10/15/2021 Forecast Update

FORECAST SUMMARY:

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

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

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

FORECAST DISCUSSION:

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

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

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

EXTENDED FORECAST:

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

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

Next forecast update: Monday, October 18th, 2021

10/11/2021 Forecast Update

FORECAST SUMMARY:

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

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

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

FORECAST DISCUSSION:

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

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

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

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

EXTENDED FORECAST:

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

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

Next forecast update: Friday, October 15th, 2021

10/4/2021 Forecast Update

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

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

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

FORECAST DISCUSSION

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

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

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

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

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

EXTENDED FORECAST:

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

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

Next forecast update: Monday, October 11th, 2021

9/27/2021 Forecast Update

FORECAST SUMMARY:

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

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

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

FORECAST DISCUSSION:

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

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

EXTENDED FORECAST:

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

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

9/24/2021 Forecast Update

FORECAST SUMMARY:

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

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

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

FORECAST DISCUSSION:

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

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

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

EXTENDED FORECAST:

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

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

Next forecast update: Monday, September 27th, 2021

9/20/2021 Forecast Update

FORECAST SUMMARY:

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

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

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

FORECAST DISCUSSION:

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

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

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

EXTENDED FORECAST:

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

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

Next forecast update: Friday, September 24th, 2021

9/13/2021 Forecast Update

FORECAST SUMMARY:

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

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

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

FORECAST DISCUSSION

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

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

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

EXTENDED FORECAST:

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

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

9/10/2021 Forecast Update

FORECAST SUMMARY

Friday, September 10th, 2021, through Monday, September 13th, 2021

OZONE: 8-hour average Ozone concentrations are expected to range between Good and Moderate through the forecast period.

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

FORECAST DISCUSSION:

After a few cool days with isolated sprinkles, warmer conditions move in for the weekend. High pressure positions itself east of the region which will produce south/southwest winds later Friday into Saturday. With that, warmer temperatures return along with possible wildfire smoke over the region.

Air quality Friday morning is Good across the state and with the low background in place, Good levels should continue through the day. On Saturday, winds pick up in speed from the south/southwest and both surface and upper-level temperatures increase. Saturday seems to be the most likely day for higher ozone concentrations, primarily along the west Michigan lakeshore. A few hourly readings may reach low-end USG; however, considering the time of year and earlier sunset, 8-hour concentrations in the USG range are not anticipated. 8-hour Ozone Saturday should range from upper Good to upper Moderate across the state.

By late Saturday/early Sunday a cold front settles in from the northwest. Expect northerly winds north of the front and southerly winds south of the boundary. The position of the boundary should be across southern Michigan Sunday and Moderate ozone may develop near and south of the boundary, but clouds should hamper a significant increase. The boundary moves close to or just south of the state Monday. Warmer temperatures remain, but again clouds should keep ozone from reaching higher than Good to low Moderate.

For fine particulate, wildfire smoke is light over the region Friday; however, models show smoke plumes moving over the state as southerly winds develop. Also, the frontal boundary lingering close to the state Sunday/Monday could allow for a fine particulate buildup. At this time, it doesn’t look as if smoke will significantly increase fine particulate levels, but the combination of smoke and a front could cause Moderate readings, especially across the southern portion of the state. We are forecasting Moderate fine particulate across central and southern locations through Monday.

EXTENDED FORECAST:

Extended models show the boundary lifting north early next week with a cold front passing Tuesday. The Tuesday front should clean out any Moderate pollution levels from Sunday/Monday.

Forecast updated by: Stephanie M. Hengesbach

Next Forecast update: Monday, September 13th, 2021

9/7/2021 Forecast Update

FORECAST SUMMARY:

Tuesday, September 7th, 2021, through Friday, September 10th, 2021

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good with a better chance of Moderates late in the week.

PM-2.5: 24-hour average Fine Particulate concentrations will be mostly Good with a few low Moderates possible, generally in the southeast.

FORECAST DISCUSSION:

Good air quality was seen this past Labor Day weekend and this trend is expected to continue much of this week. A cold front will be passing through the state Tuesday. Storms with this boundary were already across the northern half of the state late Tuesday morning. Storm chances increase further south during the afternoon/evening as the line travels east/southeast. Some of these storms could be on the strong side so they are something to keep an eye on. Temperatures will be warm further south, but clouds and precipitation move in early enough to keep ozone Good. Fine particulate may have some hourly levels in the low-Moderate range, but daily averages will also be Good.

