8/16/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, August 16th, 2021 through Friday, August 20th, 2021

Ozone: 8-hour average Ozone concentrations are expected to range from Good to Moderate with chances for Moderates increasing past mid-week.

PM-2.5: 24-hour average Fine Particulate concentrations will be in the middle Good to low Moderate range.

FORECAST DISCUSSION:

The big weather story early this week is Tropical Storm Fred making landfall across the western Florida Panhandle Monday and tracking north through midweek. Here in Michigan, increased moisture will be noted the next few days, along with increasing temperatures by Wednesday as easterly flow turns more southwesterly. There isn’t a huge trigger for storms through mid-week; however, isolated/scattered storms are in the forecast with the biggest chance coming Wednesday as a system moves up from the south. Early morning patching fog is also anticipated this week due to higher levels of moisture coupled with lighter morning winds.

As for air quality, we are starting the week with Good levels of both ozone and fine particulate, and pollution levels Monday should remain generally Good. As stated above, weak easterly winds turn more southerly around mid-week. Lighter easterly winds before then should keep fine particulate from increasing significantly; however, increased moisture and a more southerly flow will cause increases into the Moderate range as the week progresses. The same is expected for ozone concentrations. We will have a good amount of sunshine the next few days, but easterly flow and lower upper-level temperatures should keep ozone between upper Good and low Moderate. As temperatures increase past mid-week more widespread ozone concentrations could be seen. A large increase is not anticipated though since we will likely see some clouds around and there are also chances for scattered storms. Concentrations of both fine particulate and ozone should not reach higher than Moderate through Friday.

EXTENDED FORECAST:

Forecast models show a boundary moving through sometime Saturday which could bring more of a northerly flow by the end of the week; however, before then increased moisture and temperatures should continue, along with the chance for Moderate air quality. This forecast will be updated Friday to better detail conditions for the weekend, into early next week.

Forecast updated by Stephanie Hengesbach: Friday, August 16th, 2021.

Next forecast update: Friday, August 20, 2021

8/13/2021 Forecast Update

FORECAST SUMMARY:

Friday, August 13th, 2021, through Monday, August 16th, 2021

OZONE: Ozone concentrations are expected to be mostly Good for the upcoming weekend and into early next week.

PM-2.5: PM-2.5 concentrations are expected to be Good for the weekend and into early next week.

FORECAST DISCUSSION:

Upper-level winds will mainly be from the WNW for most of the weekend. An approaching High-pressure system from the west will shift these winds to a more northwest flow going into Sunday. Upper-level temperatures are expected to be in the upper teens Celsius today, Friday, but are expected to drop to the low-to-mid teens Celsius for the rest of the weekend. The combination of shifting winds and decreasing upper-level temperatures will help keep ozone concentrations at bay. There appears to be some ozone pooling over Lake Michigan, but it is forecasted to mainly stay offshore with the possibility of reaching the shoreline only for a short period of time.

After a long week of hot, humid surface temperatures, the region finally gets a break thanks to the cold front that made its way through today, Friday. Daytime dewpoint temperatures will drop to the low-mid 50s Fahrenheit and surface daytime temperatures will be in the low 80s Fahrenheit for much of the area. Surface winds will also be from the WNW for the weekend with a northerly shift going into Sunday as the High-pressure sets up over Lake Michigan. This High-pressure will help keep the weekend clear and dry. Surface PM-2.5 hasn’t been of much concern this week and it will continue not to be going into the weekend, as not much smoke has been mixing down towards the surface. Ozone concentrations will struggle to develop due to the decreasing upper-level and surface temperatures. As stated above, there will be ozone pooling over Lake Michigan with the possibility of reaching the shoreline, but not enough to put 8-hour averages into the Moderate range.

EXTENDED FORECAST:

Going forward into early next week, it is more of the same in terms of concentrations. The High-pressure moves off into Ontario but still provides us with clear skies and cooler temperatures compared to this past week.

Forecast updated by Alec Kownacki, Friday, August 13th, 2021. Next Forecast update on Monday, August 16th, 2021.

8/9/2021 Forecast Update

FORECAST SUMMARY:

Monday, August 9th, 2021, through Friday, August 13th, 2021

OZONE: Ozone concentrations are expected to be in the low-to-mid Moderate range for much of the week due to warmer temperatures and southwest winds. These concentrations will be dependent upon potential precipitation and cloud cover.

PM-2.5: After weeks of pretty steady PM2.5 concentrations, it appears we get somewhat of a break from smoke for at least the first half of the week. Mid-week concentrations will rise due to a plume making its way to the region from out west.

