06/29/2024 Forecast Update

FORECAST SUMMARY: Friday, June 28, 2024, through Monday, July 1, 2024

OZONE:

8-hour average Ozone concentrations are expected to range generally Good (Green AQI) with only a few Moderate (Yellow AQI) possible.

PM-2.5:

24-hour daily average Fine Particulate concentrations will range between Good and low Moderate.

 FORECAST DISCUSSION:

Precipitation moves from northwest to southeast across the state on Friday as a warm front moves in from the west. This front is associated with a developing low-pressure area that is forecast to track west to east across the northern Great Lakes region late Friday into Saturday. The associated cold front will follow the west-to-east track as it swings through the state on Saturday, ending the chances for showers and storms during the day. Weather conditions will be dry and cool on Sunday and Monday as high pressure settles into the region. 

 As for air quality, we are starting the forecast period with a low base, and both ozone and PM2.5 were in the Good range on Thursday. Moisture increasing ahead of the cold front may allow for some low Moderate PM2.5 concentrations across the southern portion of the state on Friday and/or Saturday, otherwise generally Good daily averages are expected through the period. While clouds seem to be prevalent Friday and Saturday, temperatures at the surface and upper levels may be warm enough for any locations that break into a fair amount of sunshine to reach Moderate for ozone. Cooler temperatures and a northerly flow on Sunday will produce Good ozone concentrations. Lighter winds develop Monday, and plenty of sunshine is expected; however, cooler temperatures at the surface and upper levels will keep ozone from reaching higher than low Moderate.

 Canadian wildfire activity is currently below average for this time of year, and air quality impacts due to wildfire smoke are not anticipated during this forecast period. We will keep track of weather conditions, smoke plume tracks, and air quality levels during the weekend, and this forecast will be updated if necessary.

EXTENDED FORECAST:

After a quiet start to the week, the next weather system brings chances for precipitation and warmer temperatures back into the forecast by Tuesday. In the extended forecast, we do not anticipate air quality to reach higher than Moderate.

Next Forecast update: Monday, July 1, 2024

06/24/2024 Forecast Update

FORECAST SUMMARY: Monday, June 24, 2024, through Friday, June 28, 2024

OZONE:

8-hour average Ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI).

PM-2.5:

24-hour daily average Fine Particulate concentrations will also range between Good and low Moderate.

 FORECAST DISCUSSION:

High pressure will dominate conditions on Monday with plenty of sunshine and seasonable temperatures. By Tuesday, however, a more active weather pattern sets up. The pattern change begins as an area of storms tracks northwest to southeast across the state late Monday night into Tuesday morning. These storms are associated with a frontal boundary that will drop in as well, and this boundary will keep precipitation in the forecast through early Wednesday. A dry out is expected Thursday into Friday as high pressure briefly settles in, but the next system moves in from the west, with precipitation moving back into the state from west to east as Friday progresses.

 As for air quality, cooler conditions, along with on-and-off clouds and precipitation, will hamper ozone development, keeping readings in the Good to Moderate range. The active weather pattern should keep the atmosphere well mixed, and at this time, the upper-level wind pattern is not expected to bring any wildfire smoke from active Canadian fires into the region. Levels of PM2.5 during the week will range from Good to low Moderate.

EXTENDED FORECAST:

Precipitation chances continue into Saturday, but high-pressure returns on Sunday, bringing in dry conditions for early next week. During this period, both ozone and PM2.5 should range between Good and Moderate.

Next Forecast update: Monday, June 24th, 2024

06/21/2024 Forecast Update

FORECAST SUMMARY: Friday June 21st, 2024, through Monday June 24th, 2024

OZONE:

Ozone concentrations are expected to be in the Mid-High Moderate (Yellow AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good (Green AQI) to low-Moderate (Yellow AQI) range.

