07/29/2022 Forecast Update

FORECAST SUMMARY: Monday, July 29th, 2022 through Sunday July 31st, 2022

OZONE: Ozone concentrations are expected to range from Good to Moderate range for the weekend.

PM-2.5: PM-2.5 concentrations are expected to range from Good to low-Moderate for the weekend.

FORECAST DISCUSSION:

The clear skies and warm, summer temperatures that Michigan will see today, Friday, will continue through the weekend as a High-pressure system slides to the east through Indiana and Ohio.

Winds during the weekend will predominantly be WSW before shifting to more southerly flow come Sunday afternoon. Thanks to the aforementioned High-pressure, skies will be clear of clouds providing ample sunlight. Upper-level temperatures are expected to be in the low-to-mid teens C for the weekend with upper-level winds WSW, similar to the lower-levels. In terms of air quality, there will be regional PM-2.5 concentrations throughout the weekend, but 24-hour averages will remain in the Good to low-Moderate range. As we have seen this past week, light low-level winds in the morning hours will allow PM-2.5 concentrations to buildup, but as the day carries on, and winds pick up, those concentrations will diminish.

Ozone was not an issue at all this past week and that trend looks to continue through the weekend. Although surface winds look to shift back to more southwesterly flow later on Sunday, the relatively clean airmass we will have going into Sunday should not pose a threat for Ozone development. Rather, Sunday looks to be a ramp up day for Ozone with Monday potentially having high Ozone concentrations develop. It is for this reason that this forecast will be updated on Sunday to see if Monday poses a threat for Ozone.

EXTENDED FORECAST:

Hot temperatures return next week with SW winds potentially creating a conducive environment for Ozone development. PM-2.5 looks to continue its trend of Good to low-Moderate.

Forecast updated by: Alec Kownacki, Friday July 29th, 2022
Next Forecast update: Sunday July 31st, 2022

07/25/2022 Forecast Update

FORECAST SUMMARY: Monday, July 25th, 2022 through Friday July 29th, 2022

OZONE: Ozone concentrations are expected to range from Good to Moderate most of the forecast period.

PM-2.5: PM-2.5 concentrations are expected to range from Good to low-Moderate for the forecast period.

FORECAST DISCUSSION:

Michigan begins the week with clear skies and pleasant surface temperatures in the 70s. This is caused by a High-pressure system lingering over the Great Lakes until Tuesday night when a frontal boundary comes through, providing a chance of rain for much of Michigan. Once the boundary passes through, another High-pressure system sets up to our west, returning conditions to relatively clear skies and warm surface temperatures through the end of the week.

.In terms of air quality, PM-2.5 concentrations look to remain in the Good to low-Moderate range for the forecast period. In the morning hours, light winds will allow some particulate buildup to occur but as the day carries on, and winds pick up, those concentrations should disperse. Ozone will be in the Good to Moderate range solely due to the wind direction we will see this week. As stated above, a High-pressure system lingers over us until Wednesday, which will keep winds predominantly westerly with some southerly winds. This will help inhibit Ozone development, although we will see ample sunlight in the coming days. Some models are showing winds over Lake Michigan having a SW component to them, so that may push some Ozone towards the shoreline, but overall 8-hour averages should remain Moderate. Any buildup that occurs will be cleaned out by the frontal boundary that comes through Tuesday evening into Wednesday. In the latter half of the week, NNW winds due to another High-pressure over the Great Lakes region helps to keep Ozone development at bay.

EXTENDED FORECAST:

The pleasant conditions carry into the weekend with Saturday mirroring Friday. As the High-pressure we’ll be under the end of this week exits the region, winds will shift to more southwesterly flow. This will increase the chances of Ozone developing come Sunday, thus another forecast update will be made Friday.

Forecast updated by: Alec Kownacki, Monday July 25th, 2022
Next Forecast update: Friday July 29th, 2022

07/22/2022 Forecast Update

FORECAST SUMMARY: Friday, July 22nd, 2022, through Monday, July 25th, 2022

OZONE: 8-hour average Ozone concentrations are expected to range from Good to Moderate most of the forecast period, but isolated USG is possible.

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

FORECAST DISCUSSION:

Warm conditions will end out the week as humidity levels increase Friday into Saturday. A shortwave passing through brings scattered storms Friday night/early Saturday, generally across the south. Clouds will decrease for a time Saturday but a stronger system approaching allows for more widespread precipitation Saturday night and continuing Sunday as a cold front crosses the state. Cooler and dryer weather can be expected by Monday as high pressure settles in from the northwest.

