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

07/01/2023 Forecast Update

FORECAST SUMMARY: Saturday July 1st, 2023 through Sunday July 2nd, 2023

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

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

FORECAST DISCUSSION:

Continued and welcomed air quality improvement has been seen in the overnight hours for PM-2.5 and Ozone. PM-2.5 values still appear to be in the mid-to-high Moderate range this morning and will continue to hang around those values throughout the day. Occasional jumps into the USG range should be expected as firework displays will be aplenty throughout the weekend and will add to PM-2.5 concentrations. The PM-2.5 values we saw earlier this week are not expected to occur later this weekend, but as stated above, occasional increase into the USG range should be expected. Winds shift to more southerly flow throughout the day which will continue to improve PM-2.5 values as concentrations to our south in Illinois and Indiana are Good and Moderate. This is a reason for not continuing the PM-2.5 alert into tomorrow as concentrations will continue to drop into the Moderate range. However, these shifts in winds will present an issue for Ozone for areas in west and southeast Michigan, for this is the reason there is an Ozone Air Quality Alert in place for those areas today. All other alerts will end at midnight tonight and tomorrow will not have any Air Quality Alerts.

This forecast will be updated tomorrow, Sunday, morning to look ahead at potential Ozone issues for Monday.

EXTENDED FORECAST: We look ahead to early next week and the 4th of July holiday which will have potential Ozone issues and considerably less smoke.

Next Forecast Update: Sunday July 2nd, 2023

06/30/2023 Forecast Update

FORECAST SUMMARY: Friday June 30th, 2023, through Saturday July 1st, 2023

OZONE: Ozone concentrations are expected to be in the USG to Unhealthy range.

PM-2.5: PM-2.5 concentrations are expected to be in the USG to Unhealthy range.

FORECAST DISCUSSION:

Although PM-2.5 concentrations appear to be improving throughout the state this Friday morning, we still expect PM-2.5 levels to be above the alert-able USG threshold for a 24-hour average today and tomorrow, Saturday. We do not expect to see Very Unhealthy concentrations which were seen earlier this week, but hourly concentrations in the Unhealthy range can be expected. To compound the wildfire smoke, 4th of July festivities including firework displays will contribute to PM-2.5 concentrations, so this a reason why concentrations may increase on an hourly basis throughout each day during this weekend and into next week.

As mentioned in yesterday’s forecast, Ozone joins in on the alert for today and into tomorrow. Ozone was expanded to statewide today because USG to Unhealthy Ozone levels were seen statewide yesterday. Since the same airmass is in place, no strong wind shift, and even more sunlight today, we expect Ozone to reach the same levels as it did yesterday and just as much widespread across the state. Tomorrow will see more clouds throughout the state, so we expect Ozone to decrease in concentration and not have as much energy needed to produce.

EXTENDED FORECAST: Sunday appears to have more clouds and larger increase in chances of rain, so that will help the overall air quality improve.

Next Forecast Update: Saturday July 1st, 2023

06/29/2023 Forecast Update

FORECAST SUMMARY: Thursday June 29th, 2023, through Friday June 30th, 2023

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

PM-2.5: PM-2.5 concentrations are expected to be in the USG to Unhealthy range.

FORECAST DISCUSSION:

Another day in Michigan, another Air Quality Alert. As we continue the PM-2.5 alert we also add an Ozone Air Quality Alert for portions of southeast Michigan and west Michigan along the Lake Michigan shoreline. Some models have been somewhat useful during this event for PM-2.5, while other models do not show or suggest any PM-2.5 concentrations over us, which of course, is not the case. NOAA guidance has PM-2.5 concentrations over the state of Michigan through at least Saturday, so this is why this forecast is being taken day-by-day. Winds today will be mainly southerly, which is the driving component of smoke hanging around and returning to our area. There are currently region-wide alerts due to this smoke with current PM-2.5 concentrations looking to persist for the time being as we await a true airmass change which will clean out the area. Again, PM-2.5 concentrations are expected to fluctuate throughout each day, so a few hours may have improved air quality, but others may return to Unhealthy levels.

