FORECAST SUMMARY:

Thursday, June 3rd, 2021 through Friday, June 4th, 2021

OZONE: 8-Hour average Ozone concentrations are expected to be mostly Good with small chances for USG along the West Michigan lakeshore.

PM-2.5: 24-hour average Fine Particulate concentrations will be in the upper Good to middle Moderate range.

FORECAST DISCUSSION:

A weak system over southwest Ontario will continue moving east today as a boundary sinks in from the north. Generally, sunny and warm conditions are expected Thursday with a bit more clouds near the systems in the southeast and northern areas. Ozone concentrations have reached just over the USG threshold at a few locations right along the lakeshore of West Michigan Wednesday, and this may happen again Thursday. The greatest chance for low-end USG will be south of Muskegon. Overall, however, Moderate ozone is expected.

The system dropping in from the north brings clouds and small chances for precipitation overnight Thursday into early Friday morning. Clouds will decrease as the day progresses Friday. Warmer conditions continue and if clouds clear out early enough a monitor or two may reach low-end USG, however, we don’t feel the threat at this time warrants an Action Day Advisory for Friday. Conditions for the weekend look to deteriorate regarding air quality. Warm surface and upper-level temperatures will be in place, skies will be sunny, and southwest/west winds prevail. Because of this, we are having another regional forecast call Friday morning to decide if Action Day Advisories will be issued for Saturday.

Fine particulate is currently ranging in the upper Good to middle Moderate range and without a clean air mass moving in, levels in the range will continue.

EXTENDED FORECAST:

Extended forecast models continue showing increased temperatures and dry conditions into early next week. This will continue to keep the threat of increased ozone levels.

Forecast updated by Stephanie Hengesbach: Tuesday, June 3rd, 2021
Next forecast update: Friday, June 4th, 2021