Gusty west/northwest winds develop behind the boundary for Wednesday and scattered to isolated showers are a possibility, generally in northern portions of the state. Cooler temperatures and west/northwest winds will keep both ozone and fine particulate Good through Thursday. Winds decrease in speed by Friday as high pressure settles closer to the region; however, primarily Good pollution levels should continue.

EXTENDED FORECAST:

Extended models show warmer conditions by Saturday and another frontal system comes into play later Saturday or Sunday. The best chance for Moderate pollution levels seems to be Saturday so we will update this forecast Friday to better detail air quality conditions for the weekend into early next week.

Forecast updated by: Stephanie Hengesbach, EGLE Meteorologist 

Next Forecast update: Friday, September 10th, 2021

9/3/2021 Forecast Update

FORECAST SUMMARY:

Friday, September 3rd, 2021, through Tuesday, September 7th, 2021

OZONE:

Ozone concentrations are expected to be mostly Good for much of Michigan with a slight chance of some hourly Moderate concentrations along the Lake Michigan shoreline.

PM-2.5:

PM-2.5 concentrations are expected to be mostly Good with some smoke entering the region from out west but should stay aloft in the upper-levels of the atmosphere.

FORECAST DISCUSSION:

Entering the holiday weekend, Michigan should experience a rather pleasant weekend to send off Summer. Upper-level temperatures will continue the trend of this past week with temperatures in the low-teens Celsius to single digits. It isn’t until Tuesday when we see a return of temperatures in the mid-to-upper teens Celsius. Going into Saturday, September 4th, winds will primarily be from the SSW before shifting to WNW for the remainder of the forecast period. This is due to a departing High-pressure system lifting off into Ontario to our east and an oncoming cold front.

Surface level temperatures will be more of the same from this past week with highs in the low-mid 70s Fahrenheit. Dew point temperature highs will be in the mid-upper 50s Fahrenheit, so a much different environment from where were just a few weeks ago. Today, Friday, and into Saturday, we will see SSE winds before they shift to more SSW winds going into Sunday. A slight cold front is expected to traverse the region Sunday which will then shift winds to a more NW flow going into Monday. This cold front will bring chances of rain to much of Michigan, but primarily to northern Michigan. It is because of these reasons that Ozone concentrations are expected to remain mostly Good for the holiday weekend. As mentioned above, PM-2.5 concentrations will be Good as well with upper-level smoke returning to the region. If anything, this smoke will provide colorful sunrises and sunsets, but is not expected to reach the surface.

EXTENDED FORECAST:

Going into next week, concentrations are expected to remain Good with high temperatures in the high-60s to low-70s Fahrenheit.

Forecast updated by: Alec Kownacki, Friday, September 3rd, 2021

Next Forecast update: Tuesday, September 7th, 2021

8/30/2021 Forecast Update

FORECAST SUMMARY:

Monday, August 30th, 2021, through Friday, September 3rd, 2021

OZONE: Ozone concentrations are expected to be mostly Good through the week with a chance of a monitor or two reaching the low Moderate range.

PM-2.5: PM-2.5 concentrations are expected to be Good as well, as heavy rainfall to our northwest aided in the suppression of the fires that were igniting there the past few weeks. 

FORECAST DISCUSSION:

After a week or so of hot and humid temperatures, the area finally gets a break thanks to the front that passed through yesterday evening. Upper-level temperatures this week will drop from the mid-teens Celsius to single digits as we get to Thursday. Upper-level winds start out early in the week coming from the northwest and shift to the northeast as we approach Wednesday.

Surface temperatures are forecasted to be in the upper-70s to low-80s Fahrenheit throughout this week with dew point temperatures expected to drop to the low-50s Fahrenheit. Surface winds will be from the NNE for most of the week with southerly flow returning Friday afternoon. After a week of ozone development and growth, the environment this week does not seem to be conducive of ozone development, but as stated above, this does not rule out a monitor or two reaching the Moderate threshold. There appears to be some O3 pooling over Lake Michigan today, Monday, and into tomorrow, but the northeast flow should keep those concentrations out over the lake.

