8/2/23 Forecast Update

FORECAST SUMMARY: Wednesday, August 2, 2023, through Monday, August 7, 2023

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

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

FORECAST DISCUSSION: The elevated layer of smoke, which significantly and noticeably dimmed the sun yesterday, will migrate eastward during Wednesday and be clear of the state by nightfall.  Fortunately, we only saw a minimum mixing down and our monitor numbers remained in the Good to Moderate range throughout the state.

There was some concern about potential elevated ozone after the smoke cleared.  But all models have lowered expectations and are keeping most of the higher numbers on the west side of Lake Michigan.  As such, I expect mostly Moderate on the west side of the state and Good to Moderate, elsewhere, during Thursday.  However, if any elevated ozone looks to shift eastward, we will modify the forecast as necessary and send an alert via EnviroFlash and AirNow.gov.  A cold front passage, Thursday night, should clean the air and keep our weekend Air Quality mostly Good.

Friday and Saturday should be pleasant days under high pressure and rain looks to move in late Sunday.  Both the extended smoke models and the ozone models are indicating no problems through the weekend, so I am extending this forecast out to Monday. 

EXTENDED FORECAST: Air Quality should be generally B to bring the next work week.

Forecast updated by Jim Haywood: Wednesday, August 2, 2023

Next forecast update Monday, August 7, 2023

8/1/23 Forecast Update

FORECAST SUMMARY: Tuesday, August 1, 2023, through Wednesday, August 2, 2023

OZONE:  8-hour average ozone concentrations are expected to be a mix of Good and Moderate.

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

FORECAST DISCUSSION: It you looked outside, this morning, you probably thought that we were under overcast skies.  Unfortunately, what you were seeing was an extremely thick layer of Canadian wildfire smoke around the 10,000-foot level.  The thickness of that smoke is enough to considerable dim the sun.  Unlike last week, that smoke is staying mostly aloft and not expected to significantly affect surface concentrations.  That said, the models do show a bit mixing down, mostly in the northern portion of the state.  But none of those models are showing concentrations increasing in excess of the USG threshold.  As such, I will be keeping the forecasted AQI in the Moderate range for today and tomorrow.

As that smoke clears out, late Wednesday, we turn our attention back to ozone.  Current projections have the ozone production increasing but are keeping it out over the lake and closer to the Wisconsin border.  As such, I do not see the need for any advisories, but I will definitely keep an eye on it in case it shifts further east than expected.  Therefore, I will be updating this forecast on Wednesday to provide the latest projections.

EXTENDED FORECAST: Air Quality should be generally Moderate for most of the middle of the week with some slight potential for elevated pollutant levels.

Air Quality should be generally Moderate for most of the middle of the week with some potential for elevated pollutant levels.

Forecast updated by Jim Haywood: Tuesday, August 1, 2023

Next forecast update Wednesday, August 2, 2023

7/31/2023 Forecast Update

FORECAST SUMMARY: Monday, July 31, 2023, through Tuesday, August 1, 2023 

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

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

 FORECAST DISCUSSION

Last week we saw a multitude of Action Days, first for smoke and then for ozone.  While this week should be less eventful than last week, we are not completely out of the woods. 

We are currently following a plume of Canadian wildfire smoke dropping down from the central and western Canadian providences.  At the moment, that smoke is staying aloft and not causing any problems other than graying skies.  Northern Minnesota is experiencing some mixing down to the surface and the question is whether or not Michigan can expect any elevated surface concentrations.  The models are not in good agreement on the magnitude, but there is some agreement that some will mix down late Tuesday and into Wednesday.  While I am not currently anticipating levels reaching USG, I would not be surprised to see high Moderate levels during that time period.  Fortunately, this will be a short episode as that smoke should get pushed out, late Wednesday.

Then we shift our focus back to ozone.  While we are starting out the week in the Good range, all indications are that ozone concentrations will begin to creep upwards on Tuesday.  The models are indicating a fairly decent buildup Tuesday into Wednesday, but is keeping the worst of it on the Illinois and Wisconsin side of the lake.  Winds shift to a more southwesterly direction on Thursday and with increasing temperatures and humidly, it could present a problem for Michigan.

 With the uncertainly of the surface level smoke and threat of increased ozone production, I will update this forecast on Tuesday.

EXTENDED FORECAST:

Air Quality should be generally Moderate for most of the middle of the week with some potential for elevated pollutant levels.

