11/17/2023 Forecast Update

FORECAST SUMMARY: Friday, November 17, 2023, through Monday, November 20, 2023

Ozone: Ozone season is now over and will start forecasting again in the spring of 2024.

PM-2.5:  24-hour average Fine Particulate concentrations are also expected to be mostly Good.

FORECAST DISCUSSION:

A cold front is passing through Michigan, Friday morning, providing showers and clouds to the area.  High pressure will build in behind the front bringing clearing skies and cooler temperatures during Friday afternoon.  Clear skies are expected to persist through the weekend with frosty mornings and daytime highs reaching the upper 40’s.  Air Quality is expected to be mostly Good through the weekend.

For the upcoming holiday week, a mid-week front is expected to pass, late Tuesday, bringing a significant cool down for midweek and Thanksgiving Day.  While temperatures are expected to be much cooler during the Thanksgiving holiday, no travel issues currently appear in the forecast.  Air Quality is expected to remain in the Good Category through the holiday.

EXTENDED FORECAST:

Air Quality should be generally Good to start the holiday week.

Next Forecast Update: Monday, November 20, 2023

11/13/2023 Forecast Update

FORECAST SUMMARY: Monday, November 13, 2023, through Friday, November 17, 2023

Ozone: Ozone season is now over and will start forecasting again in the spring of 2024.

PM-2.5:  24-hour average Fine Particulate concentrations are also expected to be mostly Good.

FORECAST DISCUSSION:

A mostly dry and mild week is underway with temperatures running above normal.  For the beginning of deer firearm season, we can expect continued dry, seasonably warm, breezy weather, during midweek, with no chance for tracking snow.  In terms of Air Quality, we should remain mostly Good for the forecast period.

The unseasonably warm temperatures and dry weather looks to hang on through Thursday.  A cold front and associated band of rain showers then ushers in cooler air Thursday night and Friday.  Weekend high temperatures still look to reach the upper 40’s, with dry weather, following that Friday frontal passage.  

It should be a good week to be outdoors enjoying the clear skies, warmer weather, and Good Air Quality!

EXTENDED FORECAST:

Air Quality should be generally Good to start the weekend.

Next Forecast Update: Friday, November 17, 2023

11/09/2023 Forecast Update

FORECAST SUMMARY: thursday, november 9, 2023, through monday, november 13, 2023

Ozone: Ozone season is now over and will start forecasting again in the spring of 2024.

PM-2.5:  24-hour average Fine Particulate levels will range mostly Good, with some Moderates mostly in southern locations early Monday and/or Wednesday.

FORECAST DISCUSSION:

Dry air is quickly moving in Thursday behind the departing system, which brought a wet midweek to the state. Aside from a small chance for lake effect precipitation in west Michigan Friday night, dry conditions prevail throughout the forecast period. The dry weather can be attributed to high pressure sliding in from the west during the coming weekend. Gusty winds with a westerly component can be expected Thursday and Friday. Wind speeds decrease Saturday as the high moves overhead, but winds pick up again from the southwest early next week as the center of the high moves east of the state.

Air quality over the past few days has been ranging Good statewide, and stronger westerly winds should keep Good levels Thursday and Friday. Lower wind speeds Saturday into Sunday may allow for localized buildup of fine particulate levels, especially during the morning hours. Daily averages of fine particulate may reach low Moderate at southern locations; otherwise, Good readings continue.

EXTENDED FORECAST:

Extended models show a system passing north of Lake Superior on Monday. This system reinforces stronger winds that should help keep fine particulate mostly Good as we move into the new workweek.

Next Forecast Update: Monday, November 13, 2023

11/06/2023 Forecast Update

FORECAST SUMMARY: Monday, November 6, 2023, through Thursday, November 9, 2023

Ozone: Ozone season is now over and will start forecasting again in the spring of 2024.

PM-2.5:  24-hour average Fine Particulate levels will range mostly Good, with some Moderates mostly in southern locations Monday and/or Wednesday.