 FORECAST DISCUSSION:

We end the week on a relatively cooler note with an emphasis on cooler due to the fact that much of southern Michigan will still reach the upper-80s. Much of northern Michigan and into the Upper Peninsula have remained unscathed from this week’s heatwave as this will continue into the weekend with temperatures in northern Michigan ranging from the 60s to 70s. A majority of us start this Friday off cloudy as well, with northern parts of the state forecasted to have clouds hang around all day with southern portions seeing clearing as the day carries on. In areas with clearing skies, temperatures will increase rather quickly as the warm, and humid airmass is still positioned over southern Michigan. As the day carries on, the warm airmass is expected to drift northward which will create a slightly warmer Saturday for southern portions of the state along with bringing more clouds to the area. Tomorrow, Saturday, is expected to be yet another hot day for southern Michiganders but lingering clouds should provide some relief. Tomorrow night will see the frontal boundary bringing warm temperatures, carry north across the state and provide rain showers into early Sunday morning. Immediately behind this front is yet another front, but as a cold front, which will help cool down temperatures before we start the next work week. The combination of cooler temperatures, lower humidity, and rain showers will help clean out the current dirty airmass we have been dealing with all week. We start Monday roughly 10 degrees cooler than what we were this past Monday and considerably less humidity.

Tomorrow, winds shift to more southwesterly flow, which would be a good indicator for Ozone in west Michigan. However, lingering clouds and a somewhat clean airmass due to Thursday’s storms, will not allow for Ozone to exceed USG concentrations for an 8-hour average. Mid-High Moderate concentrations are expected with a slight possibility of an hourly USG, but overall 8-hour averages should remain in the Moderate category. Saturday is expected to be the last possible high Ozone day for the next couple of days as the front into Sunday morning will keep the airmass clean. PM-2.5 concentrations look to be in the Good-Moderate range as well as no high smoke or particulate concentrations are expected

EXTENDED FORECAST:

As stated above, we start Monday off roughly 10 degrees cooler than this past Monday with a much cleaner airmass.

Next Forecast update: Monday June 24th, 2024

06/19/2024 Forecast Update

FORECAST SUMMARY: Wednesday June 19th, through Thursday June 20th, 2024

OZONE:

Ozone concentrations are expected to be in the high-Moderate (Yellow) to USG (Orange AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

 FORECAST DISCUSSION:

The majority of the state stays cloudy today, Wednesday, with clearing along the Lake Michigan shoreline early-to-mid afternoon. Even with the cloudy skies, surface temperatures in the lower peninsula are still expected to reach the 90s, with heat indices higher due to high dew points and associated humidity. Due to the heat and humidity, pop up rain and possible thunderstorms are possible across the southern portion of the lower peninsula, especially in the southeast Michigan area. These showers and possible storms can be expected for the remainder of the week solely due to the heat and humidity providing the “fuel” for storms to develop.

There is an active Air Quality Advisory currently for western Michigan lakeshore counties along Lake Michigan. As stated above, there will be a clearing of skies this afternoon, which will allow for Ozone to develop along the lakeshore with the help of predominantly southwesterly winds. North of the Muskegon area will stay under clouds longer than the south, which is why the cutoff for the Advisory is Muskegon County.

For tomorrow, Thursday, winds look to shift throughout the day from northerly, to southerly, and back to northerly as a weak Low-pressure system moves across the southern state borders. Ozone does not look to be an issue for western Michigan areas due to these winds shifts.

EXTENDED FORECAST:

A slight cool down comes on Friday, with an emphasis on slight, because it will still be in the upper-80s. Pop up storms are possible with a last push into the 90s coming Saturday.

Next Forecast update: Thursday June 20th, 2024

06/18/2024 Forecast Update

FORECAST SUMMARY: Tuesday June 18th, 2024, through Wednesday June 19th, 2024

OZONE:

Ozone concentrations are expected to be in the high-Moderate (Yellow AQI) to Unhealthy for Sensitive Groups (Orange AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

 FORECAST DISCUSSION:

Clouds slowly move through the state today, Tuesday, as the current heat wave continues. Although cloudier today, surface temperatures and humidity will rival yesterdays with heat indices still expected to approach 100 degrees in some areas. Ozone concentrations today are expected to be lower than yesterdays, but only slightly. Mid to high Moderate concentrations can be expected today with a possible hourly USG reading, but overall 8-hour averages should be in the high-Moderate range. An Air Quality Advisory is being issued for tomorrow, Wednesday, for west Michigan areas due to Ozone expected to exceed USG-level concentrations. Clouds look to erode in the early afternoon in the west Michigan area which will allow for Ozone to tap into sunlight along with the already warm airmass. To aid in the development, winds will predominantly be southwesterly with upper-level temperatures in the upper teens Celsius, which is prime for Ozone development. Numerous cloud models show clouds hanging around metro Detroit, tomorrow, longer, and more persistently compared to west Michigan. Due to the heat, humidity, possible peaks in between clouds and existing airmass, there is a chance for high Moderate concentrations tomorrow in the metro Detroit area.

