FORECAST SUMMARY:
Monday, December 14th, 2020 through Monday, December 21st, 2020
PM-2.5: 24-hour average Fine Particulate concentrations will be mostly Good through mid-week with levels ranging upper Good to middle Moderate the rest of the forecast period.
FORECAST DISCUSSION:
The week starts with lake effect snow showers Monday thanks to a cold northwest wind. The light snow ends Tuesday as high pressure builds in, and quiet conditions are expected the rest of the workweek. Cool temperatures are forecast Tuesday through mid-week, but readings should moderate towards the end of the week as southerly winds develop.
As for air quality, fine particulate levels should remain Good due to northwest winds Monday and easterly winds Tuesday into Wednesday. Lighter winds in the morning could allow for hourly fine particulate concentrations in the Moderate range; however, daily averages should be Good. Lighter winds by Thursday turn back to a southerly direction as weak ridging remains nearby. Some locations, especially in the south or areas with any snow accumulation, may reach Moderate for fine particulate Thursday and again Friday.
EXTENDED FORECAST:
Extended forecast models show the next weather system holding off until Saturday when rain and/or snow returns to the forecast. This does not seem to be a strong system, but northerly winds in its wake should bring any Moderate fine particulate back to Good early next week.