Tornado Threat Forecast: May 18-24, 2017

Today and Friday will be active across the Plains and into the western Midwest, with dozens of tornadoes possible. Tornado threats drop off this weekend, with a fairly quiet early-to-mid week likely next week.

1-3 Day

Thursday – Central and southern Plains

NUMBER OF TORNADOES EXPECTED: 14-32 – CONFIDENCE: Normal
Tornado Hot-spot: Kansas, Oklahoma

Pros: High instability, good low-level directional shear, good/excellent speed shear, decent upper-level support.
Cons: Unidirectional/backing winds in the mid-levels, storms could grow upscale quickly into broken lines.

Friday – Central and southern Plains, central Mississippi Valley

NUMBER OF TORNADOES EXPECTED: 10-25 – CONFIDENCE: Normal
Tornado Hot-spot: Kansas, Oklahoma

Pros: Moderate to high instability, good/excellent low-level directional, good speed shear, decent upper-level support.
Cons: Surging cold front will help storms grow upscale fairly quickly

Saturday – Midwest, central Mississippi Valley, Texas

NUMBER OF TORNADOES EXPECTED: 5-12 – CONFIDENCE: Normal
Tornado Hot-spot: Midwest

Pros: Moderate instability, decent low-level directional shear, decent upper-level support in the Midwest, decent/good speed shear.
Cons: Unidirectional winds in the mid-to-upper levels leading to a mostly linear storm mode, weak upper-level support from the central Mississippi Valley to Texas, earlier clouds and rain in the morning and early afternoon could somewhat inhibit the stronger storm formation later in the day.

4-7 Day

Sunday – Texas

NUMBER OF TORNADOES EXPECTED: 1-4 – CONFIDENCE: Normal
Tornado Hot-spot: None

Pros: Moderate instability, good directional shear.
Cons: Weak/decent speed shear, weak upper-level support.

Sunday – Ohio Valley, eastern Great Lakes

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

Pros: Decent speed shear, decent upper-level support.
Cons: Weak/decent directional shear, low instability.

Monday – Eastern New Mexico, northern Texas, Oklahoma

NUMBER OF TORNADOES EXPECTED: 2-5 – CONFIDENCE: Low
Tornado Hot-spot: None

Pros: Moderate instability, decent/good low-level directional shear, decent speed shear.
Cons: Questionable storm mode, uncertainty with how far north the unstable air gets.

Tuesday

No tornadoes expected.

Wednesday – Southeastern Mid-Atlantic, eastern Carolinas

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

Pros: Good/excellent speed shear, low to moderate instability.
Cons: Poor directional shear, linear storm mode.