FORECAST DISCUSSION:

This past weekend, some smoke made its way into the southern portion of the state, mostly due to seasonal fire activity in the central U.S. While not nearly as bad as this past summer, the smoke did aid in increasing PM2.5 concentrations on Saturday and Sunday. Daily averages Saturday remained Moderate; however, a couple monitors in the southeast recorded daily averages in the low USG category Sunday. Increased hourly readings remain at a few southeast monitors Monday morning, but the plume is expected to move out during the day. Hourly concentrations of PM2.5 may reach USG at a few southeast sites Monday; however, readings should improve during the day, with mostly Moderate daily averages expected.

On-and-off storm systems are forecast this week. The first is a low-pressure area over Lake Superior on Monday, tracking east into Tuesday. Associated precipitation ends late Monday as the system pulls east, and northerly winds develop as high pressure sinks in from the north. Quiet conditions will be short-lived as the next storm moves in from the west late Tuesday into Wednesday. A wet midweek gives way to dryer conditions for the end of the week.

Northerly winds developing later Monday into Tuesday allow for mostly Good air quality on Tuesday. Winds change to a southerly direction on Wednesday ahead of the approaching weather system. There are some seasonal fires and wildfires ongoing south of Michigan across the east and southeast U.S. It’s uncertain if any associated plumes will track north into our area; however, this is something we will keep an eye on, updating this forecast if necessary. On Thursday, winds switch back to the north, so any increase in PM2.5 Wednesday should not linger. We are forecasting Moderate PM2.5 for Wednesday to account for smoke potential, but any increase should improve towards the Good range Thursday into Friday under northerly winds.

EXTENDED FORECAST:

Extended models show dry, cool conditions as we move into the coming weekend. Northerly winds during this period should keep PM2.5 mostly Good.

Next Forecast Update: Thursday, November 9, 2023

11/03/2023 Forecast Update

FORECAST SUMMARY: Friday November 3, 2023, through Monday November 6th, 2023

Ozone: Ozone season is now over and will start forecasting again in the spring 2024.

PM-2.5:  PM-2.5 concentrations are expected to be in the Good to low-Moderate range.

FORECAST DISCUSSION:

Michigan ends the week on a higher note than when started with surface temperatures climbing into the upper 40s and low-mid 50s. Southerly flow has been building since yesterday, Thursday, bringing in warmer air and clearer skies. Today, Friday will see relatively sunny skies and winds blowing from the SSW. Overnight tonight, a weak system traverses the state with a cold front associated with it, so there may be a chance of a popup rain shower. Due to the weak cold front, tomorrow, Saturday may see slightly cooler temperatures, but the majority of Michigan will see temperatures in the upper 40s to low 50s. Sunday continues the trend of surface temperatures in the upper 40s but may see more sunshine than what is expected on Saturday. Sunday night into Monday presents us with another Low-pressure system which will influence our weather throughout the day on Monday as we start Monday warm and dry, and end cooler and wet.

For air quality, the Ozone season is now over so we will stop updating the Ozone forecast in our updates until the 2024 season starts in the spring. PM-2.5 will continue to see Moderate increases during the morning hours when winds are light. The past few days have seen rather strong winds gusts throughout the day to dissipate PM-2.5 concentrations, so this will be expected the next few days as well.

EXTENDED FORECAST:

As stated above, an early week system is expected to impact our state Monday into Tuesday. This will help keep overall air quality Good.

Next Forecast Update: Monday November 6th, 2023

10/30/2023 Forecast Update

FORECAST SUMMARY: Monday October 30th, 2023 through Friday November 3rd, 2023

Ozone: Ozone concentrations are expected to be in the Good range.

PM-2.5:  PM-2.5 concentrations are expected to be in the Good to low-Moderate range.

