4/26/2021 Forecast Update
FORECAST SUMMARY:
Monday, April 26th, 2021 through Monday, May 3rd, 2021
OZONE: 8-Hour average Ozone concentrations may reach Moderate across parts of central/southern Michigan Tuesday, otherwise expect Good levels the rest of the forecast period.
PM-2.5: 24-hour average Fine Particulate concentrations are expected to range from upper Good to middle Moderate.
FORECAST DISCUSSION:
We usually begin forecasting ozone on May 1st, but weather conditions Tuesday may cause Moderate ozone across central and southern parts of the state. Because of that, we’ve added ozone to the forecast a few days early. Good ozone and fine particulate are expected Monday with south/southeast winds, partly to mostly cloudy skies, and slight chances for afternoon precipitation.
Late Monday, into Tuesday a warm front lifts north into the state. South of the boundary expect some sunshine, good south/southwesterly winds, and warm surface and upper-level temperatures. This combination could allow ozone to reach Moderate in central and southern locations. Clouds and precipitation chances keep readings Good further north.
The frontal boundary lingers across northern lower into midweek then a wave traveling along the front pushes the boundary east and away from the region Thursday into Friday. Clouds and precipitation keep ozone Good Wednesday and Thursday. Without a period of prolonged stagnation, fine particulate through Thursday shouldn’t reach higher than low Moderate.
High-pressure building in Friday brings sunshine, but cool northerly winds prevail. Air quality will end the workweek in the Good range.
EXTENDED FORECAST:
Extended forecast models show differences in precipitation chances for the weekend. For now, it looks like quiet conditions remain Saturday, but another system may bring precipitation Sunday and/or Monday. If this general forecast pans out, ozone should remain Good and fine particulate shouldn’t reach higher than upper Good to low Moderate.