09/04/2023 Forecast Update

FORECAST SUMMARY: Monday, September 4, 2023, through Tuesday, September 5, 2023

Ozone: 8-hour average Ozone concentrations are forecast to range between Good and Moderate; with isolated USG levels possible.

PM-2.5: 24-hour average Fine Particulate levels are expected to be in the Good to Moderate range.

FORECAST DISCUSSION: This Labor Day features sunshine and warm temperatures into the 90s. By Tuesday, dew points increase ahead of an approaching system. Warm and muggy conditions will be in place, however, more prevalent cloud cover and small chances for storm development keep ozone from significantly increasing. Ozone concentrations Sunday ranged upper Good to upper Moderate, and as expected, highest readings were in west Michigan along the lakeshore. Hourly concentrations Monday morning at western locations were running lower than they were this time yesterday, but since Sunday’s max 8-hour levels were close to USG, we decided to increase the forecast from Moderate to USG for our Grand Rapids forecast area for Monday; this forecast area includes the lakeshore areas from Muskegon to Holland. Across the rest of the state Moderate readings are anticipated. With increased clouds and precipitation chances, Good to Moderate ozone is to be expected Tuesday.

Regarding PM2.5, smoke models show any plumes staying north and west of the region the next few days. Hourly concentrations at some locations were ranging low Moderate Monday morning. Increased wind speeds should keep readings from climbing much through Tuesday; daily average PM2.5 concentrations should remain upper Good to low Moderate.

EXTENDED FORECAST: Extended models continue showing a pattern change mid-week with chances for precipitation and cooler conditions. Pollution levels will be mostly Good during this period.

Next Forecast Update: Tuesday, September 5, 2023

09/03/2023 Forecast Update

FORECAST SUMMARY: Sunday, September 3, 2023, through Monday, September 4, 2023

Ozone: 8-hour average Ozone concentrations are forecast to range between Good and Moderate; with isolated USG possible.

PM-2.5: 24-hour average Fine Particulate levels are expected to be in the Good to Moderate range.

FORECAST DISCUSSION: Sunday features more sunshine than Saturday and temperatures start increasing as ridging builds in from the west. Dry conditions are expected, and gusty southerly winds develop over the region bringing in warmer, muggier conditions. This weather trend is forecast through the Labor Day holiday with highs in the 90s across much of the state.

While sunshine and warmer temperatures the next few days lead towards ozone conducive conditions, stronger winds look to hamper significant pollution development. Forecast ozone models show isolated USG levels along the west Michigan lakeshore due to influence from the lake, otherwise, concentrations remain Moderate. Based on weather maps and pollution trends, we agree with this evaluation. Isolated locations may reach USG, but mostly Moderate ozone is expected Sunday and Monday across the state. We will keep an eye on levels and if this changes, we will update the necessary area(s) to USG, triggering EnviroFlash notifications.

Regarding PM2.5, smoke models show any plumes staying north and west of the region over the next few days. Hourly concentrations across southern areas were ranging low Moderate Sunday morning. Increased wind speeds should keep readings from climbing much the next few days. Daily average PM2.5 concentrations should remain upper Good to low Moderate.

EXTENDED FORECAST: Extended models show a pattern change mid-week with chances for precipitation and cooler conditions. This will improve any pollution increases seen earlier in the week.

Next Forecast Update: Monday, September 4, 2023

09/02/2023 Forecast Update

FORECAST SUMMARY: Saturday, September 2, 2023, through Sunday, September 3, 2023

Ozone: 8-hour average Ozone concentrations are forecast to range between Good and Moderate; with isolated USG possible.

PM-2.5: 24-hour average Fine Particulate levels are also expected to be in the Good to Moderate range.

FORECAST DISCUSSION: Clouds and scattered precipitation move from north to south across the state today, Saturday, as a boundary sinks through. This system will keep air quality from reaching higher than Moderate for ozone while some low-Moderate PM2.5 is possible. The forecast is still on track for a warmup Sunday through the Labor Day holiday. High pressure dominates at the surface and an upper-level ridge builds over the area bringing in southerly winds and warm temperatures. Dew points also increase; therefore, conditions will feel muggier outside.

