08/16/2019 Forecast Update

FORECAST SUMMARY:

Friday, August 16th, 2019 through Monday, August 19th, 2019

Ozone: 8-hour Ozone concentrations will range from Good to Moderate through the forecast period.

PM-2.5: 24-hour Fine Particulate concentrations will range from Good to low-Moderate.

FORECAST DISCUSSION:

Systems will bring on and off chances for precipitation through the weekend. The first chance will be Friday evening/night; Saturday should be mostly dry; but precipitation chances return Sunday. A stronger front moves through later Monday/Tuesday cooling conditions down by mid-week.

As for air quality, seasonable surface temperatures, coupled with cooler upper level temperatures and at least scattered cloud cover, will keep ozone from reaching higher than Moderate Friday or Saturday. By Sunday, surface and upper level temperatures increase along with dew point readings. Clouds and precipitation associated with a system nearby should again keep ozone from reaching higher than Moderate. Less cloud cover is expected Monday with warmer temperatures continuing; however, the system passing through Sunday should allow for more northerly/westerly winds. Currently, ozone is not expected to get higher than Moderate on Monday.

Significant build-up of fine particulate is not anticipated. Readings should range from middle Good to low Moderate.

EXTENDED FORECAST:

Extended models show cooler conditions by mid-week allowing for Good air quality.

Next forecast update: Monday, August 19th, 2019

08/12/2019 Forecast Update

FORECAST SUMMARY:

Monday, August 12th, 2019 through Friday, August 16th, 2019

Ozone: 8-hour Ozone concentrations will range from Good to Moderate through the forecast period.

PM-2.5: 24-hour Fine Particulate concentrations will range from Good to low-Moderate.

FORECAST DISCUSSION:

A frontal boundary and associated low pressure area will bring precipitation in the forecast later Monday into Tuesday. Then, a second weaker system could trigger scattered precipitation later Wednesday. These systems should keep ozone primarily Good through mid-week. Northerly winds at upper levels then keep cooler temperatures around through Friday. Conditions dry out Thursday and Friday, but lower temperatures will keep ozone from increasing higher than a few Moderates. Moderate fine particulate in the southeast Monday into Tuesday will likely improve to Good by Wednesday, lasting through Friday.

EXTENDED FORECAST:

Extended models are hinting at a warmup for the coming weekend which could make increased ozone a possibility. There is a bit on uncertainty; therefore, this forecast will be updated Friday to detail weekend air quality conditions.

Next forecast update: Friday, August 16th, 2019

08/05/2019 Forecast Update

FORECAST SUMMARY:

Monday, August 5th, 2019 through Monday, August 12th, 2019

Ozone:  8-Hour average Ozone concentrations will be a mostly Good and Low Moderate for the first half of the week then mostly Good through the weekend.

PM-2.5:  24-hour average Fine Particulate concentrations will be mostly Good.

FORECAST DISCUSSION

The first half of the forecast period will feature some active weather patterns followed by cooler, clear weather for the weekend.

As high pressure over the region moves eastward during Monday, it is making way for a trough of low pressure to advance from the west.  There is a chance of a few isolated pop-up storms Monday afternoon ahead of a cold front.  But the better chance of storms will occur Monday night and Tuesday morning as the cold front punches through.  Air Quality should range from Good to Low Moderate on Monday.  Air Quality should be Good on Tuesday.

Another cold front is expected to pass Wednesday night into Thursday morning.  Wednesday’s Air Quality should range between Good and Low Moderate in advance of this frontal passage and Good once it passes/.

The air mass following this front will be cool and dry with sunny daytime high temperatures around 80 and clear nighttime lows around 60.  This should persist through the weekend with Good Air Quality.

EXTENDED FORECAST:

Air Quality should be mostly Good going into the next work week.

Forecast updated by Jim Haywood: Monday, August 5th, 2019
Next forecast update: Monday, August 12th, 2019

08/02/2019 Forecast Update

FORECAST SUMMARY:

Friday, August 2nd, 2019 through Monday, August 5th, 2019

Ozone: 8-hour Ozone concentrations will range from Good to Moderate through the forecast period.