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

  EXTENDED FORECAST:

Winds look to shift to more north/northeasterly for Thursday, which may provide some relief in terms of air quality. This will be looked at further Wednesday morning.

Next Forecast update: Wednesday June 19th, 2024

06/17/2024 Forecast Update

FORECAST SUMMARY: Monday, June 17th, 2024, through Tuesday June 18th, 2024

OZONE:

Ozone concentrations are expected to be in the Unhealthy for Sensitive Groups (Orange AQI) range today, Monday for counties in West and Southeast Michigan.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good (Green AQI) to Low-Moderate (Yellow AQI) range.

 FORECAST DISCUSSION:

Today, Monday, is the start of a weeklong heat wave we will be experiencing here in Michigan. Surface temperatures will climb well into the 90s with dew point temperatures well into the upper-60s to low-70s. The combination of heat and humidity will push heat indices towards 100 degrees with some areas closer to 105 degrees. Excessive heat watches and warnings are in place for the majority of the lower peninsula, with an active Air Quality Advisory in place for the counties above for today as well. Ample sunlight will be coupled with the high temperatures, both lower level and upper level, along with humidity to initiate Ozone development along the Lake Michigan shoreline as well as the metro Detroit area. This Advisory will run through midnight tonight.

Tomorrow, Tuesday, will be similar to today with the heat and humidity, however, in the afternoon, clouds move in with associated possible rain showers for the southern portions of the lower peninsula. Numerous models are showing broken to overcast cloudy skies for tomorrow afternoon which would cut off any Ozone development. Also, with possible rain showers, Ozone will not have the ingredients to produce beyond the Advisory threshold of USG for an 8-hour average. In the event some sun shines through the clouds, there may be enough initiation for hourly USG concentrations, but the overall 8-hour average should remain in the mid-high Moderate range.

  EXTENDED FORECAST:

Wednesday is looking to similar to today with the heat, humidity, and sunlight so there is a possibility of an Advisory for Wednesday. Because of this, EGLE will update the forecast tomorrow morning, and, more than likely, each morning for the remainder of the week.

Next Forecast update: Tuesday June 18th, 2024

06/16/2024 Forecast Update

FORECAST SUMMARY: Sunday, June 16, 2024, through Monday, June 17, 2024

OZONE: 8-Hour average Ozone concentrations will be trending to Moderate (AQI Yellow) in most of the interior part of the state.  An Air Quality Advisory (AQI Orange) has been issued to West and Southeast Michigan for Monday. 

PM-2.5: 24-hour average Fine Particulate concentrations are expected to remain mostly Good (AQI Green) to Moderate (AQI Yellow).

 FORECAST DISCUSSION:

Temperature and humidity will continue to increase as we begin the new week.  Temperatures in the 90’s and dew points around 70 degrees will add to the misery index for the week.  This pattern looks to persist through the week.

 With winds at all levels of the atmosphere coming from the hot southwest, Air Quality will certainly be an issue, this week.  EGLE issued an advisory for Sunday and will expand that advisory to both West and Southeast Michigan for Monday.  With conditions not expected to change, drink plenty of fluids, stay in an air-conditioned room, stay out of the sun as much a possible, and check up on relatives and neighbors.

  EXTENDED FORECAST:

Air Quality is expected to be Moderate to USG during the beginning of the upcoming work week.

Next Forecast update: Monday, June 17, 2024

06/15/2024 Forecast Update

FORECAST SUMMARY: Saturday, june 15 Through Sunday, june 16

OZONE: 8-Hour average Ozone concentrations will be trending Good (AQI Green) to Moderate (AQI Yellow) in most of the state.

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to remain mostly Good (AQI Green) to Moderate (AQI Yellow).

FORECAST DISCUSSION:

Michigan is under a dome of high pressure as we entered the weekend.  As we get on the back side of the high pressure cell during Sunday, we will fall under a southerly wind regime and a significant warmup for early next week. 

 Sunday will likely be a ramp-up day for much of the state with southeast winds becoming more southwesterly during the day.  Dew points will start out in the comfortable 50-degree range increasing into the low 60’s by the end of the day.  Most of the state should stay in the Moderate range through Sunday. 