As for air quality, there is still some question on ozone levels Sunday. Models are keeping higher concentrations confined to the west Michigan lakeshore. While more sunshine is expected tomorrow compared to today, Saturday, forecast models are picking up on some clouds as well. One thing is still on track and that’s southerly winds at the surface and upper levels bringing in warmer temperatures. At this point, we feel widespread USG ozone is unlikely Sunday in the west, and an Action Day is not warranted. Based on forecast models, higher wind speeds also hamper significant ozone development helping keep ozone Moderate. Current pollution trends will be evaluated tomorrow morning and if this changes, the Moderate forecast will be updated to USG triggering EnviroFlash notifications.

There have been some increases in PM2.5 this morning into the low-Moderate range and we expect this trend to continue. Concentrations over the next few days should range from upper Good to low Moderate.

EXTENDED FORECAST: Extended models show a pattern change mid-week with chances for precipitation and cooler conditions. This will improve any pollution increases seen earlier in the week.

Next Forecast Update: Sunday, September 3, 2023

09/01/2023 Forecast Update

FORECAST SUMMARY: Friday, September 1, 2023, through Saturday, September 2, 2023

Ozone: 8-hour average Ozone concentrations are forecast to range between Good and Moderate.

PM-2.5: 24-hour average Fine Particulate levels are also expected to be in the Good to Moderate range.

FORECAST DISCUSSION: After the mid-week cooldown, temperatures will be on the rise as we move into the Labor Day weekend. Along with warmer temperatures, dry conditions are expected thanks to high pressure dominating. This set-up, however, brings with it the threat for increased ozone. On a positive note, southerly winds through the period should keep wildfire smoke plumes from coming into the region and influencing pollution levels.

High pressure east of Michigan is forecast to sink south over the weekend. This position gives us a southerly wind flow through the period which turns a bit more westerly Saturday as a weak/dry boundary moves in from the north. Warm temperatures west of us Friday move into the area during the weekend, increasing temperatures each day. Similar conditions are expected at upper levels with warm, southerly flow over the region.

For the ozone forecast, there is currently a low background in place and while readings are likely to increase Friday, 8-hour readings higher than low-Moderate are not anticipated. The boundary Saturday brings in a cloud layer which reduces chances for increased ozone. More widespread Moderate readings are forecast Saturday and there is a small chance a monitor may reach low-end USG, but this chance is low and would be isolated. Sunshine will be more prevalent on Sunday making it a better day for ozone conducive conditions. Because of this, there will be a forecast update Saturday morning to detail if conditions warrant an Action Day.

Like ozone, there is currently a low background of PM2.5 in place. Warmer conditions and southerly winds tend to increase PM2.5 levels, but stronger winds are forecast. Increased winds lead to more mixing that should keep PM2.5 readings Good to low-Moderate.

EXTENDED FORECAST: Extended models show warm, dry conditions lingering through the Labor Day holiday. With the threat for increased ozone continuing early next week, we will be doing daily updates to the air quality forecast until the threat ceases.

Next Forecast Update: Saturday, September 2, 2023

08/28/2023 Forecast Update

FORECAST SUMMARY: Monday, August 28, 2023, through Friday, September 1st, 2023

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

OZONE: Ozone concentrations are expected to be in the Good range.

FORECAST DISCUSSION: The beautiful weekend spills over into the start of the work week with today, Monday, seeing clear, blue skies and temperatures in the low-to-mid 70s. Unfortunately, this is short-lived as a frontal boundary crosses over the state throughout the day on Tuesday; bringing cloudy skies and rain to most areas. However, we rebound rather quickly as Wednesday sees clear skies, but temperatures barely move out of the 60s due to northerly flow over the region. We slowly warm up on Thursday, as winds start to shift to more easterly flow as a High-pressure system sets up over the state. On Friday, winds shift to predominantly southerly, with some westerly component, which will bring in warmer temperatures into the 80s for most of Michigan.

In terms of air quality, due to unfavorable wind directions for Ozone development, it is not expected that Ozone will be an issue week. Also, with the cooler temperatures, Ozone will not have the proper ingredients to produce, even though there will be ample sunlight. There may be an hourly concentration, or two, in the Moderate range, but overall Ozone averages should be in the Good range. For PM-2.5, wildfire smoke is continually being monitored. For the coming days, it is not projected that wildfire smoke will cause PM-2.5 to rise higher than low-Moderate. In some smoke models, there appears to be some smoke coming down from Canada to our west over Minnesota, but the models appear to keep it west of us. As always, wildfire smoke and updated models will be monitored daily.

EXTENDED FORECAST: Going into the Labor Day holiday weekend, we see quite the warmup as winds shift to southwesterly flow, and a similar heat dome that we saw last week in the central part of the country looks to set up again. These warm temperatures and favorable winds may produce Ozone issues, but will be looked at more closely as the weekend gets closer.