Forecast updated by Jim Haywood: Monday, July 31, 2023

Next forecast update Tuesday, August 1, 2023

7/27/2023 Forecast Update

FORECAST SUMMARY: Thursday, July 27, 2023, through Monday, July 31, 2023

OZONE:  8-hour average ozone concentrations are expected to be Moderate to USG through Friday, then Good to Moderate.

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

...AIR QUALITY ACTION DAY ADVISORIES FOR THURSDAY JULY 27 and FRIDAY JULY 28...

The Action Day Advisories include the following counties:

In West Michigan:

ALLEGAN...  berrien…  CASS…  KENT...  MUSKEGON...  ottawa…  AND van buren COUNTIES

In Southeast Michigan:

LIVINGSTON…  MACOMB…  MONROE…  OAKLAND… ST. CLAIR…  WASHTENAW…  AND WAYNE COUNTIES

FORECAST DISCUSSION

The forecast preparation for Friday has been particularly challenging.  There is a lot of uncertainty, both in the forecast models and the National Weather Service discussions, about when clouds and showers may arrive Friday afternoon or evening.  A front will be dropping down from the north, during the day, bringing those clouds and showers along the way but the timing is unclear. 

The majority of the ozone models are still predicting areas of elevated ozone along the southwest shores of Lake Michigan and southeast Michigan.  The cloud models are inconsistent on when we can expect clouds to move into the same areas which would retard ozone production.  It is more likely that southeast Michigan will stay under clear skies longer than southwest Michigan.  But if southwest Michigan also stays sunny through the afternoon, their ozone production could be significant.

As elevated ozone could be significant in both areas, I will continue the Thursday Action Day advisories into Friday.  Even if clouds do move in and keep ozone levels out of the USG range, I will still be satisfied that this was the correct call on the side of caution.

Either way, the front dropping down from the north will occur Friday night putting an end to this episode.  There does not appear to be any continued threat from either smoke or ozone for the remainder of the weekend, although I will continue to monitor conditions.  As such, I do not anticipate the need for another forecast update until Monday.

EXTENDED FORECAST:

Air Quality should be generally Good to Moderate for the weekend and into the next work week.

Forecast updated by Jim Haywood: Thursday, July 27, 2023

Next forecast update Monday, July 31, 2023

7/26/2023 Forecast Update

FORECAST SUMMARY: Wednesday July 26, 2023, through Thursday, July 27, 2023

OZONE: 8-hour average ozone concentrations are expected to be Moderate to USG

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

FORECAST DISCUSSION:

..AIR QUALITY ACTION DAY ADVISORY FOR THURSDAY JULY 27...

The Action Day Advisory includes the following counties:

in West Michigan:

ALLEGAN...  BERRIEN…  CASS…  KENT...  MUSKEGON...  OTTAWA…  AND VAN BUREN COUNTIES

The Tuesday statewide Action Day advisory for fine particulates turned out to be an accurate prediction as we saw elevated concentrations at many of our statewide monitors.  In addition to the high smoke concentrations, we were surprised to see ozone values get as high as they did at several monitors.  This proves the amount of ozone precursor gases found in wildfire smoke.

 We did not extend the Action Day advisory into Wednesday as the smoke plume will be exiting the state and incoming rain and thunderstorms will help drop concentrations during the day.  That said, the eastern side of the state will be the last to see the benefits of the clearing, so I increased their AQI forecast to USG as a precautionary measure.  Although morning ozone concentrations are higher than normal, the increasing clouds and rain chances will discourage elevated production and bring those numbers back down.

 Tomorrow will be another story as it may be one of the hotter and humid days of the summer.  Predictions are for temperatures in the low 90’s with dew points around 70 degrees under sunny skies and low wind speeds.  Under normal conditions, this would qualify for elevated ozone.  But we also still have leftover ozone forming gases, courtesy of the exiting wildfire smoke, which could boost ozone production even more.  As such, I am issuing Action Day advisories in both West Michigan and Southeast Michigan for Thursday.

 Friday may be a continuation of the Action Day advisories, but I will wait until Thursday morning to make that call when the latest forecast products are available.

EXTENDED FORECAST:

 Air Quality should be generally Moderate to potentially USG through the remainder of the week.

Forecast updated by Jim Haywood: Wednesday, July 26, 2023

Next forecast update Thursday, July 27, 2023

7/25/2023 Forecast Update

FORECAST SUMMARY: Tuesday, July 25, 2023, through Wednesday, July 26, 2023

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

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be widespread Moderate to USG.

