04/25/2025 Forecast Update

FORECAST SUMMARY: Friday, April 25, 2025, through Monday, April 28, 2025

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

PM-2.5:  24-hour average Fine Particulate concentrations are expected to range between Good (AQI Green) to scattered Low Moderate (AQI Yellow) during Friday, then mostly Good (AQI Green) for the remainder of the weekend.

FORECAST DISCUSSION

A front stalled across lower Michigan will likely provide shower activity during Friday afternoon and early evening.  I am not expecting any severe weather associated with this system although a random pop-up thunderhead is not out of the question.  Air Quality will be mostly Good with occasional Low Moderate mostly confined to Southeast Michigan.

High pressure will push out the frontal activity, during early Saturday morning, bringing cooler, dryer air into the region for the weekend.  Northerly wind flow will keep temperatures on the cooler side with Saturday night lows in the 30’s.  Weekend highs will be in the 50’s to low 60’s, which is normal for this time of year.  Decreasing clouds on Saturday will lead to mostly sunny skies for Sunday and Monday.  Air Quality is expected to be mostly Good through the weekend.

EXTENDED FORECAST:

 Air Quality is expected to continue being mostly Good going into the upcoming work week.

Next forecast update:  Monday, April 28, 2025

04/21/2025 Forecast Update

FORECAST SUMMARY: Monday, April 21, 2025, through Friday, April 25, 2025

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

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

FORECAST DISCUSSION

Low pressure, with associated cold front, enters the Lake Michigan region late Monday morning and will continue to track off to the northeast.  Isolated showers and storms have developed, earlier this morning, with generally widespread precipitation.  Drier air should limit precipitation opportunities, Monday afternoon, and winds will remain gusty throughout the day.

High pressure follows Monday’s frontal passage making Tuesday likely the nicest day of the week to be outdoors.  Sunny skies are expected with afternoon temperatures reaching the mid-60’s.

A weak warm front lifts into the region Tuesday night with a chance for shower development overnight and possibly into early Wednesday.  The southern counties could see temperatures push toward 70 degrees during Wednesday with the best chance of the week to see scattered fine particulate matter in the Moderate range, mostly in the urban areas.

Precipitation chances increase Thursday night into Friday as a low-pressure system moves into the Midwest bringing the potential for both showers and thunderstorms.  Conditions then dry out for the weekend as high pressure moves back into the Upper Great Lakes region.

 All in all, the work week looks reasonably quiet, with several chances for scattered precipitation and I do not see any serious concern with Air Quality.  PM-2.5 will be a mix of mostly Good to scattered Low Moderate.  Ozone concentrations are expected to be Good throughout the week.

 EXTENDED FORECAST:

Air Quality is expected to continue being mostly Good to scattered Low Moderate going into the upcoming weekend.
Next Forecast update: Friday, April 25, 2025

04/18/2025 Forecast Update

FORECAST SUMMARY: Friday, April 18, 2025, through Monday, April 21, 2025

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

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

 FORECAST DISCUSSION:

 A storm system moving through Friday will bring periods of showers and storms as it tracks through. Some of the storms could be strong, so it’s something you may want to keep an eye on. High pressure then slides in on Saturday; however, the next system moves into the region on Sunday, bringing showers back into the forecast on Easter. Southwest winds across lower Michigan on Friday allow temperatures to reach the mid-60s to mid-70s, but readings will fall into the 50s to 60s on Saturday as northwest winds develop. Further north, temperatures are expected to range in the 50s on Friday and then into the 40-to-50-degree range during the weekend.

 As for air quality, the period begins with a mix of Good to low Moderate fine particulate levels and Good ozone readings. These concentrations will continue Friday, and an improvement to all Good is expected Saturday as northwest winds kick in. Mostly Good air quality levels are expected to linger through the coming weekend, with only a chance for low-Moderate fine particulate in the south early next week.