FORECAST DISCUSSION:

As October comes to a close this week, Mother Nature will be in the spirit of Halloween by providing much of Michigan with a chance of seeing the ever-dreaded, and scary “S-word”—snow. A Low-pressure system and associated cold front will eclipse our state tomorrow, Tuesday, and make its way east overnight into Wednesday. This will drop, and keep, high temperatures in the 30s for all of Michigan for Tuesday and into Wednesday. Wednesday will have northerly flow which will be aiding in keeping temperatures cool, along with starting the lake-effect snow machine Michigan sees around this time every year. Michiganders along the Lake Superior and Lake Michigan shorelines should expect spotty lake-effect snow essentially all week, but any snow showers are expected to remain as flurries, or dustings, at best. Winds look to shift as we get into the latter half of the week, with a cold front-turning-into-warm front-scenario occurring Thursday into Friday, raising our high temperatures back into the low-to-mid 40s. The warming trend continues into the weekend with temperatures creeping back into the 50s in some areas.

For air quality, Ozone will be in the Good range as the Ozone season comes to a close and we will soon stop forecasting Ozone as we get deeper into Fall and into Winter. For PM-2.5, overall concentrations will be in the Good range throughout the week, but there are chances for atmospheric inversions throughout the week as well. These inversions will mainly occur in the morning hours when surface winds are light and will dissipate as the days carry on and winds increase.

EXTENDED FORECAST:

As stated earlier, a weekend warmup is on the horizon for much of Michigan, and overall air quality is expected to remain Good.

Next Forecast Update: Friday, November 3, 2023

10/27/2023 Forecast Update

FORECAST SUMMARY: Friday, October 27, 2023, through Monday, October 30, 2023

Ozone: 8-hour average ozone concentrations are expected to be mostly Good.

PM-2.5:  24-hour average Fine Particulate concentrations are also expected to be mostly Good.

FORECAST DISCUSSION:

This Friday forecast marks the end of the last full week of the 2023 ozone season.  A brief recap of the season shows that it was a bit more active than average.  However, several of the high ozone episode days can be blamed on the wildfire smoke which caused exceptionally bad Air Quality events during June.

Air Quality for the current week has been mostly Good.  The warmer weather enjoyed during the week will end, today, as a cold front slides through.  It will be followed by considerably cooler and drier air making Saturday a good day for football with crisp temperatures topping out around 50 degrees.

Good Air Quality will continue through the weekend and into the next work week.  The long-range forecast has snow showers predicted for Halloween on Tuesday.  Autumn has truly arrived, and the leaves seem to be in full color for a good weekend of viewing. 

EXTENDED FORECAST:

Air Quality should be generally Good to start the next work week.

Next Forecast Update: Monday, October 30, 2023

10/23/2023 Forecast Update

FORECAST SUMMARY: Monday, October 23rd, 2023, through Friday, October 27th, 2023

Ozone: 8-hour average ozone concentrations are expected to be Good.

PM-2.5:  24-hour average Fine Particulate concentrations are also expected to be mostly Good to Low Moderate.

FORECAST DISCUSSION:

After a chilly start to Monday morning, temperatures are expected to rebound to above average for most of the week. The forecast area will be in a warm air sector and temperatures for Tuesday are expected to be in the low 70’s before settling into the mid-60’s for the rest of the work week.

While a few showers may pop up during Monday and early Tuesday, most areas should be dry. This will be welcome news for harvesters who have been sidelined with wet weather and muddy fields. Unfortunately, by Wednesday, wet weather moves back into the region with the possibilities of significant precipitation for the rest of the week.

The warmer weather should last into the weekend before a cold front moves through and temperatures drop back into the 50’s.

Air Quality during the week should be mostly Good. Ozone, at this late date, is no longer an issue. Fine particulates should be mostly Good but the abundance of moisture with warmer temperatures may produce some Low Moderate readings, especially in the more southern and more populated areas.

Fortunately, wildfire smoke season appears to be mostly behind us as most of the large Canadian wildfires are now contained to the western and northwestern most provinces.

EXTENDED FORECAST:

Air Quality should be generally Good to Low Moderate to start the weekend.