 Monday is looking more concerning as we are seeing persistent southwest winds, higher dew points, hotter temperatures, and the potential for plenty of sun.  This trend looks to persist into the work week with the concern for increasing levels of ozone as the week progresses.

  EXTENDED FORECAST:

Air Quality could be Moderate to USG during the beginning of the upcoming work week.

Next Forecast update: Sunday, June 16, 2024

06/12/2024 Forecast Update

FORECAST SUMMARY: WEDNESDAY, june 12 Through Sunday, june 16

OZONE: 8-Hour average Ozone concentrations will be generally Good (AQI Green) to Moderate (AQI Yellow).

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to remain mostly Good (AQI Green) Moderate (AQI Yellow).

FORECAST DISCUSSION:

During the Monday forecast, I expressed some concern about Thursday’s potential air quality.  Several elements were predicted to be in place which could lead to elevated ozone levels.  What was unclear was the amount of cloud cover we could expect.  Later runs of the cloud models confirmed that enough clouds should be in place to reduce that threat.

 A cold front will transverse the state, late Thursday, which will clean out the atmosphere. High pressure passing overhead, Friday and Saturday, will provide us with cooler, dryer weather and Good AQI throughout the state. 

 As we get on the back side of the high pressure cell during Sunday, we will fall under a southerly wind regime and a significant warmup for early next week.  Sunday will likely be a ramp-up day with southeast winds becoming more southwesterly during the day.  Dew points will start out in the comfortable 50-degree range increasing into the low 60’s by the end of the day.  Even with surface temperatures reaching the upper 80’s during Sunday, we are starting with a clean AQI base with southeast winds, lower dew points, and some cloud potential as a warm front pushes through.  As such, I expect elevated ozone levels during Sunday should be kept in check although I do expect an increase into the Moderate range.

 Monday is looking more concerning as we are seeing persistent southwest winds, higher dew points, hotter temperatures, and the potential for plenty of sun.  This trend looks to persist into the work week with the concern for increasing levels of ozone as the week progresses.

 Michigan is not expecting any problems Friday through Sunday, EGLE is going to postpone the usual Friday morning forecast and schedule a Sunday morning forecast, instead.  EGLE will be checking conditions Saturday morning, however, and if warranted, EGLE would issue a revised forecast at that time.

  EXTENDED FORECAST:

Air Quality could be Moderate to USG during the beginning of the upcoming work week.

Next Forecast update: Sunday, June 16, 2024

06/10/2024 Forecast Update

FORECAST SUMMARY: monday, june 10 Through WEDNESDAY, june 12

OZONE: 8-Hour average Ozone concentrations will be generally Good (AQI Green).

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to remain mostly Good (AQI Green).

FORECAST DISCUSSION:

We begin the work week under Good AQI conditions.  Monday’s winds are northerly with cool temperatures and low dew points.  Tuesday begins a slow transition as winds begin swinging around to a more southerly direction.  But dew points remain low and both surface and upper air temperatures are still on the cooler side. 

 Wednesday could be a bit of a ramp up day as winds remain southwesterly.  Temperatures, both surface and aloft, begin a slow creep along with increasing dew points.  I do expect a decent cloud cover for much of the first half of the day.  Conditions should remain safe enough that I am expecting no worse than a mixture of Good and Low Moderate conditions.

 Thursday is the first day that is causing me some concern.  Southwesterly winds, temperatures and dew points are finally aligning to potentially support ozone production.  Cloud cover ahead of an approaching front will be a key issue and the models are not yet in good agreement. 

 A cold front passage, early Friday morning, should return Air Quality back into the Good range for most of Friday and Saturday as high pressure passes overhead.  By Sunday, however, we will be on the back side of the high-pressure cell with winds again becoming more southerly accompanied by increasing temperatures and dew points. 

 However, since Thursday does have some elements that are potentially concerning, I intend to be prudent and update this forecast on Wednesday.

  EXTENDED FORECAST:

Air Quality should be generally Good during the beginning of the upcoming weekend.

Next Forecast update: Wednesday, June 12, 2024

06/07/2024 Forecast Update

FORECAST SUMMARY: Friday, June 7, 2024 Through Monday june 10

OZONE: 8-hour average Ozone concentrations are expected to be in the Good (Green AQI) range.

