12/17/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Friday, December 17th, 2021 through Monday, December 20th, 2021

PM-2.5: 24-hour average Fine Particulate levels will be generally good, with only scattered low Moderates through the forecast period.

FORECAST DISCUSSION:

After another windy storm system this week, conditions turn quieter for the end of the week and weekend. A storm system tracking across the Ohio River Valley Friday/Saturday will come close enough to bring chances for snow, but significant accumulations are not anticipated. As the system tracks east, high pressure settles in from the west/northwest and winds veering to the north/northwest could bring scattered lake effect snow Saturday. Sunday should be partly to mostly sunny but cool across the state with high-pressure overhead. The next weather system tracks a low north of Lake Superior Monday with a weak cold front passing through.

An unexpected uptick in hourly fine particulate levels was seen Thursday. Upon further evaluation, it was found this was likely due to smoke from Oklahoma wildfires being transported by the strong southwest winds. The plume was seen on satellite imagery and the plume was picked up by most monitors as it mixed to the ground. Increases in hourly concentrations did not last long in any area and the daily averages of fine particulate were not higher than low Moderate at any location.

As for the forecast, low fine particulate readings Friday will not increase much during the day and Good daily averages are expected. Winds turn easterly later Friday as the storm system tracks closer to the state and the flow then turns northerly Saturday after it passes east. Fine particulate will remain Good Saturday. Weaker winds may allow for a few increased hourly fine particulate concentrations, especially in the southeast, on Sunday; however, daily averages of fine particulate will not be higher than low Moderate.

EXTENDED FORECAST:

Extended forecast models show a weak cold front passing through early next week. Weaker southerly winds ahead of the boundary could allow for some low Moderate fine particulate Monday.

Forecast updated by Stephanie Hengesbach: Friday, December 17th, 2021.

Next forecast update: Monday, December 20th, 2021

12/13/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, December 13th, 2021 through Friday, December 17th, 2021

PM-2.5: 24-hour average Fine Particulate levels will range between Good and middle Moderate through the forecast period.

FORECAST DISCUSSION:

Quiet weather conditions are in store early this week along with warmer than normal temperatures. Dry conditions remain Monday and most of Tuesday, but as moisture increases into Wednesday so will the chance for precipitation. Warmer temperatures decrease Thursday behind a cold front and very strong winds may again be possible across parts of the state.

As for air quality, strong winds from the weekend kept fine particulate levels Good and a continuation of Good reading is expected Monday. As temperatures and moisture increase towards mid-week, fine particulate levels also increase into the Moderate range. Winds behind the Thursday cold front will bring fine particulate back to Good for the end of the workweek.

EXTENDED FORECAST:

Some uncertainty exists in the extended models, but it looks like the Thursday front stalls south across Indiana/Ohio with a system developing along the boundary for the weekend. It is unclear whether the track of this system will move into the Great Lakes region or not. While fine particulate higher than Moderate is not expected during the weekend or early next week, this forecast will be updated Friday to better detail fine particulate in the forecast period.

Forecast updated by Stephanie Hengesbach: Monday, December 13th, 2021.

Next forecast update: friday, December 17th, 2021

12/10/2021 Forecast Update

FORECAST SUMMARY: Friday, December 10th, 2021, through Monday, December 13th, 2021

PM-2.5:

Overall PM-2.5 concentrations are expected to be Good for Michigan this weekend.

FORECAST DISCUSSION:

Friday, December 10th, will be a pleasant December day with overcast skies and temperature highs ranging from the mid-20s to mid-30s Fahrenheit. Surface winds start out from the west today, Friday, then quickly shift to more northeasterly as the day goes on due to an approaching Low-pressure system. This Low-pressure system will make its way into the Great Lakes region overnight and into Saturday morning. Southern-Mid Michigan receives a warmup into the low-50s Fahrenheit Saturday morning from the warm front associated with this system. Behind the warm front is a cold front, also associated with the Low-pressure system, so temperatures will drop to the low-mid 30s Fahrenheit for all of Michigan by Saturday evening.