AIR QUALITY ACTION DAY ADVISORY FOR TUESDAY JULY 25 REMAINS IN EFFECT STATEWIDE...

FORECAST DISCUSSION

The Tuesday Air Quality Action Day Advisory remains in effect, statewide, for Fine Particulates.  Monitors are continuing to read high concentrations along the Wisconsin Lake Michigan shore and that smoke is currently moving into Michigan.  Some of our monitors are already reading in the USG range.  While I expect to see hazy conditions, outside, I do not expect to see the extremely high concentrations into the Unhealthy range that we saw a couple of weeks ago.  That said, the expected USG conditions are still of concern and our messaging to reduce outdoor strenuous activity and remain indoors with air conditioning remains intact.

Fortunately, all of the smoke models are indicating today’s smoke will be flushed out of the state during Wednesday.  Conditions may still be somewhat hazy in the morning hours but should improve during the day.  The potential for some severe weather and heavy rains also exists which would help cleanse the air.

By Thursday, the weather should return to normal hot, humid summer-like conditions under sunny skies.  Our experience with the smoke, this summer, is that some chemicals from the smoke can be left behind if there is not a total cleanout and those chemicals readily convert to ozone under favorable conditions.  And those conditions currently look favorable on Thursday.

As a result, I intend to update this forecast Wednesday morning…

EXTENDED FORECAST:

Air Quality should be generally Moderate to potentially USG through the remainder of the work week.

Forecast updated by Jim Haywood: Tuesday, July 25, 2023

Next forecast update Wednesday, July 26, 2023

7/24/2023 Forecast Update

FORECAST SUMMARY: Monday, July 24, 2023, through Tuesday, July 25, 2023

OZONE:  8-hour average ozone concentrations are expected to be mostly Moderate.

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be widespread USG.


AIR QUALITY ACTION DAY ADVISORY FOR MONDAY JULY 24, BEGINNING AT NOON...
UPPER PENINSULA ONLY

AIR QUALITY ACTION DAY ADVISORY FOR TUESDAY JULY 25...
STATEWIDE


FORECAST DISCUSSION

Smoke returns to the region courtesy of numerous large Canadian wildfires.  Smoke, aloft, has already reached Michigan and surface smoke in Minnesota and Wisconsin is already reaching the USG and Unhealthy range as it mixes down.  The higher levels of surface smoke will be reaching the Upper Peninsula as today progresses, therefore we are triggering an Action Day Advisory for the U.P. beginning at noon.  Widespread smoke will affect the entire state, during Tuesday, prompting a Statewide advisory.

Fortunately, this appears to be a short-lived event with most of the smoke pushed out of the state Tuesday night.  As we have seen in previous events, this year, the surface smoke has left behind some residual pollutants which could convert to ozone under ideal conditions.  By Thursday, we could be seeing temperatures in the low 90’s under clear skies.  Dew points will rise to around 70 degrees making for hot, muggy weather with the potential for elevated ozone.

Since we are expecting hotter weather with ozone potential, this forecast will be updated Tuesday morning and as necessary as the week progresses.


EXTENDED FORECAST:

Air Quality should be generally Moderate to potentially USG through the work week.

Forecast updated by Jim Haywood: Monday, July 24, 2023
Next forecast update Tuesday, July 25, 2023

07/23/2023 Forecast Update

FORECAST SUMMARY: Sunday July 23rd, 2023, through Monday July 24th, 2023

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

OZONE: Ozone concentrations are expected to be in the mid-to-high Moderate range.

FORECAST DISCUSSION:

Some parts of Michigan wake up this morning to moderate downpours and rumbles of thunder. These quick-hitting line of storms were initiated by an upper-level disturbance which made its way to our area overnight. These storms should move across the state throughout the morning before allowing sunshine to come in the afternoon. Any buildup of PM-2.5 and Ozone concentrations the past few days may have been impacted by this rain resulting in potentially lower concentrations today, Sunday. Ozone needed to be looked at for tomorrow, Monday, due to potential buildup but that does not look like the case anymore. Ozone is expected to stay out over the lake and not impact lakeshore areas in the long term. Winds look to stay south just long enough to keep Ozone at bay for our area. As stated yesterday, hourly concentrations may approach the USG threshold but overall 8-hour averages will be in the Moderate range. PM-2.5 looks to increase region-wide tomorrow into Tuesday with some concentrations approaching the high Moderate range; those concentrations will continue to be looked at throughout the week.