PM-2.5: 24-hour Fine Particulate concentrations will range from Good to low-Moderate.

FORECAST DISCUSSION:

Mainly dry conditions persist this weekend with only small chances for precipitation in association with a weak boundary dropping south Saturday. The next larger chance for precipitation comes into play late Monday/Tuesday as a stronger front passes through. For the most part expect seasonable, dry conditions through Sunday.

As for air quality, upper level northerly winds and cooler temperatures have kept ozone Good. With this flow persisting through the weekend, we don’t expect ozone to reach higher than Moderate. More of a southwesterly surface flow develops Monday ahead of the approaching boundary, but upper level temperatures remain low and northerly even as surface temperatures increase. Higher than Moderate ozone will not likely be seen Monday, but if this changes the forecast will be updated Sunday morning.

Fine particulate has also been Good, and a significant increase isn’t expected over the next few days. Readings should range from middle Good to low Moderate.

EXTENDED FORECAST:

Extended models show a cool down for next week after the Tuesday front passes…air quality will be Good for both ozone and fine particulate.

Next forecast update: Monday, August 5th, 2019

07/29/2019 Forecast Update

FORECAST SUMMARY:

Monday, July 29th, 2019 through Friday, August 2nd, 2019

Ozone: 8-hour Ozone concentrations will be mostly Good through mid-week, then a mix of Good and Moderates are expected.

PM-2.5: 24-hour Fine Particulate concentrations will range from Good to low-Moderate.

FORECAST DISCUSSION:

A cold front passing Monday will bring showers and/or storms. High pressure then moves in Tuesday and forecast models have this high positioned over the Great Lakes region through the end of the week. A small chance for precipitation lingers Tuesday mostly in the east, otherwise, dry conditions, seasonable temperatures, and low humidity’s can be expected.

Clouds and precipitation will keep Ozone Good Monday. Good levels continue Tuesday into Wednesday thanks to northwesterly winds and cooler surface and upper level temperatures. Temperatures will warm at the surface each day past mid-week, but upper level readings remain low through Friday. Ozone could reach Moderate in a few locations, but mostly Good levels should continue.

Fine particulate could also see slow increases starting Thursday, but readings higher than low-Moderate are not anticipated.

EXTENDED FORECAST:

Extended models keep high pressure over the region through early next week. Remaining under the same airmass for a few days could be a set up for increased pollution. At this time readings higher than Moderate are not expected, but this forecast will be updated Friday to better detail air quality conditions through early next week.

Next forecast update: Friday, August 2nd, 2019

Stephanie M. Hengesbach

Meteorologist

Air Quality Division

Michigan Department of Environment, Great Lakes, and Energy

07/22/2019 Forecast Update

FORECAST SUMMARY:

Monday, July 22nd, 2019 through Monday, July 29th, 2019

Ozone:  8-Hour average Ozone concentrations will be a mostly Good for the first half of the week then a mixture of Good and Low Moderate through the weekend.

PM-2.5:  24-hour average Fine Particulate concentrations will be mostly Good.

FORECAST DISCUSSION

After a week of hot and humid weather, we will enjoy a cooling down and Good Air Quality.  We can thank a ridge of high pressure currently located over the Plaines states.  While the center of high pressure remains to the west, we will be under a northerly wind profile.  This will yield cooler and drier air through mid-week with Good Air Quality throughout the state.  The only blemish during the first half of the week will be an upper air disturbance Tuesday afternoon which could produce some showers.

The ridge of high pressure will pass through the state early Thursday.  The wind profile on the back side of the high will become more southwesterly.  With the wind shift will come increasing temperatures and humidity for the weekend.  We will be coming off several days of very clean air and any increase in ozone will be slow in developing.

Right now, the regional forecasters do not have much concern about any elevated ozone for this forecast period.  Should it appear that conditions during the upcoming weekend start looking more threatening, the forecast will be updated.

EXTENDED FORECAST:

Air Quality should be mostly Good to Low Moderate going into the next work week.