Numerous models show slight O3 development over Lake Michigan throughout the week, but as just stated, the NNE winds will keep those concentrations from coming ashore. Also, the O3 appears to dissipate quickly throughout the day each day, instead of gradually growing throughout the week. In terms of PM-2.5, like said above, rainfall to our northwest has helped keep the fires at bay and diminish much of the smoke we were seeing last week. Some upper-level smoke is forecasted to enter the area later this week from out west but is not expected to reach the surface.

EXTENDED FORECAST:

A high-pressure system stays over us throughout the week until Friday when another frontal boundary approaches the area which will aid in concentrations remaining mostly Good.

Forecast updated by: Alec Kownacki, Monday, August 30th, 2021

Next Forecast update: Friday, September 3rd, 2021

8/27/2021 Forecast Update

FORECAST SUMMARY:

Friday, August 27th, 2021, through Saturday, August 28th, 2021

Ozone:  8-hour average Ozone concentrations are expected to be Good to Moderate, with a chance of USG on Saturday along the central West Michigan shoreline and northeast of Detroit.

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

FORECAST DISCUSSION

Thursday’s forecast held fast as only a few Moderates were reported in West Michigan and the rest of the state was Good.  Friday will have similar numbers.

Saturday looks to potentially have a different outcome.  Temperatures and humidity will be high and southwest winds will likely push high ozone concentrations onto the shore along Lake Michigan and also northeast of Detroit.  Although the cloud models are still showing mostly cloudy skies during Saturday, it has been performing poorly during the week and strong lake breezes have cleared the skies along the lake shores where we typically have high ozone issues. 

All the better ozone models are being consistent and showing large pockets of high ozone in our most susceptible areas during Saturday.  As a result, advisories are being issued in both West Michigan and SE Michigan for Saturday. 

Sunday is still uncertain.  An approaching cold front will pass through the state Sunday night and the timing of the front and associated approaching clouds will make all the difference in ozone production.  Rather than rely on Friday’s forecast model, the model will be reviewed on Saturday to run the latest models.

As a result, the forecast will be revisited Saturday morning and updated for the Sunday forecast, at that time.

EXTENDED FORECAST:

Air Quality is expected to be Good to Moderate on Friday and ranging between Moderate and USG during Saturday.  Sunday has yet to be determined.

Forecast updated by Jim Haywood: Friday, August 27th, 2021. Next forecast update: Saturday, August 28th, 2021

8/26/2021 Forecast Update

FORECAST SUMMARY:

Thursday, August 26th, 2021, through Friday, August 27th, 2021

Ozone:  8-hour average Ozone concentrations are expected to be Good to Moderate, with a chance of isolated USG.

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

FORECAST DISCUSSION

As discussed on Monday, ozone concentrations would be mostly Moderate in the susceptible areas unless we had pockets of prolonged sunlight.  We had that occur northeast of Detroit on Tuesday as a lake breeze kept skies clear over the St. Clair County area.  As a result, two monitors in that area went USG. 

During Wednesday, the Holland monitor was stuck in a rich Chicago plume, under sunny skies, and went USG.  Isolated pockets of poor Air Quality could continue to occur, which will necessitate continued close watching for the duration of the workweek. 

The cloud models have performed poorly, all week, and still showing mostly cloudy skies Thursday and Friday.  Smoke from Minnesota wildfires will likely drop south, on Thursday, for extra protection from the strong sun.  It would be a surprise to see any USG although it is possible for isolated hotspots.

Friday doesn’t seem to carry a large threat with a better chance of clouds and showers due to a warm front over the area.  The weekend outlook, however, is not as good.  The models are showed persistent southwest winds, hot temperatures, high humidity, and ample sun in advance of a Sunday night cold front.  It is a good possibility that we will see Action Day advisories, during the weekend, unless there is a change in tomorrow’s model results.

EXTENDED FORECAST:

Air Quality is expected to range between Moderate and USG going into the weekend.

Forecast updated by Jim Haywood: Thursday, August 26th, 2021. Next forecast update: Friday, August 27th, 2021

8/23/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday August 23rd, 2021, through Thursday August 26th, 2021

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 range from Good to Moderate. 

FORECAST DISCUSSION:

Despite entering the waning days of summer, temperatures will continue to be more what we would expect during July.  Temperatures through most of this work week are expected to stay in the upper 80’s with a high dew point.  Unlike much of the summer, we are not seeing the smoke layer in the upper atmosphere which helped reduce ozone production.

