12/09/2024 Forecast Update

FORECAST SUMMARY: Monday, December 9, 2024, through, Friday, December 13, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

PM-2.5: 24-hour daily average Fine Particulate concentrations will average between Good (Green AQI) and Moderate (Yellow AQI).

FORECAST DISCUSSION:

The warmest temperatures this week will be seen today, Monday, under a southerly wind flow ahead of the next weather system. Increased moisture and a chance for light precipitation exist; however, clearing may happen in western locations as the current weather system pulls away from the region. Winter weather makes a return as the week progresses with cooler air moving in behind a Tuesday frontal boundary, and snow also makes a return. Lake effect snow in a northwesterly wind pattern comes into the forecast Tuesday through mid-week. High pressure is expected to move in for a short time Friday, before another system moves across the state Saturday.

 As for air quality, increased moisture Monday could allow for low-Moderate fine particulate levels, especially across the southern portion of the state. Fine particulate concentrations in the low-Moderate range could linger into Tuesday in the southeast; otherwise, cool northwesterly winds should keep fine particulate in the Good range past mid-week. High pressure and weaker winds Friday could allow for a return to low-Moderate pollution levels.

  EXTENDED FORECAST:

Extended forecast models show a system moving through on Saturday, which brings precipitation back into the forecast. Fine particulate levels during the coming weekend will likely range from upper Good to low Moderate.

Next Forecast Update: Friday December 13th, 2024

12/06/2024 Forecast Update

FORECAST SUMMARY: Friday December 6th, through Monday December 9th 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

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

FORECAST DISCUSSION:

The first weekend of December is upon us and boy did Michigan get a snowy welcome from the month of December. Numerous areas across the state piled up snow due to persistent lake effect snow and the aforementioned Alberta Clipper that was mentioned in the Monday forecast. With the Alberta Clipper, cold temperatures were brought into the region via northwesterly winds. These frigid temperatures will persist through much of today, Friday, and the beginning half of Saturday until winds shift to a more southwesterly direction. This is due to a High-pressure system to our north moving towards the east. These southerly winds, however, will be short-lived as a Low-pressure system drops down from Canada early Sunday which will bring in slightly cooler temperatures for the northern regions of Michigan. The Michigan lake effect snow belts will see persistent flurries this weekend due to the changing wind patterns, adding to their already impressive snow totals.

For air quality this weekend, Good to low-Moderate concentrations are expected for PM-2.5. As winds shift from the south, more particulates will enter the state so scattered low-Moderate concentrations are expected then.

  EXTENDED FORECAST:

A slight, yet quick warm up is expected early next week with the 40s returning to the state. Another system looks to cross over Michigan Tuesday into Wednesday next week which will drop our temperatures back into the 20s. Overall air quality will be in the Good to low-Moderate range.

Next Forecast Update: Monday December 9th, 2024

12/02/2024 Forecast Update

FORECAST SUMMARY: Monday December 2nd, 2024, through Friday December 6th, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

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

FORECAST DISCUSSION:

The first week of December provides a wide range of scenery for Michiganders as those to the south see a dusting of snow to open grass whereas those to the north see numerous inches to feet of snow. Lake effect snow has been hammering much of the upper peninsula and northern lower peninsula since Thanksgiving Day. Communities along and slightly inland of the Lake Superior and Lake Michigan shoreline will see lake effect snow persist through today, Monday, before slowly tapering off Tuesday, but pop-up flurries throughout this week should be expected. As we approach midweek, an Alberta Clipper is expected to impact our area Wednesday and into Thursday which will drop a few more inches of snow in northern Michigan. Speaking of an Alberta Clipper, this system is merely a fast-moving low-pressure system that originates near the Alberta Province of Canada. These systems are pretty regular in winter months for the Great Lakes, hence why it is given a more specific name. They are fast-moving so impacts statewide will be more so in the wind category as wind gusts are expected to increase throughout the day on Wednesday. Additional impacts will be temperatures dropping and staying near or below freezing this week due to cold Canadian air being brought to our region. Once the clipper system leaves the area, a High-pressure system moves in from the south on Friday and into Saturday providing us calmer conditions and clear skies.

