Thunderstorms Rooting Deeper, Eyeing Supercells and Tornadoes in Western Maine — SevereWX

SPC Mesoscale Discussion 1613 highlights growing severe potential

Scattered thunderstorms are showing signs of strengthening along an outflow boundary stretching from southwestern Quebec into northern New England. As a capping layer of warm air aloft erodes this afternoon, these storms could root into a moist, unstable boundary layer with over 2000 J/kg of CAPE and surface dew points near 70°F.

By 4-6 PM EDT (20-22Z), expect scattered development to intensify, potentially evolving into supercells amid strong wind shear. The primary risks include:

• Large hail: 1.50-2.50 inches (golf ball to tennis ball size)
• Damaging winds: 65-80 mph gusts
• Tornadoes: Possible 120-145 mph (low-end EF2 to EF3)

Storms will spread across parts of western Maine, northern New Hampshire, and Vermont through early evening. SPC estimates a 60% chance of a mesoscale discussion watch.

This setup features renewed activity near a mesoscale convective vortex, but the focus is on boundary-forced intensification. Stay tuned to radar and local NWS updates.

Preparedness: Have a severe weather plan ready—seek shelter in an interior room on the lowest floor if warnings are issued, and monitor via NOAA Weather Radio or apps.