Next Forecast Update: Friday, October 27th, 2023

10/20/2023 Forecast Update

FORECAST SUMMARY: FRIDAY October 20th, 2023, through Monday October 23th, 2023

Ozone: Ozone concentrations are expected to be in the Good range.

PM-2.5:  PM-2.5 levels will range mostly Good, with only scattered low Moderates.

FORECAST DISCUSSION: The week ends with clouds and showers thanks to a system tracking east during the day Friday and another dropping in from the northwest Saturday. Conditions dry out and clouds decrease Sunday into Monday as high-pressure ridging builds in. Some much-needed sunshine is in the forecast as well; however, cooler temperatures continue.

As for air quality, PM2.5 concentrations have been mostly Good with only a handful of low-Moderate readings Thursday at some of our southern monitors. The two weather systems moving through Friday and Saturday should keep the atmosphere well mixed, keeping PM2.5 Good, then northwesterly winds Sunday will allow Good concentrations of PM2.5 to linger into early next week. Ozone has not been an issue, and Good concentrations will continue through the forecast period.

EXTENDED FORECAST:

Extended models show an active period setting up as next week progresses, with precipitation back in the forecast. Southerly winds, coupled with increased moisture, could bring PM2.5 into the low Moderate range.

Next Forecast update: Monday, October 23, 2023

10/09/2023 Forecast Update

FORECAST SUMMARY: Monday October 9th, 2023, through Friday October 13th 2023

Ozone: Ozone concentrations are expected to be in the Good range.

PM-2.5: PM-2.5:  PM-2.5 concentrations are expected to be in the Good range with some hourly low-Moderates.

FORECAST DISCUSSION: Fall has definitely fallen upon us here in Michigan with average surface temperatures remaining in the 50s for the foreseeable future and leaves ever-changing in color. This week also has its fair share of rain in the forecast with essentially every day this week having a chance of rain somewhere throughout the state. These cooler temperatures are solely due to northerly winds which will dominate the weather pattern this week. The main threat of rain this week will be Thursday and through the weekend as a Low-pressure system makes its way toward the Great Lakes from the southwest. Although the Low-pressure itself will stay just to our south, Michigan will still see impacts in the form of rain and some breezy to windy conditions. As of now, these rainy and breezy conditions look to last through the weekend.

In terms of air quality, the Ozone season is slowly but surely winding down with days becoming shorter and temperatures staying cooler. Coupled with the rain this week, Ozone will be in the Good range with rain keeping the airmass clean and cooler temperatures inhibiting the development of Ozone. Last week, we saw PM-2.5 concentrations rise into the USG range for an hour or two mainly in the Detroit and other populated areas. This is typical during early morning commutes with light winds. We usually see those conditions as mornings become cooler and, almost like clockwork, in the wintertime due to surface-level atmospheric inversions trapping air from dispersing. We may see those kinds of concentrations this week, but rain and wind later in the week will help keep PM-2.5 concentrations in the Good range as well.

EXTENDED FORECAST: The weekend continues what the work week ends with: rain and wind. Sunday starts to see the rain lifting off, but northerly winds carry on, with surface temperatures in the 50s. Overall air quality will be Good.

Next Forecast Update: Friday, October 13, 2023

10/06/2023 Forecast Update

FORECAST SUMMARY: Friday, October 6, 2023, through Monday, October 9, 2023

Ozone: 8-hour average ozone concentrations are expected to be mostly Good.

PM-2.5: PM-2.5:  24-hour average Fine Particulate concentrations are also expected to be mostly Good.

FORECAST DISCUSSION: As predicted during my Monday forecast, the 80-degree weather enjoyed during the first half of the week, exited the state during passage of a late-week cold front.  A secondary front will also pass through the state, Friday afternoon, ushering in much cooler air for the weekend.  With the northwesterly flow, I am expecting Good Air Quality with no problems from ozone, fine particulates, or smoke.

