9/2/2022 Forecast Update

FORECAST SUMMARY: Friday, September 2nd, 2022, through Tuesday, September 6th, 2022

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

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

FORECAST DISCUSSION

Surface high pressure holds on for most of Friday, but a frontal boundary is forecast to track northwest to southeast through the state later Friday into Saturday. Precipitation with this boundary will be scattered in nature so Saturday will not be a washout. Cooler temperatures move in Sunday and Monday as high pressure settles in from the northwest.

As for air quality, warm conditions at the surface and upper levels Friday and Saturday make increased ozone a possibility; however, cloud cover in more pronounced which will hamper development. Generally Moderate ozone is anticipated both days. Warmer conditions and southerly winds ahead of the frontal boundary could increase fine particulate into the Moderate range as well. Northerly winds Sunday into the Labor Day holiday should keep air quality mostly Good.

EXTENDED FORECAST:

Extended models show generally dry conditions into Tuesday with temperatures increasing on southerly winds. While significant increases in pollution is not anticipated, ozone and/or fine particulate may rise back into the Moderate range.

Forecast updated by Stephanie Hengesbach: Friday, September 2nd, 2022

Next forecast update: Tuesday, September 6th, 2022

9/1/2022 Forecast Update

FORECAST SUMMARY: Thursday, September 1st, 2022, through Friday, September 2nd, 2022

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

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

FORECAST DISCUSSION

High pressure dominating conditions will produce plenty of sunshine for the end of the workweek. Along with sunny skies, temperatures increase into the 80s across most of the region. Lighter winds Thursday pick up some from the south/southwest Friday as the high slides east of the region. With the warmer conditions comes an uptick in air quality levels.

As for air quality, we are coming off a low background so while increases in ozone are anticipated, 8-hour averages are not expected to reach higher than Moderate Thursday. Winds switch to more of a southerly component Friday; however, models are not showing significant rises in ozone. Also, we are in the later portion of the season where UGS ozone is less common. While there is always a chance an isolated monitor may reach low-end USG, Moderate readings are more likely. An increase in fine particulate is also possible with Good levels increasing to more widespread Moderates by Friday.

There is some question on a boundary sinking in late in the week that may or may not bring precipitation. We will do another update Friday to further detail air quality conditions for the Labor Day weekend.

EXTENDED FORECAST:

Extended models show warm conditions continuing into the Labor Day holiday. What is uncertain is precipitation chances, but at this time it doesn’t not look like widespread precipitation is expected. Air quality will likely range mostly Moderate into early next week.

Forecast updated by Stephanie Hengesbach: Thursday, September 1st, 2022

Next forecast update: Friday, September 2nd, 2022

8/29/2022 Forecast Update

FORECAST SUMMARY: Monday, August 29th, 2022, through Thursday, September 1st, 2022

OZONE: : 8-hour average Ozone concentrations are expected to range mostly Good to low-Moderate towards the end of the forecast period.

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

FORECAST DISCUSSION

A cold front passing west to east through the state Monday will bring showers, storms, and a west/northwesterly wind in its wake. Conditions dry out Tuesday with high pressure producing seasonable conditions through midweek. High pressure is positioned east of the state by Friday with high temperatures warming around 80 degrees.

As for air quality, clouds and storms will keep air quality Good Monday. This Good trend should continue into midweek thanks to a westerly/northwesterly flow at the surface and upper levels, coupled with cooler/seasonable temperatures. By Friday, southerly winds develop, and surface and upper-level temperatures increase. Without an airmass change, rises in ozone and/or fine particulate are likely. At this time readings higher than Moderate are not expected; however, the forecast will be evaluated again Thursday to get a better handle on air quality conditions for Friday into the coming Holiday weekend.

EXTENDED FORECAST:

Extended models show a weak boundary passing later Friday/early Saturday; however, not much precipitation is associated with the system. At this time a generally dry weekend is anticipated, and warming temperatures could allow for increased pollution.

Forecast updated by Stephanie Hengesbach: Monday, August 29th, 2022

Next forecast update: Thursday, September 1st, 2022

8/26/2022 Forecast Update

FORECAST SUMMARY: Friday August 26, 2022, through Monday August 29, 2022

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

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

FORECAST DISCUSSION

The Monday forecast was concerned with the potential for elevated ozone during the weekend.  That concern has been greatly reduced with the latest round of model runs.