The question, now, is if there will be any elevated ozone with potentially prime conditions.  Two of the models used to prepare the forecast are showing high concentrations forming over Lake Michigan during Tuesday and Wednesday.  Tuesday and Wednesday, while hot and humid with southwest winds, will most likely be overcast in advance of a late Wednesday frontal system.  The third ozone model used reflects that and has little ozone forming over the next two days.  So, despite ideal transport winds and ample heat and moisture, conditions should stay mostly Moderate unless we have isolated pockets of prolonged sun exposure.  In that case, the possibility of isolated USG exists along the Lake Michigan shore and northeast of Detroit although the shorter days will add another factor promoting lower ozone production.

Favorable winds behind that front should reduce any potential ozone issues during Thursday.  Winds do swing around to the south during Friday to set up another warm weekend. 

Since we will be getting back into a southerly wind pattern during Friday, the forecast will be updated Friday.

EXTENDED FORECAST: 

Air Quality is expected to range between Good and Moderate going into the weekend.

Forecast updated by Jim Haywood: Monday, August 23rd, 2021. Next forecast update: Thursday, August 26th, 2021

8/20/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Friday, August 20th, 2021 through Monday, August 23th, 2021

Ozone: 8-hour average Ozone concentrations are expected to be mostly Moderate Friday and Saturday with isolated chances for USG; readings early next week will be between Good and Moderate.

PM-2.5: 24-hour average Fine Particulate concentrations will be in the upper Good to middle Moderate range.

FORECAST DISCUSSION:

Summerlike conditions will linger into the weekend with sunny skies, warmer temperatures, and increased humidity. Isolated afternoon storms could be seen Friday, but most locations will remain dry. A weak front coming through later Saturday will bring in another small chance for precipitation. High pressure moves on Sunday, but temperatures behind the Saturday boundary do not significantly decrease.

As for air quality, high pressure is dominating conditions Friday with lighter winds from more of a southerly direction. Ozone has been slowly increasing the past few days and that trend is expected to continue through Saturday. Readings haven’t reached higher low Moderate through Thursday, but more widespread Moderate ozone is anticipated both Friday and Saturday. There is a chance a monitor or two could reach low-end USG either Friday or Saturday with the best chances along the west Michigan lakeshore and in the southeastern portions of the state. However, upper-level temperatures haven’t increased significantly, and dew points remain high the next few days; both should assist in hindering a significant increase in ozone concentrations that would warrant an action day. Behind the Saturday front, ozone Sunday and Monday should fall back into the Good to Moderate range.

Fine particulate has been mostly Moderate across the state and this trend is expected to continue into early next week. We do get into a lighter northerly flow after the Saturday boundary passes which could allow smoke to move back over our region. This is something we will keep an eye on, but if this happens, smoke could keep Moderate fine particulate in place through early next week.

EXTENDED FORECAST:

Extended models show warmer temperatures and dry conditions going into next week. This will allow Moderate levels of ozone and fine particulate to continue.

Forecast updated by Stephanie Hengesbach: Friday, August 20th, 2021.

Next forecast update: Friday, August 23, 2021

8/16/2021 Forecast Update

FORECAST SUMMARY:

FORECAST SUMMARY: Monday, August 16th, 2021 through Friday, August 20th, 2021

Ozone: 8-hour average Ozone concentrations are expected to range from Good to Moderate with chances for Moderates increasing past mid-week.

PM-2.5: 24-hour average Fine Particulate concentrations will be in the middle Good to low Moderate range.

FORECAST DISCUSSION:

The big weather story early this week is Tropical Storm Fred making landfall across the western Florida Panhandle Monday and tracking north through midweek. Here in Michigan, increased moisture will be noted the next few days, along with increasing temperatures by Wednesday as easterly flow turns more southwesterly. There isn’t a huge trigger for storms through mid-week; however, isolated/scattered storms are in the forecast with the biggest chance coming Wednesday as a system moves up from the south. Early morning patching fog is also anticipated this week due to higher levels of moisture coupled with lighter morning winds.

As for air quality, we are starting the week with Good levels of both ozone and fine particulate, and pollution levels Monday should remain generally Good. As stated above, weak easterly winds turn more southerly around mid-week. Lighter easterly winds before then should keep fine particulate from increasing significantly; however, increased moisture and a more southerly flow will cause increases into the Moderate range as the week progresses. The same is expected for ozone concentrations. We will have a good amount of sunshine the next few days, but easterly flow and lower upper-level temperatures should keep ozone between upper Good and low Moderate. As temperatures increase past mid-week more widespread ozone concentrations could be seen. A large increase is not anticipated though since we will likely see some clouds around and there are also chances for scattered storms. Concentrations of both fine particulate and ozone should not reach higher than Moderate through Friday.