For air quality, due to shifting winds and windy conditions midweek, PM-2.5 concentrations are expected to be in the Good to low-Moderate range this week. More populated areas like Detroit and Grand Rapids will see higher concentrations in the morning commute hours but will slowly dissipate as each day carries on.

  EXTENDED FORECAST:

Similar temperatures and weather conditions look to continue into the first weekend of December. Air quality should remain in the Good to low-Moderate range.

Next Forecast Update: Friday, December 6th, 2024

11/25/2024 Forecast Update

FORECAST SUMMARY: Monday, November 25, 2024, through Wednesday, November 27, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

24-hour average Fine Particulate concentrations are expected to be mix of Good (AQI Green) and Moderate (AQI Yellow) on Monday then mostly Good (AQI Green) for the remainder of the forecast period.

FORECAST DISCUSSION:

The holiday week is starting out under gray skies and Good Air Quality north of U.S. 10 and Low Moderate conditions south of U.S. 10.  Multiple periods of showers to expected for today and tonight as several waves of low pressure in the upper atmosphere are expected to traverse through the region.  Showers are expected to continue Monday night, as more moisture becomes available, and a cold front passes through.  Following the cold front, Air Quality is expected to be Good through the state.

 Tuesday will be noticeably cooler, following the overnight cold front passage, as temperatures begin to fall ahead of incoming colder air.  High temperatures on Tuesday are not expected to get out of the upper 30’s.  Tuesday into Wednesday should be mostly dry before some light rain/snow chances arrive for the Southern Lower later Wednesday.  As Wednesday is expected to be one of the busiest travel days of the year, it is conceivable that weather could slightly hamper travel efforts, albeit the threat is relatively low.  Much depends on the track of a low pressure system moving across the Ohio Valley, at the time, and only the far southern tier counties would be affected.  The good news is that most of it will happen after dark and, hopefully, after many are done traveling for the holiday.  Most of the effects of that system should be out of the way by daylight, Thursday morning, for Thanksgiving Day travel.

 A more serious threat occurs as we enter the Thursday night into Friday time frame.  Deeper, colder air becomes entrenched over the area with a wind flow pattern from the west-northwest.  This will favor all the western lakeshore counties likely to see advisory type snows Thursday night into Friday night. 

 Lake effect intensity should taper off, a bit, during Saturday as the forecast models are showing some high pressure ridging building in.  This will likely be short lived, however, as another short wave drops down Saturday night that could ramp up lake effect snows that could continue through the following week.

 As we will have a long holiday weekend beginning Thursday and Air Quality does not appear to be an issue, the forecast weekend forecast will be issued on Wednesday to cover the holiday weekend.

  EXTENDED FORECAST:

Air Quality is expected to remain Good going into the upcoming weekend.

Next Forecast Update: Wednesday, November 27, 2024

11/22/2024 Forecast Update

FORECAST SUMMARY: Friday, November 22, 2024, through, Monday, November 25, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

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

FORECAST DISCUSSION:

The storm system that brought much of the state its first snow of the season continues to spin near the mid-Atlantic states Friday. Cool northerly winds and scattered precipitation linger one more day before a weak high-pressure ridge moves into the Ohio River Valley late Friday into Saturday, drying conditions out. This will be short-lived, however, as the next system approaches from the west late Sunday into Monday. Precipitation returns to the forecast early in the new week.

As for air quality, the cooler, northerly wind flow Friday will keep fine particulate generally Good across the state. Weaker winds move in on Saturday, and the flow turns back to a southerly direction early next week. This will likely cause an increase of fine particulate into the low-Moderate range, especially across southern Michigan. Mild temperatures are anticipated early next week, along with precipitation chances developing late Sunday into Monday. With this weather set-up, we expect fine particulate levels to continue in the upper Good to low Moderate range through early next week.

  EXTENDED FORECAST:

 Extended forecast models show an active weather pattern setting up in the long-term forecast, including the coming Thanksgiving holiday. This will be something to keep an eye on, especially if you have travel plans. Regarding air quality, an active weather pattern hampers significant pollution development; therefore, fine particulate readings higher than low to middle Moderate are not anticipated.

