2AM Day 3 Convective Outlook for Monday, October 20. NO SEVERE THUNDERSTORM AREAS FORECAST
SUMMARY
Severe storms are unlikely Monday.
Synopsis and Discussion
The upper trough over the Northeast US is expected to mature and transition into a closed low as a powerful mid-level jet streak ejects over the Northeast Monday. A second strong trough will also intensify over the Upper Midwest, deepening a broad surface cyclone across the Great Lakes. To the east, a secondary surface cyclone will develop over the western St. Lawrence Valley at the apex of the surging cold front before merging with the broader low farther west. As the lows deepen and the front moves quickly eastward across the Atlantic Coast and across FL, southerly winds will transport a modestly moist air mass (low 50s F surface dewpoints) northward across southern New England.
One or two damaging gusts remain possible ahead of the rapidly moving cold front over parts of southern New England early Monday. Confined to a narrow warm sector with modest moisture but strong low-level winds, a shallow convective band along the front may be capable of sporadic damaging gusts before the front moves offshore by early afternoon. The primary limiting factor remains the degree of destabilization ahead of the shallow convective band. Current guidance shows little insatiability and poor lapse rates suggesting very limited severe potential.