High winds are also associated with this system. Wind Advisories have been issued all around Michigan in recent days which go into effect Saturday morning. In terms of precipitation, mid-southern Michigan will receive mostly rain throughout the day Saturday. Whereas northern-lower Michigan and the Upper Peninsula will receive snow with some portions of the Upper Peninsula in the 8-10 inches range. With the approaching Low-pressure system and associated winds, PM-2.5 concentrations will not be of concern. Any buildup of concentrations in recent days, which has been seen, will effectively be washed out with the approaching system.

EXTENDED FORECAST:

Going into next week, concentrations continue to look Good with a slight warm up in temperature on the horizon.

Forecast updated by: Alec Kownacki, Friday December 10th, 2021. Next Forecast update: Monday December 13th, 2021

12/06/2021 Forecast Update

FORECAST SUMMARY: Monday, December 6th, 2021, through Friday, December 10th, 2021

PM-2.5:

PM-2.5 concentrations early in the week are expected to be Good with localized Moderates increasing as we approach mid-late week.

FORECAST DISCUSSION:

Monday, December 6th, will be a rather windy day for all of Michigan as numerous Wind Advisories have been issued. A Low-pressure system to our north will provide a cold front that makes its way through Michigan today, Monday. The combination of the Low-pressure and cold front is the reasoning behind the windy conditions. Tuesday will have colder temperatures with highs in the 20s Fahrenheit with most of northern Michigan in the teens. The winds on Tuesday will be lighter and will be from the west. Strong winds Monday help to push out any PM-2.5 concentrations and westerly winds Tuesday help to keep the concentrations at bay.

Wednesday, winds shift to the SSW for much of Michigan which will increase PM-2.5 concentrations for the southern portions of Michigan. Going into Thursday, winds quickly shift to more SSE with temperatures in the low 30s Fahrenheit. Friday continues the trend of SSE winds with temperatures rising to the mid-30s for much of Michigan. Overall, PM-2.5 concentrations will be Good for Michigan this week, but there is a high chance of hourly Moderate concentrations come mid-late week.

EXTENDED FORECAST:

There is an increase in temperature as we approach the weekend with an increase in PM-2.5 concentrations as well, but conditions quickly change and decrease Sunday as another front makes its way through the region.

Forecast updated by: Alec Kownacki, Monday December 6th, 2021. Next Forecast update: Friday December 10th, 2021

11/29/2021 Forecast Update

FORECAST SUMMARY:

Monday November 29th, 2021, through Monday December 6th, 2021

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be mostly Good with only a few scattered Moderates during mid-week

FORECAST DISCUSSION

The early half of the week looks to be more active than the latter half.  An upper wave of low pressure will cut across the Great Lakes today and tonight.  With dry air in place, initial precipitation is expected to evaporate before it hits the ground.  By tonight, the air should be saturated enough to provide 1” to 2” of fresh snow.  I am expecting Air Quality to remain mostly Good through Monday and Tuesday. 

Wednesday may be the best chance to see some scattered Moderates throughout Michigan.  Warming temperatures and southern winds will cause some snow melt which could add enough moisture to the atmosphere to trigger a very slight increase in Fine Particulates.  That said, I believe most of the forecast area will remain Good with only a few Low Moderates.

The remainder of the forecast period looks to have favorable winds for Good Air Quality with no long-range predicted precipitation events to cause concern.

EXTENDED FORECAST:

Air Quality is expected to be mostly Good to start the next work week.

Forecast updated by Jim Haywood: Monday, November 29th, 2021
Next forecast update: Monday, December 6th, 2021

11/22/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, November 22nd, 2021 through Monday, November 29th, 2021

PM-2.5: Overall PM-2.5 concentrations are expected to be Good for Michigan this week with some mid-Moderate hourly concentrations midweek.