Forecast updated by Jim Haywood: Monday, July 22nd, 2019
Next forecast update: Monday, July 29th, 2019

07/19/2019 Forecast Update

FORECAST SUMMARY:

Friday, July 19th, 2019 through Monday, July 22nd, 2019

THE CURRENT ACTION DAY ADVISORY IS EXTENDED THROUGH SATURDAY, JULY 20th IN THE FOLLOWING MICHIGAN COUNTIES...

IN WEST MICHIGAN:

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

Ozone:  8-Hour average Ozone concentrations will be a mixture Moderate and USG during Friday and Saturday.  Air Quality should return to Good and Low Moderate for Sunday and Monday. 

PM-2.5:  24-hour average Fine Particulate concentrations will be mostly Good to Low Moderate

FORECAST DISCUSSION

The hot, humid weather will continue through Saturday.  With the current high temperatures and humidity, if we get clear skies then elevated ozone potential is very high. 

The big question is how much cloud cover will we see?  During Thursday, cloud cover was enough to keep ozone production in the Moderate range.  As this forecast is being written Friday morning, cloud cover is present but looks to be thinning.  If that trend continues, we could see ozone numbers reaching the USG levels.

The cloud cover question is also an issue for Saturday.  The various forecast models are very inconsistent with their cloud forecast.  Some of the models have significant cloud cover for Saturday while others keep it mostly clear until late afternoon.  Knowing that clear skies would lead to high ozone concentrations, to err on the side of caution the current Action Day Advisories will be extended through Saturday.  

The threat will end on Sunday following a cold front passage Saturday night.

EXTENDED FORECAST:

Air Quality should be mostly Good to Low Moderate going into the next work week.

Forecast updated by Jim Haywood: Friday, July 19th, 2019
Next forecast update: Monday, July 22nd, 2019

07/18/2019 Forecast Update

FORECAST SUMMARY:

Thursday, July 18th, 2019 through Friday, July 19th, 2019

...AIR QUALITY ACTION DAY ADVISORIES FOR THURSDAY JULY 18TH AND FRIDAY JULY 19TH...

IN WEST MICHIGAN:

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

Ozone: 8-hour Ozone concentrations will range between Good and Moderate with a threat for USG in the west and southeast.

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

FORECAST DISCUSSION:

The easy part of the forecast is the fact that hot, humid conditions can be expected through Saturday with heat indices reaching over 100 degrees in several locations. The difficult part of the forecast is determining when and where storm complexes may develop the next few days.

A storm complex Thursday traveling west to east across southern Lower Michigan was expected to be further north. We currently have Action Days in place across southwest and southeast Michigan since yesterday’s models were showing dryer conditions with plenty of sunshine. The storms may hamper ozone from reaching USG today; but, if the sun breaks out after the system passes ozone may quickly develop in the hot, humid air mass.

We have decided to err on the side of caution for Friday’s air quality forecast and we are continuing the Action Days for both southwest and southeastern parts of the state. Southwesterly winds will prevail under the continued hot, humid air mass. Storm development chances look less for tomorrow and further north. The air quality forecast will be dependent on storm development; however, even just a few hours of afternoon into early evening sunshine could allow for fast increases in ozone. So, Action Days already set in place will be continued.

Fine particulate could also see increases the next few days with readings ranging from upper Good to middle Moderate.

EXTENDED FORECAST:

Extended models show hot conditions lingering through Saturday. Air Quality Division (AQD) forecasters will be holding another call Friday morning to discuss possible Action Days for Saturday. A front passing late Saturday should end the threat for increased pollution early next week.

Next forecast update: Friday, July 19th, 2019
Update by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division Michigan Department of Environment, Great Lakes, and Energy

07/17/2019 Forecast Update

FORECAST SUMMARY:

Wednesday, July 17th, 2019 through Thursday, July 18th, 2019

...AIR QUALITY ACTION DAY ADVISORY FOR THURSDAY JULY 18TH...

IN WEST MICHIGAN:

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

Ozone: 8-hour Ozone concentrations will range between Good and Moderate with USG possible in the west and southeast Thursday.

