Tornado Threat Forecast: May 21-27, 2018

Hello? May? This can’t be May. I mean, our seasonal outlook called for a quieter than normal May, but THIS?!

1-3 Day

Monday – Ohio Valley

NUMBER OF TORNADOES EXPECTED: 0-2 – CONFIDENCE: High
Tornado Hot-spot: None

Pros: Moderate to high instability, good low-level directional shear near the warm front, decent/good speed shear.
Cons: Poor low-level directional shear south of the warm front, unidirectional mid-to-upper level winds, little to no upper-level support.

Monday – New Mexico, far western Texas

NUMBER OF TORNADOES EXPECTED: 0-2 – CONFIDENCE: High
Tornado Hot-spot: None

Pros: Moderate instability, good low-to-mid level directional shear.
Cons: Weak mid-level shear, little to no upper-level support.

Tuesday – Northern High Plains

NUMBER OF TORNADOES EXPECTED: 0-2 – CONFIDENCE: High
Tornado Hot-spot: None

Pros: Moderate instability, Good/excellent mid-to-upper level directional shear, decent/good low-level speed shear.
Cons: Weak mid-level shear, fairly unidirectional low-level shear, initially high LCLs, rising/neutral heights.

Wednesday – Northern Plains

NUMBER OF TORNADOES EXPECTED: 0-2 – CONFIDENCE: Normal
Tornado Hot-spot: None

Pros: Moderate to high instability, good low-level directional shear, decent/good low-level speed shear.
Cons: Weak mid-level shear, unidirectional/backing mid-to-upper level winds, weak upper-level dynamics.

4-7 Day

Thursday – Northern Plains, northwestern Midwest

NUMBER OF TORNADOES EXPECTED: 0-3 – CONFIDENCE: Normal
Tornado Hot-spot: None

Pros: Moderate to high instability, good low-level shear, decent upper-level support.
Cons: Weak mid-to-upper level winds, some backing of the upper-level winds.

Friday

No tornadoes expected.

Saturday

No tornadoes expected.

Sunday – Northern High Plains

NUMBER OF TORNADOES EXPECTED: 0-3 – CONFIDENCE: Low
Tornado Hot-spot: None

Pros: Moderate instability, decent/good shear overall, maybe some upper-level support.
Cons: Southerly to southeasterly mid-to-upper level winds, questionable storm mode, potential some weakness in the mid-level speed shear.