As for air quality, warm temperatures are in place Friday. Surface winds are generally west to southwest, but upper-level flow is more northwesterly. While we anticipate an uptick in ozone levels, reading should remain in the Good to Moderate range. The best chance for scattered low-end USG readings will be along the west Michigan lakeshore. Clouds increase later Friday ahead of the storms which pass overnight. Storms pull away and clouds start the day Saturday, but skies do clear out for a time late morning/early afternoon before increasing again later in the day. Temperatures, wind flow, and humidity levels are conducive for ozone; however, we don’t feel skies will be clear long enough to allow for elevated ozone to develop. If parts of the state end up with more sunshine than expected, a low-end USG may occur with the best chances again being along the western lakeshore. Clouds and precipitation should allow for mostly Good ozone Sunday.

Without a period of stagnation, fine particulate levels should remain in check over the forecast period. A mix of Good to Moderates can be expected Friday through Sunday.

EXTENDED FORECAST:

Cooler conditions after the Sunday front brings in cooler and cleaner air for early next week. Air quality should range generally Good Monday into Tuesday.

Forecast updated by: Stephanie Hengesbach: Friday, July 22nd, 2022
Next Forecast update: Monday, July 25th, 2022

07/22/2022 Forecast Update

FORECAST SUMMARY: Friday, July 22nd, 2022, through Monday, July 25th, 2022

OZONE: 8-hour average Ozone concentrations are expected to range from Good to Moderate most of the forecast period, but isolated USG is possible.

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

FORECAST DISCUSSION:

Warm conditions will end out the week as humidity levels increase Friday into Saturday. A shortwave passing through brings scattered storms Friday night/early Saturday, generally across the south. Clouds will decrease for a time Saturday but a stronger system approaching allows for more widespread precipitation Saturday night and continuing Sunday as a cold front crosses the state. Cooler and dryer weather can be expected by Monday as high pressure settles in from the northwest.

As for air quality, warm temperatures are in place Friday. Surface winds are generally west to southwest, but upper-level flow is more northwesterly. While we anticipate an uptick in ozone levels, reading should remain in the Good to Moderate range. The best chance for scattered low-end USG readings will be along the west Michigan lakeshore. Clouds increase later Friday ahead of the storms which pass overnight. Storms pull away and clouds start the day Saturday, but skies do clear out for a time late morning/early afternoon before increasing again later in the day. Temperatures, wind flow, and humidity levels are conducive for ozone; however, we don’t feel skies will be clear long enough to allow for elevated ozone to develop. If parts of the state end up with more sunshine than expected, a low-end USG may occur with the best chances again being along the western lakeshore. Clouds and precipitation should allow for mostly Good ozone Sunday.

Without a period of stagnation, fine particulate levels should remain in check over the forecast period. A mix of Good to Moderates can be expected Friday through Sunday.

EXTENDED FORECAST:

Cooler conditions after the Sunday front brings in cooler and cleaner air for early next week. Air quality should range generally Good Monday into Tuesday.

Forecast updated by: Stephanie Hengesbach: Friday, July 22st, 2022
Next Forecast update: Monday, July 25th, 2022

07/21/2022 Forecast Update

FORECAST SUMMARY: Thursday, July 21st, 2022, through Friday, July 22nd, 2022

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

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

FORECAST DISCUSSION:

A low-pressure area travels from eastern Iowa Thursday to just east of Detroit Friday. Small chances for precipitation due to this system exists overnight Thursday across the south, but most locations will remain dry. For the weekend, an upper level low well north of Lake Superior will cause on and off upper-level systems to pass by with chances for storms; the greatest threat for precipitation looks to be later Saturday into Sunday.

As for air quality, generally west to northwesterly surface and upper-level winds remain through Friday with a good amount of sunshine. Warm temperatures also remain but expected winds are not the typical flow for increased ozone. Levels Thursday and Friday may increase but readings higher than Moderate are generally not expected. There is a chance an isolated monitor could hit low-end USG along the western lakeshore, but we do not feel the threat is enough to warrant an Action Day. By Saturday, weather conditions become a bit more uncertain. A system approaches bringing with it decent chances for precipitation, however, before it arrives, winds shift to the southwest and the question will be cloud cover. If sunny skies remain most of Saturday, increased ozone could be possible. We will do a forecast update tomorrow to get a better handle on expected conditions for Saturday.