FORECAST DISCUSSION:

For much of the week, upper-level winds will be from the southwest due to a Low-pressure system sitting to our west until a front comes through Friday and shifts winds to more northwesterly flow. Upper-level temperatures will be in the upper-teens to low-twenties degrees Celsius, which will aid in the development of ozone. The combination of warm upper-level temperatures and southwest winds will ramp up the production of Ozone but broken and overcast skies may help to inhibit the production of Ozone. In terms of smoke concentrations, as mentioned above, the area receives somewhat of a break until mid-week when smoke from out west enters the area. Surface temperatures will be hot and humid for much of this week until a cold front enters the region Thursday night and into Friday.

Surface winds will primarily be from the southwest this week which tends to produce Ozone concentrations along southwest Michigan and up the Lake Michigan shoreline. Cloud cover may cut off the production of Ozone but breaks in cloud and ample sunlight will produce some Moderate concentrations. Along with the cloud cover, precipitation is forecasted for much of the week, so this too, will help cut off Ozone concentrations. Some models are showing rather heavy Ozone concentrations over Lake Michigan, with some creeping ashore, but will be dependent upon cloud cover and potential precipitation. This is the reasoning for forecasting Moderate Ozone concentrations for most of southern Michigan.

EXTENDED FORECAST:

A cold front comes through Thursday into Friday, essentially clearing out the area and setting up a High-pressure to our west. This is also when smoke concentrations appear to enter the region once again.

Forecast updated by Alec Kownacki August 9th, 2021

Next Forecast update: Friday, August 13th, 2021

8/6/2021 Forecast Update

FORECAST SUMMARY:

Friday, August 6th, 2021, through Monday, August 9th, 2021

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 range from Low to High Moderate.

FORECAST DISCUSSION:

Smoke continues to be an issue as our monitors still show concentrations higher than we normally see, but the 24-hour averages remain in the Moderate range.  This will likely continue for the short-term future.  The smoke models do have it thinning out over the weekend, but not going away.  All indications are that we will continue to fare no worse than Moderate for our 24-hour averages.

We have been focusing most of our attention on the fine particulates brought to us by the wildfires out west and in Canada.  But even though ozone production has been down lately, it is always a threat, and we cannot afford not to keep an eye on it.  The computer models are indicating a buildup over southern Lake Michigan through the weekend.  As with most of the computer ozone forecasts over the past few weeks, this is likely an overprediction with the smoke layer in the upper atmosphere reducing the sun’s power.  Add the potential for hit or miss showers through the weekend, and the potential is even less.  I expect the best chance of rain showers will occur Friday, Sunday, and Monday.  Even without the showers, there should be enough associated clouds to discourage serious ozone production.  Saturday looks to have the best chance for some prolonged sunlight, so we could see a creep in the numbers during the afternoon.  But I do not see a strong indicator that any widespread USG readings are likely.

That said, we may have some ozone creep if we do have any areas of prolonged sun.  If that happens, we could see some isolated spots of low USG, especially in the southern tier counties along Lake Michigan.  I will be keeping an eye on conditions as they develop Saturday, and make any adjustments necessary to the forecast.

An upper-level system should bring in better chances for showers late Sunday through Monday.  That will eliminate any ozone issues for late in the weekend and early next week.  But the smoke will still be lingering, and we will continue to watch that.

EXTENDED FORECAST:

Air Quality is expected to range between Good and Moderate going into the next work week.

Forecast updated by Jim Haywood: Friday, August 6th, 2021

Next forecast update: Monday, August 9th, 2021

8/4/2021 Forecast Update

FORECAST SUMMARY:

Wednesday August 4th, 2021, through Friday, August 6th, 2021

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 range from Good to High Moderate.

FORECAST DISCUSSION:

A gradual warm-up begins on Thursday as we return to a southerly air flow and more typical August temperatures and humidity.  Wildfire smoke continues to be a major issue.  Fortunately, most of the surface smoke has stayed on the west side of Lake Michigan, but the Upper Peninsula is experiencing Wednesday morning hourly concentrations in the USG range.  As such, I’ve bumped the U.P. forecast up to USG.

The forecast models are still holding our ozone in the Good to Moderate range for the remainder of the work week.  However, the fires and smoke look to hang around for the foreseeable future.  The smoke models are indicating a southerly drift of the U.P. smoke into the Upper Lower Peninsula, during Wednesday, but I am not yet seeing that reflected in the monitors. 

The smoke forecast models look to keep most of the surface smoke west of Lake Michigan.  It is anticipated that the heavier Michigan smoke, currently in the U.P., may drift southward and affect the Upper Lower Peninsula for the remainder of today and tomorrow.  That said, I think the overall 24-hour average will settle in the High Moderate range.  As southerly flow picks up during Wednesday, that smoke cloud should begin to be pushed to the northeast. 