 EXTENDED FORECAST:

 The extended weather models show precipitation continuing Monday, but dry weather returns on Tuesday. Temperatures will be cooler early in the week, but milder conditions are forecast by mid-week. Pollution levels early next week will average Good for ozone and a mix of Good to low-Moderate for fine particulate.
Next Forecast update: Monday, April 21, 2025

04/11/2025 Forecast Update

FORECAST SUMMARY: Friday April 11th, 2025, through Monday April 14th, 2025

Ozone:

Ozone concentrations are expected to be in the Good range.

PM-2.5:

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

FORECAST DISCUSSION:

High-pressure and clear skies round off the work week and kickoff the weekend for us Michiganders. Many of us will approach the 50-degree mark today, Friday, while others stay in the low-to-mid 40s. As we get into Saturday, the High-pressure system moves right over top of us providing ample sunlight and minimal clouds with surface temperatures well into the 50s throughout the state. These warming temperatures will be provided by southwesterly winds as they wrap around the High-pressure system before it moves off the to the east come Sunday. An encroaching Low-pressure system somewhat spoils the weekend fun with potential spotty rain expected on Sunday, but temperatures remain in the 50s, however. The Low-pressure system continues to move eastward throughout Sunday and into Monday as even warmer temperatures are expected Monday to kick off the next week.

While winds stay more stagnant today, PM-2.5 concentrations are expected to remain in the Good to low-Moderate range. Shifting winds tomorrow will help decrease and keep these concentrations at bay for the time being. As winds shift to a more southerly direction, particulate from the south may increase concentrations to the low-Moderate range for much of Sunday and into Monday. For Ozone, like a broken record, it is still not warm enough for any real Ozone development this weekend. As temperatures warm into the 60s on Monday, however, we may see a few monitors eclipse the Moderate range for an hour or so, especially in more populated areas.

EXTENDED FORECAST:

The aforementioned Low-pressure system will bring a cold front along with it which will cool down temperatures for Tuesday, but we quickly rebound come midweek. Air quality should reman in the Good range.

Next Forecast update: Monday April 14th, 2025

04/07/2025 Forecast Update

FORECAST SUMMARY: Monday April 7th, 2025, through Friday April 11th, 2025

Ozone:

Ozone concentrations are expected to be in the Good range.

PM-2.5:

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

FORECAST DISCUSSION:

The first full week of April is upon us, and it looks like Michiganders will have to wait a few more days to see warm April weather. A cold front drops down from our north throughout the day today bringing north-northwesterly winds and snowfall for the entire state. The upper peninsula and northern lower peninsula will see most of the accumulation with mid-Michigan and southward only seeing flurries with trace amounts of accumulating snow. The cold front leaves clear conditions in its wake for Tuesday and a good amount of Wednesday before another Low-pressure system approaches the Great Lakes late Wednesday and kicking up rain showers for southern portions of the state. Once we get through the first half of the week, there is a rather steady incline in temperatures which will carry us into the weekend ahead. For the latter half of the week, we will see High-pressure hanging around with winds coming from the south—providing temperatures returning to the 50s and 60s.

Northerly winds for the beginning half of the week will help keep air quality in the Good range as there appears to be little to zero smoke or dust in the area to impact PM-2.5 concentrations and it is still too cold for Ozone to develop. Once we get into the latter part of the week, warmer temperatures may bring hourly Moderate concentrations for PM-2.5 These concentrations will mainly be contained to the morning rush hour timeframe with dissipating concentrations throughout the day. It should be noted that there are current fires burning in southern plain states, so there will be continued smoke entering the atmosphere. As of now, this smoke does not look to impact Michigan, but smoke concentrations will be monitored. Ozone may see an increase towards Moderate, but it will still be too cold for any real Ozone development.

EXTENDED FORECAST:

As mentioned above, warm and clear conditions look to be on deck for the weekend ahead. Air quality is expected to remain in the Good range.

Next Forecast update: Friday April 11th, 2025

04/04/2025 Forecast Update

FORECAST SUMMARY: Friday, April 4, 2025, through Monday, April 7, 2025

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

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be a mixture of Good (AQI Green) to scattered Low Moderate (AQI Yellow).