EXTENDED FORECAST:

We see a warmup this week with surface temperatures well into the 90s. Air quality will be monitored throughout the week.

Next Forecast update: Monday July 24th, 2023. Forecast Updated by Alec Knowacki.

07/22/2023 Forecast Update

FORECAST SUMMARY: Saturday July 22nd, 2023, through Sunday July 23rd, 2023

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

OZONE: Ozone concentrations are expected to be in the mid-to-high Moderate range.

FORECAST DISCUSSION:

This Saturday morning provides winds staying more southerly throughout today and tomorrow, Sunday. This will keep our surface temperatures in the upper-70s to low-80s throughout the state, through the weekend and into next week. An upper-level disturbance makes its way through the lower peninsula overnight which may trigger some short-lived rain during the Sunday morning hours. As the afternoon approaches, the rain should be moving off to the southeast and bringing the clouds with it as the sun is expected to come back out mid-afternoon.

As stated in yesterday’s forecast update, Ozone will be continued to be looked at but as of now, it does not look like widespread Ozone will be an issue for western lakeshore counites. The wind direction predominantly staying southerly, cloudy morning and early afternoon conditions, along with potential rain shower will help keep Ozone production low. If by chance Ozone does develop, it will mainly stay out over the lake and may only impact hourly concentrations. Overall 8-hour averages for Ozone are expected to be in the mid-to-high Moderate range for Sunday and Monday, as of now. Ozone for Monday will be looked at tomorrow morning. PM-2.5 looks to remain in the Good to moderate range throughout the state.

EXTENDED FORECAST:

Next week sees quite the warmup with surface temperatures well into the 90s with southerly winds. Overall air quality will be looked at throughout the week.

Next Forecast update: Sunday July 23rd, 2023. Forecast Updated by Alec Knowacki

07/21/2023 Forecast Update

FORECAST SUMMARY: Friday July 21st, 2023 through Saturday July 22nd, 2023

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

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

FORECAST DISCUSSION:

How we end the work week is exactly how we start off the weekend with partly sunny skies and surface temperatures hanging around the upper-70s to low-80s. The airmass that was brought to us with the passing cold front yesterday, Thursday, hangs around through the weekend, with no major change in airmass until Monday. Winds will remain predominantly NNE today before slowly shifting to WSW tomorrow afternoon. As we approach Sunday, winds complete their shift and becoming more southwesterly flow all day Sunday and through Monday.

Due to the warm temperatures, ample sunlight and favorable winds for Ozone development, this forecast will be updated tomorrow, Saturday, to get a better look at conditions for Sunday. Upper-level temperatures appear to remain in the low-teens Celsius throughout the weekend, but this year has shown us Ozone developing in atypical scenarios. Traditionally, upper-level temperatures in the mid-to-upper teens Celsius and a southwest wind would be indicative of Ozone development, but we have seen cooler temperatures be conducive for Ozone this year. As of now, most models are not showing too much Ozone developing ashore in West Michigan, or at least over the USG threshold, but to play it safe, I will take a better look tomorrow with updated models and forecasts. For PM-2.5, we continue to see low-mid Moderate in some areas, and Good concentrations in other areas. Wildfire smoke does not look to be an issue for the foreseeable future.

EXTENDED FORECAST:

A front comes through most of the state on Monday but looks to stall over the southern portion of the lower peninsula. Winds look to remain SW so this will be looked at throughout the weekend.

Next Forecast update: Saturday July 22nd, 2023. Forecast updated by Alec Knowacki.

07/17/2023 Forecast Update

FORECAST SUMMARY: Monday July 17th, 2023, through Friday July 21st, 2023

PM-2.5:PM-2.5 concentrations will range from Moderate to USG to start off the week before declining more into the Moderate range.

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

PM-2.5 Air Quality Action Day Advisory for Monday, July 17th, 2023

The Action Day Advisory for Monday, July 17th is for the following counties in the central and southern portions of the Lower Peninsula:

Mason, Lake, Osceola, Clare, Gladwin, Arenac, Oceana, Newaygo, Mecosta, Isabella, Midland, Bay, Huron, Muskegon, Montcalm, Gratiot, Saginaw, Tuscola, Sanilac, Ottawa, Kent, Ionia, Clinton, Shiawassee, Genesee, Lapeer, St. Clair, Allegan, Barry, Eaton, Ingham, Livingston, Oakland, Macomb, Van Buren, Kalamazoo, Calhoun, Jackson, Washtenaw, Wayne, Berrien, Cass, St. Joseph, Branch, Hillsdale, Lenawee, and Monroe