Following an overnight frontal passage, Friday should provide clearing skies under northerly winds and Good Air Quality as high pressure moves over the state.  That trend should continue through Saturday with clear skies and pleasant weather. 

As the high pressure moves off during Sunday, we should see winds shift from southeast to southerly.  An advancing trough of low pressure will generate increasing cloudiness from west to east during the day.  With the shorter hours of sunlight, that should be enough to reduce the risk of elevated ozone although we will probably get into the Moderate range in Southeast Michigan. 

As that front continues to approach during Monday, showers and thunderstorms become more likely and the potential for heavy rains increase.  Air Quality should remain Good during this time.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Friday, August 26, 2022

Next forecast update: Monday, August 29, 2022

8/22/2022 Forecast Update

FORECAST SUMMARY: Monday August 22, 2022, through Friday August 26, 2022

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

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

FORECAST DISCUSSION

With high pressure continuing to move into the area on Monday, a mostly quieter, drier, and slightly warmer weather pattern will prevail over the next couple of days.  Prevailing northerly winds should keep our Air Quality Good through Tuesday.  By Wednesday, increasing temperatures will range from lower-80s to mid-80s.  Coupled with the dew points in the lower 60s and mostly clear skies, it will make for some pretty nice weather.  However, nearly calm winds could allow for some urban areas to see ozone increases into the Moderate range.

By Thursday, a cool front will bring slightly cooler temperatures and increased chances for showers and few thunderstorms on Thursday through Thursday night.  Another, ridge of high pressure begins to move into the region Friday bringing a return to drier and slightly warmer weather for the area for the weekend.

Along with the predicted warmer weather, the models are showing a return to good southern flow and the potential for some elevated ozone if the skies remain clear during the weekend.  The cloud models are not consistent, at this time, so I will be reviewing and updating this forecast on Friday.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Monday, August 22, 2022

Next forecast update: Friday, August 26, 2022

8/19/2022 Forecast Update

FORECAST SUMMARY: Friday August 19th, 2022, through Monday August 22nd, 2022

 

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 Good to low-Moderate range.

FORECAST DISCUSSION:

The pleasant weather conditions Michigan has had all week will carry into the weekend with a chance of spotty rain showers for areas across the state. Saturday looks to have surface temperatures ranging from the mid-70s to mid-80s the more south you go. Winds will be dependent upon the impending Low-pressure and associated cold front that will drift across the state early Sunday. On Saturday, winds will predominantly be southerly but become more mixed as the Low-pressure approaches and they eventually become more northerly as we get into Sunday afternoon. As stated above, the rain will be spotty across Michigan, with the majority of the rain occurring overnight into Sunday morning. There will be some left-over rain on Monday, but we eventually dry out as Monday carries on.

In terms of air quality, more of the same when it comes to PM-2.5 concentrations. Light early-morning winds will cause a buildup in concentrations that will slowly dissipate as mid-day winds pick up. For Ozone, aside from the rain hindering development, unfavorable winds for Ozone development will be present for the majority of the weekend. There will be some hours on both Saturday and Sunday where winds shift to more SW flow, which is favorable for Ozone, but it will not be long enough to build up concentrations here in Michigan. As stated above, the spotty rain showers will help keep concentrations at bay for both Ozone and PM-2.5 and will also help to clean out any build up.

EXTENDED FORECAST:

Air quality looks to remain in the Good range as we start the next work week.

Next Forecast update: Monday August 22nd, 2022

8/15/2022 Forecast Update

FORECAST SUMMARY: Monday August 15th, 2022, through August 19th, 2022

 

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

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

FORECAST DISCUSSION:

The pleasant weather Michigan experienced this past weekend looks to continue as we start off this mid-August week. For the majority of this week, surface temperatures hang around the 70s with southern Michigan eclipsing the 80-degree mark on some days. We also look to remain dry as High-pressure helps to keep rain chances at bay. The High-pressure also causes surface winds to predominately have an eastern component to them. Throughout the week, winds will shift from northeasterly to southeasterly, but as stated, will mainly be easterly. Upper-level winds mirror surface-level winds with northeasterly and southeasterly flow along with upper-level temperatures in the low teens for much of the week.