While that should clear out the current smoke by late Thursday, by Friday morning, I expect the old smoke cloud that has been over the Ohio Valley to move back north on the southerly return air flow.  That smoke cloud should be thinner and more elevated, but some could still mix down during daytime convection. 

The weekend looks to be very warm and humid with the chance of showers.  The question is whether enough elevated smoke will help reduce ozone formation and whether there be enough clouds/showers from a stalled frontal boundary to the north to thwart ozone production.  Either way, I think a forecast update on Friday will be necessary to nail down these possibilities. 

EXTENDED FORECAST:

Air Quality is expected to be Good increasing to Moderate going into the weekend.

Forecast updated by Jim Haywood: Wednesday, August 4th, 2021

Next forecast update: Friday, August 6th, 2021

8/2/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, August 2nd, 2021, through Wednesday, August 4th, 2021

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:

Following a prolonged event with wildfire smoke affecting our monitors with fine particulates, I am expecting a quieter week from an Air Quality perspective.  Yesterday (Sunday), we saw several hours of smoke mixing down and causing some of our West Michigan monitors to reach the Unhealthy range.  Fortunately, those high impact hours were brief, and the overall 24-hour averages stayed in the Moderate range.

This work week starts with cooler weather and monitors showing mostly Good Air Quality as the overhead smoke gets pushed southward.  I expect the cooler weather to persist through mid-week and Air Quality to remain mostly Good.

The latter half of the week will experience a gradual warming trend, and we can expect near 90-degree weather during the weekend.  I anticipate the warmup will cause a creep in ozone concentrations by the end of the week.  So far, the smoke models are showing little overhead smoke throughout the work week, but the wildfires can be unpredictable.

Conditions look to stay dry until the weekend.  A shortwave trough looks to be on track for Saturday which could prompt some cloud cover and the chance of showers.  But it’s too early to nail that one down, precisely.

Since I am expecting a warmup, starting on Wednesday, and we are still in peak ozone season, I will be updating this forecast at that time.

EXTENDED FORECAST:

Air Quality is expected to be Good increasing to Moderate going into the weekend.

Forecast updated by Jim Haywood: Monday, August 2nd, 2021

Next forecast update: Wednesday, August 4th, 2021

7/30/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Friday, July 30th, 2021 through Monday, August 2nd, 2021

Ozone: Ozone concentrations are predicted to be mostly Good for most of the weekend. Winds out of the west-southwest Saturday may bring Ozone from over Lake Michigan to the shoreline but concentrations should not cross the 8-hour average Moderate threshold.

PM-2.5: PM-2.5 concentrations will be mostly Good as well with a north wind clearing the wildfire smoke from the region until Saturday. Wildfire smoke will enter the region Saturday which may present Moderate concentrations and will track southward but, will exit the region come Sunday afternoon.

FORECAST DISCUSSION:

Upper-level winds will be from the north for most of today, Friday, with winds shifting to more west-southwest flow come Saturday due to the low-pressure system to our north-northeast. As the low-pressure moves out of the area, winds return to a northerly flow Sunday. Upper-level temperatures will be cooler this weekend with temperatures barely approaching the teens, hovering around 10 degrees Celsius for much of the weekend. The combination of north winds and lower temperatures will inhibit the development of Ozone, which is why concentrations will be mostly Good. As mentioned above, the north wind will help with PM-2.5 concentrations as well as clearing out the area.

Surface winds follow similarly to upper-level winds with the flow coming from the north today, Friday, and into Saturday before winds shift to westerly flow as the pressure-system treks across Ontario. The shift to westerly flow may bring some hourly Ozone concentrations to Moderate, but overall, 8-hour average concentrations are expected to be Good. As mentioned above, the west wind on Saturday will return some smoke concentrations to the area and will present Moderate concentrations but will quickly exit the area as the winds shift to northerly on Sunday. Once the low-pressure exits the area, some rainfall may occur which will help with concentrations as well.

EXTENDED FORECAST:

The low-pressure system treks off to the East and opens the door for a High-pressure system to set up to the West with cooler temperatures. Concentrations are expected to remain Good going into early next week.

Forecast updated by Alec Kownacki/Stephanie Hengesbach: Friday, July 30th, 2021.

Next forecast update: Monday, August 2, 2021

7/26/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, July 26th, 2021 through Friday, July 30th, 2021

Ozone: 8-hour Ozone concentrations are expected to be mostly Good throughout the week. There will be some pooling of Ozone concentrations over Lake Michigan and up the shoreline, so this may allow some West Michigan areas to approach low-Moderate concentrations.