FORECAST DISCUSSION:

Today, Monday, is an Air Quality Action Day for portions of the central and southern Lower Peninsula due to PM-2.5 concentrations hanging around from Canadian wildfire smoke. These concentrations are expected to move off to the east as the day carries on with overall PM-2.5 values expected to remain below the alert threshold through the work week. To start off the week, we see surface temperatures scattered throughout the 70s with some 80s in the southern areas with mainly westerly winds flowing through the region. This trend continues as we go into Tuesday with a High-pressure system sliding into areas to the north, which will shift winds to a more southerly direction through Wednesday. Wednesday going into Thursday is expected to bring us a frontal boundary and associated cold front with a chance of rain showers. This system exits the area rather quickly but not without dropping temperatures back into the 70s for Friday.

As mentioned above, PM-2.5 concentrations are expected to diminish as the work week carries on, with no real threat of returning wildfire smoke for the foreseeable future. Since smoke models only forecast out a couple of days, we will keep an eye on updated model runs and will make updates to the forecast as needed if any alert-able smoke is looking to impact the state. Ozone does not look to be a threat this week as westerly winds and temperatures predominantly in the low-80s keep Ozone concentrations at bay. There may be an uptick in concentrations on Wednesday, but widespread Ozone issues are not expected. The airmass change and chance of rain on Thursday will help clean out any concentration buildup of both PM-2.5 and Ozone.

EXTENDED FORECAST:

Extended forecast looks relatively similar to this week’s forecast with temperatures in the 70s and low-80s with mainly westerly winds. Overall air quality will be in the Good to Moderate range.

Next Forecast update: Friday July 21st, 2023. Forecast updated by Alec Knowacki.

07/16/2023 Forecast Update

FORECAST SUMMARY: Sunday, July 16, 2023, through Monday, July 17, 2023

OZONE: 8-hour average Ozone concentrations will average mostly Moderate.

PM-2.5: 24-hour average Fine Particulate levels will range from Moderate to Unhealthy for Sensitive Groups (USG).

Air Quality Action Day Advisories have been issued for Sunday, July 16th and Monday, July 17th, 2023

The Action Day Advisory for Sunday, July 16th is a Statewide Alert.

The Action Day Advisory for Monday, July 17th is for the following counties in the central and southern portions of the Lower Peninsula:

Mason, Lake, Osceola, Clare, Gladwin, Arenac, Oceana, Newaygo, Mecosta, Isabella, Midland, Bay, Huron, Muskegon, Montcalm, Gratiot, Saginaw, Tuscola, Sanilac, Ottawa, Kent, Ionia, Clinton, Shiawassee, Genesee, Lapeer, St. Clair, Allegan, Barry, Eaton, Ingham, Livingston, Oakland, Macomb, Van Buren, Kalamazoo, Calhoun, Jackson, Washtenaw, Wayne, Berrien, Cass, St. Joseph, Branch, Hillsdale, Lenawee, and Monroe

FORECAST DISCUSSION:

Smoke forecast models continue to show the smoke plume tracking through the state Sunday into Monday and this plume is clearly seen on satellite imagery Sunday morning. Increases in PM2.5 concentrations have been recorded Sunday morning across the western portion of the state and increases in concentrations will move east and continue through much of today. Air Quality Index (AQI) levels into the Unhealthy for Sensitive Groups range are likely with possible hourly concentrations into the Unhealthy level. The smoke plume pushes south Monday as a boundary moves through. This will improve PM2.5 levels across the northern portion of the state. The plume, however, remains across central and southern locations keeping the threat for increased PM2.5. Because of this, we are extending the Air Quality Action Day into Monday for the counties noted above.

Chances for precipitation Sunday, then cooler surface and upper-level temperatures Monday should keep ozone from increasing the next few days. However, increases in PM2.5 are known to enhance ozone production. We are forecasting Moderate ozone Sunday and Monday, but we will be watching ozone levels and if we feel ozone will increase into the USG range, we will update the necessary forecast areas to reflect the change, triggering EnviroFlash notifications.

 EXTENDED FORECAST:

There are signs the smoke plume could clear the region early next week, but lingering fine particulate could keep both PM2.5 and ozone in the Moderate range.

