Tornado Threat Forecast: April 24-30, 2017

#HotTakes edition. There has been a lot of deliberation on social media concerning the storm system at the end of the week, with some optimistic and some pessimistic with respect to the tornado potential. And for good reason… subtle changes will make or break what we end up seeing from Friday onward.

1-3 Day

Monday

No tornadoes expected.

Tuesday – Eastern Oklahoma, eastern Kansas, western Arkansas

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

Pros: Low to moderate instability, good/excellent speed shear, decent/good low-level directional shear, decent upper-level support.
Cons: Storm mode will quickly go more linear as a cold front forms and organizes most of the storm activity, mostly unidirectional winds in the mid-to-upper levels, capping issues in the southernmost areas.

Wednesday – Central and southern Mississippi Valley

NUMBER OF TORNADOES EXPECTED: 3-8 – CONFIDENCE: Low
Tornado Hot-spot: Southern Mississippi Valley

Pros: Low to moderate instability, good/excellent speed shear, good upper-level support.
Cons: Poor/decent directional shear, mostly linear storm mode.

4-7 Day

Thursday – Southeast

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

Pros: Low to moderate instability, good speed shear.
Cons: Poor/decent directional shear, mostly linear storm mode, fairly weak upper-level dynamics.

Friday – Southern Plains, southern Mississippi Valley

NUMBER OF TORNADOES EXPECTED: 4-10 – CONFIDENCE: Low
Tornado Hot-spot: None

Pros: Moderate to high instability, good/excellent speed shear, decent/good low-level directional shear,
Cons: Questionable storm mode due to mostly unidirectional mid-to-upper level shear, weak upper-level support.

Saturday – Southeastern Plains, southern Mississippi Valley

NUMBER OF TORNADOES EXPECTED: 12-30 – CONFIDENCE: Low
Tornado Hot-spot: None

Pros: Moderate to high instability, good directional shear, good speed shear.
Cons: Somewhat weak upper-level support, uncertainty with the level of instability.

Sunday – Southern Mississippi Valley, Southeast, Ohio Valley

NUMBER OF TORNADOES EXPECTED: 10-25 – CONFIDENCE: Low
Tornado Hot-spot: Southeast

Pros: Good/excellent speed shear, decent/good directional shear, low to moderate instability, decent upper-level support.
Cons: Northern areas face more concerns with low instability and weaker directional shear, the best dynamics (north) are separated from the best instability (south).