Hourly fine particulate in the low Moderate range early Thursday is likely due to a light plume of smoke making its way to the surface. There has been a small increase in fine particulate due to this here in Michigan, but more significant increases have been reported south and west across parts of Illinois and Indiana. The plume was pushing south Thursday with improving conditions. West to northwesterly winds the next couple of days should keep daily concentrations of fine particulate mostly Good to low Moderate.

EXTENDED FORECAST:

A stronger boundary brings decent chances for storms later Saturday into Sunday. With increased clouds, precipitation, and cooler conditions after the boundary passes, elevated air quality conditions are not anticipated early next week.

Forecast updated by: Stephanie Hengesbach: Thursday, July 21st, 2022
Next Forecast update: Friday, July 22nd, 2022

07/19/2022 Forecast Update

FORECAST SUMMARY: Tuesday, July 19th, 2022, through Thursday, July 21st, 2022

OZONE: 8-hour average Ozone concentrations are expected range from Moderate to USG Tuesday with Good to Moderate readings the rest of the forecast period.

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

FORECAST DISCUSSION:

A frontal boundary positioned over northern Michigan brings clouds and chances for precipitation. Further south, high pressure dominates with plenty of sunshine and warm temperatures both at the surface and upper levels. This coupled with southwesterly winds and dew points in the low-middle 60s makes increased ozone a good possibility. Because of this, we have an Action Day in place for both west and southeastern portions of the state.

As Wednesday progresses, the boundary in the north tracks north as an associated cold front approaches from the west. This cold front brings increased clouds and chances for precipitation. Surface and upper-level temperatures will still be warm, but increased dew points close to the 70s, and more clouds, should hamper increases in ozone. There is a small chance a monitor or two in the far southwest may reach low-end USG, otherwise reading should not reach higher than Moderate.

There will not be much of a temperatures drop behind the front Thursday, but stronger northwesterly winds develop. Sunny skies will prevail, but we expect the northwesterly flow at the surface and upper levels to hamper ozone increases. Levels Thursday should range from Good to Moderate. Weak high pressure moves in Friday with winds turning back to the southwest. We feel conditions Friday warrant another look; therefore, this forecast will be updated Thursday to detail expected air quality conditions for Friday.

As for fine particulate, readings have been running between middle Good and low Moderate and we expect levels to continue in that range through mid-week. As the upper-level flow turns northwesterly Thursday smoke forecast maps show a smoke plume sinking south from Canada. Maps are keeping this thicker plume to our west over Minnesota, Wisconsin, and parts of western Illinois and Indiana. We felt this should be noted since if the plume pulls further east, we may see increased fine particulate due to smoke closer to the ground. Even with the increase, however, levels during the week should not reach higher than middle Moderate. At this time, we feel the plume will not do much to change expected ozone concentrations. If our thoughts on this changes, we will send out an updated forecast.

EXTENDED FORECAST:

Weekend forecast maps show a boundary positioned around southern Michigan with disturbances bringing on and off showers/storms for the weekend. If this pans out, air quality through early next week should stay between Good and Moderate.

Forecast updated by: Stephanie Hengesbach: Tuesday, July 19th, 2022
Next Forecast update: Thursday, July 21st, 2022

07/18/2022 Forecast Update

FORECAST SUMMARY: Monday, July 18th, 2022, through Tuesday, July 19th, 2022

OZONE: 8-hour average Ozone concentrations are expected range from Moderate to USG Monday and Tuesday.

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

FORECAST DISCUSSION:

A frontal boundary sinking south into northern portions of Michigan into Tuesday will bring clouds and chances for precipitation. Further south, high pressure dominates with northerly winds Monday changing to a south/southwesterly flow Tuesday. Surface and upper-level temperatures increase the next couple days and as southwesterly winds develop Tuesday; increased ozone becomes more likely. There is already an Action Day Advisory in place Monday for the southeastern portion of the state. We will continue the Action Day into Tuesday and will add to the Action Day locations in west Michigan as well.

The frontal boundary takes its time sinking south and depending on the timing, increased ozone in the southeast may continue into Wednesday. We will be issuing another forecast update Tuesday to determine if the Action Day will need to be extended in the southeast for Wednesday. At this time, it looks like cloud cover and high dew points will keep ozone from increasing above Moderate Wednesday across most of the state.

As for fine particulate, readings will likely increase towards mid-week with more widespread Moderates by Wednesday. Until then, readings will continue in the upper Good to low Moderate range.