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

FORECAST DISCUSSION:

The heatwave that has been forecast a few days now is ready to begin. Wednesday the region is still experiencing increased moisture, scattered clouds and small chances for precipitation from the remnants of what was Hurricane Barry. This system finally pulls out of the area; however, upper level ridging builds in Thursday bringing very warm surface and upper level temperatures. Humidity levels will also be increasing with heat indexes approaching or exceeding 100 degrees in many locations. As for air quality, when and where storms may develop is making the forecast tricky.

For Wednesday, partly sunny skies and winds with a northeasterly component should keep ozone in the Good to Moderate range. On Thursday, a storm complex is expected to develop over northern Wisconsin and track east early in the day. Current models keep this complex from slipping into the southern half of Lower Michigan. This means, sunshine will be more prevalent in the south and that, coupled with warm surface and upper level temperatures, and southwesterly winds, make increased ozone a good possibility. The threat is high enough to warrant Action Days for Thursday in both the southwest and southeastern portions of the state.

The threat for increased ozone could linger into Friday, therefore, the regional forecasters will talk Thursday morning to determine if the Action Day should be continued.

Fine particulate could also see slow increases the next few days with readings ranging from upper Good to lower Moderate.

EXTENDED FORECAST:

Extended models show hot conditions lingering through most of the weekend. AQD forecasters will be keeping eye on conditions to determine if Action Days are needed over the weekend.

Next forecast update: Thursday, July 18th, 2019
Update by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division Michigan Department of Environment, Great Lakes, and Energy

07/15/2019 Forecast Update

FORECAST SUMMARY: Monday,

July 15th, 2019 through Wednesday, July 17th, 2019

AN ACTION DAY ADVISORY REMAINS IN EFFECT FOR MONDAY, JULY 15th IN THE FOLLOWING MICHIGAN COUNTIES...

IN WEST MICHIGAN:

ALLEGAN...  KENT...  MUSKEGON...  AND OTTAWA COUNTIES

Ozone:  8-Hour average Ozone concentrations will be a mixture of Good and Moderate through Wednesday.  Several areas may experience USG levels on Monday

PM-2.5:  24-hour average Fine Particulate concentrations will be mostly Good to Low Moderate.

FORECAST DISCUSSION

As of noon, Monday’s forecast for elevated ozone in West Michigan and Southeast Michigan looks to be a good forecast.  Morning hourly concentrations have been steadily climbing and most of the skies in the southern half of the Lower Peninsula are clear.  There are possibilities of pop-up showers, later in the afternoon, but those will be hit or miss.

Tuesday and Wednesday do not appear to be much of a threat for Air Quality as the remnants of Tropical Storm Barry work its way into the Midwest bringing clouds and shower potential.

The three-day stretch of Thursday through Saturday looks to be problematic.  It promises to be true summer with high temperatures and humidity with little cloud relief.  With the sun as strong as it is during July and light winds, it is easy to imagine that we could see elevated ozone over those days.  As such, the forecasters are planning another discussion on Wednesday.

EXTENDED FORECAST:

There is a potential for poor Air Quality during the end of the week as hot, muggy weather settles in.

Forecast updated by Jim Haywood: Monday, July 15th, 2019
Next forecast update: Wednesday, July 17th, 2019

07/14/2019 Forecast Update

FORECAST SUMMARY:

Sunday, July 14th, 2019 through Monday, July 15th, 2019

AN ACTION DAY ADVISORY IS IN EFFECT FOR MONDAY, JULY 15th IN THE FOLLOWING MICHIGAN COUNTIES...

IN WEST MICHIGAN:

ALLEGAN...  KENT...  MUSKEGON...  AND OTTAWA COUNTIES

Ozone: 8-Hour average Ozone concentrations will be a mixture of Good and Moderate through Sunday. Several areas may experience USG levels on Monday

PM-2.5: 24-hour average Fine Particulate concentrations will be mostly Good to Low Moderate.

FORECAST DISCUSSION

Sunday looks to remain in theGood/Moderate category, throughout the state, with favorable winds and temperatures.