Next Forecast Update: Friday, September 1st, 2023

08/25/2023 Forecast Update

FORECAST SUMMARY: Friday, August 25, 2023, through Monday, August 28, 2023

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

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

FORECAST DISCUSSION: Hot, humid conditions ended Thursday evening as strong storms associated with a cold front moved through the southern portion of the state. Some areas are cleaning up Friday due to storm damage and several locations are without of power. Moisture lingering Friday keeps scattered light precipitation in the forecast under mostly clouds skies. Small chances for precipitation remain late Friday/early Saturday as another weaker boundary sinks through. High pressure moves in from the north Sunday, drying conditions and providing ample sunshine for the start of the new week.

While hourly ozone concentrations in the southwest reached USG for a short time Thursday afternoon clouds moved in hampering development keeping 8-hour concentrations Moderate. Ozone will not be an issue this weekend into early next week thanks to northerly winds and cooler temperatures in the 70s. Ozone concentrations through Monday should range mostly Good.

The southwest portion of the state also saw Moderate PM2.5 Thursday; however, readings Friday morning were running Good statewide. Northerly flow is expected through the period and wildfire smoke maps show only light smoke plumes over the region this weekend. We will keep an eye on this through the forecast period making updates, if necessary, but at this time smoke does not look to influence ground level PM2.5 and concentrations should range Good to low Moderate through early next week.

EXTENDED FORECAST: Extended models show the next chance for precipitation Tuesday as a cold front moves through the region. Behind that, a cool down is expected with highs only in the 60s by mid-week. Aside from possible small increases in pollution ahead of the boundary Tuesday, levels should generally be Good.

Next Forecast update: Monday, August 28, 2023

08/23/2023 Forecast Update (Copy)

FORECAST SUMMARY: Wednesday, August 23, 2023, through Friday, August 25, 2023

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

OZONE: 8-hour average Ozone concentrations are expected to be Good to Moderate across much of the state, with USG possible in the southwest Wednesday and Thursday.

FORECAST DISCUSSION: As forecast, a complex of storms tracked from the Upper Peninsula southeast into central and southeastern areas Wednesday morning. As Wednesday progresses, a warm front pushes in from the west before stalling for a time across the central part of the state. Strong southerly winds develop south of this boundary bringing in very warm surface and upper-level temperatures and high dew points. This will cause hot, humid conditions to develop Wednesday afternoon into Thursday, especially across the southern portions of the state. The frontal boundary will also be the focus of storm development over the next two days. Temperature and humidity levels improve Friday as the boundary sinks south and northerly winds bring in cooler temperatures and lower dew points.

The threat for increased ozone remains Wednesday and continues into Thursday across the southwestern portions of Michigan. Because of this, we are continuing the current Air Quality Action Day through Thursday and forecasting ozone concentrations in the Unhealthy for Sensitive Groups (Orange AQI) range for the counties listed above. Along and north of the forementioned boundary, cloud cover and higher chances for storm development are expected. These conditions should keep ozone from reaching higher than Moderate, and possibly Good further north. Ozone concentrations improve with the airmass change and northerly winds Friday. Readings Friday should range between middle Good and low Moderate.

Wildfire smoke maps were reviewed and we do not expect wildfire smoke to have an influence on pollution levels the rest of the week. With southerly winds and increased moisture along and south of the boundary, PM2.5 is likely to increase, but readings higher than Moderate are not expected. Any increase in PM2.5 should improve to Good on Friday.

EXTENDED FORECAST: Extended models show another cold front passing late Friday/early Saturday bringing precipitation back into the forecast. Regardless on the exact timing of this boundary, cooler temperatures are expected during the upcoming weekend which should help keep pollution levels low. This forecast will be updated Friday to better detail the coming weekend into early next week.

Next Forecast update: Friday, August 25, 2023

08/22/2023 Forecast Update

FORECAST SUMMARY: Tuesday, August 22, 2023, through Wednesday, August 23, 2023

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

OZONE: 8-hour average Ozone concentrations are expected to be Good to Moderate across much of the state, with USG possible in the southwest Wednesday.