Next Forecast Update: Monday, November 25, 2024

11/18/2024 Forecast Update

FORECAST SUMMARY: Monday, November 18, 2024, through, Friday, November 22, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

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

FORECAST DISCUSSION:

Today, Monday, starts with foggy conditions across much of the state. Due to the stagnation and increased surface moisture, fine particulate concentrations are in the Moderate range at several central and southern locations. The fog should dissipate as the day progresses, and hourly fine particulate levels will also improve. Daily concentrations on Monday should range from upper Good north to middle Moderate south.

On the weather map early this week, a storm system will track from the Southern Plain states on Monday, northeast through Minnesota on Tuesday. During this time, an associated frontal boundary lifts into the Great Lakes region. Precipitation with this boundary moves southwest to northeast through the state late Monday into Tuesday. Beyond Tuesday, the surface low north of Minnesota merges with another northern low. This combined system is expected to settle east of Michigan past mid-week. Cooler air is anticipated to settle in at that time, and some models are showing snow as a possibility with the colder air in place. Regardless of the type of precipitation, cooler conditions linger through the end of the week, along with chances for precipitation.

 As for air quality, moisture trapped at the surface early Monday will cause Moderate concentrations of fine particulate across the central and southern portions of the state, while readings should remain Good further north. The expected boundary lifts north of the state early Tuesday, and winds should pick up in speed from the south. Increased moisture will be in place, but stronger winds will hamper air stagnation, and fine particulate levels should not be any higher than low Moderate Tuesday. Cooler air filters in later Wednesday into Thursday as winds switch to the northwest. Fine particulate concentrations in the Good range are expected past Wednesday, lasting the rest of the workweek.

  EXTENDED FORECAST:

Extended forecast models show chances for precipitation and cooler temperatures continuing into the start of the weekend. Fine particulate levels during this period will likely range between Good and low Moderate

Next Forecast Update: Friday, November 22, 2024

11/14/2024 Forecast Update

FORECAST SUMMARY:Thursday November 14th through Monday November 18th 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

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

FORECAST DISCUSSION:

Most of us Michiganders wake up to damp and dreary skies as a Low-pressure system is moving to the east just to the south of us near the Ohio border. This pressure system brought in rain overnight with some areas seeing rain taper off with others seeing a persistent rain. By tomorrow, Friday morning, the system will be well off to the east, but lingering rain showers may persist especially along the Lake Michigan shoreline due to lake enhanced forcing causing pop up rain showers, much alike lake effect snow. By Friday afternoon the majority of Michigan is dry but overcast skies will last essentially throughout the entire weekend, even though a High-pressure system moves in. Even though it will be cloudy, the High-pressure system will shift winds to more southerly flow which will bring in warmer air with some areas approaching the mid-50s on Saturday and Sunday. Another pressure system moves into the region early Monday which will shift winds back to more northerly flow, thus cooling us down into the upper 40s.

PM-2.5 concentrations are expected to be in the Good to low-Moderate range with most of the areas seeing Moderate concentrations being more populated areas like Grand Rapids and Detroit. Once winds shift to southerly flow, this may bring in more PM-2.5 concentrations but nothing major, although slightly noticeable on monitors throughout Saturday and Sunday. Overall, Good to low-Moderate averages are expected.

  EXTENDED FORECAST:

Next week will see numerous pressure systems influencing our weather with mid-to-late next week possibly seeing snowflakes across the state. With the multiple rounds of pressure systems, air quality is expected to be in the Good range.

Next Forecast Update: Monday, November 18, 2024

11/12/2024 Forecast Update

FORECAST SUMMARY:Tuesday November 12th through Thursday November 14th, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

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

FORECAST DISCUSSION:

We enter the middle of November with forecasted surface high temperatures hanging around normal temperatures for this time of the year. After a few days of sporadic and spotty rain showers, High-pressure and associated clear conditions, set in for the next day or so. As we get into Wednesday, although the High-pressure moves off to the northeast, conditions throughout the day will be rather identical to today, Tuesday. The next Low-pressure system to bring in rain will move into the region late Wednesday and into Thursday with showers hanging around throughout Thursday but slowly tapering off as we approach the evening.

For air quality and associated PM-2.5 concentrations, as a result of the cold front and rain we experienced this past weekend, PM-2.5 concentrations received a good cleanout therefore conditions are currently sitting in the Good range. Regionally Good concentrations will aid the multi-day Good conditions we will see for PM-2.5 in the Great Lakes state. These conditions are expected to continue due to the aforementioned Low-pressure system and rain forecasted to traverse the state Wednesday into Thursday.

