Day 3 Convective Outlook
Issued: · Valid: –
Summary
Severe thunderstorms are possible across portions of New England during Tuesday afternoon and evening. Additionally, strong to severe thunderstorms may develop across parts of western and central Montana on Tuesday afternoon.
Product Text
000 ACUS03 KWNS 120731 SWODY3 SPC AC 120730 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun Jul 12 2026 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND... ...SUMMARY... Severe thunderstorms will be possible during the afternoon and evening across portions of New England on Tuesday. Additional strong-to-severe thunderstorms will be possible across parts of western and central Montana. ... Synopsis ... An expansive mid-level ridge centered over the north-central US will begin to retrograde on Tuesday as a strong short-wave trough digs southeast out of Canada toward New England. As the ridge builds west, the mid-level height gradient will increase across the northwestern US as a seasonably strong mid-level trough/closed low remains anchored off the Washington/Oregon coasts. ... New England ... Thunderstorms are expected to develop across portions of Quebec on Tuesday afternoon as a strong mid-level trough and attendant surface cold front move across the region. Ahead of this cold front, southwesterly surface winds will transport in rich boundary layer moisture, which will combine with diurnal heating to support MUCAPE in the 1500-2500 J/kg range. Strong vertical shear (on the order of 50-60 knots) will overspread the region during the afternoon and evening, which will support one or more clusters of severe thunderstorms moving from Quebec into and across portions of New England during the late afternoon, evening, and early morning hours. All severe hazards will be possible with any sustained thunderstorm. One mitigating factor for a more significant severe weather event will be the timing of the storms. At this time, it appears thunderstorms will be moving across New England well after peak heating and into the overnight. Should the timing of storms be earlier than currently expected, greater coverage of thunderstorms may result and higher severe probabilities would be warranted. ... Portions of Western and Central Montana ... Showers and thunderstorms are expected to develop across the higher terrain of southwest Montana during the afternoon on Tuesday. Surface moisture will be better (surface dewpoints in the 50Fs) than in previous days, which should support greater afternoon buoyancy and in turn stronger thunderstorm updrafts. Strong south-southwesterly mid-level flow in between the trough to the west and ridge to the east will support thunderstorm organization and some severe potential as some of the storms move northeast off the higher terrain. ..Marsh.. 07/12/2026 $$