PM-2.5: PM-2.5 concentrations are expected to dissipate throughout the day and throughout the week. There are still smoke plumes aloft over Michigan, but excessive smoke is not expected to mix downwards toward the surface for the first half of the week. Smoke models are showing some near-surface smoke towards Wednesday and the latter half of the week.

FORECAST DISCUSSION:

Upper-level winds are expected to be west to north westerly (WNW) throughout the week until Thursday. Upper-level temperatures are expected to be in the mid-upper teens today and into Tuesday until a cold front moves into the area which helps to lower upper-level temperatures. These lower temperatures are expected Tuesday through Friday.

Surface temperatures are expected to be in the low-mid 80s for the week with dewpoint temperatures in the mid-upper 60s all week. The cold front on Tuesday gives way to a High-pressure system that hangs around the area until Saturday. Surface winds are expected to be WNW until the front comes through and makes the winds more variable. Along with upper-level winds, Thursday and into Friday, surface winds shift to a more northerly flow. Overcast skies Tuesday and Thursday may inhibit the development of Ozone concentrations at the surface but Wednesday has partly cloudy skies until the front moves in. After reassessing concentrations on Wednesday and further updates to the forecast will be made if necessary. 

EXTENDED FORECAST:

High-pressure sticks around until Saturday when another frontal boundary enters the area and quickly exits the region. After the front moves out on Sunday, another High-pressure establishes itself in the Great Lakes region.

Forecast updated by Alec Kownacki/Stephanie Hengesbach: Monday, July 26th, 2021.

Next forecast update: Friday, July 30th, 2021

7/22/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Thursday, July 22nd, 2021, through Monday, July 26th, 2021

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

PM-2.5:  24-hour average Fine Particulate concentrations are expected to increase from Good to Mid-Moderate throughout the forecast period.

FORECAST DISCUSSION

Recent forecasts have focused on the smoke transport into Michigan and how that is affecting Air Quality.  Fortunately, the wind patterns gave a momentary respite starting Tuesday evening and lasting through Thursday.  Unfortunately, the smoke and wildfire models are predicting the smoke will reenter the state during Friday.  While that will give the state hazy skies, the high-altitude smoke will stay mostly aloft.  Some will mix down, as seen earlier in the week, but our monitors should fare no worse than Moderate concentrations.

Currently, high pressure centered over SE Michigan is causing winds to shift back to a weak southerly direction.  As that high-pressure cell slips eastward, we will see our weather evolve into a more active weekend.  We are looking at a strong southwesterly flow, on Saturday, which will pump in high levels of moisture and the potential for convective activity.

A cold front is expected to drop down during Sunday and eliminate any threat from ozone.  However, since atmospheric smoke is expected to linger through the weekend, the state will be kept at Moderate levels.

EXTENDED FORECAST

Air Quality is expected to be Good increasing to Moderate going into the weekend.

Forecast updated by Jim Haywood: Thursday, July 22nd, 2021

Next forecast update: Monday, July 26nd, 2021

7/19/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, July 19th, 2021, through Thursday, July 22nd, 2021

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

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

FORECAST DISCUSSION

Air Quality for last week was really Good for ozone concentrations, which is very nice to see this time of year.  Fine particulates, however, ran well into the Moderate range, in many areas,  due mostly to atmosphere transport smoke from numerous large fires in the western United States and Canada.

This week will start off similarly.  For the first half of the week, ozone should be held at bay with northwesterly airflow. A pooling of ozone is expected over the bottom of Lake Michigan and perhaps some higher numbers could occur in the very southwest corner of the state if it bleeds inland.  The fire and smoke maps are showing coverage over almost the entire 48 lower contiguous states.  Only the very southeast and southwest corners of the country appear smoke-free.  This will help lower ozone numbers as effectively as a cloud cover.  But as some of that smoke mixes down to the surface, the monitors will reflect that in PM-2.5 creep. The fine particulate numbers will be similar to last week with concentrations ranging from Low Moderate to Mid-Moderate.

As high pressure slips eastward during the first half of the week, Expect a wind shift by late Thursday to the southwest.  With that shift comes the ozone forming pollutants from Illinois/Indiana and Southeast Michigan.  Because of that, the forecast will be updated on Thursday to reflect expected weekend conditions.

EXTENDED FORECAST

Air Quality is expected to be mostly Low Moderate going into the weekend.