  EXTENDED FORECAST:

Conditions this weekend look clear with temperatures in the low-50s, clearing skies, and Good overall air quality.

Next Forecast Update: Thursday, November 14, 2024

11/08/2024 Forecast Update

FORECAST SUMMARY: Friday, November 8, 2024, through Tuesday, November 12, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

24-hour average Fine Particulate concentrations are expected to be mostly Good (AQI Green).

FORECAST DISCUSSION:

After enjoying unseasonably warm weather early in the week, things have settled back into more seasonable fall temperatures. 

 High pressure will slide over the Great Lakes region during Friday to begin the weekend weather.  Under sunny skies, afternoon highs will reach the 50’s and clear, dry nights can reach down to the freezing mark.  Air Quality is expected to be Good. 

 As the high pressure ridge quickly exits the region, clouds will roll in late Saturday in advance of an approaching low pressure system.  The front associated with that system will pass through Michigan during Sunday with expected precipitation amounts around a third of an inch.  Although winds will briefly shift to the southwest prior to the frontal passage, Air Quality should remain in the Good range.

 Another, less juicy front, approaches the region on Monday and is expected to be pushed southward over the Great Lakes during Tuesday by a high pressure cell over Ontario.  Not much precipitation is expected with this frontal passage with Air Quality still in the Good category.

Due to the Veteran’s Day holiday on Monday, this forecast will be updated on Tuesday.

  EXTENDED FORECAST:

Air Quality is expected to remain Good going into the upcoming work week.

Next Forecast Update: Tuesday, November 12, 2024

11/05/2024 Forecast Update

FORECAST SUMMARY: Monday, November 4, 2024, through Friday, November 8, 2024

OZONE:

November marks the end of the 2024 ozone season. The 2025 ozone season will begin on March 1st.

 PM-2.5:

24-hour average Fine Particulate concentrations are expected to be mostly Good (AQI Green).

FORECAST DISCUSSION:

As we enter the first full week of November, ozone season is now complete, and we focus solely on PM-2.5.  Wildfire smoke does not appear to be an issue with the number of fires in western U.S. and Canada greatly reduced.  In fact, the smoke models are not showing any significant smoke, anywhere. 

 The particulate models are still showing some areas of Low Moderate PM-2.5 so I will keep Moderate in the forecast for the lower half the Lower Peninsula, during Monday.  But then it clears out and I expect Good Air Quality for the remainder of the forecast period.

 In terms of the weather outlook, it looks to be very wet through Tuesday and into Wednesday morning.  Moist southerly winds are bringing in high potential rainfall amounts, up to 3” in some areas of western Michigan.  The rain looks to be joined by strong winds during election day (Tuesday).  The wet weather will eventually end on Wednesday and things will dry out under sunny skies for Thursday and Friday.

  EXTENDED FORECAST:

Air Quality is expected to remain Good going into the upcoming weekend.

Next Forecast Update: Friday, November 8, 2024

10/29/2024 Forecast Update

FORECAST SUMMARY: Monday, October 28, 2024, through, Friday, November 1, 2024

OZONE:

Ozone concentrations are expected to be mostly Good (Green AQI), but a few locations may reach low Moderate (Yellow AQI) Tuesday and/or Wednesday.

 PM-2.5:

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

FORECAST DISCUSSION:

The new workweek starts with a dry, mild Monday, but the next few days feature a rollercoaster of temperatures. Yes, the end of October is quickly approaching; however, record-breaking temperatures are possible Tuesday and Wednesday. A warm front pushing north through the state late Monday/early Tuesday brings with it chances for showers and/or storms but also a gusty southwest wind in its wake. This strong, southerly flow brings in warm air Tuesday and Wednesday, with highs well into the 70s expected. The next chance for precipitation arrives late Wednesday into Thursday as a cold front tracks west to east through the Great Lakes region. This boundary may result in wet conditions for trick-or-treaters on Halloween. The start of November features cooler and dry conditions as high pressure moves in behind the Thursday cold front.