However, hopes of staying in the Good/Moderate category, during Monday, have been diminished with the latest model runs. All the weather models have surface winds shifting from southeast, in the morning hours, to the south/southwest during the afternoon. Temperatures are expected to reach near 90 with a muggy dew point around 70. Earlier model runs were indicating a decent cloud cover, Monday afternoon, which would have reduced ozone production. But the later runs are trending more for clearer skies although pop-up showers could occur.

Almost all the ozone models are showing significant ozone production in the Allegan, Ottawa, Kent, and Muskegon area, which would be consistent with the wind pattern. As such, an Action Day Advisory has been issued for those counties.

EXTENDED FORECAST:

There is potential for poor Air Quality during the next work week as hot, muggy weather settles in.

Forecast updated by Jim Haywood: Sunday, July 14th, 2019

Next forecast update: Monday, July 15th, 2019

07/12/2019 Forecast Update

FORECAST SUMMARY:

Friday, July 12th, 2019 through Sunday, July 14th, 2019

Ozone:  8-Hour average Ozone concentrations will be a mixture of Good and Moderate through Sunday.

PM-2.5:  24-hour average Fine Particulate concentrations will be mostly Good with some Low Moderate.

FORECAST DISCUSSION

We will enter into the weekend with Air Quality on the Good side.  That trend will last through Saturday as a cold front drops down through the state.  There may be some convective activity associated with the frontal passage but the indicators are that this is more unlikely than likely.  Winds will shift to the northwest during the afternoon and provide a good cleanout of the atmosphere.

Post-frontal winds, during Sunday, will be light and biased to the northeast shifting to southeast.  The areas most at risk for any ozone creep will be west of the Detroit area, such as Flint.  But, coming off a clean Saturday, it is unlikely that the creep would be any worse than Moderate.

The upcoming work week may be challenging for Air Quality forecasting.  Indications are that we will be entering a prolonged period of hot, humid weather ripe for ozone production.  The wild card is Tropical Storm Barry, currently in the Gulf of Mexico, and not knowing how it will influence our upcoming weather.

Considering the uncertainty, the latest model runs will be reviewed on Sunday and this forecast will be updated.

EXTENDED FORECAST:

Air Quality is currently expected to remain mixed Good to Moderate going into the next work week.

Forecast updated by Jim Haywood: Friday, July 12th, 2019
Next forecast update: Sunday, July 14th, 2019

07/08/2019 Forecast Update

FORECAST SUMMARY:

Monday, July 8th, 2019 through Friday, July 12th, 2019

Ozone: 8-hour Ozone concentrations will range between Good and Moderate.

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

FORECAST DISCUSSION:

Pleasant July weather can be expected Monday and Tuesday with plenty of sunshine and seasonable temperatures. One notable feature will be the hazy sunshine due to smoke in the upper atmosphere associated with wildfires burning in Canada. A weather change comes into play Wednesday as a low-pressure area crossing the upper Great Lakes region brings a cold front through. High pressure then builds back in for the end of the week.

As for air quality, cooler upper level temperatures and southeasterly winds should keep ozone from increasing higher than Moderate Monday or Tuesday. Clouds increase Wednesday in most locations which should keep ozone Good to Moderate. However, with the later frontal passage in the southeast, more sunshine is expected. This coupled with southwesterly winds and warmer surface and upper levels temperatures may produce increased ozone in that portion of the state. Weather maps will be re-evaluated Tuesday and this forecast will be updated if ozone levels change. Northwesterly winds develop after the Wednesday frontal passage bringing back Good ozone readings.

Fine particulate will likely linger in the upper Good to Moderate range most of the week.

EXTENDED FORECAST:

Extended models show high pressure in place for the coming weekend and models also differ on chances for precipitation. Models do, however, agree that another warmup is in store. Regional forecasters will be talking Friday morning to discuss the potential for increased pollution levels later in the period.