FORECAST DISCUSSION

High pressure will remain centered over the Great Lakes, during Friday, and will maintain dry conditions and seasonal temperatures through late afternoon.  The center of the high will drift across the northern Great Lakes, today, maintaining an easterly component and light winds.

Another low-pressure system will pass through the already battered mid-south states during Saturday and Sunday.  While most of our forecast area should receive some additional rainfall, the best chance of significant rain will be south of our border.  The border counties up to I-94, however, could see up to 1.25 inches of additional rain.  The timing of that event could begin late Friday afternoon or early evening with the heaviest showers tonight into early Saturday morning.

Colder air will begin to move in Saturday night into Sunday due to a strong upper-level low approaching through southern Canada.  As that low moves eastward during Monday and high pressure builds in behind it, cold northerly air will stream in keeping daytime high temperatures around 40 degrees during Monday and Tuesday.  As the center of the high-pressure ridge passes during mid-week, the forecast region returns to southern air flow and warming temperatures.

All in all, next week looks considerable quieter than what have been experiencing the past couple of weeks.  From an Air Quality perspective, I do not see any issues for the weekend or early next week.  PM-2.5 will be a mix of mostly Good to scattered Low Moderate with Ozone concentrations expected to be Good.

  EXTENDED FORECAST:

 Air Quality is expected to be mostly Good to scattered Low Moderate going into the upcoming work week.

03/31/2025 Forecast Update

FORECAST SUMMARY: Monday, March 31, 2025, through Friday, April 4, 2025

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

 PM-2.5:  24-hour average Fine Particulate concentrations are expected to be a mixture of Good (AQI Green) to scattered Low Moderate (AQI Yellow).

FORECAST DISCUSSION

The weekend turned out to be quite wild with the ice storm up north and severe weather in the south.  I have read that six Michigan counties have over 80% power outages, Monday morning, between the two storms.

 This work week starts out quiet, but cooler, following the passage of a cold front but it looks to get bumpy again during mid-week.  Tuesday night model results suggest precipitation starting as all snow changing over to rain by daybreak south of I-96. North of I-96, surface air stays cold longer with accumulating snow and freezing rain likely.

 As Wednesday progresses, we get into a warm air sector ahead of the front with afternoon temperatures increasing into the 60’s.  Atmospheric instability will become significant with the increasing possibility of severe weather by late Wednesday.  Current models have an Enhanced Risk of severe weather (Level 3/5) south of I-96 with a Slight Risk (Level 2/5) north of I-96.  Precipitation models have rain potentials of 1-2 inches with more likely in thunderstorm downpour areas.

 Air Quality will not be an issue in this week’s forecast.  PM-2.5 will be a mix of Good to scattered Low Moderate.  Ozone once again becomes part of our forecast as we enter into April with concentrations expected to be Good.

  EXTENDED FORECAST:

 Air Quality is expected to be mostly Good to scattered Low Moderate going into the upcoming weekend.

Next forecast update:  Friday, April 4, 2025

03/28/2025 Forecast Update

FORECAST SUMMARY: Friday, March 28, 2025, through Monday, March 31, 2025

 PM-2.5:  24-hour average Fine Particulate concentrations are expected to be a mixture of Good (AQI Green) to Moderate (AQI Yellow) through Sunday, then mostly Good (AQI Green) during Monday. 

FORECAST DISCUSSION

 A warm front will push northward through the state during Friday.  That front will eventually stall out leaving most of the lower half of the Lower Peninsula in the warm air sector of the associated low-pressure system.  That will push temperatures in the warm air sector into the mid-60’s, for most of the weekend.  The front will essentially become a stationary front and will probably oscillate a little bit southward by the end of the weekend, but the lower half of the state will stay warm through Sunday. 

 Clouds and scattered precipitation will be with us through the weekend, although no severe weather or hard rains are expected.  Our experience with stalled fronts is that it can trap particulates near the ground.  Since we are starting with a relatively clean base, the region should not expect anything worse than Moderate in the more populated areas.