FORECAST DISCUSSION: As expected, a complex of showers and storms is moving through the Upper Peninsula southeast towards the Detroit area Tuesday. This area keeps clouds and precipitation in the forecast for all but the southwest portion of the state. High pressure which has been dominating with a northeasterly flow the past two days tracks east Tuesday. As this happens, a frontal boundary to our south begins moving north towards the state. The easterly flow Tuesday switches to the south Wednesday ushering in warm/humid conditions, especially in the southwest. The frontal boundary is expected to stall across central lower Michigan into Thursday and associated moisture keeps showers and storms in the forecast across northern, central, and eastern locations.

Good to low Moderate ozone and PM2.5 levels can be expected Tuesday thanks to easterly winds and cooler surface and upper-level temperatures. Clouds and precipitation near and north of the frontal boundary Wednesday should keep ozone from reaching higher than Moderate, but models show less clouds in the southwest. More sunshine in the southwest along with southerly winds and increases in temperatures makes ozone conditions likely. Forecast models seem to align with our thoughts, picking up on this ozone increase as well. To cover the threat for ozone in the Unhealthy for Sensitive Groups (Orange AQI) range, we have issued an Air Quality Action Day on Wednesday for the southwestern counties listed above. The threat for increased ozone looks to continue Thursday so we will evaluate current trends and weather maps Wednesday morning to determine if the Action Day will be continued and/or expanded Thursday.

Wildfire smoke maps were reviewed and there is still a light plume lingering over the region, but PM2.5 levels have improved to mostly Good early Tuesday. We do not expect wildfire smoke to be a large influence in pollution levels this week, however, increases of PM2.5 into the Moderate range can be expected in central and southern areas with the southerly flow, humid conditions, and pooling that typically happens along frontal boundaries.

EXTENDED FORECAST: The warm-up Wednesday and Thursday may be short-lived due to a cold front expected to pass through late in the week. If this pans out, the threat for increased ozone should come to an end Friday.

Next Forecast update: Wednesday, August 23, 2023

08/21/2023 Forecast Update

FORECAST SUMMARY: Monday, August 21, 2023, through Tuesday, August 22, 2023

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

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

FORECAST DISCUSSION: A weak cold front moved through late Sunday/early Monday bringing in northeasterly winds and less humid conditions. Monday will feel more comfortable than Sunday with lower dew points and temperatures in the upper 70s to low 80s. A switch back is in store, however, as heat and humidity build to our west Monday and Tuesday. Surface high pressure north of the state tracks east, as a boundary lifts north Wednesday. This changes winds back to a southerly direction by mid-week bringing the heat and humidity east and into Michigan. Overnight storms are also a possibility both Monday night into Tuesday morning, and more so Tuesday night into Wednesday morning. Current forest models show these systems missing the southwest portion of the state both periods, keeping conditions dry. 

High clouds and northeasterly/easterly winds through Tuesday should keep pollution levels in check with readings higher than Moderate not anticipated for either ozone or PM2.5. Southerly winds developing Wednesday, coupled with increases in both surface and upper-level temperatures, brings a threat for increased ozone. Ozone models are picking up on this as well, showing increases into the Unhealthy for Sensitive Groups range, mostly in the southwest, by Wednesday. A forecast update will be done Tuesday morning to evaluate updated models, and to determine if an Action Day for ozone will be necessary Wednesday.

Wildfire smoke maps were reviewed and there is still a plume lingering over the region. Thankfully, the smoke has for the most part remained at upper levels only resulting in small PM2.5 increases. Daily averages of PM2.5 were in the upper Good to low Moderate range this past weekend. Smoke models do show a bit of an improvement Tuesday, but the plume looks to linger, mostly at upper levels, this week. With smoke remaining overhead, PM2.5 should continue in the upper Good to low Moderate range. Along with ozone trends, we will be keeping an eye on smoke models and PM2.5 readings, making updates if necessary.

EXTENDED FORECAST: The warm-up Wednesday and Thursday may be short-lived due to a cold front expected to pass through late in the week. If this pans out, the threat for increased ozone should come to an end Friday.

Next Forecast update: Tuesday, August 22, 2023

08/18/2023 Forecast Update

FORECAST SUMMARY: Friday, August 18, 2023, through Monday, August 21, 2023

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

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

FORECAST DISCUSSION:

Over the past few days, the smoke models have been painting an ugly picture of poor Air Quality over Minnesota and Wisconsin with Michigan eventually to follow.  Fortunately, the smoke has stayed aloft, and surface smoke has not gotten any worse than High Moderate on the western side of the Lake.  Even though one model continues to predict dire surface concentrations, the remaining models have backed off and are more in line with what we are actually seeing on the ground.  Those models are now predicting no worse than Moderate and that that will be pushed out in the next couple of days.  As such, the Michigan PM-2.5 AQI forecast will be kept in the Moderate range until it clears out.

