Lower Severe Storm Threat, Accumulating Snow? Tornado Outbreak Possible For Ohio & Indiana.

Severe Threat Summary:

Severe Weather chances here in western and southwestern lower Michigan have been further reduced and the "All-Hazards" risk for tornadoes, damaging wind gusts, and large hail has been replaced with a risk only for locally damaging wind gusts and large hail.

NWS Storm Prediction Center - Day 1 Categorical Severe Weather Outlook (Moderate Risk - 4/5) [Issued: 2:00 AM/06Z]

A dangerous day of severe weather with the potential for hurricane-force wind gusts, large to very-large hail over baseball size in diameter, and several intense, long-track tornadoes is possible for our neighbors to the south/southeast in southeastern Indiana and central/southwestern Ohio later this afternoon.

Local Severe Storm Risk Discussion:

Locally, the severe weather threat has changed/weakened some, as aforementioned. The Marginal Risk (Level 1/5 - Dark Green) is now only in place for southeastern portions of our coverage area including southeastern Cass, southeastern St. Joseph, and Branch Counties.

This threat is indicative of the risk (5%) for a couple of isolated borderline severe wind gusts and/or large hail reports. The threat of tornadoes is now negligible (less than 2%) in all of lower Michigan.

The threat of severe weather is a conditional one, as we have seen in all of our severe threats so far this year, and will be highly dependent on two main factors; first, the ability for warm, moist air to advect, or move, north into southern lower Michigan, and the quality of said warm/moist air return and second; the effect that prefrontal and/or frontal rain showers that will be ongoing through much of the day today and will serve to hamper the already weak/negligible instability.

Some rumbles of thunder are possible across the remainder of the West Michigan Weather Coverage area today as high wind shear values and some weak, elevated instability in place across the region may allow for some convective rain showers to produce some intermittent/isolated lightning.

Accumulating Snow Potential:

As the thunderstorm threat subsides this afternoon, colder air will move in this evening and the rain will begin to mix with snow. Computer weather models have been all over the place with the potential for western lower Michigan to see accumulating snow with this system, ranging from Winter Storm type totals to less than an inch over the last several days.

Current guidance is beginning to narrow in on a solution that would result in largely negligible snow accumulation across the area, and hence, any winter travel impacts should also be kept fairly minimal. Some snow accumulation to around the 1-inch mark is still possible, however, especially across northern parts of our coverage area. At this point we don't foresee a need to issue School Closing Outlooks for this event but we'll continue to monitor trends throughout the day.