As for air quality, Thursday is Halloween, but it also officially marks the end of the 2024 ozone season. Warmer temperatures on a southerly wind may allow for a few locations to reach low-Moderate for ozone either Tuesday or Wednesday; however, mostly Good readings will close out the 2024 season. For fine particulate, the strong southerly wind may transport in some smoke from seasonal agricultural fires well south of the state. We are seeing this trend in current weather models, and it is being picked up on smoke forecast models as well. We do not expect significant increases in fine particulate at the surface, but readings in the Moderate range are likely, especially across much of lower Michigan. We will keep an eye on both the weather forecast and smoke models during the week, and this forecast will be updated if daily averages higher than Moderate become likely.

  EXTENDED FORECAST:

Extended forecast models show the next storm system approaching Sunday, which will bring precipitation back into the forecast. Air quality levels higher than low-Moderate are not expected during this period.

Next Forecast Update: Friday, November 1, 2024

10/25/2024 Forecast Update

FORECAST SUMMARY: Friday October 25th through Monday October 28th2024

OZONE:

Ozone concentrations are expected to be in the Good range.

 PM-2.5:

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

FORECAST DISCUSSION:

Although cooler, another Pure Michigan Fall weekend is in store after most of us woke up to rain this Friday morning. This rain was accompanied by a cold front, hence the slight cool down we will see today and into tomorrow. Once the Low-pressure carrying the cold front moves off to the east, a High-pressure system fills in behind it throughout the day tomorrow, Saturday. High temperatures will hang right around normal, with slightly below normal in some areas, tomorrow as the High-pressure moves in bringing north to northwesterly winds. As the High-pressure traverses through the Midwest and into the Ohio River Valley, winds will shift to more southerly flow which will provide us a warmup going into Sunday. Accompanying this High-pressure will be clear skies for most areas on Saturday and Sunday. As we round out the weekend and head into Monday, Michigan will be sandwiched between two pressure systems, one Low and the other High. For the beginning half of the week, we will be in the warm sector of those pressure systems with the 70s returning to the Great Lakes State. Along with the warmth, conditions will be rather breezy as being between two pressure systems increases the pressure gradient thus causing gusty winds. In these situations, wind blows from High-pressure to Low-pressure, so since the position of the High-pressure will be south of Michigan, warm air will be pushed into the state.

For air quality, after Friday’s rain a good cleanout of concentrations occurred for both Ozone and PM-2.5. Ozone will continue to remain in the Good range as the Ozone season ends on Thursday, October 31st. PM-2.5 concentrations will hang around the Good range, but once winds shift to more southerly flow, PM-2.5 concentrations may increase but only into the low-Moderate range.

 EXTENDED FORECAST:

We will see the 70s return to start off next week with overall air quality remaining Good.

Next Forecast Update: Monday October 28th, 2024

10/21/2024 Forecast Update

FORECAST SUMMARY: Monday October 21st, through Friday October 25th 2024

OZONE:

Ozone concentrations are expected to be in the Good to low-Moderate range.

 PM-2.5:

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

FORECAST DISCUSSION:

Summer-like warmth returns for the beginning half of this week with some areas in Michigan approaching the 80-degree mark today and tomorrow, Tuesday. This late-October warm up is solely due to the persistent High-pressure sitting to our southeast, bringing in warm air from the south via southwesterly winds. As we approach midweek, however, a Low-pressure system and associated cold front will traverse the Great Lakes region bringing a cool down back to near-normal temperatures and the potential for rain showers throughout the day on Wednesday. As quickly as the Low-pressure enters the region is as quickly as it leaves as Thursday, although cooler, will see a High-pressure and associated clear skies sitting right over us in the Great Lakes state. In Pure Michigan fashion, however, we rollercoaster into another Low-pressure system with more potential for rain on Friday. Yet another High-pressure will fill in behind this Low-pressure providing clearing skies for the last weekend of October.