Even though we are expecting a nice warmup over the weekend, ozone looks to behave.  Cooler Friday temperatures will give way to warmer 80-degree weather during Saturday and Sunday under clear skies.  One of the ozone models is showing an ozone buildup over the southern tip of Lake Michigan on Sunday, but it is standing alone in that prediction compared with other models.

At this point, it looks safe to continue this forecast through the weekend with Monday as the next update.  However, the conditions will be monitored over the weekend and if the smoke aloft starts mixing down over Michigan or ozone numbers start to creep up, the forecast will be updated as necessary.

EXTENDED FORECAST:

Air Quality should be generally Good to Moderate to start the next work week.

Next Forecast update: Monday, August 21st, 2023. Forecast updated by Jim Haywood

08/14/2023 Forecast Update

FORECAST SUMMARY: Monday, August 14, 2023, through Friday, August 18, 2023

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

OZONE: 8-hour average ozone concentrations are expected to be Good with scattered Low Moderate.

FORECAST DISCUSSION:

A slow-moving low-pressure system will approach and pass through Michigan later Monday and into Monday night.  There is a good chance for significant precipitation as this system passes through and Air Quality is expected to be Good.  Some residual showers during Tuesday and a drying out during Wednesday with continued Good Air Quality are expected.

We will get into a southwesterly air flow pattern late Wednesday and into Thursday as another front approaches and passes through the region.  This will provide another precipitation event however probably not as widespread or heavy as anticipated for late Monday. 

Air Quality should remain mostly Good with scattered Low Moderates for the duration of the work week.  The long-range forecast has the weekend warming up with daily highs climbing back into the mid to upper 80’s.  While the days are getting noticeably shorter, we are still in the midst of ozone season and this forecast will be updated on Friday to provide the weekend outlook. 

Wildfires is still widespread in Canada.  Fortunately, projected wind patterns are not showing any significant amount traveling over the Midwest during this forecast period.

EXTENDED FORECAST:

Air Quality should be generally Good to start the weekend, but ozone concentrations are likely to increase during the course of the weekend.

Next Forecast update: Friday, August 18th, 2023. Forecast updated by Jim Haywood

08/11/2023 Forecast Update

FORECAST SUMMARY: Friday, August 11th, 2023, through Monday, August 14th, 2023

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

OZONE: Ozone concentrations are expected to be in the Good to Moderate range.

FORECAST DISCUSSION:

The majority of Michigan wakes up to a beautiful morning on this Friday. However, it is short-lived as a weather system traverses the region this afternoon bringing cooler temperatures and rainy skies. Indeed, the work week ends, as the work week began—dreary. Although, as we get into Saturday morning, the precipitation clears to the east and clear skies return with surface temperatures in the upper-70s to low-80s, with WNW winds cooling down the temperatures. We are in this airflow until Monday when winds shift to more southerly flow due to yet another approaching frontal boundary.

In terms of air quality, due to the rain we are expecting later this afternoon, I do not expect Ozone to be an issue today and through the weekend. With winds shifting to more northerly Saturday and Sunday, and with temperatures barely reaching the 80s, Ozone will not have the proper ingredients to develop. Upper-level temperatures will be in the mid-to-upper teens Celsius however, but I do not expect those upper-level temperatures to initiate any USG Ozone development. For PM-2.5, there will be regional smoke hanging around through the weekend due to the ongoing Canadian wildfires. I do not expect PM-2.5 concentrations to reach anything higher than Moderate.

EXTENDED FORECAST:

Another system is expected to come through on Monday before exiting the area on Tuesday. This will help keep overall air quality Good.

Next Forecast update: Monday, August 14th, 2023. Forecast updated by Alec Knowacki.

08/07/2023 Forecast Update

FORECAST SUMMARY: Monday, August 7th, 2023, through Friday, August 11th, 2023

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

OZONE: Ozone concentrations are expected to be in the Good to Moderate range.

FORECAST DISCUSSION:

The majority of Michigan wakes up to overcast skies and damp grass from overnight showers. The sun will begin to peak out later in the day and into tomorrow as the system that brought the rain leaves the region. A high-pressure system sets up to our northwest tomorrow which will provide sunny skies and surface temperatures in the low-80s. This weather pattern remains the same until Wednesday night into Thursday when a low-pressure system traverses the area, shifting us back into possible rainy conditions. Possible multiple rounds of on and off rain will be present until Friday and into Saturday.