FORECAST DISCUSSION:

Monday, November 22nd, will turn out to be a pleasant late-November day with a warmup Tuesday into Wednesday with surface temperatures nearing the mid-40s Fahrenheit for southern Michigan and low-40s Fahrenheit for northern Michigan. This warmup will be due to SSW winds lofting a warmer airmass to the Great Lakes region. Cooler temperatures return just in time for Thanksgiving as winds shift more northwesterly accompanied by a cold front Wednesday and into Thursday. This will bring temperatures back down to the low-30s Fahrenheit for much of Michigan. Going into the weekend, temperatures stick around the low-mid 30s Fahrenheit range with westerly winds.

In terms of concentrations, today, Monday, will have Good fine particulate concentrations. As winds shift to SSW midweek, concentrations will approach the Moderate range, with some pockets of mid-Moderate. As the winds shift back to NW along with the cold front later this week, the fine particulate concentrations will be pushed out of the region and return back to Good. For the weekend, concentrations will be in the Good category with some pockets of low-Moderate.

EXTENDED FORECAST:

Temperatures hang around the low-mid 30s Fahrenheit range with WNW winds going into next week. Concentrations are expected to be Good.

Forecast updated by Alec Kownacki, Monday, November 22nd, 2021

Next forecast update: Monday, November 29th, 2021

11/15/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, November 15th, 2021 through Monday, November 22nd, 2021

PM-2.5: PM-2.5: 24-hour average Fine Particulate levels will range between Good and middle Moderate through the forecast period.

FORECAST DISCUSSION:

Aside from snow showers across the northern lower peninsula, conditions are expected to be cold, but relatively drier Monday. A warm-up is expected starting Tuesday lasting into Wednesday as the high-pressure system tracks through and brings southerly winds. However, a cold front and an upper trough will bring cooler air back over the state Thursday into Friday. On and off chances for precipitation can be expected this week. With an active pattern starting mid-week prolonged periods of stagnation are not anticipated. This will help keep fine particulate from significantly increasing.

Northerly winds should keep fine particulate levels Good on Monday. Winds change to a southerly component as we approach mid-week. Moisture can be expected to increase around then as well which could aid in increases of fine particulate towards the low Moderate range Tuesday and Wednesday. Any Moderate readings should improve to Good Thursday and Friday as a cold front and upper trough bring in cleaner air on a cold northwest wind.

EXTENDED FORECAST:

Extended models show a high-pressure system quickly passing through the region with warmer air again Saturday, but the next system could bring precipitation and cooler air back into the forecast as early as Sunday. The on and off weather systems through the weekend will hamper significant increases in fine particulate. Levels should range from Good to low/middle Moderate through early next week.

Forecast updated by Stephanie Hengesbach: Monday, November 15th, 2021.

Next forecast update: Monday, November 22nd, 2021

11/08/2021 Forecast Update

FORECAST SUMMARY:

Monday November 8th, 2021, through Monday November 15th, 2021

PM-2.5:  24-hour average Fine Particulate concentrations are expected to Moderate early in the week transitioning to Good by mid-week and enduring through the weekend.

FORECAST DISCUSSION 

Southerly winds will keep the Lower Peninsula running in the Moderate range for Fine Particulates during the early in the work week.  Light, northernly winds should help clean out the atmosphere during late Tuesday and Wednesday for mostly Good to Low Moderate in most places in the State.

The biggest weather event of the week will come mid-week with a strong Fall storm currently forming out over the Pacific.  Winds will turn southerly in advance of the Thursday frontal passage which could push Fine Particulates briefly back into the Low Moderate range.  Once the front has passed Thursday afternoon and evening, cleaner air will follow which should keep our Air Quality mostly Good going into the remainder of the work week and weekend.

EXTENDED FORECAST:

Air Quality is expected to be mostly Good to start the next work week.