Forecast updated by Jim Haywood: Monday, July 19th, 2021

Next forecast update: Monday, July 22nd, 2021

7/16/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Friday, July 16th, 2021 through Monday, July 19th, 2021

Ozone:  8-hour Ozone concentrations are expected to be mostly Good throughout the weekend. There will be some pooling of Ozone over Lake Michigan but with a northeast wind over the weekend, it should keep Ozone concentrations at bay.

PM-2.5: More of the same with PM-2.5 concentrations, northeast winds will keep potential wildfire smoke from entering the area and keeping PM-2.5 concentrations Good.

FORECAST DISCUSSION:

Upper-level temperatures will be in the low-teens for much of the weekend and into next week. Upper-level winds will be from the east which will help to keep wildfire smoke out of our area. Into the weekend a High-pressure system sets up over the Upper Peninsula providing clear and sunny skies for the region.

Surface temperatures look to be in the low-mid 80s for much of the weekend with the lower half of the state dealing with a stalled front which will provide relatively cooler temperatures to start the weekend, but the front will move out going into Saturday night. Surface winds appear to be easterly-northeasterly for the weekend, which, stated above, will help keep near-surface smoke from entering the area. In terms of dewpoint, there will be a rather sharp dewpoint gradient across the state Saturday ranging from the upper 50s to the north and upper 60s to the south. This is due to the stalled front over the Michigan/Ohio border. Going into Sunday as the front moves out, dewpoints drop across the state to the mid-50s.

EXTENDED FORECAST:

Going into Monday and next week, the High-pressure sticks around until a fast-moving cold front comes through from north to south Tuesday and into Wednesday. This cold front may produce some rain, but nothing too much. Overall, for the start of next week, concentrations should be mostly Good.

Forecast updated by Alec Kownacki/Stephanie Hengesbach: Friday, July 16th, 2021.

Next forecast update: Monday, July 19th, 2021

7/12/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, July 12th, 2021 through Friday, July 16th, 2021

Ozone:  8-hour average Ozone concentrations are expected to be mostly Good throughout the week with a chance of Moderate concentrations in West Michgian along the Lake Michigan shoreline on Wednesday.

PM-2.5:  24-hour average fine Particulate concentrations will be mostly Good with low-Moderates possible from Canadian wildfire smoke plumes in the Upper Peninsula.

FORECAST DISCUSSION:

Upper-level temperatures will be in the low-teens for much of the week with some increasing into the mid-teens. Winds aloft shift from easterly at the beginning of the week to more west/southwesterly by mid-week. Clouds, precipitation chances, and easterly winds should keep air quality Good Monday into Tuesday.

The Low-pressure has a warm front associated with it that will result in warm air advection past mid-week as the boundary pulls north. This will also bring moisture into the region increasing surface dewpoint temperatures and humidity. Accompanied with the warmer temps, southwest winds are expected; however, clouds and precipitation move in the forecast Thursday into Friday as another Low-pressure area moves in. Clouds may clear long enough Wednesday to allow for a few Moderates ozone concentrations in western lakeshore areas; otherwise, levels will be generally Good. Fine particulate is expected to remain Good Wednesday. Clouds and precipitation should again keep ozone generally Good Thursday and Friday while fine particulate will likely be a mix of middle Good to low Moderate.

A weak cold front is expected Friday afternoon associated with the back end of the Low-pressure. This will make way for a High-pressure system to set up for the weekend. Canadian wildfires still present smoke plumes for the upper-Midwest region. The Upper Peninsula has a rather thick plume aloft on Monday which is expected to diminish in the coming days due to east-southeast winds for the first half of the week. These winds will also help to keep the plume out of the lower peninsula during the week, but northerly winds during the weekend may bring the plume back over the state.

EXTENDED FORECAST:

A high-pressure system sets up over the western Upper Peninsula region behind the cold front which should bring relatively clear skies and Good Ozone concentrations. We will update this forecast Friday to better detail possible pollution increases due to the wildfire smoke.

Forecast updated by Alec Kownacki/Stephanie Hengesbach: Monday, July 12th, 2021.

Next forecast update: Friday, July 16th, 2021

7/6/2021 Forecast Update

FORECAST SUMMARY: Tuesday, July 6th, 2021, through Monday, July 12th, 2021

OZONE: 8-Hour average Ozone concentrations are expected to be Moderate on Monday then transitioning to mostly Good to Moderate during Tuesday and for the remainder of the forecast period.

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

FORECAST DISCUSSION:

 The 4th of July holiday weekend is ideally hot and dry, but not too uncomfortable.  The past weekend, temperatures reached the 90-degree mark but did not feel too oppressive.  