In terms of air quality, wildfire smoke looks to remain out of the region for this week, so PM-2.5 concentrations will remain in the Good to Moderate range. For Ozone, multiple changes in airmass will keep the air clean of stagnation and a buildup of Ozone concentrations. The one day we will keep an eye on is Wednesday, which will have surface temperatures in the low-to-mid 80s and predominantly southwest winds. This may allow for Ozone to develop in the southwest Michigan area but is not expected to be widespread. The approaching system may increase clouds Wednesday afternoon, so this may help hinder Ozone development. We are rather confident that Ozone will not be a widespread issue on Wednesday and the rest of the week, so this forecast will be updated on Friday for the weekend ahead.

EXTENDED FORECAST:

Cooler summer temperatures remain in place for the weekend with a chance of rain as of right now. Overall air quality will remain Good.

Next Forecast update: Friday, August 11th, 2023. Forecast updated by Alec Knowacki.

8/2/23 Forecast Update

FORECAST SUMMARY: Wednesday, August 2, 2023, through Monday, August 7, 2023

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

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

FORECAST DISCUSSION: The elevated layer of smoke, which significantly and noticeably dimmed the sun yesterday, will migrate eastward during Wednesday and be clear of the state by nightfall.  Fortunately, we only saw a minimum mixing down and our monitor numbers remained in the Good to Moderate range throughout the state.

There was some concern about potential elevated ozone after the smoke cleared.  But all models have lowered expectations and are keeping most of the higher numbers on the west side of Lake Michigan.  As such, I expect mostly Moderate on the west side of the state and Good to Moderate, elsewhere, during Thursday.  However, if any elevated ozone looks to shift eastward, we will modify the forecast as necessary and send an alert via EnviroFlash and AirNow.gov.  A cold front passage, Thursday night, should clean the air and keep our weekend Air Quality mostly Good.

Friday and Saturday should be pleasant days under high pressure and rain looks to move in late Sunday.  Both the extended smoke models and the ozone models are indicating no problems through the weekend, so I am extending this forecast out to Monday. 

EXTENDED FORECAST: Air Quality should be generally B to bring the next work week.

Forecast updated by Jim Haywood: Wednesday, August 2, 2023

Next forecast update Monday, August 7, 2023

8/1/23 Forecast Update

FORECAST SUMMARY: Tuesday, August 1, 2023, through Wednesday, August 2, 2023

OZONE:  8-hour average ozone concentrations are expected to be a mix of Good and Moderate.

PM-2.5:  24-hour average Fine Particulate concentrations are also expected to be Good increasing to Moderate.

FORECAST DISCUSSION: It you looked outside, this morning, you probably thought that we were under overcast skies.  Unfortunately, what you were seeing was an extremely thick layer of Canadian wildfire smoke around the 10,000-foot level.  The thickness of that smoke is enough to considerable dim the sun.  Unlike last week, that smoke is staying mostly aloft and not expected to significantly affect surface concentrations.  That said, the models do show a bit mixing down, mostly in the northern portion of the state.  But none of those models are showing concentrations increasing in excess of the USG threshold.  As such, I will be keeping the forecasted AQI in the Moderate range for today and tomorrow.

As that smoke clears out, late Wednesday, we turn our attention back to ozone.  Current projections have the ozone production increasing but are keeping it out over the lake and closer to the Wisconsin border.  As such, I do not see the need for any advisories, but I will definitely keep an eye on it in case it shifts further east than expected.  Therefore, I will be updating this forecast on Wednesday to provide the latest projections.

EXTENDED FORECAST: Air Quality should be generally Moderate for most of the middle of the week with some slight potential for elevated pollutant levels.

Air Quality should be generally Moderate for most of the middle of the week with some potential for elevated pollutant levels.

Forecast updated by Jim Haywood: Tuesday, August 1, 2023

Next forecast update Wednesday, August 2, 2023

7/31/2023 Forecast Update

FORECAST SUMMARY: Monday, July 31, 2023, through Tuesday, August 1, 2023 

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

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

 FORECAST DISCUSSION

Last week we saw a multitude of Action Days, first for smoke and then for ozone.  While this week should be less eventful than last week, we are not completely out of the woods. 