An upper-level low, that will move through Saturday, will influence our weather over the next week.  As the cooler air travels across Lake Michigan, we can expect the weekend in the western half of the state to be mostly cloudy with periodic rains showers and perhaps even a rumble or two of thunderstorms.

With the shortening days, ozone will cease to be a concern and the ozone season will officially end at the end of October.  Wildfires in Canada are on the wane, as well.  Many of the fires in eastern and central Canada that caused so many issues in our Midwest and Eastern seaboard states during June have been extinguished or reduced and have become less of a problem.  Most of the large Canadian fires still burning are now contained in the Alberta, British Columbia, and Northwest Territories provinces in western Canada.

Columbus Day (Monday) should show a gradual return to clearer skies but still cooler temperatures with daily highs in the low 50’s and continued Good Air Quality.

EXTENDED FORECAST: Air Quality should be generally Good to start the next work week.

Next Forecast Update: Monday, October 9, 2023

10/02/2023 Forecast Update

FORECAST SUMMARY: Monday, October 2, 2023, through Friday, October 6, 2023

Ozone: 8-hour average ozone concentrations are expected to be a mixture of Good to Moderate through Wednesday then Good.

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be a mixture of Good to Moderate through Wednesday then Good.

FORECAST DISCUSSION: The high pressure ridge currently over the Great Lakes region will persist through Wednesday and, in fact, some locations could see record high temperatures during Tuesday. 

While very rare to see significant ozone development in Michigan during October, it is not unlikely that we could see some High Moderates along the Lake Michigan coast during Tuesday.  With the shorter hours of daylight, getting to USG would be difficult although not impossible.  However, since the possibilities are too remote and unlikely, no type of Action Day is being considered.

A pair of quick hitting cold fronts will put an end to the current summer-like conditions.  The first cold front will arrive during the early Thursday morning time frame.  I expect high temperatures Thursday afternoon will be some 20 degrees cooler than what we will see during the first half of the week.  Any Air Quality issues should be removed at that time.

The second front will follow-up during Friday and usher in significant cooler air.  I expect high temperatures on Saturday to be 30 degrees cooler than the high temperatures we will see during Monday through Wednesday.

EXTENDED FORECAST: Air Quality should be generally Good to start the next work week.

Next Forecast Update: Friday, October 6, 2023

09/29/2023 Forecast Update

FORECAST SUMMARY: Friday, September 29, 2023, through Monday, October 2, 2023

Ozone: 8-hour average Ozone concentrations will range Good to Moderate.

PM-2.5: 24-hour average Fine Particulate levels will range between Good and Moderate.

FORECAST DISCUSSION: A frontal boundary brings precipitation in the forecast Saturday in the Upper Peninsula while high pressure produces dry weather across the rest of the state. Temperatures increase through early next week as warmer air ushers in on a southerly wind. Temperatures for the end of September/early October will be more summer-like than fall-like. Highs climb into the 70s Saturday and approach the 80-degree mark early next week. After the Saturday precipitation up north, the next chance for precipitation across the state should hold off until midweek next week.

As for air quality, both PM2.5 and ozone have been Good the past few days and Good readings should continue Friday. Less cloud cover in the Lower Peninsula and warmer surface and upper-level temperatures on a southerly wind makes weather conditions conducive for ozone starting Saturday, lasting through the period. What hampers ozone development, however, is less solar radiation that makes ozone generation less likely. While we anticipate ozone to increase into the Moderate range across parts of the state, readings into the USG range are not likely.

The current weather scenario does not bring wildfire plumes over the state which would result in increased PM2.5. But weaker winds from the south may allow for increased levels, especially in the southeast portion of the state. PM2.5 concentrations will range from middle Good to middle Moderate.

EXTENDED FORECAST: Warmer/dry conditions lingering early next week keep the chance for Moderate ozone and PM2.5 in the extended forecast.

Next Forecast Update: Monday, October 2, 2023

09/25/2023 Forecast Update

FORECAST SUMMARY: Monday, September 25, 2023, through Friday, September 29, 2023

Ozone: 8-hour average Ozone concentrations remain Good through the forecast period.