As high pressure slipped eastward through the weekend, surface and upper-air winds were favorable through Saturday, and Air Quality Good.  As the center of the high-pressure ridge passed by on Sunday, surface winds turned to the southwest.  With that wind direction, especially this time of year, we tend to get concerned.  However, anyone who spent time outside probably noticed a thick haze over the sky which filtered out the harshest of the sun’s rays.  That haze was a thick layer of smoke over much of the Midwest courtesy of Canadian wildfires.  The wind shift on Sunday thinned out the layer of smoke and we did see a creep in the ozone numbers during Sunday and Monday, but it got no worse than Moderate.  

Fine particulates over a 4th of July holiday weekend always tend to run high due to fireworks.  While this weekend was no different, I do not think it was as bad as some years in the past.  That said, the Dearborn monitor did creep into the USG range on Sunday, but the rest of the state remained Moderate.  I did notice some of the northern monitors starting to creep into the Moderate range earlier in the weekend but that was likely the smoke layer mixing down to the surface.

Tuesday will still experience heat and plenty of Moderates for ozone and fine particulates, but the threat of elevated levels of ozone should be low and confined to the southwest corner of the state.  As a cold front drops through on Wednesday, that will eliminate any additional threats for the rest of the week.  We will be in a cleaner, cooler air mass and have Good Air Quality.  We will likely still see a smoke haze aloft and it will be interesting to see if any of that mixes down to the surface.  

Another warm-up is not expected until early next week, in advance of a low-pressure system.  As such, this forecast should be good through the weekend. 

EXTENDED FORECAST:

Air Quality should be Good to Low Moderate going into the next work week.

Forecast updated by Jim Haywood: Tuesday, July 6th, 2021.

Next forecast update: Monday, July 12th, 2021

7/3/2021 Forecast Update

FORECAST SUMMARY: Saturday, July 3rd, 2021, through Tuesday, July 6th, 2021

OZONE: 8-Hour average Ozone concentrations are expected to range from Good to Moderate.

PM-2.5: 24-hour average Fine Particulate concentrations will also be in the Good and Moderate range.

FORECAST DISCUSSION:

 The forecast is on track with generally sunny skies and warming temperatures this July 4th weekend. There is usually a bright blue sky in the current weather set-up, but it may look a bit hazy the next few days. That can be attributed to wildfire smoke sinking south from fires in Canada. The next weather system is a frontal boundary moving in later Monday. This system should bring some clouds later in the day and small chances for precipitation into Tuesday

For air quality, as mentioned wildfire smoke is traveling in from the north/northwest. While much of the plume should stay at upper levels, there is the possibility some may mix down increasing fine particulate concentrations into the Moderate range for a period of time. Because of this, they are forecasting Moderate fine particulate for the next two days. Another reason for a Moderate forecast increases in fireworks displays in celebration of the July 4th Holiday. These displays will cause short-term high spikes in fine particulate for a few hours afterward that could, in turn, allow for Moderate daily averages.

For ozone, there is currently a low background in place thanks to the stronger northwesterly winds the past few days. While surface and upper-level temperatures will continue to increase, the wind field remains from a non-conducive direction through most of Sunday. There is a small chance for a monitor or two right along the west Michigan lakeshore to reach low-end USG, but they do not foresee any widespread ozone concerns through July 4th.

A frontal boundary sinks closer to the region Monday. While winds turn more southwesterly, clouds look to move in early enough to hamper a significant ozone development. This is something that will be keeping an eye on, but for now, we are forecasting Moderate ozone Monday. They plan to take a look at weather maps again Sunday morning and will update this forecast if our thoughts change and we feel ozone concentrations higher than Moderate become a concern. The smoke plume forecast will be monitored and updated this forecast if warranted.

EXTENDED FORECAST:

The system dropping in from the north later Monday/early Tuesday should bring in cooler temperatures and cleaner air. Air quality by Tuesday should improve towards the Good range.

Forecast updated by Stephanie M. Hengesbach: Friday, July 2nd, 2021. Next forecast update: Tuesday, July 6, 2021

7/2/2021 Forecast Update

FORECAST SUMMARY: Friday, July 2nd, 2021, through Saturday, July 3rd, 2021

OZONE: 8-Hour average Ozone concentrations are expected to be mostly Good with only a few Moderates possible through Saturday.

PM-2.5: 24-hour average Fine Particulate concentrations will also be mostly Good.

FORECAST DISCUSSION:

High pressure to the southwest of the state will provide plentiful sunshine and northerly winds should keep air quality generally Good both Friday and Saturday. As it progresses into the holiday weekend, forecast models are showing a smoke plume dropping in from Canada. At this point, the smoke plume is expected to stay at upper levels and shouldn’t impact air quality significantly.