 In terms of air quality, PM-2.5 concentrations will not be of concern this week. With light morning winds, however, concentrations will build up due to morning commute activity. As the day carries on, those concentration will dissipate as winds pick up. For Ozone, although this week will be rather sunny, winds shifting from northeasterly to southeasterly will keep Ozone precursors at bay and will diminish the threat of Ozone development substantially. Also, cooler upper-level temperatures will lower the already small threat of Ozone developing. 

EXTENDED FORECAST:

As we go into the weekend, rain chances increase slightly with a few Low-pressure systems entering and exiting the area. This will help keep air quality in the Good category.

Next Forecast update: Friday August 19th, 2022

8/12/2022 Forecast Update

FORECAST SUMMARY: Friday, August 12th, 2022, through Monday, August 15th, 2022

 

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

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

FORECAST DISCUSSION:

High pressure settled over Lake Michigan Friday morning is allowing for light to northerly winds, plenty of sunshine, and comfortable temperatures. The next storm system passing just southwest of the state will increase clouds late Friday into Saturday with precipitation chances increasing from northwest to southeast as Saturday progresses. Precipitation may linger into Sunday but high pressure moving back into the region should decrease clouds later in the day. High pressure dominates early in the workweek with sunshine and seasonable temperatures.

As for air quality, aside from a monitor or two in the southeast with low end Moderate fine particulate and/or ozone, pollution levels have been in the Good range this week. Abundant sunshine can be expected Friday; however, lower surface and upper-level temperatures along with a light northerly wind will keep air quality mostly Good. The clouds and precipitation expected Saturday will keep the mostly Good air quality trend going, which will likely extend into Sunday with cooler temperatures, southeasterly winds, and clouds most of the day. Sunshine returns Monday thanks to high pressure moving back in and seasonable temperatures can be expected. Winds at the surface and upper levels should have an easterly to northeasterly component; therefore, the trend of generally Good air quality is expected to continue.

EXTENDED FORECAST:

Extended models show dry conditions as we progress towards mid-week but then an upper-level system may move into the region bringing scattered precipitation into the forecast. Based on current forecast maps the potential for increased pollution next week doesn’t seem likely, but this forecast will be updated Monday to get a better handle on air quality as we move into mid-August.

Next Forecast update: Monday, August 15th, 2022

8/08/2022

FORECAST SUMMARY: Monday, August 8th, 2022, through Friday, August 12th, 2022

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

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

FORECAST DISCUSSION:

A low-pressure area and associated boundary bring clouds and chances for precipitation Monday. With plenty of moisture in the lower atmosphere, precipitation could be heavy at times into early Tuesday morning. Skies clear out Tuesday as the boundary travels east and high pressure moves in. Another weak boundary passing late Wednesday into Thursday could cause scattered precipitation, but this looks to be a dry front so most locations will not see precipitation. High pressure settles back in from the northwest allowing for dry and comfortable conditions through the end of the workweek.

As for air quality, clouds, high dew points, and precipitation chances hamper ozone development Monday. A monitor in the south may reach low-Moderate but most locations remain Good. Cooler surface and upper-level temperatures, coupled with a northerly wind, will keep generally Good ozone around Tuesday. Temperatures make a short-lived rebound Wednesday ahead of the boundary forecast to pass by; however, upper-level winds remain calm to northwesterly which isn’t conducive for ozone development. Moderate levels may be seen Wednesday but cooler air moving in from the northwest behind the boundary allows for mostly Good ozone Thursday and Friday.

Fine particulate has been mostly Good the past few days and with systems moving through and northerly winds being reinforced every couple of days, this trend is expected to continue.

EXTENDED FORECAST:

Extended models show dry conditions for the coming weekend and a continuation of comfortable temperatures. While an outbreak of high pollution is not anticipated, winds may turn more southerly late in the period. Sunny conditions also remain, so this may be our next chance for an increase in pollution. We will evaluate forecast maps Friday and submit an update then detailing air quality conditions through the weekend into early next week.

Next Forecast update: Friday, August 12th, 2022

8/5/2022 Forecast Update

FORECAST SUMMARY: Friday August 5, 2022, through Monday August 8, 2022

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

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

FORECAST DISCUSSION

The cold front that moved through two nights ago has been slowly moving south and is stretched along the Michigan/Indiana/Ohio border this morning. Models show that it will move south and east through the day, which should move morning moisture out of the region by the late afternoon.

