Tornado Threat Forecast: June 21-27, 2012

1-3 DAY

Thursday

No tornadic activity expected.

Friday

Central High Plains — POTENTIAL: Low — CONFIDENCE: Normal
Storms forming in the vicinity of a weak shortwave pulse will be in a strongly-rotational environment with moderate CAPE, but a weak cap, somewhat-anemic mid-level speed shear and height rises will inhibit tornado formation.

Saturday

Montana — POTENTIAL: Low — CONFIDENCE: Normal
As the main upper-level low spins over the Pacific Northwest, strong, rotational shear will combine with an area of low to moderate CAPE to produce isolated supercells. One or more of these supercells may be able to drop a tornado despite potential capping issues.

4-7 DAY

Sunday

Montana — POTENTIAL: Very Low — CONFIDENCE: Normal
Nearly the same setup as Saturday’s threat, only the latest models show less storm coverage on this day as height rises enter the region.

Northern Illinois, northern Indiana — POTENTIAL: Very Low — CONFIDENCE: Normal
Low to moderate CAPE will be available in an atmosphere with weak westerly flow at the surface and moderate strong northwesterly flow aloft, allowing for rotating storms to possibly put down a tornado. The tornado potential will be limited by weak directional shear throughout most of the risk area and weak low/mid-level lapse rates.

Monday

Southern Mid-Atlantic, North Carolina — POTENTIAL: Very Low — CONFIDENCE: Low
Storms forming along/ahead of a cold front are expected to be in an environment with low to moderate CAPE and shear, allowing for some tornadic potential if storms can stay discrete and overcome possible lapse rate issues. Poor model agreement concerning the timing and the risk area will keep confidence low.

Tuesday

Northern High Plains — POTENTIAL: Very Low — CONFIDENCE: Normal
Storms forming in a narrow corridor of favorable CAPE and shear could possibly become tornadic, but capping concerns and storm coverage will also be there to inhibit the overall potential.

Wednesday

No tornadic activity expected.