EXTENDED FORECAST:

The cold front passes east by Thursday bringing in a dryer airmass; however, temperatures do not drop off much in its wake. Pollution levels will likely range from Good to Moderate towards the end of the workweek.

Forecast updated by: Stephanie Hengesbach: Monday, July 18th, 2022
Next Forecast update: Tuesday, July 19th, 2022

07/17/2022 Forecast Update

FORECAST SUMMARY: Sunday, July 17th, 2022, through Monday, July 18th, 2022

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

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

FORECAST DISCUSSION:

A storm system in northern Illinois will track northeast towards Ontario Monday. This system increases chances for precipitation Sunday into early Monday, especially across the south. Clouds decrease from west to east Monday, and a northwest wind flow will prevail. High pressure moves over Lower Michigan on Tuesday.

As for air quality, easterly winds and increased clouds keep both ozone and fine particulate in the Good to Moderate range Sunday. Decreasing clouds and warmer temperatures Monday could allow for increases in ozone, but northwesterly winds could work against levels increasing. Looking at smoke maps, a plume from fires in Canada sinks south over the region. While this plume looks to stay at upper levels, some maps do show a potential for the plume to make its way closer to the surface. While it is unlikely that we will see widespread increased ozone on Monday, there are some ingredients in place that make it a possibility, especially in the southeast. Fine particulate both Sunday and Monday will range from upper Good to low Moderate.

EXTENDED FORECAST:

Forecast models show high pressure Tuesday with southwesterly winds both at the surface and upper levels. Temperatures will also be increasing. Another forecast update will be issued on Monday to detail expected air quality conditions for the rest of the week.

Forecast updated by: Stephanie Hengesbach: Sunday, July 17th, 2022
Next Forecast update: Monday, July 18th, 2022

07/14/2022 Forecast Update

FORECAST SUMMARY: Thursday, July 14th, 2022, through Sunday, July 17th, 2022

OZONE: 8-hour average Ozone concentrations are expected to start Good phasing to Moderate by the end of the weekend.

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

FORECAST DISCUSSION:

Air Quality has been Good, this week, with favorable winds, cooler temperatures and low humidity.  Traditional summer weather returns for the weekend as winds shift southerly importing increased temperatures and humidity.  Cloud cover and rain shower potential look plentiful Friday night through Sunday which should eliminate elevated ozone potential.

Monday is not as certain with conflicting model results, especially in southeast Michigan.  Those model results range from southwest winds with clouds to northwest winds and clearing skies. As a result, the forecast will be updated on Sunday as it pertains to potential Monday ozone levels.

EXTENDED FORECAST:

Air Quality should be Moderate to begin the next work week.

Forecast updated by: Jim Haywood: Thursday, July 14, 2022
Next Forecast update: Sunday, July 17, 2022

07/11/2022 Forecast Update

FORECAST SUMMARY: Monday, July 11th, 2022, through Thursday, July 14th, 2022

OZONE: 8-hour average Ozone concentrations are expected to be Low Moderate to USG during Monday then mostly Good for the remainder of the forecast period.

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

FORECAST DISCUSSION:

An Air Quality Action Day remains in effect through Monday, July 11th, 2022 for the following counties in west Michigan:

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

Monday will prove to be the only day of concern during this forecast period.  An advancing cold front has placed the area under warm southwest winds with plenty of moisture.  As such, Action Day Advisories have been issued for the southern part of the western lakeshore and Southeast Michigan.  The major uncertainty in the forecast was the timing of the approaching cloud cover, especially in Southeast Michigan, which is more likely to stay clear longer into the day.

Once the advancing cold front passes Monday night, the remainder of the forecast period should be pleasant with northerly wind flow, mostly sunny skies, low dew points, and temperatures in the low 80’s.

The next chance of elevated ozone levels comes Friday or Saturday when the winds turn southerly, again, in advance of a late weekend cold front.  While it does not yet look like a slam dunk for elevated ozone, it definitely warrants a serious look and re-evaluation later in the week.

EXTENDED FORECAST:

Air Quality should be mostly Good to begin the next work week.

Forecast updated by: Jim Haywood: Monday, July 11, 2022
Next Forecast update: Thursday, July 14, 2022

07/10/2022 Forecast Update

FORECAST SUMMARY: Sunday July 10th, 2022, through Monday July 11th, 2022

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

PM-2.5: PM-2.5 concentrations are expected to range from Good to low-Moderate. 