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

FORECAST DISCUSSION:

The cooler conditions that set in this past week will remain through this forecast period. On-and-off precipitation is in the forecast due to the cooler temperatures and a few disturbances moving through. The weekend will not be a complete washout in regard to precipitation, but a few showers may be seen. Since ozone-conducive weather conditions are not expected, levels should remain Good.

Surface and upper-level winds from the west/northwest through Sunday change to more of a northerly direction Monday as a boundary drops in from Canada. Current wildfires exist far to our northwest in Canada, and while the wind direction is expected to come from that region, the fire activity has been low the past few days, not producing significant amounts of smoke. This is something we will keep an eye on, updating this forecast if necessary; however, at this time, PM2.5 is expected to remain Good through early next week.

 EXTENDED FORECAST:

 Extended forecast models show dry conditions to start next week with a slow warmup as next week progresses. Air quality levels towards mid-week may get back into the Moderate range; until then, levels should be mostly Good. 

Next Forecast update: Monday, June 10, 2024

06/03/2024 Forecast Update

FORECAST SUMMARY: Monday, June 3, 2024, through Friday, June 7, 2024

OZONE: 8-hour average Ozone concentrations are expected to range from Good (Green AQI) to Moderate (Yellow AQI) across central and southern locations Monday and Tuesday, and a few locations in the east/southeast may reach the low-end Unhealthy for Sensitive Groups (USG, Orange AQI). The rest of the period readings will range from Good to Moderate.

PM-2.5: 24-hour daily average Fine Particulate concentrations will range between upper Good and low Moderate through the forecast period.

FORECAST DISCUSSION:

As a warm front lifts north into the state, warm, humid conditions can be expected Monday and Tuesday with storm chances, generally in northern locations. Locations Monday and Tuesday that experience more sunshine will also see an increase in ozone concentrations, and there is a small chance an isolated monitor in the southeast could reach the low-end USG range. We feel, however, that clouds will be prevalent enough on Tuesday to keep concentrations Moderate. The timeframe for the highest ozone concentrations Monday and Tuesday will be during the mid-afternoon to early evening hours. A storm system and associated boundary bring more widespread precipitation to the state late Tuesday into Wednesday. This produces a good airmass change with cooler temperatures on a northwesterly flow that lasts the rest of the week. Ozone concentrations past Tuesday should range Good through the rest of the forecast period.

Fog that developed early Monday morning resulted in PM2.5 increases, with hourly concentrations ranging from the upper Moderate to low-end USG range during the morning hours. As the fog dissipated, PM2.5 levels improved into the Good to low-Moderate range. Increased humidity on Monday, lasting until the frontal passage on Wednesday, may allow for increases in PM2.5 into the Moderate range, especially in southern locations. Past Wednesday, we expect primarily Good PM2.5 levels. We are keeping an eye on wildfires far to our northwest in Canada, and current smoke models are not picking up smoke coming into the region, even as winds turn northwesterly later in the week. This is something we will keep an eye on, and this forecast will be updated if necessary.

EXTENDED FORECAST:

Extended forecast models show cooler temperatures and scattered chances for precipitation late in the period. If this forecast remains on track, pollution levels should be generally Good.

Next Forecast update: Friday, June 7, 2024

05/31/2024 Forecast Update

FORECAST SUMMARY: friday may 31, 2024 Through monday june 3

OZONE: Ozone concentrations are expected to be in the Good (Green AQI) to low-Moderate (Yellow AQI) range.

 PM-2.5: PM-2.5 concentrations are expected to be in the Good (Green AQI) to low-Moderate (Yellow AQI) range.

FORECAST DISCUSSION:

We end the month of May on a high note with sunny skies and surface temperatures ranging from the 60s to the 70s throughout the state. A High-pressure system is sitting just to our southeast providing these weather conditions. The current conditions begin to erode as a rather weak frontal boundary crosses over the state tomorrow, Saturday, morning into Saturday afternoon. This will provide spotty rain showers across the state while dropping temperatures slightly. The rebound comes on Sunday as we stay mostly dry with temperatures ranging from the 60s to 70s as we start off the first week of June.