PM-2.5: 24-hour average Fine Particulate levels will range between Good and Moderate.

FORECAST DISCUSSION: Two systems will influence weather conditions this week. High pressure to our northeast keeps dry conditions further north while a slow-moving low-pressure area traveling from Minnesota Monday to southwest Michigan early Thursday produces a cool, showery pattern for most of the lower peninsula. High temperatures through the period will range mostly in the middle and upper 60s with an east/southeasterly wind flow in place.

While not as prevalent as this past summer, wildfires persist in Quebec and Ontario, Canada. Looking back to Sunday, smoke over the region did produce low Moderate PM2.5 across some northern and central monitors. Satellite imagery Monday morning shows a smoke plume dropping southwest towards the upper Great Lakes region. The smoke plume moving towards northern locations may allow for Moderate PM2.5 through Wednesday. We do not anticipate daily averages of PM2.5 to reach higher than Moderate, but this is something we will monitor, and the forecast will be updated if conditions worsen. Overall, daily averages of PM2.5 levels should range between middle Good and middle Moderate this week.

On Thursday, some showers linger in southern areas, but high pressure becomes more dominant for the end of the week. Winds become more southerly and warmer/dry conditions are anticipated. Moderate PM2.5 may persist in the south, but smoke plume models show any lingering plumes pushing north of the area. Concentrations of PM2.5 should end the forecast period in the Good to low Moderate range.

Cooler temperatures, precipitation across much of the state, and a lower sun angle this time of year should keep ozone Good through the week.

EXTENDED FORECAST: Extended models show dry weather and warmer conditions for the coming weekend. Pollution levels may increase towards Moderate late in the forecast period.

Next Forecast Update: Friday, September 29, 2023

09/22/2023 Forecast Update

FORECAST SUMMARY: Friday September 22nd, 2023, through Monday September 25th 2023

Ozone: Ozone concentrations are expected to be in the Good to Moderate range.

PM-2.5: PM-2.5 concentrations are expected to be in the Good to low-Moderate range.

FORECAST DISCUSSION: After a week of relatively picturesque weather conditions, we can expect much of the same for this picture-perfect weekend ahead for us Michiganders. High-pressure is still dominating the area with the High-pressure system sitting over central Ontario currently and is expected to stay there through the weekend. This will result in winds being predominantly easterly with some northerly component shifting the direction throughout the weekend. A warming pattern that we saw to end the work week continues into the weekend with surface temperatures well into the 70s for much of Michigan and the region.

For air quality, relatively light surface winds in the morning hours may result in PM-2.5 concentrations to build up in more populated areas. Per usual, as the day carries on, and winds increase, those concentration will decrease. Ozone will not have the required ingredients to produce high concentrations. There may be Moderate Ozone sprinkled across the state, which was seen this past week, but nothing over mid-Moderate should be expected.

EXTENDED FORECAST: The current weather pattern looks to continue into next week, with cooler temperatures expected. Overall air quality is expected to remain Good.

Next Forecast Update: Monday September 25th, 2023

09/18/2023 Forecast Update

FORECAST SUMMARY: Monday September 18th, through Friday September 22nd, 2023

Ozone: Ozone concentrations are expected to be in the Good to Moderate range.

PM-2.5: PM-2.5 concentrations are expected to be in the Good to low-Moderate range.

FORECAST DISCUSSION: As this past weekend most definitely felt like Fall, we see a gradual warmup throughout this week for the majority of Michigan. We start off the week with two High-pressure systems dominating the region and look to hang around through the end of the work week. Surface winds look to be predominantly southerly with slight variations in the easterly and westerly direction throughout the week. These southerly winds are the reason for surface temperatures approaching, and even eclipsing, 80 degrees towards the end of the work week. Also thanks to the High-pressure systems, every day will see a fair amount of sunshine. As we approach the weekend, the High-pressures start to move off the east with a building low-pressure system setting up over the Great Plains, which will influence our weather towards the end of the weekend.