FORECAST DISCUSSION:

Today, Sunday, continues the trend of this weekend with sunny skies and warm temperatures. This trend somewhat comes to an end tomorrow as winds shift to the southwest and surface temperatures increase slightly. Dewpoint temperatures hang around the low-60s F range for most of the day. Upper-level temperatures for southern Michigan are predicted to be in the upper-teens C with upper-level winds being mostly westerly.

It is for these reasons an Air Quality Action Day is being called for the counties listed above. USG-level Ozone is expected to impact Lake Michigan lakeshore counties due to warm temperatures, both surface and upper-level, and southwest winds. Southeast Michigan will be impacted as well by another Ozone plume due to the warming temperatures and southwest winds. The amount of clouds will play a big role in the development of Ozone tomorrow. Most models are showing a good amount of clouds for the majority of the state tomorrow afternoon. However, some Ozone is expected to develop with morning and early afternoon sunlight. 

EXTENDED FORECAST:

A cold front is expected to impact Michigan going into Tuesday morning which will drop surface temperatures down to the mid-70s F. This front will help clean out any concentrations buildup and result in Good air quality.

Forecast updated by: Alec Kownacki, Sunday July 10th, 2022
Next Forecast update: Monday July 11th, 2022

07/08/2022 Forecast Update

FORECAST SUMMARY: Friday July 8th, 2022, through Sunday July 10th, 2022

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

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

FORECAST DISCUSSION:

There is a chance of rain showers this afternoon and evening for southern Michigan with areas in northern Michigan remaining dry. Once the rain exits the area, a High-pressure system positions itself over the western Upper Peninsula on Saturday until it slides to the south over the Saginaw Bay region Sunday morning. This will result in relatively clear skies and light winds for the majority of the weekend. With the High-pressure in place, surface winds will predominately be from the northeast with surface temperatures ranging from the upper-70s to low-80s F. Upper-level winds appear to be from the northeast as well with upper-level temperatures in the low-teens C.

In terms of air quality, as stated earlier in the week, regional PM-2.5 concentrations hang around, but concentrations should not reach anything higher than the low-Moderate range. Light winds in the morning hours will cause a buildup in concentrations but those will slowly dissipate as each day carries on. Ozone is not predicted to be an issue this weekend with the help of northeast winds and cooler upper-level temperatures. Ozone development looks to be a potential issue come Monday as a warm front comes through, shifting winds to the southwest. That is why this forecast is made out to Sunday, with an updated forecast for Monday coming Sunday morning.

EXTENDED FORECAST:

As stated above, a slight warmup is predicted for Monday with winds shifting to the southwest, so the forecast will be updated Sunday morning.

Forecast updated by: Alec Kownacki, Tuesday July 8th, 2022
Next Forecast update: Sunday July 10th, 2022

07/05/2022 Forecast Update

FORECAST SUMMARY: Tuesday July 5th, 2022, through Friday July 8th, 2022

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

PM-2.5: PM-2.5 concentrations are expected to range from Good to low-Moderate throughout the forecast period.

FORECAST DISCUSSION:

Many areas in Michigan woke up to rain and clouds this Tuesday morning with clouds looking to persist throughout the day today. In fact, there looks to be intermittent cloudiness throughout the entire forecast period, which is a change of pace from the relatively sunny skies Michigan had this past holiday weekend. A cold front slides in from the north today which will drop temperatures to the upper-70s to low-80s for the remainder of the week. The front will also shift winds from southwesterly flow to more easterly flow with intermittent northeast and southeast winds throughout the week. Dewpoint temperatures hang around the low-to-mid 60s for much of southern Michigan for the week which will initiate some potential rain showers Wednesday into Thursday, but those will be short-lived, if they even occur.

In terms of air quality, left over PM concentrations from 4th of July festivities are hanging around the area but as the front moves through, those concentrations are expected to clean out. According to some models, regional PM concentrations look to be present throughout the week, but those concentrations will be in the low-Moderate range. After a few days of relatively high Ozone this past weekend, ample clouds and easterly winds look to keep Ozone development at bay this week. Winds over Lake Michigan are expected to have a northerly component to them as well, so this will help hinder Ozone building up over the lake and reaching the west Michigan shoreline. Also, the frontal system coming through later today will help to clean out any concentration buildup. Due to the time of year and the potential for some sunlight peeking through this week, Ozone concentrations are expected to reach the Moderate range, however.