Forecast updated by Jim Haywood: Monday, November 8th, 2021

Next forecast update: Monday, November 15th, 2021

11/05/2021 Forecast Update

FORECAST SUMMARY: Friday, November 5th, 2021, through Monday, November 8th, 2021

 

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

FORECAST DISCUSSION:

Cold temperatures and lake effect rain/snow showers earlier in the week will be replaced by dry conditions, sunshine, and warming temperatures. This change can be attributed to high pressure dominating our weather. The center of the high is near southeast Michigan early Friday and this system lingers southeast of our region through early next week. With this set up, expect warmer, southwesterly winds as high temperatures increase each day. The warmest readings can be expected Sunday and Monday.

As for air quality, weak winds Friday morning in southern Michigan has caused increased hourly fine particulate readings in the high Moderate to low USG range. However, as winds increase during the day hourly levels should improve. Daily fine particulate averages will range between upper Good and upper Moderate Friday. Warmer southwesterly winds continuing this weekend will keep increased fine particulate in the forecast, but stronger winds Saturday and Sunday, especially closer to the lakeshore, should hamper a significant development. I am anticipating mostly Moderate fine particulate across the state during the weekend into early next week.

EXTENDED FORECAST:

Extended models show a weak boundary moving through Tuesday. Not much precipitation is associated with it, but winds switching to the northwest will help improve Moderate fine particulate levels.

Next Forecast update: Monday, November 8th, 2021

11/01/2021 Forecast Update

FORECAST SUMMARY: Monday, November 1st, 2021, through Friday, November 5th, 2021

PM-2.5: 24-hour average Fine Particulate readings remain mostly Good through the week.

FORECAST DISCUSSION:

The first snowflakes of the season may be seen this week thanks to cold northwesterly winds triggering lake effect rain and/or snow showers. However, don’t anticipate much accumulation as that should stay to the most prone lake effect areas of the Upper Peninsula and Northern Lower. High pressure moving in from the Plain states ends lake effect precipitation around mid-week as winds decrease and shift to more of southwesterly direction. As the high slides south of the state towards the end of the week, temperatures increase back to more seasonable readings.

The week starts with Good fine particulate thanks to cold northwesterly winds. As winds decrease and switch direction past mid-week, fine particulate will have a greater chance to develop. Hourly levels in the Moderate range early Thursday and again Friday will likely improve resulting in upper Good daily averages. The greatest chance for low Moderate fine particulate later in the week will be in the southeastern portion of the state. We will keep an eye on levels and update to a Moderate forecast once we notice levels increasing.

While fine particulate higher than Moderate is not anticipated through next Monday, we will update the forecast Friday to detail how widespread Moderate readings may be through the weekend and early next week.

EXTENDED FORECAST:

Extended models show moderating temperatures and southerly winds into early next week which may result in Moderate fine particulate.

Next Forecast update: Friday, November 5th, 2021

10/25/2021 Forecast Update

FORECAST SUMMARY:

Monday, October 25, 2021, through Monday, November 1, 2021 

OZONE: Ozone concentrations are expected to be Good for Michigan this week.

PM: PM-2.5 concentrations are expected to be Good for Michigan this week.

FORECAST DISCUSSION:

Monday, October 25th is expected to be a literal wash as the majority of Michigan, with the exception of the Upper Peninsula, is expected to receive rain for much of the day.

Upper-level temperatures for this week are expected to hover around zero degrees Celsius with winds mainly from the NNE, with some SE flow Thursday. As we approach Tuesday early morning, the low-pressure system that is providing all of this rain will move off to the east. This will set up a high-pressure system which will move across Michigan Wednesday morning and track more southeastward.

Moving down to the surface, temperatures for this week will be around seasonal averages with the sun coming out mid-week due to the aforementioned high-pressure system. Surface winds this week will be similar to the upper levels with winds coming from the NNE for the majority of the week.