We are currently following a plume of Canadian wildfire smoke dropping down from the central and western Canadian providences.  At the moment, that smoke is staying aloft and not causing any problems other than graying skies.  Northern Minnesota is experiencing some mixing down to the surface and the question is whether or not Michigan can expect any elevated surface concentrations.  The models are not in good agreement on the magnitude, but there is some agreement that some will mix down late Tuesday and into Wednesday.  While I am not currently anticipating levels reaching USG, I would not be surprised to see high Moderate levels during that time period.  Fortunately, this will be a short episode as that smoke should get pushed out, late Wednesday.

Then we shift our focus back to ozone.  While we are starting out the week in the Good range, all indications are that ozone concentrations will begin to creep upwards on Tuesday.  The models are indicating a fairly decent buildup Tuesday into Wednesday, but is keeping the worst of it on the Illinois and Wisconsin side of the lake.  Winds shift to a more southwesterly direction on Thursday and with increasing temperatures and humidly, it could present a problem for Michigan.

 With the uncertainly of the surface level smoke and threat of increased ozone production, I will update this forecast on Tuesday.

EXTENDED FORECAST:

Air Quality should be generally Moderate for most of the middle of the week with some potential for elevated pollutant levels.

Forecast updated by Jim Haywood: Monday, July 31, 2023

Next forecast update Tuesday, August 1, 2023

7/27/2023 Forecast Update

FORECAST SUMMARY: Thursday, July 27, 2023, through Monday, July 31, 2023

OZONE:  8-hour average ozone concentrations are expected to be Moderate to USG through Friday, then Good to Moderate.

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

...AIR QUALITY ACTION DAY ADVISORIES FOR THURSDAY JULY 27 and FRIDAY JULY 28...

The Action Day Advisories include the following counties:

In West Michigan:

ALLEGAN...  berrien…  CASS…  KENT...  MUSKEGON...  ottawa…  AND van buren COUNTIES

In Southeast Michigan:

LIVINGSTON…  MACOMB…  MONROE…  OAKLAND… ST. CLAIR…  WASHTENAW…  AND WAYNE COUNTIES

FORECAST DISCUSSION

The forecast preparation for Friday has been particularly challenging.  There is a lot of uncertainty, both in the forecast models and the National Weather Service discussions, about when clouds and showers may arrive Friday afternoon or evening.  A front will be dropping down from the north, during the day, bringing those clouds and showers along the way but the timing is unclear. 

The majority of the ozone models are still predicting areas of elevated ozone along the southwest shores of Lake Michigan and southeast Michigan.  The cloud models are inconsistent on when we can expect clouds to move into the same areas which would retard ozone production.  It is more likely that southeast Michigan will stay under clear skies longer than southwest Michigan.  But if southwest Michigan also stays sunny through the afternoon, their ozone production could be significant.

As elevated ozone could be significant in both areas, I will continue the Thursday Action Day advisories into Friday.  Even if clouds do move in and keep ozone levels out of the USG range, I will still be satisfied that this was the correct call on the side of caution.

Either way, the front dropping down from the north will occur Friday night putting an end to this episode.  There does not appear to be any continued threat from either smoke or ozone for the remainder of the weekend, although I will continue to monitor conditions.  As such, I do not anticipate the need for another forecast update until Monday.

EXTENDED FORECAST:

Air Quality should be generally Good to Moderate for the weekend and into the next work week.

Forecast updated by Jim Haywood: Thursday, July 27, 2023

Next forecast update Monday, July 31, 2023

7/26/2023 Forecast Update

FORECAST SUMMARY: Wednesday July 26, 2023, through Thursday, July 27, 2023

OZONE: 8-hour average ozone concentrations are expected to be Moderate to USG

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

FORECAST DISCUSSION:

..AIR QUALITY ACTION DAY ADVISORY FOR THURSDAY JULY 27...

The Action Day Advisory includes the following counties:

in West Michigan:

ALLEGAN...  BERRIEN…  CASS…  KENT...  MUSKEGON...  OTTAWA…  AND VAN BUREN COUNTIES

The Tuesday statewide Action Day advisory for fine particulates turned out to be an accurate prediction as we saw elevated concentrations at many of our statewide monitors.  In addition to the high smoke concentrations, we were surprised to see ozone values get as high as they did at several monitors.  This proves the amount of ozone precursor gases found in wildfire smoke.

 We did not extend the Action Day advisory into Wednesday as the smoke plume will be exiting the state and incoming rain and thunderstorms will help drop concentrations during the day.  That said, the eastern side of the state will be the last to see the benefits of the clearing, so I increased their AQI forecast to USG as a precautionary measure.  Although morning ozone concentrations are higher than normal, the increasing clouds and rain chances will discourage elevated production and bring those numbers back down.