 The low-pressure system will eventually clear the area, Sunday night, and return us to cooler, northerly wind flow, cooler temperatures, and Good Air Quality.

EXTENDED FORECAST:

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

Next forecast update:  Monday, March 31, 2025

03/24/2025 Forecast Update

FORECAST SUMMARY: Monday, March 24, 2025, through Friday, March 28, 2025

 PM-2.5: 24-hour daily average Fine Particulate concentrations will range generally Good (Green AQI) through mid-week with Moderates (Yellow AQI) possible late in the forecast period.

 FORECAST DISCUSSION:

 Although the calendar shows spring, winter-like conditions can be expected thanks to a low-pressure area across the northern portion of the region. Snow showers are possible across much of the state, with mixed precipitation or rain further south. Northern locations may see accumulations of snow, while little to no accumulation is anticipated further south. Along with precipitation chances, a strong northwest wind will keep temperatures cold for this time of year. As this storm system pulls away, precipitation on Tuesday should be kept to the most prone northwest flow lake effect areas. Weak high pressure moves in by mid-week, but cooler temperatures remain as we are positioned under a cool northwesterly wind pattern.

 As for air quality, the strong northwest winds on Monday will keep fine particulate levels in the Good range. As the storm system moves east Tuesday, surface winds decrease and precipitation ends; however, northwest winds at upper levels continue to prevent pollution from building up. With the anticipated weather conditions, you can expect Good air quality through Thursday. By Friday, the next storm system moves in, bringing a warm front across the southern portion of the state. There is some uncertainty on the placement this far out, but the warmer temperatures and precipitation could cause the fine particulate levels to increase into the low Moderate range, especially in locations south of or close to the boundary.

 EXTENDED FORECAST:

 The extended weather models show a warm front lifting north to south through the state Friday into Saturday. If this forecast pans out, warmer air will move into the state, along with chances for precipitation. Air quality during the first half of the weekend is expected to range from Good north of the boundary to low Moderate near and south of it.

 Next Forecast update: Friday, March 28, 2025

03/21/2025 Forecast Update

FORECAST SUMMARY: Friday March 21st, 2025, through Monday March 24th, 2025

PM-2.5:

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

FORECAST DISCUSSION:

We end this work week on a relative high note with southwesterly winds providing a boost in surface temperatures across the state. An encroaching Low-pressure system is causing these winds today and as we head into Saturday; the system crosses over Michigan and shifts winds to more northwesterly flow, dropping temperatures back into the low-to-mid-30s. With the passing of the cold front, there is a chance for isolated rain and snow showers early Saturday morning with most tapering off as the afternoon approaches. The system moves out of Michigan come late Saturday morning and what is left is mostly sunny skies and surface temperatures in the mid-30s. Michiganders will see more of the same on Sunday with a High-pressure system drifting down from Canada and shifting winds back to more southerly flow, but temperatures still hang around the upper-30s to low-40s for much of Sunday. The next precipitation-maker crosses over the state later on Sunday with a mix of rain and snow depending on where one is on the peninsulas. The upper peninsula will see a few inches of additional accumulating snow with the northern lower peninsula seeing a little less and the southern peninsula seeing mostly rain. This system will carry into early Monday with residual showers persistently hanging around for most of Monday.

For air quality, there was a resurgence of dust and smoke in the upper atmosphere this past week from southern plains states. Fortunately, however, this plume stayed in the upper atmosphere and did not make its way towards the surface unlike last weekend. For the weekend ahead, low-Moderate concentrations can be expected today due to southwesterly winds, but only for a few hours around commuting hours. Into Saturday and Sunday, PM-2.5 concentrations will hang around the Good range due to northerly winds and precipitation keeping concentrations at bay. Although it is officially Ozone season, it has not been warm enough for ample Ozone development.

EXTENDED FORECAST:

Cooler temperatures look to hang around into next week as Spring gets off to a slow start. Air quality looks to remain in the Good range.