EXTENDED FORECAST:

A cold front looks to push through later this week and sets up a High-pressure system over the Great Lakes region for the weekend. Air quality concentrations look to remain in the Good to Moderate range.

Forecast updated by: Alec Kownacki, Tuesday July 5th, 2022
Next Forecast update: Friday July 8th, 2022

07/01/2022 Forecast Update

FORECAST SUMMARY: Friday, July 1st through Tuesday, July 5th, 2022

OZONE: 8-hour average Ozone concentrations are expected to generally range from Good to Moderate through the holiday weekend; isolated USG is possible Sunday.

PM-2.5: 24-hour average Fine Particulate will primarily range from upper Good to middle Moderate, however, expect elevated hourly readings of USG or possibly higher during the late evening/early overnight hours in locations with fireworks displays.

FORECAST DISCUSSION:

A frontal boundary Friday continues traveling southeast through the state with chances for precipitation across the southeast as it moves through. Conditions dry out Saturday and Sunday as high pressure dominates the region. Another boundary moves in on July 4th bringing possible precipitation later in the day.

As for air quality, winds switching to the northwest after the fontal passage Friday will help keep ozone generally Good, however, the later frontal passage in the southeast may allow for Moderate ozone there. High pressure to our west Saturday produces north/northwesterly winds. This flow will help keep pollution levels from increasing. A few locations may experience Moderate ozone, but that should not be widespread. By Sunday, high pressure settles more overhead and light winds become southerly later in the day. Seasonable temperatures will be in place, but upper-level temperatures do not increase significantly. There is a chance an isolated monitor or two could reach low-end USG, but we expect most locations to be Moderate. By July 4th, a frontal boundary is sinking in from the northwest. Increasing clouds and chances for precipitation later in the day should keep ozone from reaching higher than Moderate.

Now for fine particulate, with it being the July 4th weekend we do expect the usual spikes in fine particulate with hourly readings well into the USG range during the late evening/early overnight hours in locations with fireworks displays. The days for the increases will vary depending on when areas have fireworks scheduled. Without a prolonged period of stagnation forecast through Monday, high hourlies should improve bringing daily averages of fine particulate closer to the Moderate range.

EXTENDED FORECAST:

Extended forecast models show a front passing by late Monday/early Tuesday. This should keep pollution levels from increasing higher than Good to low-Moderate as we move towards mid-week.

Forecast updated by: Stephanie M. Hengesbach: Friday, July 1, 2022
Next Forecast update: Tuesday, July 5, 2022

06/29/2022 Forecast Update

FORECAST SUMMARY: Wednesday, June 29th, 2022, through Friday, July 1st, 2022

OZONE: 8-hour average Ozone concentrations are expected to be mostly Moderate Wednesday and Thursday except for possible USG levels Thursday in West Michigan. Friday should have readings ranging from Good to Moderate.

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

FORECAST DISCUSSION:

A weak front brought precipitation early Wednesday across parts of the state. This boundary sinks south into northern Indiana and Ohio before lifting back north as a warm front early Thursday. Precipitation ends and clouds dissipate as Wednesday progresses and as the front lifts back north on Thursday, we can expect warm temperatures and increased humidity to return. Precipitation chances do make its way back into the forecast late Thursday into Friday as a cold front travels from northwest to southeast through the state.

As for air quality, light winds with a northerly to westerly component should hamper ozone development Wednesday with readings ranging from Good to Moderate. On Thursday, warm south/southwesterly winds at both the surface and upper levels develop. This coupled with amble sunshine and dew points in the low 60s makes a good set up for ozone, especially in west Michigan. Because of this, we have an Action Day in place Thursday for the counties we feel have the highest threat for USG levels of ozone. While there is a small chance a monitor may reach USG in the southeast, the stronger southwest winds in that portion of the state should hamper ozone from increasing significantly; therefore, we will forecast Moderate for that portion of the state.

Clouds will be more prevalent Friday and chances for precipitation develop as a cold front sinks in from the northwest. Southern portions of the state that experience more sunshine due to the later frontal passage may reach middle to upper Moderate for ozone, otherwise, reading should be Good to low Moderate. Without a prolonged stagnation setup expected the next few days, PM2.5 during the period should range from middle Good to low Moderate.

EXTENDED FORECAST:

After a cold front passes Friday, extended forecast models show primarily dry conditions for the coming weekend. What is uncertain at this point is a system that may bring rain by the July 4th holiday. With the uncertainty in the forecast, we will do a Friday update to get a better handle on weather conditions, and in turn air quality conditions, for the weekend into the July 4th holiday.

