Summary:
Issued 04/16/2024 09:11 AM EDT
A lower, smaller area of severe potential for the far southwest corner of Berrien County today. A larger, somewhat higher severe weather threat exists for tomorrow (Wednesday) across much of the area along and south of the I-96 corridor, especially east of the US-131 corridor.
Today's Threat (04/16/2024):
A very small portion of extreme southwestern Berrien County remains in the Marginal (Level 1/5) Risk for Severe Weather this evening.
This threat is driven by the low-end risk of an isolated damaging wind gust to 60 MPH or a large diameter hailstone to about 1 inch in diameter. The threat of a tornado appears negligible (less than 2%) at this time.
Current computer weather model guidance suggests that a broken line of showers and storms will move in from the southwest as they move out of Illinois and cross Lake Michigan as early as 6:00 PM, perhaps with some stronger, more discrete cells out ahead of the main line.
A couple of components will serve to largely hamper and weaken the overall threat of severe weather this evening.
Very skinny, short CAPE (the amount of instability - or energy - that storms need to develop, intensify, and sustain a severe threat) profiles will cause storms to struggle in terms of intensity and longevity.
Timing of storms will occur well after peak heating and will occur during, or even after, sunset this evening resulting in decreased surface heating.
Again, this threat will be isolated in nature and on the lower end of the severe weather intensity scale but persons in the risk area should remain alert and listen for later forecasts as the threat is updated throughout the day.
Tomorrow's Threat (04/17/2024):
The SPC has upgraded tomorrow's risk to a Slight Risk (Level 2/5) for severe weather across much of southern and southeastern lower Michigan extending into parts of the West Michigan Weather coverage area. A smaller Marginal Risk delineation surrounds the broader slight risk area.
Current computer weather model guidance suggests a more robust, widespread threat as compared to today's risk. 00z and 06z suites both indicate that a line of showers and storms will move from west to east across the state in the early morning hours from around 5:00 AM to 10:00 AM.
After the morning convection clears out we should have modest to robust clearing across much of the region and the atmosphere should be fairly destabilized as we approach peak heating in the afternoon with some models indicating upwards of 1,500 J/kg to as much as 2,000 J/kg of MUCAPE.
Based on the 06z CAM suites Owen and I would anticipate a westward shift and/or expansion of the Slight Risk delineation with the Day 2 Afternoon SPC Update that comes out around 1:30 PM this afternoon. 06z HRRR, RRFS, MPAS, and to a lesser degree the NAM 3km, suggesting that the most destabilization ahead of the severe convection in the afternoon may occur across west-central into south-central lower Michigan and allow for an increased wind/hail/tornado threat across the western part of the current risk area. This model guidance will continue to be monitored and we'll provide an update(s) this afternoon/evening regarding this 'trend' as the 12z and 18z guidance comes in.
A couple of caveats to tomorrow's threat will be that the primary convective line is expected to come through after a round of morning convection. Depending on timing, this may hamper the afternoon line from intensifying to severe levels. Another limiting factor may be that the primary line of convection, regardless of the morning convection, is currently forecasted to arrive just prior to peak afternoon heating and atmospheric destabilization. Shear, or wind profiles, are also only modest at best with effective 0-3km bulk shear forecasted at as much as 45kts.
Overall, tomorrow is certainly a threat that is worth watching and may prove to pose a decent threat for a couple of isolated tornadoes. Everyone in southern lower Michigan needs to remain #WeatherAware and stay tuned for future forecast updates. Follow us on social media and here on our website for additional information.
Storm Chasing Operations:
Storm Chase Mode will not be activated for today.
We are planning to activate Storm Chase Mode tomorrow and are currently targeting somewhere along the I-196/US-131 interchange. Make sure that you're following us on Twitter (X) and Facebook, and/or subscribed to our YouTube channel to tune in live! Links are all at the top of the page in the site menu.
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