Air quality is forecasted to be Good for the week, as the Ozone season comes to an end. The combination of rain today, seasonal temperatures and NNE winds, both Ozone and PM-2.5 concentrations are expected to be Good. There is a slight possibility for pockets of low-Moderate PM-2.5 concentrations mid-week, but the overall 24-hour average is expected to remain Good.

EXTENDED FORECAST:

The extended forecast is more of the same with Good concentrations and seasonal temperatures.

Forecast updated by Alec Kownacki, Monday, October 25, 2021. Next forecast update: Monday, November 1, 2021.

10/22/2021 Forecast Update

FORECAST SUMMARY:

Friday, October 22nd, 2021, through Monday, October 25th, 2021

OZONE: 8-hour average Ozone concentrations will be Good through the forecast period.

PM-2.5: 24-hour average Fine Particulate readings will also remain Good.

FORECAST DISCUSSION:

Cool northerly winds may trigger scatted lake enhanced showers Friday; however, most locations will experience a pleasant fall day. The next weather system moves from the Plain states Saturday, tracking across northern Indiana and Ohio early next week. Steadier precipitation comes in the forecast late Sunday into Monday as the system moves through.

Good air quality levels Friday can be attributed to cool temperatures and a northerly wind. Calm to light winds early Saturday may allow for some hourly Moderate fine particulate readings, but daily averages are expected to be Good. Lighter winds are also expected early Sunday that could bring hourlies into the Moderate range; however, winds change to an easterly direction as the storm system moves closer to the region. Easterly winds should allow for Good daily averages of fine particulate

Cooler temperatures, less daytime heating, and precipitation chances early next week will keep ozone Good through the forecast period.

EXTENDED FORECAST:

Extended models show northeasterly winds Monday as the system moves further east and then a break in precipitation Tuesday. The anticipated weather conditions will keep pollution levels Good into early next week.

Forecast Updated by Stephanie M. Hengesbach Friday, October 22nd, 2021. Next Forecast update: Monday, October 25th, 2021.

10/18/2021 Forecast Update

FORECAST SUMMARY:

Monday, October 18th, 2021, through Friday, October 22nd, 2021

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

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

FORECAST DISCUSSION:

Pleasant fall conditions will be in place Monday and Tuesday thanks to a large high-pressure area south and east of the region. The next storm system comes into play Wednesday and precipitation chances increases from west to east as the day progresses. Rain showers linger Thursday as a cold front tracks through the region. Cooler air filtering in behind the front brings more seasonable fall temperatures, and cooler temperatures could aid in the development of scattered lake effect showers Friday, possibly into Saturday.

As for air quality, plenty of sunshine and warmer temperatures both Monday and Tuesday will do little to increase ozone with it being so late in the season. Winds shifting to more of a southerly component could allow for some hourly Moderate fine particulate readings, but daily averages of both fine particulate and 8-hour ozone are expected to remain Good through mid-week. Northerly winds develop Thursday into Friday bringing in clean air. Both ozone and fine particulate will end the week in the Good range.

EXTENDED FORECAST:

Extended models are a bit unclear on a potential system for early next week. Regardless on the timing of the next system, temperatures remain at more seasonable levels through early next week. Ozone will remain Good and at worst, fine particulate would be low Moderate.

Forecast Updated by : Meteorologist Stephanie M. Hengesbach.
Next Forecast update: Friday, October 22nd, 2021

10/15/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Friday, October 15th, 2021 through Monday, October 18th, 2021

Ozone: Ozone concentrations are expected to be Good for Michigan this weekend and going into next week.

PM-2.5: There will be some hourly Moderate concentrations of PM-2.5 for today, Friday, but will return to Good for the rest of the weekend.

FORECAST DISCUSSION:

Fall temperature norms continue through the weekend after a mid-October warmup earlier this week. Upper-level temperatures hang around 10 degrees Celsius for much of today, Friday, before dropping to near-zero for the remainder of the weekend and into early next week. Upper-level winds will be from the NW for the weekend, which is a reasoning behind the return to Fall temperature norms.