Another note as we move into the holiday weekend is the anticipated high fine particulate concentrations in locations with fireworks displays. Wind speeds should be high enough where levels will not stay high for a long period of time. Hourly levels during, and for a few hours after displays, maybe USG; however, daily averages should not be higher than low to middle Moderate.

Temperatures will increase Saturday and Sunday both at the surface and upper levels. By later Sunday winds turn more westerly as high pressure moves east. Plenty of sunshine will remain and the threat of increased ozone comes into play. This is something that will be monitored. This forecast will be updated Saturday to detail pollution levels for Sunday and Monday.

EXTENDED FORECAST:

Extended forecast models show the next system possibly bringing small chances for precipitation by late Monday or Tuesday. Until then, pollution levels may be increasing early next week for both ozone and fine particulate.

Forecast updated by Stephanie M. Hengesbach: Friday, July 2nd, 2021. Next forecast update: Saturday, July 3nd, 2021

6/28/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, June 28th, 2021, through Friday, July 2nd, 2021

OZONE: 8-Hour average Ozone concentrations are expected to be mostly Good throughout the week with a chance of a few low Moderate concentrations due to southwesterly flow.

PM-2.5: 24-hour average Fine Particulate concentrations will be mostly Good with low-Moderates possible.

FORECAST DISCUSSION:

Monday, June 28th, presents relatively clear skies with dewpoints in the upper 60s to low 70s for the first half of the week. A lingering front provides a chance of some rain showers Monday afternoon and into the evening. The lingering front starts to lift off to the north as a Low-pressure system approaches the Great Lakes region and brings a cold front with it going into Wednesday, June 30th. With this frontal passage, winds shift from a southwesterly flow to a more westerly flow through mid-week. After the frontal passage Wednesday, a high-pressure system makes its way into the region from the north.

Going into Thursday, winds shift to a more northerly flow with temperatures in the upper-70s thanks to the passing cold front and this pattern stays relatively the same going into Friday, July 2nd. There is some question on an upper-level system bringing scattered precipitation Thursday and/or Friday, but by the end of the week and into the weekend a high-pressure system sets up directly over the Great Lakes region providing relatively clear skies. ozone levels will remain Good throughout the week and into the weekend with perhaps a few Moderates due to the southwesterly flow earlier on in the week. Particulate Matter appears to remain mostly Good with some areas reaching low Moderate levels throughout mid-week.

EXTENDED FORECAST:

Extended forecast models show a high-pressure system sitting over the Great Lakes region for much of the weekend. Going into Monday, July 5th, there appears to be a cold front approaching the region from the north which may impact the area early next week. We will post a forecast update on Friday to better detail air quality conditions for the July 4th weekend.

Forecast updated by Alec Kownacki: Monday, June 28th, 2021. Next forecast update: Friday, July 2nd, 2021

6/21/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, June 21st, 2021 through Monday, June 28th, 2021

Ozone:  8-hour average Ozone concentrations are expected to be mostly Good to Low Moderate through the forecast period.

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

FORECAST DISCUSSION:

Following late Sunday thunderstorms, a cold front will pass through the state during Monday.  A cool down is expected behind the front with high pressure filling in for late Monday and Tuesday.  Air Quality is expected to be Good during the first half of the work week.

As the high pressure shifts eastward during mid-week, winds will migrate to a southerly direction.  Thursday promises to be the warmest day of the forecast period but not likely to persist long enough to promote any serious buildup of poor Air Quality.  That said, Moderate conditions during Thursday are to be expected.  Another cold front, late Friday, should push out any buildup that occurred during Thursday. 

Air Quality is expected to be Good Saturday and Sunday with a chance for a creep into the Moderate range on Monday as winds swing back to the south.

Overall, the Air Quality will be mostly Good, during the week, with Moderates during Thursday and possibly Monday.

EXTENDED FORECAST:

Air Quality should be Good to Low Moderate going into the next work week.

Forecast updated by Jim Haywood: Monday, June 21st, 2021. Next forecast update: Monday, June 28th, 2021

6/18/2021 Forecast Update

FORECAST SUMMARY:

FRIDAY, JUNE 18, THROUGH MONDAY, JUNE 21, 2021

OZONE: 8-hour Ozone concentrations are expected to be Good throughout the weekend with possible Moderate levels in place along the Lake Michigan shoreline and Metro Detroit. Into Monday, levels are expected to be Good due to another system making its way into the region.

PM-2.5: 24-hour average Fine Particulate concentrations will be Good to low Moderate over much of the region.

