Tornado Threat Forecast: Nov 16-17, 2013

A strong disturbance will work into the Midwest today into tomorrow, with the threat of a tornado outbreak looming on Sunday. As is typical with these cold season threats, this system has a high shear/low CAPE environment with conditional risks to both sides. Regardless of the risks, tomorrow’s setup looks prime for widespread severe winds and some tornadoes.

Saturday

Central Mississippi Valley — POTENTIAL: Low — CONFIDENCE: Normal
Pros: Strong shear (both directional and speed), left-exit region of an upper-level jet.
Cons: Very little instability, weak lapse rates.

Sunday

Midwest, Tennessee Valley — POTENTIAL: High — CONFIDENCE: Normal
Pros: Very strong speed shear, good directional shear, very strong forcing, improving mid-level lapse rates, surface dewpoints in the 60s, pre-frontal supercells possible.
Cons: Instability could be limited by widespread cloud cover and rain in the warm sector. Storms could turn linear faster, which would limit the supercell potential.