 In terms of air quality, PM-2.5 continues to be a non-issue compared to what was seen earlier in the summer. Southerly winds this week will also help keep any residual Canadian wildfire smoke to our north, hence why the PM-2.5 forecast is Good to low-Moderate. However, due to the High-pressure we will see this week, early morning stagnation could be possible in more populated areas due to morning commutes and low winds. For Ozone, we expect overall Good concentrations for this week mainly due to cooler temperatures than what produces high concentrations of Ozone and the fact of days becoming shorter and less overall energy coming from the sun. Although, with winds periodically being southwesterly in the latter half of the week, there may be some low-end Moderate Ozone concentrations more so towards west and southwest Michigan.

EXTENDED FORECAST: A change in airmass is expected towards the end of the weekend which will help clean out any buildup from the High-pressures this week. Overall air quality is expected to be Good.

Next Forecast Update: Friday, September 22, 2023

09/15/2023 Forecast Update

FORECAST SUMMARY: Friday, September 15, 2023, through Monday, September 18, 2023

Ozone: 8-hour average Ozone concentrations will remain generally Good with only a few Moderates possible.

PM-2.5: 24-hour average Fine Particulate levels are expected to range between Good to Moderate.

FORECAST DISCUSSION: This forecast period features a frontal boundary moving northwest to southeast through the state between Friday and Sunday. Precipitation chances begin Friday across the Upper Peninsula while generally sunny, dry conditions are seen across the Lower Peninsula. Clouds increase late Friday into Saturday in the south as the boundary sinks southeast and precipitation comes in the forecast. Precipitation may linger in the south Sunday; however, dryer weather moves in late as high pressure settles in from the northwest.

Wildfires persist far to our northwest in Canada and smoke models show a plume sinking in from the northwest behind the weekend front. The smoke plume does not look dense enough to cause significant increases in PM2.5 concentrations, but readings in the upper Good to low Moderate range are possible. We will keep a Moderate forecast Saturday and Sunday as a conservative measure, and levels by Monday are anticipated to fall back into the Good range.

Sunny skies and southwesterly winds in the south Friday are typically conducive for ozone development, but cooler temperatures and less daylight this time of year help keep levels generally Good. Increased clouds and precipitation chances Saturday into Sunday allow for Good readings to continue. Conditions dry out for the start of the new work week, but Good ozone persists thanks to cooler temperatures from northerly winds. 

EXTENDED FORECAST: Extended models show dry weather through midweek with warming temperatures during the period. If this forecast remains on track, pollution levels may increase into the low Moderate range.

Next Forecast Update: Monday, September 18, 2023

09/11/2023 Forecast Update

FORECAST SUMMARY: Monday, September 11, 2023, through Friday, September 15, 2023

Ozone: 8-hour average Ozone concentrations will remain Good through Thursday with scattered Moderates possible Friday

PM-2.5: 24-hour average Fine Particulate levels are expected to be mostly Good with only a few low Moderate readings possible.

FORECAST DISCUSSION:The start of this forecast period favors clouds and rain as a low-pressure area and associated boundary pass through the state. Upper-level energy and cooler temperatures keep rain around Tuesday, but precipitation will be more scattered in nature. High pressure moves in from the west Wednesday drying conditions out and clearing skies. The coolest temperatures are projected Wednesday into Thursday morning with the center of the high overhead. Highs Wednesday struggle to reach out of the 50s across the northern portion of the state; further south readings in the low-middle 60s are expected. Thursday morning lows dip down into the 30s across the north with 40s elsewhere.

Regarding ozone this week, clouds Monday and Tuesday, northerly winds late Monday through Thursday, and cooler conditions hamper ozone development keeping readings Good. The high-pressure area tracks east of the state Friday, and southerly winds bring warmer temperatures back into the region. Plenty of sunshine is anticipated as well, and the combination of sunshine and warmer air may lead to increases in ozone. However, considering the time of year a significant development is not expected and ozone concentrations should not reach higher than low-Moderate in southern and/or western locations.