FORECAST DISCUSSION:

After a system made its way through the region Friday morning, subtle clearing is expected to occur for much of the afternoon with a moderate chance of additional storms to develop later Friday afternoon into the evening. Left over rain is expected into Saturday morning as another Mesoscale Convective System is predicted to make its way through central-southern Michigan. With this MCS, WSW winds are expected, which helps to explain the Moderate Ozone levels along the Lake Michigan shoreline.

Into the day on Saturday, a stalled front is expected over mid-Michigan, which will slightly lift off to the north later Saturday night, eventually making its way on a more SE track into Sunday and Monday. The stalled front will result in a Low-pressure system over the MI/IN border and will lift off as the front leaves the area. This front will be responsible for the expected rain on Monday. Overall, Ozone levels are expected to generally be Good with some Moderate levels of Ozone near west/southwest MI. In the southeast, low-Moderate PM2.5 concentrations could occur as well.

EXTENDED FORECAST:

With the frontal passage next Monday, we expect Good Air Quality for the start of the week as the rain showers exit the area. This will give way to a High-pressure system to our south which will present us with relatively clear skies.

FORECAST UPDATED BY ALEC KOWNACKI/STEPHANIE HENGESBACH: FRIDAY, JUNE 18, 2021

NEXT FORECAST UPDATE: MONDAY, JUNE 21, 2021

6/14/2021 Forecast Update

FORECAST SUMMARY:

MONDAY, JUNE 14, THROUGH FRIDAY, JUNE 18, 2021

OZONE: 8-Hour average Ozone concentrations are expected to be mostly Good through mid-week with Moderates possible Thursday. Good levels return Friday.

PM-2.5: 24-hour average fine particulate concentrations will be mostly Good with low-Moderates possible past midweek.

FORECAST DISCUSSION:

A cooler, cleaner airmass will be in place through mid-week with generally Good levels of ozone and fine particulate. Weak upper-level systems bring scattered to isolated diurnal showers in the forecast Monday and again Tuesday. Otherwise, surface high pressure moving in keeps primarily dry, pleasant conditions in place. The next weather system is a cold front forecast to pass later Thursday into Friday.

 With a northerly wind in place mostly Good ozone and particulate is expected through Wednesday. Lighter winds in the morning may allow hourly fine particulate to reach low Moderate for a few hours in the southeast; however, daily averages should remain mostly Good. By Thursday, a warmer southwest flow returns ahead of the next system. Thursday has the best chance for Moderate ozone and/or fine particulate. At this time, I don’t foresee pollution reaching higher than Moderate, but if our thoughts on that change, we will update this forecast Wednesday. Clouds and precipitation by Friday should keep ozone Good while fine particulate may reach low Moderate in a few locations.

EXTENDED FORECAST:

Extended forecast models show high pressure and warming temperature by the end of the weekend, but showers and storms may return Monday. Considering the time of year, we will update this forecast Friday to better detail expected air quality conditions for the weekend into early next week.

FORECAST UPDATED BY STEPHANIE HENGESBACH: MONDAY, JUNE 14, 2021
NEXT FORECAST UPDATE: FRIDAY, JUNE 18, 2021

6/7/2021 Forecast Update

FORECAST SUMMARY:

MONDAY, JUNE 7, THROUGH MONDAY, JUNE 14, 2021

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good to Moderate through the forecast period.

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

FORECAST DISCUSSION:

The past weekend was a bit busy in terms of forecasting elevated ozone.  Mother Nature did share the pain throughout the state with West Michigan having the most impacted monitors on Friday, Southeast Michigan hit hardest on Saturday, and Seney in the U.P. was the lone high monitor on Sunday. 

This week will still have temperatures in the mid-80’s but we should not see much in the way of elevated ozone.  We can thank mostly overcast skies and frequent chances of precipitation to keep ozone levels in check for most of the work week.  Fine particulates, however, could still reach the Moderate levels as sunlight is not necessary for the growth of PM-2.5 particulates.

Right now, the long-range forecast is showing a warm front boundary over Michigan on Saturday followed by a cold front passage on Sunday.  This would clean out the atmosphere and start the next week in the Good category with cooler temperatures and less humidity.  As such, the chances for any pollutants reaching the USG levels during this forecast period are low and the next forecast is scheduled for next Monday.  Should conditions change we will update this forecast, as necessary.

EXTENDED FORECAST:

Air Quality should be mostly Good going into the next work week.

FORECAST UPDATED BY JIM HAYWOOD: MONDAY, JUNE 7, 2021
NEXT FORECAST UPDATE: MONDAY, JUNE 14, 2021