Forecast updated by: Stephanie M. Hengesbach: Monday, June 29, 2022
Next Forecast update: Friday, July 1st, 2022

06/27/2022 Forecast Update

FORECAST SUMMARY: Monday, June 27th, 2022, through Wednesday, June 29th, 2022

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

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

FORECAST DISCUSSION:

Cool high pressure dominates Monday allowing for Good pollution levels across the state. As the high settles further east Tuesday, southwesterly winds develop and surface temperatures warm; however, cooler upper-level readings will keep ozone from reaching higher than Moderate. A weak frontal boundary drops over the state Wednesday which seems to dissipate over the area. Not much precipitation will be associated with the front but clouds earlier in the day and northwesterly winds later in the day should keep ozone from reaching higher than Moderate. Fine particulate Wednesday will range between upper Good and low Moderate.

The next chance for increased ozone comes into play Thursday. By then, high pressure will be east of the region and both surface and upper level flow turns southwesterly. Along with that, temperatures and dew points reach levels more common for ozone development. Clouds may be moving in from the north during the day, but with it being a few days out, we feel another look is warranted. We will be doing a forecast update Wednesday morning to better detail expected pollution levels for Thursday and into the coming July 4th weekend.

EXTENDED FORECAST:

After a cold front passes Friday, extended forecast models show primarily dry conditions for the coming weekend. While at this time a weather setup conducive for ozone development does not seem probable, along with the Wednesday update, another forecast update will likely be done Friday to detail conditions through the coming holiday.

Forecast updated by: Stephanie M. Hengesbach: Monday, June 27, 2022
Next Forecast update: Wednesday, June 29th, 2022

06/24/2022 Forecast Update

FORECAST SUMMARY: Friday, June 24th, 2022, through Monday, June 27th, 2022

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good to Moderate, statewide, on Friday.  Saturday will be mostly Moderate on the West Side of the state. A clean-out occurs on Sunday.

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

FORECAST DISCUSSION:

Pleasant summer weather continues into Friday as we start the day with a clean air mass. We will see a slow creep in ozone concentrations, during the day, as high pressure slips to the east and winds swing around to the south. We anticipate that the shifting winds will keep the worst of the forming ozone plume over Lake Michigan pushed to the west side of the lake. Wisconsin, Illinois and Northwest Indiana have responded by calling Action Days in their states.

Michigan should be spared from the higher concentrations along the lakeshore as the shifting winds keep most of the higher elevations away from our lakeshore. Low dew points will also help slow ozone formation. There is a slight possibility that an isolated pocket of higher ozone could reach an isolated monitor with the lake breeze, but that possibility is fairly remote.

The dynamics change Saturday. An advancing cold front should provide enough cloud cover to keep West Michigan ozone in check. 

The advancing cold front should pass through the rest of the state, during Sunday, cleaning out any remaining dirty air. Cooler, cleaner air will flow into the region for the beginning of the next work week.

EXTENDED FORECAST:

Air Quality should be mostly Good to begin the next work week.

Forecast updated by: Jim Haywood: Friday, June 24, 2022
Next Forecast update: Monday, June 27, 2022

06/23/2022 Forecast Update

FORECAST SUMMARY: Thursday, June 23rd, 2022, through Friday, June 24th, 2022

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good on Thursday transitioning to Moderate on Friday. There is a slight chance of an isolated USG along the lakeshore, during Friday.

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

FORECAST DISCUSSION:

Thursday looks to be an ideal summer day with sunny skies, lower temperatures, and low humidity.  Air Quality is currently very clean across the state.

We will be under the same air mass as we start the day Friday morning.  As the high-pressure drifts eastward, winds will return to a southwesterly direction.  The surface winds will be the first to switch back to the southwest in the morning followed by the upper air winds early in the afternoon. 

During this wind shift, the models are being pretty consistent moving the ozone plume over the lake more towards the Wisconsin side and they have responded by issuing an Action Day for Friday.  Chances appear to be low for our lakeshore to be adversely affected on Friday.  This can be attributed to starting with a clean base, low dewpoints, and winds not becoming problematic until later in the day.

That said, we are still under the strongest solar radiation period of the year with the longest hours of daylight.  Winds will be light, meaning we will have an afternoon lake breeze along the shore.  As such, there is the possibility that an isolated monitor could see some elevated ozone although that possibility is slight for Friday. 