Next Forecast update: Monday March 24th, 2025

03/15/2025 Forecast Update

FORECAST SUMMARY: Saturday, March 15, 2025, through Monday, March 17, 2025

 PM-2.5:  Saturday morning Fine Particulate concentrations have dramatically increased in SW Michigan into the USG range (AQI Orange) due to high dust transport.  We expect this to eventually transition back to mostly Good (AQI Green) to Moderate (AQI Yellow) during Sunday.

FORECAST DISCUSSION

In an unexpected development, strong winds have been pushing high levels of dust up from the southern Plaines states.  We have observed monitor readings jump as much as 50 ug/m3, over a short time, at many of our southwest monitors.  As a result, we are modifying our forecast to reflect USG in the southwest quadrant of the state, for the remainder of Saturday.  The remainder of the state will remain Moderate. 

A cold front will move through the region during the early Sunday morning hours.  The wind shift from southwest to northwest should put an end to this episode.  Concentrations should return to the Good/Moderate levels for Sunday and the remainder of the forecast period.  However, since this is a rapidly changing episode, we will continue monitoring and keep the forecast updated if conditions change.

EXTENDED FORECAST: 

Air Quality is expected to be Good to Moderate going into the next work week.

03/14/2025 Forecast Update

FORECAST SUMMARY: Friday, March 14, 2025, through Monday, March 17, 2025

 PM-2.5:  24-hour average Fine Particulate concentrations are expected to transition from mostly Low Moderate (AQI Yellow) to Good (AQI Green) during the forecast period.

FORECAST DISCUSSION

 As we enter the St. Patrick’s Day weekend, the weather will continue to be downright warm and early Spring-like.  The last couple of days, with calm winds and sunny skies, have certainly whetted our appetite for warmer weather to come and stay.

 That warm weather trend will continue through Saturday, but calm winds will yield to increasing winds as a deep low-pressure system approaches from the west.  Packed isobars will increase the Friday afternoon winds into the mid-teen range with gusts in the mid-20 mph range. 

 Early Saturday morning will experience a storm passage associated with the low-pressure system.  Any storms that do develop should move through by sunrise with warm, moist southerly flow continuing to flow.  That should keep Saturday afternoon temperatures up around 70 and we will likely see stronger, sustained winds with gusts up to the mid-40 mph range.

 Colder air arrives for Sunday with daily high temperatures back in the mid-40’s.  Fortunately, that cooling off will be short lived as zonal flow brings back warmer air into the area through the first half of the upcoming week.  Spring is coming!

 In terms of Air Quality, most of the state is experiencing Low Moderate conditions for Friday.  However, as the upcoming system moves through the state, it will act as a broom to sweep out the Low Moderates and should restore Good conditions for the remainder of the weekend. 

EXTENDED FORECAST:

 Air Quality is expected to be mostly Good going into the next week.

03/10/2025 Forecast Update

FORECAST SUMMARY: Monday, March 10, 2025, through Friday, March 14, 2025

PM-2.5: 24-hour daily average Fine Particulate concentrations will range from Good (Green AQI) to Moderate (Yellow AQI) during this forecast period.

 FORECAST DISCUSSION:

We can expect spring-like weather across Michigan this week. Above-normal temperatures and plentiful sunshine dominate Monday, but a quick cool down is expected Tuesday before warmer air makes a return mid-week. While a few locations in the north may see light precipitation late Monday into Tuesday as the boundary passes, most locations will remain dry. High pressure moving in behind the cold front sets up warm southerly winds, bringing a return to above-normal temperatures. Dry conditions with a fair amount of sunshine are also anticipated for the rest of the workweek. High temperatures by Friday are expected to range from the 50s in the north to around 70 degrees south.

The warmer temperatures and sunshine on Monday will cause snow to melt in areas where snow still exists. This increased surface moisture often produces increases in fine particulate levels; however, stronger winds developing, especially in the north where snow remains, will hamper pollution development. Good to low-Moderate fine particulate readings can be expected Monday. Northwesterly winds behind the cold front on Tuesday should keep air quality Good across the state. As temperatures increase and southerly winds develop past mid-week, fine particulate levels should also increase into the Moderate range.