For air quality, throughout this past weekend there was an upper-level wildfire smoke plume that hung around the Midwest. This Monday morning appears to see that same plume hanging around with some of the smoke dropping down to the mid-to-lower levels of the atmosphere due to the ongoing High-pressure regime. Intermittent hazy skies can be expected through Wednesday until the Low-pressure comes in and cleans out the atmosphere. PM-2.5 concentrations near the surface are expected to be in the Moderate range, with some of the more populated areas seeing hourly values in the high-Moderate range. But overall daily averages for PM-2.5 should average out in the low-to-mid Moderate range. For Ozone, we start the last full week of the 2024 Ozone season with the potential of Moderate to possibly high-Moderate concentrations due to the warming temperatures today, Monday and tomorrow, Tuesday. Nothing more than Moderate concentrations is expected, especially as the Low-pressure and cold front on Wednesday will help to clean out any build up.

 EXTENDED FORECAST:

As mentioned above, we may see intermittent rain on Friday, but skies clear for the weekend thanks to a High-pressure system. Overall air quality is expected to remain in the Good to Moderate range.

Next Forecast Update: Friday October 25th, 2024

10/18/2024 Forecast Update

FORECAST SUMMARY: Friday October 18th, 2024 through Monday October 21st

OZONE:

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

 PM-2.5:

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

FORECAST DISCUSSION:

After a rather Fall-like week, surface temperatures increase throughout this upcoming weekend with the 70-degree mark making its return throughout the state. High-pressure is set up just to our southeast which is bringing warmer air via southwesterly flow. Starting with today, Friday, each of the next two or three days are essentially copy and paste of one another with clear skies, plenty of sunshine and above average temperatures. Due to the High-pressure to our south, winds will be rather light as well, so PM-2.5 concentrations may increase into the upper Moderate range in the morning hours but will slowly dissipate throughout each day. Ozone will continue to be a non-issue as we round out the middle of October and count down the days to the end of the 2024 Ozone season.

There appears to be a plume of upper-level wildfire smoke that will hang around the Great Lakes region throughout this weekend. The aforementioned High-pressure will bring the smoke towards the Great Lakes and the smoke will then rotate around the High-pressure interfering with our blue skies. None of the smoke is expected to reach the surface but will, however, gray out some skies and provide colorful sunrises and sunsets.

 EXTENDED FORECAST:

The 70-degree temperatures continue into the next week until Wednesday when a Low-pressure and cold front enters the region. Overall air quality will remain in the Good range.

Next Forecast Update: Monday, October 21st, 2024

10/14/2024 Forecast Update

FORECAST SUMMARY: Monday October 14th through Friday October 18th, 2024

OZONE:

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

 PM-2.5:

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

FORECAST DISCUSSION:

The chill of Fall has slowly set in the past week or so with a further decrease in temperatures expected this week, but some slight increases as we approach the weekend.

Much needed rain fell across the state this past weekend with some residual showers early this morning. The remnants of the cold front and associated rain that came through will completely move out of the area later today, with northerly winds and cooler temperatures filling in behind it. There is a chance of pop-up lake effect rain showers in the beginning half of this week, but the majority of Michigan will remain dry and in the upper-40s to mid-50s temperature range. As we get into Wednesday, winds shift to a more southwesterly direction, which will cut off any remaining lake-effect rain showers while also increasing surface temperatures across the state. Into Thursday, High-pressure sets up to our east and will stay there into the weekend, providing us warmer temperatures and clear skies.

For air quality, Ozone will be in the Good range as we enter the middle of October and nearing the end of the annual Ozone season. This past weekend saw light, elevated wildfire smoke with some of it still hanging around this Monday morning, Throughout the beginning part of this week, this residual smoke will move out of the region with clear skies moving in behind it. There are still fires burning in west Canada and western US states, but smoke associated with those fires are not expected to impact our upper-levels or surface PM-2.5 concentrations as Good to low-Moderate concentrations are expected.

 EXTENDED FORECAST:

The upcoming weekend looks to be yet another picturesque Michigan Fall weekend with sunny skies and temperatures in the 60s and 70s.

Next Forecast Update: Friday October 18th, 2024

10/11/2024 Forecast Update

FORECAST SUMMARY: Friday, October 11, 2024, through, Monday October 14, 2024

OZONE:

8-hour average Ozone concentrations are expected to be Good (Green AQI) through the forecast period.

 PM-2.5:

24-hour daily average Fine Particulate concentrations will average between Good and Moderate (Yellow AQI).