On top of the presence of smoke, Ozone will make an appearance in southeast Michigan and west Michigan along the Lake Michigan shoreline. It is suspected that the current PM-2.5 concentrations will be adding enough precursors to the environment and enabling Ozone to develop even though there is a thick plume over Michigan blocking out some of the sun. Enough of the sun’s radiation will make it to the Earth’s surface to interact with Ozone precursors. Also, as we typically see, Ozone will develop over Lake Michigan and be blown ashore as we expect SSW winds tomorrow, Friday. For most of the day tomorrow, clouds will be present but scattered and broken so the sun will be shining in areas that will be impacted by Ozone. On top of this, surface temperatures are expected to be in the mid-to-upper 80s in west and southeast Michigan aiding in the development of Ozone.

EXTENDED FORECAST: This current airmass remains in place for the time being. Air quality is expected to remain poor until we receive a good cleanout from a strong front and complete change in wind direction. As such, this forecast will be updated daily.

Next Forecast Update: Friday June 30th, 2023

06/28/2023 Forecast Update

FORECAST SUMMARY: Wednesday June 28th, 2023, through Thursday June 29th, 2023

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

PM-2.5: PM-2.5 concentrations are expected to be in the USG to Unhealthy range.

FORECAST DISCUSSION:

The majority of Michiganders woke up to a continued blanket of haze and wildfire smoke this Wednesday morning. We are continually being impressed by the PM-2.5 values we are seeing at the monitors across the state this morning and overnight. A dense plume of smoke came down from these fires overnight and almost all of southern Michigan is dealing with the smoke with PM-2.5 values in the Unhealthy and Very Unhealthy range. PM-2.5 values will improve slightly throughout the day today, but many areas will still be above the alert threshold of USG and possibly into the Unhealthy range still.

Winds looks to shift throughout the day from southerly to more NNW as we approach the evening as two High-pressures look to set up to our north and south. Going into tomorrow, winds will mainly be southerly which has us concerned with the amount of smoke and PM-2.5 concentrations returning to the region from being blown down south the past few days. Many models and forecast guidance have Michigan in the USG to Unhealthy range tomorrow. It is because of this the Air Quality Alert is being extended through tomorrow, Thursday. Tomorrow morning, the forecast will be reassessed but as of now, it looks like enough of the wind shift will blow smoke concentrations out of our area Thursday night into Friday. As we approach Friday, however, Ozone may become an issue once more as clear skies will allow for Ozone to develop.

EXTENDED FORECAST: High-pressure sets up to our north and south, reversing the winds to southerly and providing warmer air. Wildfire smoke may still be an issue and Ozone looks to make a return going into the weekend.

Next Forecast Update: Thursday June 29th, 2023

06/27/2023 Forecast Update

FORECAST SUMMARY: Tuesday June 27th, 2023, through Wednesday June 28th, 2023

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

PM-2.5: PM-2.5 concentrations are expected to be in the USG to Unhealthy range.

FORECAST DISCUSSION:

Hazy skies blanket the state of Michigan today, Tuesday, as Canadian wildfire smoke continues to impact the region. PM-2.5 concentrations across the state are even higher than the values we saw earlier this month with our first round of PM-2.5 Air Quality Alerts. The smoke and associated PM-2.5 concentrations will persist through the day today with heavier plumes potentially mixing in this afternoon. These plumes will be coming in waves, so it is possible to see concentrations decreasing for an hour or two, then increasing; it may be a back-and-forth scenario with concentrations. We currently have numerous monitors in the Very Unhealthy range for PM-2.5, mainly on the west side of the state. Due to this, the forecast for those areas is being upgraded from USG to Unhealthy for those areas for a 24-hour PM-2.5 average. Those Very Unhealthy concentrations may drift eastward towards the metro Detroit area later this evening before decreasing overnight.