Like said above, Fall temperatures continue through the weekend with surface temperatures in the upper-50s to low-60s Fahrenheit. A Low-pressure system and accompanied frontal boundary will make its way through Michigan today, bringing rain showers for much of today, Friday. This, too, is a reasoning behind the Fall-like temperatures this weekend and will shift surface winds to WNW for the remainder of the weekend.

In terms of concentrations, Ozone shouldn’t be of any concern this weekend as upper-level temperatures plummet to near-zero, surface temperatures returning to seasonal norms, and winds coming from the WNW. PM-2.5 concentrations will have hourly concentrations in the Moderate range in some areas today, Friday. As the Low-pressure and frontal boundary moves through Michigan, the PM-2.5 concentrations will filter out. Therefore, PM-2.5 concentrations will be in the Good range for remainder of the weekend and going into next week.

EXTENDED FORECAST:

Early next week provides more of the same conditions that we will see Saturday and Sunday with seasonally normal temperatures and Good concentrations.

Forecast updated by Alec Kownacki: Friday, October 15th, 2021.

Next forecast update: Monday, October 18th, 2021

10/11/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, October 11th, 2021 through Friday, October 15th, 2021

Ozone: Ozone concentrations are expected to be Good for Michigan this week, with some areas potentially reaching Moderate for hourly concentrations earlier in the week.

PM-2.5: PM-2.5 concentrations are expected to be Good for Michigan this week, as well as some hourly Moderate concentrations earlier in the week.

FORECAST DISCUSSION:

Summer-like temperatures return today as surface temperatures for much of the region will reach the low 80s Fahrenheit. Fall temperatures will return mid-week as a cold front and low-pressure system make its way through the area.

Upper-level temperatures will be in the mid-upper teens Celsius. The upper-level winds coming from the SSW might cause a rise in temperatures. As we approach mid-week, upper-level temperatures drop to the single digits Celsius before returning to the mid-teens towards the end of the week. Upper-level winds remain in a WSW pattern after the cold front exits the region Tuesday and into Wednesday. These winds will then shift back to SSW flow as another Low-pressure system approaches from the west and stays to our northwest later this week.

Surface temperatures follow a similar trend to upper-level temperatures with summer-like temps returning Monday. Surface winds will be from the SW before turning more southerly Tuesday, as the approaching low-pressure treks through the region. Once the low-pressure and the cold front leaves the region, winds will be in a WSW pattern for the rest of the week.

Ozone concentrations are expected to be mostly Good, but some concentrations in the Moderate range for hourly concentrations can be expected Monday. The combination of warmer upper-level and surface temperatures along with SW winds will create a conducive environment for Ozone development. However, the 8-hour average concentration will potentially be Good. Once the cold front moves through, it will clean out the atmosphere and will present Good concentrations for the rest of the week. PM-2.5 concentrations have a similar trend today due to smoke concentrations lingering around the Midwest but will be filtered out once the cold front moves through.

EXTENDED FORECAST:

A cool down can be expected towards the weekend, with surface highs in the upper-50s Fahrenheit and westerly winds. Overall, concentrations are expected to remain Good.

Forecast updated by Alec Kownacki: Monday, October 11th, 2021.

Next forecast update: Friday, October 15th, 2021

10/4/2021 Forecast Update

FORECAST SUMMARY: Monday October 4th, 2021, through Monday October 11th, 2021

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

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

FORECAST DISCUSSION

 A low-pressure center is moving across lower Michigan Monday that has kicked off some heavy rain shower activity during the morning hours.  That activity will diminish as the low tracks southeastward during the day.  Air Quality will remain Good during Monday.

 Dryer conditions will return Tuesday through Wednesday following the passage of the Monday system.  Air Quality will remain mostly Good on mostly on northeast to easterly winds.