Due to somewhat stagnation today, Friday, PM-2.5 concentrations can be expected to hang around the Moderate range, but no higher than mid-high Moderate. The boundary coming through on Saturday will help to clean out any buildup with Sunday having residual concentrations hanging around, but nothing higher than the low-Moderate range. For Ozone, temperatures are still too cool for any serious Ozone development. Surface winds are looking to stay mainly southerly until Sunday, which may allow for Moderate concentrations over Lake Michigan and into the eastern Upper Peninsula. Numerous Ozone forecasts are showing low-mid Moderate concentrations over the lake and slowly moving north up the lake due to the winds. As just stated, however, Moderate concentrations are expected at worst in some lakeshore areas.

 EXTENDED FORECAST:

We start off June with pretty typical surface temperatures for this time of the year, however a cool down is expected for later next week. Air Quality should remain in the Good to Moderate range.

 Next Forecast update: Monday, June 3, 2024

05/28/2024 Forecast Update

FORECAST SUMMARY: Tuesday, May 28, 2024 through friday may 31, 2024

OZONE: Ozone concentrations are expected to be in the Good (Green AQI) range.

 PM-2.5: PM-2.5 concentrations are expected to be in the Good (Green AQI) to low-Moderate (Yellow AQI) range.

FORECAST DISCUSSION:

We start the final week of May with surface temperatures just below normal for this time of the year. Rain showers yesterday and overnight, along with northerly winds are the cause of these cooler temperatures. With northerly winds in place for much of midweek, these current temperatures should be expected until a change in airmass enters our area later this week. Come Thursday, a High-Pressure system moves in from the west and looks to cross over the upper peninsula. Winds will still be mainly northerly but as the pressure system moves more north, another High-Pressure sets up to our south which will shift winds to a more southerly wind. This will help to clear skies and bring warmer, and more seasonally normal, temperatures to our area just in time for the first weekend of June.

For air quality this week, PM-2.5 concentrations look to hang around the Good (Green AQI) category as surface smoke has moved out of the area with persistent northerly winds. PM-2.5 concentrations can be expected to reach the Moderate (Yellow AQI) towards the tail end of this week due to light winds from the aforementioned High-pressure systems. With cooler temperatures throughout this week, Ozone does not look to be a threat either. Good (Green AQI) concentrations are expected this week with an uptick heading into the weekend due to warming temperatures and clearing skies. Ozone for the weekend will be looked at on Friday.

 EXTENDED FORECAST:

We warm up as we enter June with air quality expected to remain in the Good (Green AQI) to Moderate (Yellow AQI) range.

 Next Forecast update: Friday, May 31, 2024

05/24/2024 Forecast Update

FORECAST SUMMARY: mONDAY, may 24, 2024, through Tuesday, May 28, 2024

OZONE: 8-Hour average Ozone concentrations will be Good (AQI Green) to Moderate (AQI Yellow).

 PM-2.5: 24-hour average Fine Particulate concentrations are expected to remain mostly Good (AQI Green)..

FORECAST DISCUSSION:

We are entering the holiday weekend that is generally considered the unofficial start of summer.  Friday will remain mostly sunny and warm with Air Quality in the Good to Moderate range.  That will be interrupted by cold front passing through the State, Friday night.  Some severe weather in the form of gusty winds and localized heavy rains could occur during Friday night.

 That system will clear out Saturday morning with cooler, clearer weather in its wake.  That clear weather pattern should persist for the remainder of Saturday and through most of the day Sunday with Good Air Quality.

 Another system approaches during Sunday, as a leading warm front passes during the day.  That system will drag a cold front through the area, Sunday night, with the potential for more severe weather.  Scattered shower activity and cool weather should persist through Monday with Air Quality remaining Good.

 EXTENDED FORECAST:

 Air Quality should be generally Good to follow the holiday weekend.

 Next Forecast update: Monday, May 28, 2024

05/20/2024 Forecast Update

FORECAST SUMMARY: mONDAY, may 18, 2024, through fRIDAy, May 24, 2024

OZONE: 8-Hour average Ozone concentrations will be Good (AQI Green) to Moderate (AQI Yellow).

 PM-2.5: 24-hour average Fine Particulate concentrations are also expected to remain mostly Good (AQI Green) to Moderate (AQI Yellow).

FORECAST DISCUSSION:

After a series of events, which included wildfire smoke mostly to our west and higher temperatures over the weekend leading to our first Air Quality Advisory of the season, we are looking at better Air Quality during the current work week.