FORECAST DISCUSSION:

We expect breeze conditions today, Friday, as a frontal boundary approaches from the northwest and high pressure departs to our east. The gusty southwest wind flow between these systems, along with dry conditions, will make an environment more prone to fire development. The National Weather Service has either Red Flag Warnings or Fire Weather Watches in place today across the northern half of the lower peninsula to highlight this risk.
The cold front passes through the state Friday, then stalls across northern Indiana and Ohio this weekend. A small chance for precipitation exists as the boundary passes Friday, but a better chance for rain comes in the forecast for later Saturday into Sunday as a disturbance travels along the boundary just south of the state. High temperatures on Friday will be above normal, generally in the 70s, but readings decrease behind the cold front, with temperatures during the weekend falling from the 50s north to the 60s south.

 As for air quality, warmer temperatures are in place Friday with a southwest flow, but being so late in the ozone season, we expect readings to remain in the Good range through the forecast period. Similar to this past Sunday, the cold front passing through the state on Friday looks to bring in some smoke from fires far to the north and west of the region. This will likely cause increases in hourly fine particulate concentrations, but it does not look like higher readings would last for a long time. While hourly concentration may reach into the upper Moderate range, we do not anticipate daily averages of fine particulate to reach higher than the low to middle Moderate range. After the frontal passage, fine particulate may continue in the Moderate range across the south, closer to the stalled boundary, with Good concentrations expected across the rest of the state. The late Saturday into Sunday system should help keep fine particulate from developing, and readings are expected to average mostly Good.

 We will keep an eye on conditions during the weekend, and if conditions change from what is currently expected, this forecast will be updated to reflect the change.

 EXTENDED FORECAST:

Extended forecast models show cooler temperatures with chances for precipitation continuing into early next week. Air quality in the long term should not be any higher than low-Moderate.

Next Forecast Update: Monday, October 14, 2024

10/07/2024 Forecast Update

FORECAST SUMMARY: Monday, October 7, 2024, through Friday, October 11, 2024

OZONE:

Ozone concentrations will be Good .

 PM-2.5:

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

FORECAST DISCUSSION:

Unexpected hourly increases in PM2.5 concentrations were seen across the state on Sunday. These increases were caused by upper-level wildfire smoke being brought down to the surface behind a cold front that passed through. All monitors experienced hourly increases, with most locations reaching into the upper Moderate range; however, the increases only lasted a few hours, and daily averages remained low-Moderate. The highest increases in hourly concentrations were seen at our Grand Rapids area monitors, where readings reached the Unhealthy for Sensitive Groups (USG-Orange AQI) for a couple of hours. Like other areas, the increases were partly due to the upper-level smoke being transported to the ground, but more so they were influenced by area fires that developed in Ottawa County. The plumes from those fires were pushed east, towards the monitors. Those fires were put out during the day, with the increased PM2.5 concentrations only lasting a few hours.

 For this week, Canadian high pressure sinking in will produce cooler fall-like conditions. A shortwave passing by northern locations early this week may kick off light precipitation; otherwise, dry conditions prevail under a northwesterly wind flow. By Friday, the high-pressure area weakens and moves east, allowing winds to turn more southerly. High temperatures this week will primarily be in the 60s, increasing towards 70 late in the week. Cool nighttime temperatures in the 30s to 40s can be expected, along with areas of frost some mornings.

 Air quality conditions during the week are expected to average mostly Good, aside from a low-Moderate daily PM2.5 concentration mixing in. During the week, we will keep an eye on weather conditions along with any changes in expected smoke transport and/or local fire development that may occur. Updates will be made to this forecast if conditions change from what we currently expect.

 EXTENDED FORECAST:

Extended forecast models show a boundary moving in from the north that may bring in a small chance for precipitation. Air quality in the long term should not be any higher than low-Moderate.

Next Forecast Update: Friday, October 11, 2024

10/04/2024 Forecast Update

FORECAST SUMMARY: Friday October 4th, through Monday October 7th, 2024

OZONE:

Ozone concentrations will be Good .