By Wednesday night, a low-pressure system to our south is predicted to merge with an oncoming Pacific system and slowly move north into the Midwest.  This will likely kick off more clouds and showers and keep Air Quality mostly Good.

Temperatures are likely to warm up during the weekend as a stronger system pushes up from the southwest.  During the advance of that system, we will be in the warm air sector during Saturday and early Sunday and can expect temperatures in the mid-70’s before that system passes late Sunday.  During that time, it is possible to see some Moderate conditions.

Fortunately, our ozone season is winding down and we really do not expect to see much in the way of elevated ozone.  Wildfires have also diminished which added much smoke to our air during the summer months.  Some fires still burn in Manitoba and out in the Western U.S., but current smoke plumes do not seem to be getting east of Minnesota.

EXTENDED FORECAST:

Air Quality is expected to be Good to Moderate during the weekend.  Monday and early next week will be Good Air Quality.

Forecast updated by Jim Haywood: Monday, October 4th, 2021

Next forecast update: Monday, October 11th, 2021

9/27/2021 Forecast Update

FORECAST SUMMARY:

Monday, September 27th, 2021, through Monday, October 4th, 2021 

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

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

FORECAST DISCUSSION:

A cold front passing north to south through the state Monday will do little but increase clouds for a time as it passes by. High pressure then settles into the region becoming the dominating weather feature for the rest of the week. Expect seasonable fall conditions with comfortable temperatures and generally sunny skies. Southerly winds before the Monday frontal passage turn more northeasterly, then southeasterly through Friday.

As for air quality, a few hourly low Moderate fine particulate concentrations further south will improve during the day with a Good 24-hour average expected statewide. Cooler surface and upper-level temperatures, along with an easterly component to the wind, will keep both fine particulate and ozone generally Good through the week.

EXTENDED FORECAST:

Extended models show a weather system possibly moving in during the weekend into early next week which could bring some scattered, light precipitation. The exact timing and location for this system is not clear at this time, but regardless of how the system pans out, ozone will remain Good during the weekend into next week, and fine particulate would not reach higher than low Moderate.

Forecast updated by Stephanie M. Hengesbach, Friday, September 27th, 2021. Next Forecast update: Monday, October 4th, 2021

9/24/2021 Forecast Update

FORECAST SUMMARY:

Friday, September 24th, 2021, through Monday, September 27th, 2021

Ozone: Ozone concentrations are expected to be Good for Michigan this weekend and going into next week.

PM-2.5: PM-2.5 concentrations are expected to be Good for Michigan this weekend and going into next week.  

FORECAST DISCUSSION:

After a week full of Fall temperatures and soaking rain, Michigan receives somewhat of a break from rain until another frontal boundary enters the region early Saturday morning.

Upper-level temperatures will remain in the single digits Celsius for much of the weekend until late-Sunday when warmer upper-level temperatures return to the region. Upper-level winds this weekend start out coming from the southwest due to a Low-pressure just to our north wrapping the winds around its circulation. As the Low exits the region Saturday afternoon, winds shift to more westerly and zonal flow going into next week.

Surface temperatures increase a little bit from the 50s Fahrenheit that Michigan was seeing the past two days. For much of the weekend, surface high temperatures are expected to be in the upper-60s Fahrenheit to low-70s Fahrenheit. Surface winds will be from the SSW for much of the weekend but should not pose a threat for Ozone development as we sometimes see with that particular wind pattern. Cooler temperatures at the surface and aloft, as well as the increasing rain chance from the frontal boundary Saturday morning, will inhibit any Ozone development over Michigan. Although there looks to be some slight pooling of Ozone over Lake Michigan, this will not be an issue for the Lake Michigan shoreline. The wildfires to the north have since died down which will keep PM-2.5 concentrations from entering the area. It is for these reasons that both Ozone and PM-2.5 concentrations will remain Good for this weekend and into next week.