NOAA guidance and multiple models have the smoke hanging around through tomorrow, Wednesday. Once the current Low-pressure exits the area, two High-pressures, north and south of us, set up and essentially reverse the winds bringing some of the smoke back with it. The majority of the smoke looks to remain in the lower peninsula, but due to how this smoke has been behaving this year and the current fire situation, we are extending the Statewide Air Quality Alert through tomorrow, Wednesday. This forecast will be updated tomorrow morning to reassess the smoke situation and to turn our heads to Ozone, as that may be an issue later this week.

EXTENDED FORECAST: High-pressure sets up to our north and south, reversing the winds to southerly and providing warmer air. Wildfire smoke may still be an issue and Ozone looks to make an appearance later this week.

Forecast updated by: Alec Kownacki: Monday, June 27, 2023

Next Forecast Update: Wednesday June 28th, 2023

06/26/2023 Forecast Update

FORECAST SUMMARY: Monday, June 26th, 2023, through Tuesday, June 27th, 2023

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

PM-2.5: PM-2.5 concentrations are expected to be in the Moderate to USG range, with some hourly concentrations in the Unhealthy range

FORECAST DISCUSSION:

Updated models for smoke are now showing wildfire smoke impacting the majority of the Lower Peninsula tomorrow, June 27th. Due to the spontaneous nature of these smoke plumes, we are issuing an Air Quality Alert for the entire Lower Peninsula tomorrow, June 27th, making the in-place Air Quality Alert, a Statewide Alert. This is in addition to the already in-place Air Quality Alert for the Upper Peninsula today, June 26th and tomorrow, June 27th. As of now, the majority of the smoke will stay to the west towards the Lake Michigan shoreline, but smoke should be expected to drift eastward. The main cause of this plume is the aforementioned Low-pressure moving out of the area and wrapping the smoke around with it. Southeast Michigan may receive less PM-2.5 concentrations but if there are any remaining background concentrations, the combination of the two may cause concentrations to reach the USG level.

EXTENDED FORECAST: Once the Low-pressure leaves the area, a High-pressure system sets up to our north bringing clear skies and a warmup.

Forecast updated by: Alec Kownacki: Monday, June 26, 2023

Next Forecast Update: Tuesday, June 27, 2023

06/24/2023 Forecast Update

FORECAST SUMMARY: Saturday, June 24th, 2023, through Monday, June 26th, 2023

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

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

FORECAST DISCUSSION: ‘Tis a busy day for Michigan air quality today, June 24th. There is currently an Air Quality Alert for Ozone for west portions of the state along the Lake Michigan shoreline. There is also an Air Quality Alert for PM-2.5 across the entire Upper Peninsula.

For Ozone, a dirty airmass will persist through the day today over Lake Michigan and will be blown ashore through a relatively strong lake breeze. Overall light winds will allow for this lake breeze to set up and persist for a couple hours. Today will also be one of the warmer days of the year with clear skies in the impacted areas, so there will be a rather conducive environment for Ozone to develop. For PM-2.5, wildfires in Ontario, Canada will impact the Upper Peninsula today and a little into the early morning hours tomorrow. The Seney monitor in the Upper Peninsula hit USG for a PM-2.5 24-hour average yesterday, and those values are expected to persist through today. Both the HRRR and RAP smoke models have a rather large plume expected to reach the Upper Peninsula this afternoon and will hang around for the remainder of the day. Some of the smoke may drift southward into the northern Lower Peninsula, but those concentrations will be short-lived and should only reach the Moderate range.

We get relief from the poor air quality tomorrow as a Low-Pressure and frontal boundary eclipse our state throughout the day. Rain is in the forecast for the majority of the state, along with shifting winds. Both the rain and changing of wind direction will help clean out the airmass and bump us back to Good air quality. These conditions last through Monday as rain hangs around into the start of next week.

EXTENDED FORECAST: Rain and clouds hang around the area to start next week, so overall air quality will be Good.

