FORECAST SUMMARY: Monday, June 3, 2024, through Friday, June 7, 2024
OZONE: 8-hour average Ozone concentrations are expected to range from Good (Green AQI) to Moderate (Yellow AQI) across central and southern locations Monday and Tuesday, and a few locations in the east/southeast may reach the low-end Unhealthy for Sensitive Groups (USG, Orange AQI). The rest of the period readings will range from Good to Moderate.
PM-2.5: 24-hour daily average Fine Particulate concentrations will range between upper Good and low Moderate through the forecast period.
FORECAST DISCUSSION:
As a warm front lifts north into the state, warm, humid conditions can be expected Monday and Tuesday with storm chances, generally in northern locations. Locations Monday and Tuesday that experience more sunshine will also see an increase in ozone concentrations, and there is a small chance an isolated monitor in the southeast could reach the low-end USG range. We feel, however, that clouds will be prevalent enough on Tuesday to keep concentrations Moderate. The timeframe for the highest ozone concentrations Monday and Tuesday will be during the mid-afternoon to early evening hours. A storm system and associated boundary bring more widespread precipitation to the state late Tuesday into Wednesday. This produces a good airmass change with cooler temperatures on a northwesterly flow that lasts the rest of the week. Ozone concentrations past Tuesday should range Good through the rest of the forecast period.
Fog that developed early Monday morning resulted in PM2.5 increases, with hourly concentrations ranging from the upper Moderate to low-end USG range during the morning hours. As the fog dissipated, PM2.5 levels improved into the Good to low-Moderate range. Increased humidity on Monday, lasting until the frontal passage on Wednesday, may allow for increases in PM2.5 into the Moderate range, especially in southern locations. Past Wednesday, we expect primarily Good PM2.5 levels. We are keeping an eye on wildfires far to our northwest in Canada, and current smoke models are not picking up smoke coming into the region, even as winds turn northwesterly later in the week. This is something we will keep an eye on, and this forecast will be updated if necessary.
EXTENDED FORECAST:
Extended forecast models show cooler temperatures and scattered chances for precipitation late in the period. If this forecast remains on track, pollution levels should be generally Good.
Next Forecast update: Friday, June 7, 2024