EXTENDED FORECAST:

The beginning of next week presents a slight warm up into the mid-70s Fahrenheit for southern Michigan. Northern Michigan will be in a northerly wind pattern, so surface high temperatures will remain in the 60s Fahrenheit. In terms of Ozone and PM-2.5 concentrations, both will remain Good to start off the week.

Forecast updated by: Alec Kownacki, Friday, September 24th, 2021

Next forecast update: Monday, September 27th, 2021

9/20/2021 Forecast Update

FORECAST SUMMARY:

Monday, September 20th, 2021, through Friday, September 24th, 2021

Ozone: Ozone concentrations are expected to be mostly Good for much of Michigan.

PM-2.5: PM-2.5 concentrations are expected to be Good for the majority of Michigan, with some areas potentially reaching the Moderate threshold, but only for a short while. 

FORECAST DISCUSSION:

After a pleasant Fall weekend, Michigan will have similar weather for most of today, Monday, until a cold front comes through Tuesday afternoon.

Upper-level temperatures are expected to be in the mid-teens Celsius for today and into tomorrow until the frontal boundary enters the region. After the boundary exits the region, upper-level temperatures plummet to near zero Celsius for the remainder of the week until Friday afternoon. Upper-level winds will be from the SSW for much of today, Monday and into tomorrow, Tuesday, until the front moves through and shifts the winds to northerly flow. This northerly shift in winds is the reasoning behind cooler upper-level temperatures and cooler surface temperatures.

Surface temperatures will be in the mid-60s to low-70s Fahrenheit today and tomorrow until the cold front comes through with cooler temperatures. After Tuesday, surface high temperatures will be in the upper-50s to low-60s Fahrenheit for much of the region. Surface winds follow a similar trend to upper-level winds with being from the SSW today and tomorrow, before shifting to NNW for the remainder of the week. The combination of cooler temperatures and northerly flow is the reasoning behind Good concentrations for Ozone. Along with the cold front moving through, the chance of rain increases as the front treks across the region. Much of Tuesday afternoon and Wednesday morning will have a high chance of rain for Michigan.

EXTENDED FORECAST:

Going into Friday and the weekend, another cold front quickly enters and exits the region by the time we reach Saturday morning. This front will increase the chances of rain while also clearing out the area in terms of any Ozone or PM-2.5 buildup. For that reason, concentrations should remain mostly Good.

Forecast updated by: Alec Kownacki, Monday, September 20th, 2021

Next forecast update: Friday, September 24th, 2021

9/13/2021 Forecast Update

FORECAST SUMMARY:

Monday September 13th, 2021, through Friday September 17th, 2021

Ozone:  8-hour average Ozone concentrations are expected to be mostly Good with some scattered Moderates during the latter half of the work week.

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

FORECAST DISCUSSION

Monday and Tuesday will be the most weather active days of the week.  During Monday, a stationary front along the Michigan/Indiana border will trigger scattered shower and thundershower activity.  That front will advance northward, during Tuesday, as a warm front triggering more active shower/thundershower potential.  The trailing cold front with that system should pass late Tuesday to end the active weather.  Air Quality should remain Good for both ozone and fine particulates during Monday and Tuesday.

The latter half of the week should contain pleasant weather as high-pressure ridging builds in behind the cold front.  As we get into southerly flow by the end of the week, we will experience a warming trend that could reach well into the upper 80’s by the end of the weekend.  Even though the days are getting shorter with cooler nights, a few hours of southwest winds, under sunny skies, could push us into the High Moderate range for ozone along our western lakeshore and northeast of Detroit. 

As such, I will be updating this forecast on Friday.

EXTENDED FORECAST:

Air Quality is expected to be Good to Moderate during the weekend.  Monday and early next week will be unseasonable warm with Good to Moderate Air Quality.

Forecast updated by Jim Haywood: Monday, September 13th, 2021
Next forecast update: Friday, September 17th, 2021