EML Cap Cracks Open Supercell Path in Western Maine, Northern New Hampshire — SevereWX

EML Cap Cracks Open Supercell Path in Western Maine, Northern New Hampshire

A mesoscale convective vortex crossing from Quebec is setting the stage for a serious severe weather bout this afternoon. Thunderstorms along its trailing outflow boundary are showing fresh signs of life, especially where rich moisture (dewpoints near 70°F) meets high CAPE over 2000 J/kg.

The key player? A warm elevated mixed-layer (EML) cap that's slowly lifting northward, allowing these storms to root deeper into unstable surface air. SPC's latest Mesoscale Discussion (1613) highlights scattered thunderstorms intensifying by 4-6 PM EDT (20-22Z), potentially evolving into supercells amid strong shear.

Threats include:

• Large hail: 1.5-2.5 inches (golf ball to tennis ball size)
• Damaging winds: 65-80 mph gusts
• Tornadoes: Possible 120-145 mph (EF2 strength)

This setup spans parts of western Maine, northern New Hampshire, and nearby Vermont near the international border. A watch issuance carries 60% odds within the next two hours.

Storms could spread east-southeast, impacting populated areas through early evening. Keep an eye on radar as development ramps up.

Stay prepared: Monitor local NWS alerts, secure outdoor items, and have a severe weather plan ready with multiple alert sources like NOAA Weather Radio or apps.