The 2025 ozone season officially started on March 1st; however, we don’t typically begin forecasting for ozone until May. With the warmer temperatures expected, I wanted to mention that we expect maximum 8-hour ozone concentrations this week to remain in the Good range. As always, we will update this air quality forecast if our thoughts on the current trends change.

EXTENDED FORECAST:

The extended weather models show a strong weather system moving in for the end of the week. Despite its uncertain track and strength, this system is expected to bring showers and storms. Air quality levels higher than the Moderate range are not expected during this period.

 Next Forecast update: Friday, March 14, 2025

03/07/2025 Forecast Update

FORECAST SUMMARY: Friday, March 7, 2025, through Monday, March 10, 2025

 PM-2.5: 24-hour daily average Fine Particulate concentrations will begin the period mostly Good (Green AQI), with Moderates (Yellow AQI) developing early next week.

 FORECAST DISCUSSION:

 This forecast period will feature a few chances for light precipitation, mostly snow. This occurs as weak systems move through the region on Friday, then again Saturday and Sunday. However, these are not big weather makers, and many locations will remain precipitation-free. The bigger weather story is the warmup that begins late in the weekend, continuing into next week. The warmest air of the season moves into the state starting on Sunday as high pressure moves in from the west. While the warm-up is welcomed by many, the warmer air moving over areas with current snowpack could cause increases in pollution levels.

 As for air quality, a cool, northerly flow is reinforced over the region Friday and again Saturday, keeping air quality mostly Good. Warmer air is forecast to move in on Sunday, continuing into Monday; fine particulate will begin increasing, especially in areas with melting snowpack. Currently, we do not expect fine particulate levels to reach higher than daily averages in the Moderate range; however, if our thoughts on this change during the weekend, we will update this forecast to reflect the deteriorating air quality conditions.

 EXTENDED FORECAST:

 The extended weather models show warmer than normal temperatures the first few days of the new workweek, along with sunshine. Fine particulate levels averaging mostly in the Moderate range can be expected during this period. The next chance for precipitation looks to arrive towards midweek.

 Next Forecast update: Monday, March 10, 2025

03/03/2025 Forecast Update

FORECAST SUMMARY: Monday, March 3, 2025, through Friday, March 7, 2025

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

 FORECAST DISCUSSION:

 Monday starts relatively quiet, aside from some light precipitation across the south. The big weather maker comes in Tuesday into Wednesday as a low-pressure area travels from northern Missouri Tuesday evening to the Saginaw Bay area Wednesday evening. Precipitation moves in well ahead of the system with freezing rain possible overnight Monday into early Tuesday across the northern portions of the state. As the system moves closer, precipitation chances increase, and surface temperatures are expected to warm enough for all rain Tuesday. Wet conditions continue Wednesday as the system passes through, and a wide range in temperatures is likely, with 30s north to 50s south. As the system pulls away, strong winds usher in cold air from the north. Temperatures start falling in the Upper Peninsula early Wednesday, then continue south into Wednesday evening. As temperatures fall, rain is expected to change over to snow. Light precipitation ends Thursday as high pressure settles in.

 As for air quality, increasing moisture and southerly winds through early Wednesday produces an environment more prone to increased fine particulate, especially across southern locations. Expect concentrations of fine particulate to range from Good north to low Moderate south through Wednesday. Strong, northerly winds developing later Wednesday bring in a clean airmass and Good fine particulate levels are anticipated Thursday. A weak system may pass through Friday, bringing in snow showers north and rain south. Fine particulate levels late in the week could return to low Moderate across the south.

 EXTENDED FORECAST:

 The extended weather models show dry conditions Saturday with hints at another system moving in on Sunday. Fine particulate levels during this period should not be higher than low Moderate.