 Warmer than average weather will continue with the threat of some severe weather including locally damaging winds and potentially damaging hail Monday afternoon.  Tuesday will be warm and quite humid and most of the day will should dry.  Some scattered showers and thunderstorms are likely to develop from mid to late afternoon and turning potentially severe Tuesday night. 

 A cold front traverses the State during Wednesday putting an end to the hot, stormy weather.  Air Quality should range from Good to Moderate during this turbulent weather period.

 The latter half of the week looks pleasant with seasonal temperatures in the 70’s with sunny skies and mostly Good Air Quality.  This weather pattern looks to extend into the holiday weekend, although with a better chance of scattered showers and continued mostly Good Air Quality.

 EXTENDED FORECAST:

Air Quality should be generally Good to begin the holiday weekend.

 Next Forecast update: Friday, May 24, 2024

05/18/2024 Forecast Update

FORECAST SUMMARY: Saturday, may 18, 2024, through Monday, May 20, 2024

OZONE: 8-hour average Ozone concentrations are expected to be mostly Moderate (Yellow AQI), but locations along the western lakeshore and in the southeast may reach Unhealthy for Sensitive Groups (USG, Orange AQI) on Saturday; concentrations Sunday and Monday will range from upper-Good to Moderate.

 PM-2.5: 24-hour daily average Fine Particulate concentrations will range between upper Good (Green AQI) and Moderate through the forecast period.

FORECAST DISCUSSION:

Weak high pressure is dominating conditions on Saturday, with warm surface and upper-level temperatures, plenty of sunshine, and a light southerly wind. This set-up creates conditions conducive to ozone development, especially in the most prone locations. Because of this threat, we have an AQA in place along the West Michigan shoreline and in the southeastern portion of the state. The timing for the highest concentrations will be in the afternoon, into the mid-evening hours. The threat of increased ozone will diminish after Saturday due to a frontal boundary passing the state on Sunday.

The Sunday boundary brings in a wind shift to the northwest. Precipitation with this boundary moves into the Upper Peninsula and Northern Lower on Saturday night into early Sunday. Less chances for precipitation will be seen across the central and southern lower portions of the state, aside from scattered development in the southeast on Saturday afternoon or evening. Areas across lower Michigan that remain sunny may reach Moderate for ozone concentrations on Sunday; otherwise, readings should be in the Good range. A mix of Good and Moderate ozone concentrations is expected again on Monday ahead of the next approaching weather system.

The frontal boundary that passed earlier this past week brought the first plume of wildfire smoke into the state. While only moderate increases in PM2.5 were experienced here in Michigan, we have been in generally the same airmass this week, and PM2.5 concentrations are still ranging from low-Moderate across portions of the state. Moderate concentrations may improve on Sunday behind the weak cold front, but southerly winds and increased moisture by Monday may keep daily averages ranging from Good to low-Moderate through early next week.

EXTENDED FORECAST:

 Extended forecast models show a strong weather system moving in on Monday into Tuesday. Good pollution levels are anticipated across the northern portions of the state during this period, and readings by Tuesday will be back to the Good range in southern areas.

 Next Forecast update: Monday, May 20, 2024

05/17/2024 Forecast Update

FORECAST SUMMARY: Friday, May 17, 2024, through Saturday, May 18, 2024

Air Quality Advisory for Saturday, May 18, 2024

 The Air Quality Advisory is in effect for the following Michigan counties: In West Michigan:

Allegan, Kent, Muskegon, Ottawa, Berrien, Cass, and Van Buren Counties

 Ozone: 8-hour average Ozone concentrations are expected to be mostly Moderate (Yellow AQI), but locations along the western lakeshore and in the southeast may reach Unhealthy for Sensitive Groups – USG (Orange AQI) on Saturday.

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

FORECAST DISCUSSION:

A weak system is moving through Friday and another boundary early Sunday; however, neither system produces a good airmass change. Levels of PM2.5 have been lingering in the low-Moderate range the past couple of days, and without a clean airmass moving in, readings are likely to remain in the upper-Good to low-Moderate range through the weekend.

