central Michigan region. ...Synopsis... A ridge centered across the northern Plains will drift slowly east through the period. To the east of this ridge, a mid-level trough and associated jet streak will dig into the Great Lakes. To the west of this ridge, several embedded shortwave troughs are forecast within moderate southwesterly flow. ...Eastern Oregon to northern Montana and far northwest North Dakota... Scattered thunderstorms are forecast within a zone of steep low/mid-level lapse rates from eastern Oregon into much of Montana. Effective shear of 25 to 30 knots will support some storm maintenance/organization including the potential for multicell clusters. A hot and well-mixed boundary layer featuring 40-50F dewpoint depressions will support some threat for isolated severe wind gusts from this activity. However, weak instability should limit a greater severe weather threat. ...Upper Midwest across Lake Michigan and much of central/northern Lower Michigan... Elevated thunderstorms may be ongoing at the beginning of the period across eastern South Dakota/western Iowa on the nose of the low-level jet. This activity should weaken during the morning. Weak to moderate instability is forecast do develop during the afternoon from the Upper Midwest to northern/central Lower Michigan. A weak mid-level shortwave trough is forecast to move southeastward across this region Wednesday afternoon. As this occurs, isolated to potentially scattered thunderstorms are possible. 35 to 40 knots of mid-level flow may support some storm organization, including the potential for transient supercells. Isolated large hail and damaging wind gusts will be the primary threat. ..Bentley.. 07/01/2025 $$