 Next Forecast update: Friday, March 7, 2025

02/28/2025 Forecast Update

FORECAST SUMMARY: Friday February 28th 2025 through Monday March 3rd 2025

PM-2.5:

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

FORECAST DISCUSSION:

We round off the month of February with a melting snowpack in southern Michigan, and winter weather in northern Michigan and throughout the upper peninsula. A relatively strong Low-pressure system is traversing the state as one reads this forecast with winter storm warnings and winter weather advisories impacting northern Michigan. Accompanying these winter advisories and warnings are wind advisories peppering the Great Lakes state as the aforementioned Low-pressure system tightens the pressure gradient in the state, thus creating windy conditions throughout this afternoon. This system will be off to the east come Saturday morning leaving a fresh snowpack to those in the north, and light winds and cold temperatures for all Michiganders. In the wake of the Low-pressure system, winds shift to more northwesterly flow which will bring arctic air back into Michigan for Saturday and into Sunday. Although cold, the arctic airmass will be relatively stable and quiet, with no additional snow or wind for the remainder of the weekend. Come Sunday afternoon, the majority of Michiganders reach the freezing mark with an upward trajectory of temperatures on the horizon for the week ahead.

Windy and cold conditions will help keep PM-2.5 concentrations at bay for the weekend ahead with clean, northerly winds aiding that as well. We should not see an increase in PM-2.5 concentrations until early next week when temperatures increase into the 40s.

EXTENDED FORECAST:

Similar to this week, we see an increase in temperatures early next week with the upper-40s returning. Overall air quality should remain in the Good range.

Next Forecast update: Monday February March 3rd 2025

02/24/2025 Forecast Update

FORECAST SUMMARY: Monday February 24th, 2025 through Friday February 28th, 2025

PM-2.5:

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

FORECAST DISCUSSION:

Mostly sunny skies and above normal temperatures kick off this last week of February. Southerly flow for the next few days will bring in warmer air as the windy conditions we have been seeing the last few days slowly calms as we approach midweek. Much of Monday and into Tuesday are copy and paste of one another with the next weather system approaching the region come Wednesday. A Low-pressure system enters the Great Lakes region early Wednesday and lingers for most of the day until moving off to the east on Thursday. This system will bring precipitation in the form of rain for most areas as surface temperatures will still be in the upper-30s to low-40s. Areas to the north may see a wintry mix, but overall precipitation should be rain. Along with precipitation, temperatures drop back down to seasonal norms in the mid-30s come Thursday and Friday with a High-pressure system setting up to our north.

With a rather dense snowpack across the state and consistent 40-degree temperatures for much of this week, PM-2.5 concentrations increasing into the Moderate range should be expected, especially in more populated areas near and around the morning commute. Breezy conditions today, Monday, and into tomorrow, Tuesday will help keep concentrations at bay as atmospheric conditions will not be stagnant. However, as snow melts and releases particulates into the atmosphere, concentrations will increase. As stated above, though, increases should not be higher than the mid-Moderate range. Once the Low-pressure sweeps through the region later this week, any buildup of concentrations that occur are expected to be cleaned out with shifting and increasing winds.

EXTENDED FORECAST:

We kick off March with relatively normal temperatures with even more melting of snow expected. PM-2.5 concentrations and overall air quality should range between Good and low-Moderate.

Next Forecast update: Friday February 28th, 2025

02/21/2025 Forecast Update

FORECAST SUMMARY: Friday, February 21, 2025, through Monday, February 24, 2025

PM-2.5:  24-hour average Fine Particulate concentrations are expected to transition from mostly Good (AQI Green) early in the forecast period to Low Moderate (AQI Yellow) for the remainder of the forecast period.

FORECAST DISCUSSION

Yesterday (Thursday) marked the “one-month-until-Spring” date.  With the unseasonably cold weather we have been experiencing of late, it brings hope of warmer weather and longer days to come.  In fact, depending on how you view it, Spring could come even sooner.  A recent conversation with my work colleagues brought up the topic of different definitions of Spring. 

The traditional Spring season, called Astronomical Spring, begins with the vernal equinox that will occur on March 20, 2025.  But meteorologists recognize March 1 as the first day of Meteorological Spring, which is based on annual temperature cycles and the Gregorian calendar.  While it will not make anything warmer, it feels good to think one definition of Spring will occur one week from tomorrow (Saturday).