Forecast updated by: Alec Kownacki: Saturday, June 24, 2023

Next Forecast Update: Monday, June 26, 2023

06/23/2023 Forecast Update

FORECAST SUMMARY: Friday, June 23rd, 2023, through Saturday, June 24th, 2023

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

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

FORECAST DISCUSSION: Today, Friday, will see relatively cooler temperatures than what we have been seeing the past few days. This is due to northerly winds wrapping around our state caused by a Low-pressure system just to our east over southern Ontario. This may also produce some pop-up rain showers for southern portions of the state throughout today. The current wind direction is also bringing Canadian wildfire smoke to our state as well, more specifically, to the northern areas. A couple hours throughout the day may see PM-2.5 numbers jump into the USG range, but the overall 24-hour average should be in the Moderate range. The Low-pressure moves more eastward as we approach tomorrow, Saturday, which will open the door for sunshine and an increase in temperatures due to southerly flow returning and bringing warmer air to the region. This will be short-lived as we will be sandwiched between two Low-pressure systems with the second impacting us on Sunday. Before we get to Sunday, however, Ozone will be an issue for western Michigan lakeshore counties on Saturday. The past few days have not seen a change in airmass, so the current airmass over Lake Michigan is considered dirty with pollutants. Southerly flow, light winds, and clear skies will allow for Ozone to develop over Lake Michigan and be blown into lakeshore counties. This is why an Action Day is called for every Lake Michigan lakeshore county in the lower peninsula. Winds over the lake will shift from south to southwest throughout the day reinforcing the Ozone plume in the impacted areas. Most models have an Ozone plume in and around the Traverse City area along with relatively strong lake breezes due to overall light winds. Therefore, it was decided to extend the alert northward towards the Mackinac Bridge because of the large Ozone plume and the strength of the lake breeze. With lake breezes, winds over the lake shift to blow inland, so all of the pollutants and Ozone that sit over the lake blow inland as well, which is more often than the not, the main proponent of Ozone in lakeshore counties. South Lake Michigan areas will have more southwesterly flow which will blow the Ozone plume into southwest Michigan counties. This appears to be a one day event, but this forecast will be updated Saturday morning to reassess the forecast for Sunday and Monday.

EXTENDED FORECAST: The approaching Low-pressure from the west provides cloudy conditions and rain on Sunday and into Monday. This will help the overall air quality bringing it back into the Good range.

Forecast updated by: Alec Kownacki: Friday, June 23, 2023

Next Forecast Update: Saturday, June 24, 2023

06/22/2023 Forecast Update

FORECAST SUMMARY: Thursday, June 22nd, 2023, through Friday, June 23rd, 2023

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

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

FORECAST DISCUSSION: Yesterday, June 21st, the summer solstice, saw some areas in Michigan reach the USG range for Ozone concentrations. The areas that reached Moderate were not far behind as most monitors were at least in the upper-Moderate range. Today, Thursday, there is a continued Air Quality Alert in place for Ozone for the west and southwestern portions of the state. Continued sunlight and prime Ozone conditions remain in place for those areas as other portions of the state may see increasing cloud cover throughout the day and winds increasing as well. Also, the east and southeastern portions of the state will have upper-level smoke in place from Ontario wildfires, which help blanket the area and block out solar radiation. Upper-level smoke will sometimes cut off Ozone production due to the lack of solar radiation making its way to the surface to complete the Ozone chemical reaction. I am keeping an eye on the upper-level smoke to see if large amounts will mix down to the surface. It appears some will make its way to the surface pushing PM-2.5 concentrations into the USG range but only for isolated hours and should not be a multi-hour event. The overall 24-hour average for PM-2.5 will be in the Moderate range for the majority of the state for today and tomorrow. Due to this smoke and how unpredictable it can be, this forecast will be updated tomorrow, Friday. Also, shifting winds for Saturday may be interesting for Ozone for northern Lake Michigan areas. A few models are showing an Ozone plume around the Traverse City area that stretches into the upper peninsula, so this is another reason this forecast will be updated tomorrow.

EXTENDED FORECAST: Later on Saturday, clouds move in, with Sunday being mostly overcast for the majority of the day. Sunday into Monday presents a Low-pressure system and associated cold front that may bring us some rain as well.