 Tomorrow will be another story as it may be one of the hotter and humid days of the summer.  Predictions are for temperatures in the low 90’s with dew points around 70 degrees under sunny skies and low wind speeds.  Under normal conditions, this would qualify for elevated ozone.  But we also still have leftover ozone forming gases, courtesy of the exiting wildfire smoke, which could boost ozone production even more.  As such, I am issuing Action Day advisories in both West Michigan and Southeast Michigan for Thursday.

 Friday may be a continuation of the Action Day advisories, but I will wait until Thursday morning to make that call when the latest forecast products are available.

EXTENDED FORECAST:

 Air Quality should be generally Moderate to potentially USG through the remainder of the week.

Forecast updated by Jim Haywood: Wednesday, July 26, 2023

Next forecast update Thursday, July 27, 2023

7/25/2023 Forecast Update

FORECAST SUMMARY: Tuesday, July 25, 2023, through Wednesday, July 26, 2023

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

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be widespread Moderate to USG.

AIR QUALITY ACTION DAY ADVISORY FOR TUESDAY JULY 25 REMAINS IN EFFECT STATEWIDE...

FORECAST DISCUSSION

The Tuesday Air Quality Action Day Advisory remains in effect, statewide, for Fine Particulates.  Monitors are continuing to read high concentrations along the Wisconsin Lake Michigan shore and that smoke is currently moving into Michigan.  Some of our monitors are already reading in the USG range.  While I expect to see hazy conditions, outside, I do not expect to see the extremely high concentrations into the Unhealthy range that we saw a couple of weeks ago.  That said, the expected USG conditions are still of concern and our messaging to reduce outdoor strenuous activity and remain indoors with air conditioning remains intact.

Fortunately, all of the smoke models are indicating today’s smoke will be flushed out of the state during Wednesday.  Conditions may still be somewhat hazy in the morning hours but should improve during the day.  The potential for some severe weather and heavy rains also exists which would help cleanse the air.

By Thursday, the weather should return to normal hot, humid summer-like conditions under sunny skies.  Our experience with the smoke, this summer, is that some chemicals from the smoke can be left behind if there is not a total cleanout and those chemicals readily convert to ozone under favorable conditions.  And those conditions currently look favorable on Thursday.

As a result, I intend to update this forecast Wednesday morning…

EXTENDED FORECAST:

Air Quality should be generally Moderate to potentially USG through the remainder of the work week.

Forecast updated by Jim Haywood: Tuesday, July 25, 2023

Next forecast update Wednesday, July 26, 2023

7/24/2023 Forecast Update

FORECAST SUMMARY: Monday, July 24, 2023, through Tuesday, July 25, 2023

OZONE:  8-hour average ozone concentrations are expected to be mostly Moderate.

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be widespread USG.


AIR QUALITY ACTION DAY ADVISORY FOR MONDAY JULY 24, BEGINNING AT NOON...
UPPER PENINSULA ONLY

AIR QUALITY ACTION DAY ADVISORY FOR TUESDAY JULY 25...
STATEWIDE


FORECAST DISCUSSION

Smoke returns to the region courtesy of numerous large Canadian wildfires.  Smoke, aloft, has already reached Michigan and surface smoke in Minnesota and Wisconsin is already reaching the USG and Unhealthy range as it mixes down.  The higher levels of surface smoke will be reaching the Upper Peninsula as today progresses, therefore we are triggering an Action Day Advisory for the U.P. beginning at noon.  Widespread smoke will affect the entire state, during Tuesday, prompting a Statewide advisory.

Fortunately, this appears to be a short-lived event with most of the smoke pushed out of the state Tuesday night.  As we have seen in previous events, this year, the surface smoke has left behind some residual pollutants which could convert to ozone under ideal conditions.  By Thursday, we could be seeing temperatures in the low 90’s under clear skies.  Dew points will rise to around 70 degrees making for hot, muggy weather with the potential for elevated ozone.

Since we are expecting hotter weather with ozone potential, this forecast will be updated Tuesday morning and as necessary as the week progresses.


EXTENDED FORECAST:

Air Quality should be generally Moderate to potentially USG through the work week.

Forecast updated by Jim Haywood: Monday, July 24, 2023
Next forecast update Tuesday, July 25, 2023