Forecast updated by: Stephanie Hengesbach on Sunday, July 16th, 2023

Next Forecast Update: Monday, July 17th, 2023

07/15/2023 Forecast Update

FORECAST SUMMARY: Saturday, July 15, 2023, through Sunday, July 16, 2023

OZONE: 8-hour average Ozone concentrations will average mostly Moderate.

PM-2.5: 24-hour average Fine Particulate levels will range from Moderate to Unhealthy for Sensitive Groups (USG).

An Air Quality Action Day Advisory has been issued for Sunday, July 16th, 2023 for PM-2.5.

This is a statewide alert.

FORECAST DISCUSSION:

Smoke forecast models continue to show a large plume originating from wildfires in western and central Canada sinking in from the northwest. Evidence of this is seen by increased PM2.5 readings late Friday and early Saturday to our west across Minnesota and northwest Wisconsin. As the plume continues moving east/southeast, increases in ground level PM2.5 across our state are expected.

This plume will affect the Upper Peninsula first and we have an Air Quality Action Day in place Saturday highlighting the threat for USG PM2.5 concentrations. The threat for USG PM2.5 moves south across the rest of the state Sunday; therefore, we are issuing a statewide Air Quality Action Day for Sunday. While we anticipate daily averages of PM2.5 to stay USG hourly concentrations into the Unhealthy level are possible during this event.

Clouds in the forecast with rain chances should keep ozone in check Saturday and Sunday, but ozone concentrations will be watched along with the PM2.5 trends. Increased PM2.5 is known to enhance ozone production. We are forecasting Moderate ozone both Saturday and Sunday across the state, but if we feel ozone will increase into the USG range, we will update our forecast areas to reflect the change, triggering EnviroFlash notifications.

 EXTENDED FORECAST:

There are signs the smoke plume could clear the region early next week, but lingering fine particulate could increase ozone concentrations. Conditions will be evaluated daily until the threat for increased pollution ends across the state.

Forecast updated by: Stephanie Hengesbach on Saturday, July 15th, 2023

Next Forecast Update: Sunday, July 16th, 2023

07/14/2023 Forecast Update

FORECAST SUMMARY: Friday, July 14th, 2023, through Saturday, July 15th, 2023

OZONE: 8-hour average Ozone concentrations will range between Good and Moderate.

PM-2.5: 24-hour average Fine Particulate levels will range from Good to Moderate.

FORECAST DISCUSSION:

Smoke forecast models show a large plume originating from wildfires in western and central Canada sinking in from the northwest behind a frontal boundary late Friday into Saturday. As the plume tracks southeast, increases in ground level PM2.5 are expected in the Upper Peninsula. With that, an Air Quality Action Day has been issued for some Upper Peninsula counties.

Across the rest of the state, PM2.5 concentrations should not reach higher than Moderate on Saturday. However, as the boundary and plume both continue moving south/southeast, the rest of the state may experience elevated PM2.5 levels on Sunday. We will be evaluating updated smoke and forecast models Saturday morning to determine if an Air Quality Action Day will need to be issued for Sunday.

The forementioned boundary will bring in the threat for showers and storms at the end of this week. During this period ozone concentrations should remain in check with readings higher than Moderate not expected.

 EXTENDED FORECAST:

Forecast models show an unsettled weather period with on and off chances for precipitation. There are signs the smoke plume could clear the region early next week, but conditions will be evaluated daily until the threat for increased pollution ends across the state.

Forecast updated by: Stephanie Hengesbach on Friday, July 14th, 2023

Next Forecast Update: Saturday, July 15th, 2023

07/10/2023 Forecast Update

FORECAST SUMMARY: Monday, July 10th, 2023, through Friday, July 14th, 2023

OZONE: 8-hour average Ozone concentrations Monday will range between Good and Moderate north and Moderate to USG south; Good to Moderate readings are expected the rest of the forecast period.

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

FORECAST DISCUSSION:

A boundary sinking into the region brings clouds and precipitation chances Monday across the Upper Peninsula while dry conditions can be expected further south in the Lower Peninsula. Ample sunshine combined with southerly winds and warm surface and upper-level temperatures sets the stage for ozone development in the most prone locations; the western lakeshore and the southeastern portions of the state. We had an Air Quality Action Day in place on Monday in those areas to cover this threat. As the boundary treks southeast through the state, clouds and precipitation move with it late Monday into the day Tuesday. This boundary looks to stall just south of the state Wednesday with cooler temperatures in its wake.