EXTENDED FORECAST:

Forecast models show a boundary moving through sometime Saturday which could bring more of a northerly flow by the end of the week; however, before then increased moisture and temperatures should continue, along with the chance for Moderate air quality. This forecast will be updated Friday to better detail conditions for the weekend, into early next week.

Forecast updated by Stephanie Hengesbach: Friday, August 16th, 2021.

Next forecast update: Friday, August 20, 2021

8/13/2021 Forecast Update

FORECAST SUMMARY:

Friday, August 13th, 2021, through Monday, August 16th, 2021

OZONE: Ozone concentrations are expected to be mostly Good for the upcoming weekend and into early next week.

PM-2.5: PM-2.5 concentrations are expected to be Good for the weekend and into early next week.

FORECAST DISCUSSION:

Upper-level winds will mainly be from the WNW for most of the weekend. An approaching High-pressure system from the west will shift these winds to a more northwest flow going into Sunday. Upper-level temperatures are expected to be in the upper teens Celsius today, Friday, but are expected to drop to the low-to-mid teens Celsius for the rest of the weekend. The combination of shifting winds and decreasing upper-level temperatures will help keep ozone concentrations at bay. There appears to be some ozone pooling over Lake Michigan, but it is forecasted to mainly stay offshore with the possibility of reaching the shoreline only for a short period of time.

After a long week of hot, humid surface temperatures, the region finally gets a break thanks to the cold front that made its way through today, Friday. Daytime dewpoint temperatures will drop to the low-mid 50s Fahrenheit and surface daytime temperatures will be in the low 80s Fahrenheit for much of the area. Surface winds will also be from the WNW for the weekend with a northerly shift going into Sunday as the High-pressure sets up over Lake Michigan. This High-pressure will help keep the weekend clear and dry. Surface PM-2.5 hasn’t been of much concern this week and it will continue not to be going into the weekend, as not much smoke has been mixing down towards the surface. Ozone concentrations will struggle to develop due to the decreasing upper-level and surface temperatures. As stated above, there will be ozone pooling over Lake Michigan with the possibility of reaching the shoreline, but not enough to put 8-hour averages into the Moderate range.

EXTENDED FORECAST:

Going forward into early next week, it is more of the same in terms of concentrations. The High-pressure moves off into Ontario but still provides us with clear skies and cooler temperatures compared to this past week.

Forecast updated by Alec Kownacki, Friday, August 13th, 2021. Next Forecast update on Monday, August 16th, 2021.

8/9/2021 Forecast Update

FORECAST SUMMARY:

Monday, August 9th, 2021, through Friday, August 13th, 2021

OZONE: Ozone concentrations are expected to be in the low-to-mid Moderate range for much of the week due to warmer temperatures and southwest winds. These concentrations will be dependent upon potential precipitation and cloud cover.

PM-2.5: After weeks of pretty steady PM2.5 concentrations, it appears we get somewhat of a break from smoke for at least the first half of the week. Mid-week concentrations will rise due to a plume making its way to the region from out west.

FORECAST DISCUSSION:

For much of the week, upper-level winds will be from the southwest due to a Low-pressure system sitting to our west until a front comes through Friday and shifts winds to more northwesterly flow. Upper-level temperatures will be in the upper-teens to low-twenties degrees Celsius, which will aid in the development of ozone. The combination of warm upper-level temperatures and southwest winds will ramp up the production of Ozone but broken and overcast skies may help to inhibit the production of Ozone. In terms of smoke concentrations, as mentioned above, the area receives somewhat of a break until mid-week when smoke from out west enters the area. Surface temperatures will be hot and humid for much of this week until a cold front enters the region Thursday night and into Friday.

Surface winds will primarily be from the southwest this week which tends to produce Ozone concentrations along southwest Michigan and up the Lake Michigan shoreline. Cloud cover may cut off the production of Ozone but breaks in cloud and ample sunlight will produce some Moderate concentrations. Along with the cloud cover, precipitation is forecasted for much of the week, so this too, will help cut off Ozone concentrations. Some models are showing rather heavy Ozone concentrations over Lake Michigan, with some creeping ashore, but will be dependent upon cloud cover and potential precipitation. This is the reasoning for forecasting Moderate Ozone concentrations for most of southern Michigan.