 PM-2.5:

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

FORECAST DISCUSSION:

As Fall colors start to pop and temperatures slowly begin to cool, we enter the first weekend of October with a few sprinkles across the state, but clear skies later into today and tomorrow, Saturday. The remnants of a cold front that passed over us last night has a few rain showers and clouds hanging around. As stated prior though, clear skies will dominate the region this afternoon as a High-pressure system moves in just in time to kick off the weekend. Saturday will be a picturesque Fall day with warmer than normal temperatures well into the 70s for most areas across the state. Just as quickly as the High-pressure moves in is just as quickly as it leaves due to a Low-pressure system and associated cold front moving in late Saturday night into early Sunday morning. Northerly areas across Michigan will see more rain due to this cold front as southerly areas may see a few spotty showers, but nowhere is expected a complete washout. The cold front moves out as we approach noon on Sunday and some areas will be greeted by the sun come Sunday afternoon. Monday will see a continuation a clear skies but cooler temperatures near our normal highs as we start the first full week of October.

For air quality, Ozone will continue to be a non-issue as temperatures start to cool off more and sunlight becomes less intense. PM-2.5 concentrations will hover around the low-Moderate range for the more populated areas, especially in the morning time as wind is lighter. Any residual build up will surely be cleaned out early Sunday morning as the cold front passes. In the upper levels of the atmosphere, there appears to be a light plume of wildfire smoke which will be over Michigan tomorrow and into Sunday. The smoke will stay in the upper atmosphere but may cause milky skies and colorful sunrises and sunsets.

 EXTENDED FORECAST:

High-pressure looks to sit over the Midwest to start off next week which will help keep the overall air quality Good.

Next Forecast Update: Monday, October 7th, 2024

09/30/2024 Forecast Update

FORECAST SUMMARY: Monday September 30th, through Friday October 4th, 2024

OZONE:

Ozone concentrations will be Good .

 PM-2.5:

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

FORECAST DISCUSSION:

Most of us Michiganders woke up to sun this morning while others woke up to overcast skies and fog. Central Michigan and northward are sitting under clear skies whereas southern Michigan has a persistent cloud deck which is expected to dissipate as the day carries on. Much alike last week, we’ll see both similar surface temperatures, although slightly cooler, and partly cloudy to sunny skies for most of the week. There appears to be two days with rain chances with the first being tomorrow, Tuesday as a cold front moves through the Great Lakes region. The rain showers will be rather widespread and nothing too alarming in terms of amount of rain. Once the cold front moves out, Wednesday and Thursday will see clear skies thanks to a High-pressure system setting up to our south. Come Friday, however, will see the same High-pressure move towards the southeast which will open the door for a Low-pressure system, associated cold front, and chances for rain. This system may pose higher amounts of rain compared to Tuesday, but not a complete washout as the rain will begin to taper off in the Friday evening timeframe.

For air quality, as we round out September and start October this week, we enter the last month of the designated Ozone season with Good Ozone concentrations expected. Temperatures will barely reach the mid-70s this week, which is nice for a slightly above-normal high temperature and keeping Ozone at bay. For PM-2.5, early morning commute hours may pose some hourly Moderate concentrations, but overall daily average should remain in the Good to low-Moderate range. There looks to be a chance of upper-level smoke entering the region midweek but will stay in the upper atmosphere and may create some milky skies and colorful sunrises and sunsets.

 EXTENDED FORECAST:

Once the Low-pressure and cold front move out of the region Friday, a High-pressure sets up for next week providing clear skies for the first weekend of October.

Next Forecast Update: Friday, October 4th, 2024

09/27/2024 Forecast Update

FORECAST SUMMARY: Friday, September 27, 2024, through Monday, September 30, 2024

OZONE:

Ozone concentrations will be Good (AQI Green)..

 PM-2.5:

PM-2.5 concentrations are also expected to be mostly Good (AQI Green).

FORECAST DISCUSSION:

Friday is expected to stay mostly dry under high pressure with continued Good Air Quality.  However, as the remnants of Hurricane Helene travel northwards and begin squeezing that high pressure ridge, winds will increase with some significant wind gusts.

An upper level low over Tennessee will merge with the remnants of Hurricane Helene.   That will send moisture into southern Lower Michigan, tonight, and should be enough to generate light showers throughout the weekend.

High pressure will attempt to build back in Sunday night into Monday, ahead of a cold front on track to move through on Tuesday.

During this time, Air Quality is expected to remain Good, throughout the state.

 EXTENDED FORECAST:

Air Quality is expected to remain Good going into the upcoming work week.

Next Forecast Update: Monday, September 30, 2024