Next forecast update: Friday, July 12th, 2019
Update by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy

07/03/2019 Forecast Update

FORECAST SUMMARY:

Wednesday, July 3rd, 2019 through Monday, July 8th, 2019

...AIR QUALITY ACTION DAY ADVISORY FOR WEDNESDAY JULY 3RD... IN SOUTHEAST MICHIGAN:LENAWEE... MACOMB... MONROE... OAKLAND... ST. CLAIR... WASHTENAW... AND WAYNE COUNTIES

Ozone: 8-hour Ozone concentrations will range between Good and Moderate, with scattered USG possible.

PM-2.5: 24-hour Fine Particulate concentrations will range from upper Good to middle Moderate; USG is possible during the evening and overnight in areas with fireworks displays.

FORECAST DISCUSSION:

The weather forecast through Friday hasn’t changed much with warm, muggy conditions continuing, along with the chance for scattered storms. Storm chances Wednesday are confined more to the southern portion of the state closer to a frontal boundary. The threat for storms does increase for the July 4th Holiday and for Friday.

Ozone levels the past few days has increased in some locations, generally the southeastern and southwestern portions of the state. This trend could continue in areas that have more in the way of sunshine. With winds remaining lighter, the best chance for increased ozone Wednesday would be in the southeast and we have an Action Day in place to cover this threat. Storm chances increase Thursday and Friday. Conditions will be warm and southwesterly winds develop. A few locations may reach low-end USG if sunshine prevails; however, storms and associated clouds should stop levels from increasing higher than Moderate Thursday or Friday. An airmass change begins late Friday/Saturday with northeast winds developing as high pressure slides in from the northwest. This will improve ozone levels for Saturday.

As for fine particulate, levels have been ranging from Good to Moderate and this trend will continue. The caveat to this is areas near fireworks displays in celebration of the July 4th Holiday. Fine particulate will quickly increase into the USG range in those localized areas which could linger into the overnight hours.

EXTENDED FORECAST:

Extended models show high pressure in place early next week bringing pleasant conditions Sunday, into Monday. With plenty of sunshine and seasonable temperatures, Moderate ozone may develop; however, levels higher than that are not expected. Fine particulate should be Good early next week.

Next forecast update: Monday, July 8th, 2019
Updated by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy, 517-284-6746 | hengesbachs1@michigan.gov

07/02/2019 Forecast Update

FORECAST SUMMARY:

Tuesday, July 2nd, 2019 through Wednesday, July 3rd, 2019

...AIR QUALITY ACTION DAY ADVISORY FOR WEDNESDAY JULY 3RD IN SOUTHEAST MICHIGAN: LENAWEE... MACOMB... MONROE... OAKLAND... ST. CLAIR... WASHTENAW... AND WAYNE COUNTIES

Ozone: 8-hour Ozone concentrations will range between Good and Moderate, with scattered USG possible.

PM-2.5: 24-hour Fine Particulate concentrations will range from upper Good to middle Moderate.

FORECAST DISCUSSION:

The warm, muggy conditions will continue through the July 4th Holiday as will chances for scattered storms each day. This threat for storm development continues to make the air quality forecast a bit difficult. Ozone levels have been steadily increasing, especially in the southeast, and without a front/system to clean out conditions, this increase will likely continue. Forecast models show less in the way of clouds in the southern portion of the state both today and tomorrow. Ozone will be Moderate Tuesday, and isolated USG is possible in areas that have more in the way of sunshine.

For Wednesday, there will be some clouds, but they will be higher clouds which will allow for sunlight to go through. Storm chances are not great and without an airmass change there is enough risk for USG ozone in the southeastern portion of the state to warrant an Air Quality Action Day. Scattered USG could also be seen in the southwest, but clouds should be more prevalent keeping ozone generally Moderate.

Looking ahead to the July 4th Holiday, more in the way of cloud cover is expected along with higher chances for storms. At this time, it doesn’t look like we’d need to continue the Action Day into Thursday; however, conditions will be evaluated and the forecast will be updated tomorrow.

As for fine particulate, levels have been ranging from Good to Moderate and this trend will continue. Again, with the holiday approaching, remember that USG fine particulate levels will be likely in areas holding fireworks displays later this week.