Mainly quiet weather is expected on Saturday with hot temperatures that look to climb into the upper 80s and low 90s during the afternoon.  Southwesterly low-level winds will continue to import a very moist airmass into the Great Lakes over the weekend.  Dew point temperatures are expected to be in the low 70’s.  Models have been consistent showing ozone production staying in check throughout Michigan keep conditions in the Moderate range

On Sunday, an approaching cold front is expected to swing down into the Great Lakes, potentially stalling across the area raising potential precipitation values across the warm sector ahead of the cold front around two inches and perhaps well above this.

The chance for locally heavy rainfall may continue into Monday morning across parts of the area.  Most of the rain is expected to end by Monday afternoon/evening as the cold front swings south of the area.  Behind this system, surface high pressure builds into the Great Lakes and looks to remain in place for most of next week, helping to keep the chance for precipitation low.  Otherwise, highs in the low to mid 80s are expected through next week.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Friday, August 5, 2022

Next forecast update: Monday, August 8, 2022

8/1/2022 Forecast Update

FORECAST SUMMARY: Monday August 1, 2022, through Friday August 5, 2022

OZONE: 8-hour average Ozone concentrations are expected to be Good to Low Moderate during the work week.

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

FORECAST DISCUSSION

We begin August under mostly cloudy skies and a threat of rain. A cold front will be dropping through the state, during the course of Monday. Rain and storm potential look to increase from west to east during Monday afternoon with Air Quality remaining mostly Good throughout the state. A secondary front, mostly unnoticed, will drop through the state later this evening.

Clearing skies will following during Tuesday as high pressure moves overhead with continued Good Air Quality.

Wednesday had been previously predicted to be a hot day with potential Air Quality issues. However, the more recent models are showing that while it will still warm up and be very humid, it will not be as hot as originally predicted. There will be a lot of moisture in the air and some of the models are showing up to 2 inches of rain are possible during Wednesday. That should remove any threat of elevated ozone.

Following the passage of the Wednesday front, the remainder of the work week should be clear with favorable winds for Good Air Quality. The models are currently predicting a return to southerly wind and mostly sunny skies for Saturday. As such, I will revisit this forecast on Friday for the latest predictions of weekend Air Quality.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Monday, August 1, 2022

Next forecast update: Friday, August 5, 2022

07/31/2022 Forecast Update

FORECAST SUMMARY: Sunday, July 31st, 2022 through Monday August 1st, 2022

OZONE: Ozone concentrations are expected to range from Good to Moderate range tomorrow.

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

FORECAST DISCUSSION:

Another beautiful weekend in the Mitten State as we have been experiencing relatively clear skies and low-80s for surface temperatures. Today, Sunday, continues the trend with surface temperatures in the low 80s, light winds and scattered clouds. A change in the forecast comes tomorrow, Monday, as a Low-pressure and associated cold front makes its way through the region. Rain chances remain predominantly in the morning hours with sunny skies returning in the afternoon for some areas in Michigan. With the frontal system, surface temperatures decrease slightly due to a wind shift to more west-northwesterly flow.

In terms of air quality, PM-2.5 remains the same as last week. Regional concentrations will increase in the morning hours due to light winds but will diminish as winds increase throughout the day. For Ozone, initially there were conditions in place for a conducive environment for Ozone growth tomorrow, Monday, but with updated models and forecasts, that does not look like the case. As stated above, morning clouds and potential rain help to clean out any Ozone buildup over the weekend, and also inhibits morning growth due to cloudy conditions. The skies clear in the afternoon, but that is right around when the frontal boundary passes through and shifts winds to the WNW, which is not ideal for Ozone development. It is for these reasons we predict Ozone to be in the Moderate range for the majority of Michigan tomorrow. There will some areas in southwest Michigan that may see concentrations in the high Moderate range, but overall 8-hour averages should remain in the low-mid Moderates.

EXTENDED FORECAST:

Rain chances return Wednesday evening with the latter half of the week in the low 80s with chances of rain as well. Air quality for this week should remain in the Good to Moderate range.

Forecast updated by: Alec Kownacki, Sunday July 31st, 2022

Next Forecast update: Monday August 1st, 2022

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