In fact, we will begin a warming period, starting this weekend.  Sunday should be the first day that most of Michigan Lower Peninsula heads north of the freezing mark.  The warming cycle continues into the first half of next week with temperatures reaching into the 40’s. 

With the warming temperatures comes the snow melt.  The added moisture to the atmosphere acts as a catalyst for the growth of fine particulates.  As such, the Good Air Quality, experienced during the recent cold snap, will give way to Low Moderate Air Quality conditions.  This cycle will likely persist through most of next week.

EXTENDED FORECAST:

 Air Quality is expected to be mostly Low Moderate going into the next week.

02/18/2025 Forecast Update

FORECAST SUMMARY: Tuesday, February 18, 2025, through Friday, February 21, 2025

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be a mix of mostly Good (AQI Green) to Low Moderate (AQI Yellow) for the forecast period.

FORECAST DISCUSSION

Many areas did not see the snow that was predicted for the weekend.  In Lansing, we were predicted to have 9 inches and wound up with less than 2 inches.  While I am sure some were disappointed at the lack of additional snow, I was not among that group. 

With cloud cover dissipating under high pressure, very cold temperatures have again descended upon us with what has been called Polar Vortex v2.0.  If you think January and February have been unusually cold, you are not wrong.  Being the numbers geek that I am, I looked at the departure from normal, average temperatures since January 1.  If the summed daily average temperature deviations were zero, then we would be exactly normal.  If that summed number is negative, then we are colder than normal, and if that number is positive, then we are warmer than normal.  For Grand Rapids, the summed deviations from average temperatures was -114 while Detroit was -104. So, yes, we’ve been much colder than normal.

Fortunately, this week looks to be relatively quiet. The models are not predicting any major snow events other than a small disturbance around the Wednesday night to Thursday morning time frame with less than an inch predicted.  The western lake shore counties, however, will continue to see some lake effect through Thursday.

High pressure settles in for the end of the week with clearing skies and a slow rebound in temperatures.  High temperatures finally getting north of the freezing mark are expected by Sunday and continuing into next week.

 Air Quality should remain Good for most of the forecast period although we could see some creep into Low Moderates by the end of the week with the slowly warming temperatures.

EXTENDED FORECAST:

 Air Quality is expected to be mostly Good to Low Moderate going into the weekend.

02/10/2025 Forecast Update

FORECAST SUMMARY: Monday February 10th, 2025, through Friday February 14th, 2025

PM-2.5:

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

FORECAST DISCUSSION:

Sporadic sunshine is waking Michiganders up this February morning as surface temperatures hang around the teens to low twenties this morning and for much of today, Monday. We start off this work week relatively quiet with no major systems impacting us today or tomorrow, Tuesday, but an abrupt change is on the horizon with the next snowmaker coming on Wednesday. A Low-pressure system is expected to move across the Great Lakes region Wednesday evening into Thursday with most of the lower peninsula seeing accumulating snow. Southern Michigan and into mid-Michigan will see the highest totals with snow tapering off come Thursday morning. Once the Low-pressure leaves the area, a High-pressure system sets up to the south over Indiana and Ohio which will provide calm conditions on Friday to wrap up the work week.

Clearing skies and southerly flow will potentially increase PM-2.5 concentrations today and into Tuesday. These increases will predominately be in and around the metro areas of Detroit and Grand Rapids and mostly in the morning time. Come Wednesday evening, however, concentrations will be moved out as the impending Low-pressure and frontal boundary clean out the low-level atmosphere. The High-pressure system on Friday may cause an increase in PM-2.5 concentrations due to calm conditions and slight melting of the fresh snowpack we will be receiving from the aforementioned snow system. Any PM-2.5 increases will only slightly eclipse the Moderate threshold with most concentrations in the Good to low-Moderate range.

EXTENDED FORECAST:

Another snow system looks to impact the Great Lakes on Saturday with snow totals still being calculated. Air quality will remain in the Good to low-Moderate range.

Next Forecast update: Friday February 14th, 2025