The forecast will be updated on Friday morning.   Once we get past Saturday, a cold front will clean the air and start the new week with cooler, dryer conditions.

EXTENDED FORECAST:

Air Quality should be mostly Good to begin the next work week.

Forecast updated by: Jim Haywood: Thursday, June 23, 2022
Next Forecast update: Friday, June 24, 2022

06/21/2022 Forecast Update

FORECAST SUMMARY: Tuesday, June 21st, 2022, through Thursday, June 23rd, 2022

OZONE: 8-hour average Ozone concentrations are expected to be USG to Unhealthy on Tuesday in West Michigan with SE Michigan staying mostly in the High Moderate range. Wednesday and Thursday should be a mix of Good to Moderate.

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

AN AIR QUALITY ACTION DAY ADVISORY REMAINS IN EFFECT FOR TUESDAY, JUNE 21ST FOR THE FOLLOWING COUNTIES…

IN WEST MICHIGAN:

ALLEGAN…BERRIEN…CASS… KENT… MASON…MUSKEGON…OCEANA…OTTAWA… VAN BUREN COUNTIES

FORECAST DISCUSSION:

The West Michigan Action Day forecast for Monday was spot-on.  All of the West Michigan monitors exceeded the 8-hour average 70 ppb threshold for USG with six of those monitors reaching the Unhealthy category.  Unfortunately, this episode will almost certainly continue through Tuesday as the Action Day remains in effect. 

Fine Particulates have remained in check, during this episode, and should continue to do so during the Tuesday Action Day.

This episode will end after a cold front sweeps through the state, Wednesday morning.  While we will see a clean-out in terms of Air Quality, temperatures will still be running on the hotter side with daily highs in the upper 80’s.

Winds look to swing back to the southwest during Friday.  With the long periods of daylight and strong solar radiation, this could pose a concern for Air Quality.  As a result, the forecast will be updated on Thursday morning.  Hopefully, this would only be one day of concern as Saturday looks to be mostly cloudy and another cold front sweeps through on Sunday with cooler weather to follow.

EXTENDED FORECAST:

The warm temperatures and sunny skies look to stick around for the next couple of days. Air quality will be monitored throughout the week.

Forecast updated by: Jim Haywood: Tuesday, June 21, 2022
Next Forecast update: Thursday, June 23, 2022

06/20/2022 Forecast Update

FORECAST SUMMARY: Monday, June 20th, 2022, through Tuesday, June 21st, 2022

OZONE: Ozone concentrations are expected to be in the Moderate range with USG-levels in West Michigan.

PM-2.5: PM-2.5 concentrations are expected to range from Good to low-Moderate. 

…AIR QUALITY ACTION DAY ADVISORY FOR MONDAY, JUNE 20TH AND TUESDAY, JUNE 21ST FOR THE FOLLOWING COUNTIES…

IN WEST MICHIGAN:

ALLEGAN…BERRIEN…CASS… KENT… MASON…MUSKEGON…OCEANA…OTTAWA… VAN BUREN COUNTIES

FORECAST DISCUSSION:

Along with an increase in surface temperatures, winds shift to southwesterly flow Monday morning and stay that way through Tuesday. These winds, along with a warm front, will bring warmer temperatures Tuesday with highs reaching the mid-90s F.

In terms of air quality, West Michigan counties are expected to reach USG-level Ozone concentrations for Monday and Tuesday. Surface winds coming from the southwest, mostly clear skies, surface temperatures in the upper-80s F to mid-90s F, and upper-level temperatures hovering around the low-20s C are all reasons behind the forecasted Ozone development.

Monday update: As of Monday, June 20th, the forecast looks to remain the same from Sunday morning. West Michigan is expected to receive USG-level Ozone concentrations as high surface temperatures return along with relatively clear skies and southwest winds. There was uncertainty Sunday morning about how southeast Michigan would fare with Ozone on Tuesday. As the day progresses on Tuesday, winds look to shift to more westerly flow which should help hinder high Ozone concentrations to form in that area.

PM-2.5 concentrations look to remain in the Good to Moderate range.

EXTENDED FORECAST:

The warm temperatures and sunny skies look to stick around for the next couple of days. Air quality will be monitored throughout the week.

Forecast updated by: Alec Kownacki, Monday, June 20th, 2022.
Next Forecast update: Tuesday, June 21st, 2022.