As mentioned above, we had an Air Quality Action Day in place on Monday where 8-hour ozone concentrations into the USG range were possible. Across the rest of the state, levels will average Good to Moderate. Clouds increase from northwest to southeast Tuesday. This increase in cloud cover should help keep ozone from significantly developing, but Moderate readings are still possible, especially in the south/southeast. If clouds hold off Tuesday in the southeast where mostly sunny conditions linger there is a chance a monitor may increase back into the USG range, but that threat isn’t high enough at this time to warrant an action day. For the rest of the period, unsettled conditions are expected as the Wednesday boundary stalls south of the state. Some cloud cover and on and off storm chances should keep ozone from increasing higher than Moderate Thursday and Friday. If this changes, the forecast will be updated.

As for fine particulate, smoke models were evaluated, and a plume is overhead Monday with another plume associated with the approaching frontal boundary expected to move in as the front passes. The plumes, however, are not expected to significantly increase ground level fine particulate concentrations. As a conservative measure, we are forecasting Moderate levels both Monday and Tuesday. Cooler northerly winds should bring levels closer to Good, but the boundary south of the region may allow for Moderate levels in the south Thursday and Friday.

 EXTENDED FORECAST:

Forecast models show cooler temperatures with on and off precipitation chances through the coming weekend. If this forecast pans out, air quality levels in the long-term period should be Good to low Moderate.

Forecast updated by: Stephanie Hengesbach on Monday, July 10th, 2023

Next Forecast Update: Friday, July 14th, 2023

07/09/2023 Forecast Update

FORECAST SUMMARY: sunday, july 9, 2023 through monday, july 10, 2023

OZONE: 8-hour average Ozone concentrations will range between Good and Moderate Sunday, with USG levels possible Monday

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

FORECAST DISCUSSION:

After a rainy Saturday, conditions dry out Sunday with high pressure in control. Plenty of sunshine is expected with seasonable temperature. Surface winds turn southerly during the day, but a northerly upper-level flow and cooler temperatures should keep ozone and fine particulate in the Good to Moderate range.

By Monday, the high slides east with southerly winds both at the surface and upper-levels bringing in warmer conditions. The next weather system will be approaching from the northwest. Clouds and precipitation move into the upper portion of the state, but plenty of sunshine is expected across most of the lower Peninsula. Mondays anticipated weather conditions are conducive for increased ozone; therefore, we are issuing an Air Quality Action Day for ozone on Monday in parts of west and southeast Michigan.

As for fine particulate, smoke models were evaluated and a plume sinks into the region Monday ahead of the next weather system. The plume does not seem to be thick enough to significantly increase fine particulate, but Moderate readings by Monday are likely.

 EXTENDED FORECAST:

Forecast models show on and off precipitation chances through the coming week. Air quality levels will be detailed tomorrow with the Monday update, but at this time we don’t anticipate readings higher than Moderate.

 Next Forecast update: Monday, July 10, 2023

07/07/2023 Forecast Update

FORECAST SUMMARY: friday, july 7, 2023 through sunday, july 9, 2023

OZONE: 8-hour average Ozone concentrations will range between Good and Moderate.

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

FORECAST DISCUSSION:

High pressure in control Friday provides comfortable, less humid conditions. A storm system moves through the region Saturday bringing precipitation chances from west to east starting late Friday night into Saturday. High pressure then moves back into the area drying conditions out Sunday into Monday.

As for air quality, plenty of sunshine will be seen Friday, however, cooler surface and upper-level temperatures keep ozone Good to low Moderate. Clouds increase Saturday and precipitation moves into the forecast as well. These conditions should keep ozone in the Good range. Clouds decrease Sunday as high pressure moves in, but cooler temperatures and northerly winds allow for ozone to average Good to Moderate.

Smoke forecast models keep thick smoke out of the region through the coming weekend. With that, we anticipate fine particulate levels to remain mostly Good to low Moderate. The only exception would be in locations yet holding fireworks displays in celebration of the July 4th holiday. Any evening hourly PM2.5 increases should improve by late morning/early afternoon the following day.

 EXTENDED FORECAST:

 Forecast models show sunny, warmer conditions by Monday as winds switch to more of a southerly direction. With that, the threat for increased ozone exists. This forecast will be updated Sunday to determine if ozone readings will increase to levels requiring an Action Day.

 Next Forecast update: Sunday, July 9, 2023

07/04/2023 Forecast Update

FORECAST SUMMARY: TUESDAY, July 4TH, 2023, THROUGH FRIDAY, JULY 7, 2023

OZONE: 8-hour average Ozone concentrations will range between Moderate and USG Tuesday and Wednesday, then Good to Moderate Thursday and Friday.