Surface and upper-level temperatures begin increasing Friday, and the warming trend continues Saturday. While a few storms could develop across southern portions of the state on Friday afternoon, most of the state will remain dry. Ample sunshine is expected on Saturday. A calm wind starts the day, but then light winds with a southerly component develop. All these combined results in ozone-conducive conditions for Saturday. The areas of greatest concern are along the west Michigan lakeshore, from Muskegon south, and in southeast locations. Because of this, we have issued an Air Quality Advisory for Saturday, May 18, 2024, for some counties in both west and southeast Michigan. The timing of the highest ozone concentrations will be during the afternoon and into the mid-evening hours. It is recommended that, when possible, you avoid strenuous outdoor activities, especially those with respiratory diseases such as asthma.

There is a possibility that ozone-conducive conditions could linger into Sunday. Because of this, we will be updating the forecast tomorrow to detail the expected air quality conditions for early in the new week.

EXTENDED FORECAST:

 Extended forecast models show a system moving into the state Monday which should bring clouds and chances for rain. Air quality levels higher than Moderate are not expected early in the new workweek.

 Next Forecast update: Saturday, May 18, 2024

05/10/2024 Forecast Update

FORECAST SUMMARY: Friday, may 10, 2024, through Monday, May 13, 2024

OZONE: Concentrations are expected to be in the Good to low-moderate range.

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

FORECAST DISCUSSION:

We end the work week on a relative high note with clear skies and surface temperatures in the mid-50s to low-60s range. Winds are predominantly out of the north today so that explains the somewhat cooler temperatures for today, Friday. As we get into the weekend, a Low-pressure system is expected to cross over the state on Saturday bringing rain showers for all of Michigan. Periodic rain is expected throughout the day with rain totals below half an inch with surface temperatures struggling to get out the low-50s in some areas. As quickly as the Low-pressure enters the region is as quickly as it exits as a High-pressure system fills in behind on Sunday. Winds shift to more southwesterly which will bring in warmer air thus providing surface temperatures in the 60s for all of Michigan. Sunday is looking to be a picturesque Mother’s Day with clear skies and temperatures near normal for this time of the year.

For air quality, with the frontal boundary and rain on Saturday, any Ozone and PM-2.5 concentrations will be cleaned out of the airmass providing Good concentrations for much of the weekend. With winds shifting to southwesterly on Sunday, there may be a chance of low-moderate concentrations for both pollutants, but only for a short while as Monday is expected to bring in yet another frontal boundary.

 EXTENDED FORECAST:

As mentioned above, another cold front will make an appearance on Monday, but we clear out on Tuesday with temperatures hanging around the 60s. Overall air quality is looking to remain Good.

  Next forecast update: Monday, May 13, 2024

05/06/2024 Forecast Update

FORECAST SUMMARY: Monday, may 6, 2024, through Friday, May 10, 2024

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

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

FORECAST DISCUSSION:

Michigan started off May in a picturesque way with temperatures well into the 60s and 70s throughout the state and ample sunshine coupled with the warm air. Rain showers hung around the state, but the majority of showers occurred in the overnight hours and did not hinder daily activities. We start off this work week the same way as the weekend ended—warm and mostly sunny. Today’s weather will give way to a Low-pressure system and associated rain showers tomorrow, Tuesday, afternoon with a chance of organized storms for Tuesday afternoon and evening hours for southern Michigan. On Wednesday, we look to bounce back with relatively dry conditions in the southern portions of the state with the upper peninsula having some left-over showers from the exiting pressure system. Thursday presents us with yet another pressure-system along with providing us additional rain showers for much of the state and a slight cool down for Thursday and Friday. The Low-pressure system on Thursday will shift winds for Thursday and Friday towards the northerly direction, which is the reasoning for the cooler temperatures for parts of the state. We end the work week with dry conditions and temperatures hanging around the 60s for much of the state.

For air quality, low end Moderate conditions can be expected throughout the week due to shifting wind directions and multiple frontal boundaries crossing the state. For Ozone, surface temperatures are not expected to be warm enough for Ozone development, along with an unfavorable wind direction throughout the week. Changes in airmass due to the aforementioned frontal boundaries will keep not only Ozone at bay, but PM-2.5 concentrations at bay as well. Stagnation does not seem to be a threat this week due to the wind shifts and cleaning out of airmasses early-to-mid week.

 EXTENDED FORECAST:

The weekend looks to be on the wetter side of the forecast, with spotty rain showers Saturday and decreasing rain chances on Sunday. This will keep overall air quality near the Good range.

  Next forecast update: Friday, May 10, 2024