Wildfire smoke models are not showing any substantial plumes the next few days; therefore, we do not expect wildfire smoke to influence PM2.5 conditions this week. Our expectation for PM2.5 is that increased moisture Monday into Tuesday may allow for low Moderate readings, generally across the southern portion of the state, otherwise, Good levels are expected. Light winds Wednesday and Thursday morning may allow for hourly concentrations in the Moderate range during the morning hours, but increases should mix out and decrease during the day allowing for 24-hour averages to be mostly Good. Southerly winds developing Friday may bring in some scattered low Moderate readings across the southern portion of the state.

EXTENDED FORECAST: Extended models show a continuation of dry conditions and warmer temperatures for the start of the weekend. Pollution levels may reach low Moderate during this period.

Next Forecast Update: Friday, September 15, 2023

09/08/2023 Forecast Update

FORECAST SUMMARY: Friday, September 8, 2023, through Monday, September 11, 2023

Ozone: 8-hour average ozone concentrations are expected to be Good.

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be Good to Moderate

FORECAST DISCUSSION: The cloudy, drab weather that has been with us since midweek will finally start to give way as the current slow moving low-pressure system finally begins exiting the region.  The good news is that Air Quality is currently Good with all pollutant levels very low.

Low level moisture will persist through much of Friday providing clouds and the occasional sprinkle.  Light north to northeast wind will prevail into Saturday as Canadian high pressure builds into the western Great Lakes.  Incoming dryer air will chase away the cloud cover providing sunny skies through Saturday and Sunday with cool temperatures in the lower 70’s.

The smoke we were watching over the Plaines states during the week remained in that region and never threatened Michigan.  Computer models have that smoke breaking up over the next few days and we may see some light residuals of that smoke but no worse than Low Moderate.

The next low pressure is currently predicted to arrive during Monday bring a good chance of rain and cooler temperatures during the first half of next week.

EXTENDED FORECAST: Air Quality should be generally Good to start the next work week.

Next Forecast Update: Monday, September 11, 2023

09/05/2023 Forecast Update

FORECAST SUMMARY: Tuesday, September 5, 2023, through Friday, September 8, 2023

Ozone: 8-hour average ozone concentrations are expected to be Good to Low Moderate.

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be Good to Low Moderate

FORECAST DISCUSSION: Tuesday may well be the last hot and humid day for summer 2023. Temperatures are expected to top out in the low 90’s in the southern half of the state with dew points in the mid-60’s.  With that level of temperature and humidity, it is possible to see popup thunderstorms during the afternoon.  A slow-moving front will bring an end to this episode of hot and humid weather during Wednesday and Thursday along a decent dose of precipitation.  Following the frontal passage, temperatures by the end of the week and into the weekend should be in the lower 70-degree range with mostly dry conditions.

The heat and humidity of the holiday weekend brought concerns about potentially elevated ozone, especially along the western lake shore counties.  While we did see numbers in that area reach the mid to upper 60 ppb range, we fortunately did not see any USG values.

As has been the pattern for most of this summer, Air Quality concerns have bounced between ozone problems and smoke problems, with occasional episodes where both have simultaneously been a problem.  As we get past the high ozone potential during the holiday weekend, we now look to smoke issues currently in the Plaines states.  A series of wildfires in the North Dakota and Montana are combining with nearby wildfires in Canada to present smoke problems in that area.  Fortunately, all the smoke models are in good agreement that for the next few days, the smoke should get no closer than western Minnesota and Iowa. 

As our ozone season winds down with shorter, cooler days, fine particulates in smoke are not limited by temperature, solar intensity, or season.  As such, we will keep a close eye on the smoke out west.  As that smoke currently does not look to travel this far east, I do not see a need to update this forecast before our regular weekend forecast update posted on Friday.

EXTENDED FORECAST: Air Quality should be generally Good to Moderate through the weekend.

Next Forecast Update: Friday, September 8, 2023