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

FORECAST DISCUSSION:

The forecast remains on track for warm, humid conditions to continue this July 4th holiday. The sunny conditions compiled with southerly winds and warm surface and upper-level temperatures will make a good setup for increased ozone. Due to this threat, we have issued an Action Day for ozone for Tuesday, July 4th. The threat for higher ozone lingers into Wednesday, therefore, we are continuing the Action Day into July 5th as well. A change in the forecast comes later Wednesday into Thursday as a cold front passes through the state. Precipitation comes into play as the boundary moves through and cooler temperatures in its wake brings in lower ozone concentrations. Levels Thursday and Friday should range Good to Moderate.

 Daily average PM2.5 readings the past few days have been between Good to Moderate. Some locations have experienced evening hourly concentrations into the USG range, but those increases have been associated with fireworks displays in celebration of the July 4th holiday. Any evening hourly PM2.5 increases should improve by late morning/early afternoon the following day. We anticipate daily PM2.5 averages to continue Good to Moderate the next few days with levels improving towards Good behind the Thursday front as winds switch to a northerly direction.

EXTENDED FORECAST: Forecast models show sunny and seasonable conditions for the end of the week. This forecast will be updated Friday to detail expected air quality levels for the weekend.

Next Forecast Update: Next Forecast update: Friday, July 7, 2023

07/03/2023 Forecast Update

FORECAST SUMMARY: MONDAY, JULY 3RD, THROUGH TUESDAY, July 4TH, 2023

OZONE: Ozone concentrations will range mostly Moderate Monday with a range of Moderate to USG Tuesday.

PM-2.5: 24-hour average Fine Particulate through the period should range mostly Moderate.

FORECAST DISCUSSION:

As anticipated, ozone concentrations look to begin increasing Monday and more so Tuesday as winds switch to a southerly direction. Contributing to the threat for increased ozone will be plentiful sunshine, southerly winds, and warmer temperatures both at the surface and upper levels. Maximum 8-hour ozone Monday should remain generally Moderate, with isolated USG possible along the western lakeshore and in the southeast. The threat for higher concentrations remains Tuesday and being the second day with this set-up, increased ozone in the Unhealthy for Sensitive Groups (USG) range is more likely. Therefore, we are issuing an Action Day for Tuesday covering the western lakeshore areas and the southeast portion of the state.

Overall PM2.5 levels continue to improve as wildfire smoke has less ground level influence over the region. We anticipate daily averages of PM2.5 to remain generally Moderate, however, localized higher concentrations can be expected due to fireworks displays in celebration of the 4th of July. Any evening hourly PM2.5 increases should improve by late morning/early afternoon the following day. 

This forecast will be updated tomorrow, Tuesday, July 4, to look ahead at potential Ozone issues for Wednesday.

EXTENDED FORECAST: Forecast models show sunny and warm conditions continuing Wednesday before a frontal boundary brings precipitation into the forecast. The possibility exists for another day of increased ozone on Wednesday; therefore, this forecast will be updated tomorrow to determine if the Action Day will need to be continued.

Next Forecast Update: Tuesday, July 4, 2023

07/02/2023 Forecast Update

FORECAST SUMMARY: Sunday July 2nd, 2023, through Monday July 3rd

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

PM-2.5: PM-2.5 concentrations are expected to be in the mid-to-high Moderate range.

FORECAST DISCUSSION:

We have seen great improvement in the overall air quality throughout the day yesterday and into this morning. Some PM-2.5 values were still relatively high on the west side of Michigan near Holland, MI, where the 24-hour average there for PM-2.5 was above the USG level. Everywhere else in Michigan was in the mid-to-high Moderate range. We will see this continue throughout the day and, throughout the week until we get a good airmass change with a strong frontal boundary. These high PM-2.5 concentrations will be aided by firework displays throughout the holiday weekend and heading into the 4th of July, so values may increase above the USG threshold for a few hours but return to the Moderate range.

Ozone may continue to increase throughout the day due to precursors staying within the air into tomorrow, Monday. Some areas in southeast Michigan may increase into the USG threshold but will not be widespread enough to issue an Ozone Air Quality Alert. Ozone levels will be watched throughout the day tomorrow, however.

EXTENDED FORECAST: We look towards Tuesday as Ozone may become a widespread issue across the state.

Next Forecast Update: Monday July 3rd, 2023