EXTENDED FORECAST:

Ozone and fine particulate levels are expected to improve later in the week as a cold front finally brings back northwesterly winds. This airmass change should happen Friday into Saturday.

Next forecast update: Wednesday, July 3rd, 2019
Update by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy, 517-284-6746 | hengesbachs1@michigan.gov

07/01/2019 Forecast Update

FORECAST SUMMARY:

Monday, July 1st, 2019 through Tuesday, July 2nd, 2019

Ozone: 8-hour Ozone concentrations will range between Good and Moderate, with isolated USG possible.

PM-2.5: 24-hour Fine Particulate concentrations will range from upper Good to middle Moderate.

FORECAST DISCUSSION:

Warm, muggy conditions will be noticed this week and chances for scattered storms exist each day. Not all areas will see precipitation, however, and this makes the air quality forecast a bit tricky. For today, clouds are not expected to be as prevalent as weekend forecast models were making conditions out to be. Therefore, ozone Monday may be higher than expected to where isolated monitors in the west and/or southeast could get into the low-end USG range. Otherwise, mostly Moderate levels will persist.

Looking ahead to Tuesday, a boundary is expected to be positioned across the southern portion of the state. It does look like more clouds will be overhead compared to Monday which should hamper significant ozone development. The flip side to that is, ozone may increase quickly in areas that have more in the way of sunshine. Overall, clouds and increased chances for afternoon/evening storms will keep ozone from reaching higher than Moderate.

Tuesday’s chances for precipitation look a bit higher than Wednesday so the threat for increased ozone could continue. With so much uncertainty in the forecast, the regional forecasters are having another call Tuesday morning to determine expected conditions for Wednesday.

As for fine particulate, with increased moisture and a boundary lingering across the state, Moderate levels are expected. With the July 4th holiday a few days away, make note that USG fine particulate levels will be likely in areas holding fireworks displays later this week.

EXTENDED FORECAST:

Ozone and fine particulate levels are expected to improve later in the week as a cold front finally brings back northwesterly winds. This airmass change should happen Friday into Saturday.

Next forecast update: Tuesday, July 2nd, 2019
Forecast by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy

06/29/2019 Forecast Update

FORECAST SUMMARY:

Saturday, June 29th, 2019 through Monday, July 1st, 2019

Ozone: 8-Hour average Ozone concentrations will be a mixture of Good and Moderate through Monday.

PM-2.5: 24-hour average Fine Particulate concentrations will be mostly Good with some Low Moderate.

FORECAST DISCUSSION

Rain showers in the mid and upper portion of the Lower Peninsula, during Friday, provided a nice cleanout and kept all monitors below USG levels. As a weak front slips down into Indiana/Ohio, weak northerly flow will set up in Michigan as high pressure builds in.

The high pressure and northerly flow are expected to continue throughout Sunday which will result in relatively pleasant summertime conditions with sunny skies, calm to light winds, and daytime highs persisting in the low to mid-80s. Since the northerly winds will be clean in nature, Air Quality will be in the Good to Moderate range. The only caveat is that the winds, albeit northerly and clean, will be light in nature. This could allow some stagnation to occur in urban areas and a lake breeze could draw in some dirtier air over the lake. These scenarios fall into a low percentage category and Moderate is the worst we will see.

High pressure will continue to build and hold over the upper Midwest which will allow weak shortwaves to ride across the northern tier of that ridge that will set up over Michigan. Increase in instability and passage of multiple waves will bring the chance for showers and storms everyday next week.

EXTENDED FORECAST:

Air Quality is expected to remain mixedGood to Moderate going into the next work week.

Forecast updated by Jim Haywood: Saturday, June 29th, 2019 | Next forecast update: Monday, July 1st, 2019

Jim Haywood ǀ Senior Meteorologist ǀ Air Quality Division ǀ  ( 517.284.6745

06/28/2019 Forecast Update

FORECAST SUMMARY:

Friday, June 28th, 2019 through Saturday, June 29th, 2019

Ozone:  8-Hour average Ozone concentrations will be a mixture of Good and Moderate through Friday.