Forecast updated by: Alec Kownacki: Thursday, June 22, 2023

Next Forecast Update: Friday, June 23rd, 2023

06/21/2023 Forecast Update

FORECAST SUMMARY: Wednesday June 21st, 2023, through Thursday June 22nd, 2023

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

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

FORECAST DISCUSSION: There is currently an air quality alert for surface-level Ozone in place for areas in southeast Michigan and along the Lake Michigan shoreline. Surface temperatures well into the 80s, warm upper-level temperatures, relatively light winds and ample sunlight are the main culprits for this ozone development. The air quality alert for west and southwest Michigan has been extended through tomorrow as warmth and sunlight persists. Southeast Michigan may see more clouds building throughout the day tomorrow, so we expect ozone development to be hampered by that. We traditionally do not see high ozone with predominantly easterly winds, but we have seen ozone production with easterly winds already this year in Michigan and throughout the region, so we are heeding what has happened earlier this year and continuing the alert for west Michigan counties. Also, later in the afternoon tomorrow, it looks like winds over Lake Michigan shift to more northwesterly flow, so pollutants and ozone over the lake could be blown into southwest Michigan areas.

This forecast will be updated tomorrow to reassess the forecast for ozone.

EXTENDED FORECAST: There appears to be a chance of rain Friday and into Saturday which will help clean out the airmass of pollutants.

Forecast updated by: Alec Kownacki: Wednesday, June 21, 2023

Next Forecast Update: Thursday June 22nd, 2023

06/20/2023 Forecast Update

FORECAST SUMMARY: Tuesday, June 20, 2023, through Wednesday, June 21, 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 mostly Moderate.

FORECAST DISCUSSION: As the smoke threat diminishes somewhat, ozone is back on the radar.  Michigan experienced some widespread higher ozone concentrations during Monday and a scattered few on Sunday.  Unfortunately, the reporting software for our monitoring network was down Sunday and Monday and we could not verify the numbers for forecasting purposes.  The network is back up and it is clear that we are seeing elevated numbers, even with the eastern wind.  As such, I will be issuing an Action Day Advisory for tomorrow, Wednesday, for both sides of the state.

The weather forecast remains mostly unchanged: hot, dry and easterly winds.  The dew points are rising, so some moisture is coming in which could potentially trigger scattered afternoon showers. 

With the persistent dry weather, fires and smoke will continue to be a concern on top of the current ozone threat.  As such, I expect this forecast to be updated, daily.

EXTENDED FORECAST: Air Quality should be generally Moderate to USG through the week.

Forecast updated by: Jim Haywood: Tuesday, June 20, 2023

Next Forecast update: Wednesday, June 21, 2023

06/19/2023 Forecast Update

FORECAST SUMMARY: Monday, June 19, 2023, through Tuesday, June 20, 2023

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

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

FORECAST DISCUSSION: Smoke levels held in the Moderate range during Sunday and ozone remains the secondary pollutant of concern in the Good to Moderate range.  Not much has changed with the short and long range forecast.  High pressure persists over the region with extremely dry conditions and high fire danger. Easterly winds persist with daytime high temperatures in the upper 80’s and approaching 90.  Relative humidity remains in the 20-30% range.

There is still a thick layer of smoke, aloft, which is dimming the sun and giving us gray rather than blue skies.  At the surface, fine particulate readings have been mostly in the 20-30 ug/m3 range, which is Mid-to-High Moderate.  The smoke models are predicting an improvement with a slight lowering of those numbers today and tomorrow. 

While ozone numbers have been behaving during this high smoke episode, we are in the time of year where the threat of elevated ozone is the highest.  The lower numbers we have been seeing may be partially due to the smoke layer aloft which has been dimming the amount of sun reaching the surface and reducing photochemical conversion of surface pollutants.  The ozone models are predicting that our numbers will remain in the Good to Moderate range for the next couple of days, and I am not seeing anything to challenge that conclusion.

Dry conditions are predicted to persist, at least into the weekend.  Hopefully we will see some scattered shower potential, by the weekend.