EXTENDED FORECAST:

A cold front comes through Thursday into Friday, essentially clearing out the area and setting up a High-pressure to our west. This is also when smoke concentrations appear to enter the region once again.

Forecast updated by Alec Kownacki August 9th, 2021

Next Forecast update: Friday, August 13th, 2021

8/6/2021 Forecast Update

FORECAST SUMMARY:

Friday, August 6th, 2021, through Monday, August 9th, 2021

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 range from Low to High Moderate.

FORECAST DISCUSSION:

Smoke continues to be an issue as our monitors still show concentrations higher than we normally see, but the 24-hour averages remain in the Moderate range.  This will likely continue for the short-term future.  The smoke models do have it thinning out over the weekend, but not going away.  All indications are that we will continue to fare no worse than Moderate for our 24-hour averages.

We have been focusing most of our attention on the fine particulates brought to us by the wildfires out west and in Canada.  But even though ozone production has been down lately, it is always a threat, and we cannot afford not to keep an eye on it.  The computer models are indicating a buildup over southern Lake Michigan through the weekend.  As with most of the computer ozone forecasts over the past few weeks, this is likely an overprediction with the smoke layer in the upper atmosphere reducing the sun’s power.  Add the potential for hit or miss showers through the weekend, and the potential is even less.  I expect the best chance of rain showers will occur Friday, Sunday, and Monday.  Even without the showers, there should be enough associated clouds to discourage serious ozone production.  Saturday looks to have the best chance for some prolonged sunlight, so we could see a creep in the numbers during the afternoon.  But I do not see a strong indicator that any widespread USG readings are likely.

That said, we may have some ozone creep if we do have any areas of prolonged sun.  If that happens, we could see some isolated spots of low USG, especially in the southern tier counties along Lake Michigan.  I will be keeping an eye on conditions as they develop Saturday, and make any adjustments necessary to the forecast.

An upper-level system should bring in better chances for showers late Sunday through Monday.  That will eliminate any ozone issues for late in the weekend and early next week.  But the smoke will still be lingering, and we will continue to watch that.

EXTENDED FORECAST:

Air Quality is expected to range between Good and Moderate going into the next work week.

Forecast updated by Jim Haywood: Friday, August 6th, 2021

Next forecast update: Monday, August 9th, 2021

8/4/2021 Forecast Update

FORECAST SUMMARY:

Wednesday August 4th, 2021, through Friday, August 6th, 2021

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

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

FORECAST DISCUSSION:

A gradual warm-up begins on Thursday as we return to a southerly air flow and more typical August temperatures and humidity.  Wildfire smoke continues to be a major issue.  Fortunately, most of the surface smoke has stayed on the west side of Lake Michigan, but the Upper Peninsula is experiencing Wednesday morning hourly concentrations in the USG range.  As such, I’ve bumped the U.P. forecast up to USG.

The forecast models are still holding our ozone in the Good to Moderate range for the remainder of the work week.  However, the fires and smoke look to hang around for the foreseeable future.  The smoke models are indicating a southerly drift of the U.P. smoke into the Upper Lower Peninsula, during Wednesday, but I am not yet seeing that reflected in the monitors. 

The smoke forecast models look to keep most of the surface smoke west of Lake Michigan.  It is anticipated that the heavier Michigan smoke, currently in the U.P., may drift southward and affect the Upper Lower Peninsula for the remainder of today and tomorrow.  That said, I think the overall 24-hour average will settle in the High Moderate range.  As southerly flow picks up during Wednesday, that smoke cloud should begin to be pushed to the northeast. 

While that should clear out the current smoke by late Thursday, by Friday morning, I expect the old smoke cloud that has been over the Ohio Valley to move back north on the southerly return air flow.  That smoke cloud should be thinner and more elevated, but some could still mix down during daytime convection. 

The weekend looks to be very warm and humid with the chance of showers.  The question is whether enough elevated smoke will help reduce ozone formation and whether there be enough clouds/showers from a stalled frontal boundary to the north to thwart ozone production.  Either way, I think a forecast update on Friday will be necessary to nail down these possibilities. 

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Wednesday, August 4th, 2021

Next forecast update: Friday, August 6th, 2021