PM-2.5:  24-hour average Fine Particulate concentrations will be mostly Good with some Low Moderate.

FORECAST DISCUSSION

A large area of rain and storms have impacted a line from southern Wisconsin through mid-Michigan much of Friday morning.  Not only does this impede any new ozone formation but it also provides a cleaning out effect as clean upper air is drawn down to the surface and clouds prevent the photo-chemical process.  That should eliminate any serious threat of elevated ozone during Friday.

Some cloud cover and potential showers will linger through Saturday morning as a stagnant front, down by the border area, finally slips southward as a cold front.  Winds behind that front will be light but biased to the northwest.  While the afternoon is expected to be sunny, hot, and humid, it should be relatively clean air.

While Sunday is expected to be sunny and hot, it probably will not be quite as hot as Saturday.  Winds will still be light but remain biased to the northwest keeping the bad air to our south.

Since any slight jiggle in the expected meteorology could cause a significant change to the forecast, latest predictions will be reviewed Saturday morning, and the forecast will be updated.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Friday, June 28th, 2019
Next forecast update: Saturday, June 29th, 2019

06/27/2019 Forecast Update

FORECAST SUMMARY:

Thursday, June 27th, 2019 through Friday, June 28th, 2019

Ozone:  8-Hour average Ozone concentrations will be mostly Good to Low Moderate through Friday.

PM-2.5:  24-hour average Fine Particulate concentrations will also be mostly Good with some Low Moderate through Friday.

FORECAST DISCUSSION

A weak frontal boundary will linger over Michigan throughout the weekend.  The movement of that frontal boundary over the next few days is hard to nail down and that makes the forecast difficult.

This promises to be the most interesting weekend for forecasting, so far.  There isn’t too much concern about Thursday.  The wind pattern should keep ozone over Lake Michigan, but wind speeds are light enough that a late afternoon breeze could push a bit of ozone inland.  It does not warrant any advisories, however.

Friday should have less potential for elevated ozone with higher wind speeds to mix the atmosphere and a better chance of cloud cover.

The weekend looks more problematic.  Saturday will be cloudy enough to keep numbers in check.  Sunday has the greatest chance to have elevated ozone.  Since there are so many variables in the forecast, the regional forecasters have decided to have daily calls to discuss the each day’s forecast.  As such, there will be update to this forecast on Friday.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Thursday, June 27th, 2019
Next forecast update: Friday, June 28th, 2019

06/24/2019 Forecast Update

FORECAST SUMMARY:

Monday, June 24th, 2019 through Thursday, June 27th, 2019

Ozone:  8-Hour average Ozone concentrations will be mostly Good to Low Moderate through the forecast period.

PM-2.5:  24-hour average Fine Particulate concentrations will also be mostly Good with some Low Moderate through the forecast period.

FORECAST DISCUSSION

A front moving through Michigan during Monday will provide clouds and scattered rain showers. Tuesday should begin a drying out period with the exception of some potential showers Tuesday night.  Temperatures will also start a warming trend with climbing into the upper 70’s with a rising dew point into the 60’s. 

Wednesday will be warm and dry with a westerly wind pattern and mostly clear skies.  We could see some creep in ozone values into the Low Moderate range along the southern Lake Michigan shoreline and Southeast Michigan.

Thursday could continue the ozone creep, although it should not get into the USG range.  Temperatures will climb into the lower 80’s with scattered cloud cover and light winds.  I will keep an eye on Thursday to make sure it doesn’t get any worse. 

The upcoming weekend looks to be the first real “summer-like” weekend of the season.  Temperatures will climb into the mid-80’s with a juicy dew point in the upper 60’s.  Winds will be light and skies partly cloudy.  The wind direction is not ideal for ozone formation, but the low wind speed could allow for some stagnation.  As this time year is optimal for ozone potential, it will certainly need watching.  As such, the regional forecasters will have another call on Thursday to finalize a weekend forecast.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Monday, June 24th, 2019
Next forecast update: Thursday, June 27th, 2019