Due to the unpredictable nature of smoke, I will be updating this forecast Tuesday morning.

EXTENDED FORECAST: Air Quality should be generally Moderate through the week.

Forecast updated by: Jim Haywood: Monday, June 19, 2023

Next Forecast update: Tuesday, June 20, 2023

06/18/2023 Forecast Update

FORECAST SUMMARY: Sunday, June 18, 2023, through Monday, June 19, 2023

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be mostly Moderate with scattered USG.

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

FORECAST DISCUSSION: Smoke continues to dominate the forecast as hot, dry weather persists and wildfires continue to burn across Canada.  Smoke over Michigan had been forecast to stay mostly elevated and that has been the case, for the most part.  Friday night, however, we did notice a plume mixing down over Indiana and Ohio that seem to catch the southeast corner of Michigan giving those monitors some higher numbers.  Saturday morning, those monitors were still running in the low USG range so I bumped up the local forecast to USG.  Since the winds were pushing that air mass out of the area and the numbers dropped into the Moderate range by early afternoon, no Action Day advisory was necessary.

As of Sunday morning, monitors across Michigan are showing Moderate readings.  Some local fires in northwest Indiana are creating USG conditions in that area, but it has not bled over into Michigan.

The smoke models are still forecasting the smoke to stay aloft, although as we saw Friday night, some pockets can mix down to the surface.  I will revisit the conditions Monday morning and update the forecast, at that time.  Should any areas start seeing higher concentrations, today, I will update those locations to USG and if the area is widespread and persistent, I will issue an Action Day advisory.  But for the moment, I will hold to the Moderate forecast, across the state.

Ozone has been holding in the Good range. Since the current dry, hot weather pattern is expected to last into next weekend, expect this forecast to be updated frequently.

EXTENDED FORECAST: Air Quality should be generally Moderate with the potential for scattered USG going into the next work week.

Forecast updated by: Jim Haywood: Sunday, June 18, 2023

Next Forecast update: Monday, June 19, 2023

06/16/2023 Forecast Update

FORECAST SUMMARY: Friday, June 16, 2023, through Sunday, June 18, 2023

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be mostly Moderate through the forecast period.

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

FORECAST DISCUSSION: Last week, Michigan experienced elevated smoke concentrations due to wildfires northeast of Sault Ste. Marie.  With northerly winds and only 300 miles to travel before hitting southern Michigan counties, there was no time for smoke to dissipate.  As such, we experienced some of the highest smoke readings in the history of fine particulate air monitoring, in Michigan, and we issued our first ever Action Day advisories for fine particulates.

This week, surface smoke has receded as those fires have mostly diminished, but we have been keeping our eyes on large wildfires in the Alberta Province.  Smoke from those fires impacted Minnesota heavily and Wisconsin to a smaller extent.  Fortunately for Michigan, that smoke was well elevated before it reached us, and our ground level concentrations stayed in the Good to Moderate range.  Fortunately, the smoke models are indicating that the elevated smoke scenario should remain unchanged through the weekend.

 Ozone was never far from our minds during the smoke episode.  Looking at the upcoming weekend forecast, northerly winds will continue to keep our ozone concentrations in check under gradually clearing skies through Saturday.  On Sunday, however, surface winds will shift to a southeasterly direction under sunny skies.  Low dew points should keep ozone in check, but I do expect a creep in concentrations downwind from the Detroit area to the Flint area. 

Currently, Monday is of larger concern to me.  We will be under an easterly wind regime by Monday but, as we saw a couple weeks ago, that did not spare us elevated ozone.  Temperatures will be increasing, and Monday’s high temperature could come close to 90 degrees under sunny skies and increasing humidity.  As such, I plan to update this forecast, Sunday morning, while also tracking smoke plumes and looking for any unexpected changes throughout the weekend.

As far as rain in the forecast, the long-range models have Michigan under a high pressure dome through next week and into the next weekend, extending the current drought.

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

Forecast updated by: Jim Haywood: Friday, June 16, 2023

Next Forecast update: Sunday, June 18, 2023