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

06/20/2019 Forecast Update

FORECAST SUMMARY:

Thursday, June 20th, 2019 through Monday, June 24th, 2019

Ozone: 8-hour Ozone concentrations will range between Good and Moderate through the forecast period.

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

FORECAST DISCUSSION:

Precipitation across lower Michigan will finally end Thursday afternoon as the storm system tracks east. This will be replaced with weak high pressure for Friday which will bring in dry conditions and warmer temperatures. The dry conditions may be short-lived, however, as an active weather pattern is expected for this weekend into early next week. Warm temperatures will remain in place through the period.

Cool, wet conditions Thursday will allow for Good air quality. More in the way of sunshine is expected Friday and surface temperatures will increase, but northerly winds and cooler upper level temperatures will hamper ozone development. Ozone is expected to range between Good and Moderate, and fine particulate will be mostly Good with a few low Moderates possible in the southeast. Storm chances may come into play early Saturday as a complex is expected to track southeast from Wisconsin early in the day. The exact track of this isn’t certain and parts of the state may remain dry. Upper level temperatures again remain lower, especially over the southeastern portion of the state. At this time a significant increase in ozone is not expected with both ozone and fine particulate levels ranging from upper Good to Moderate.

By Sunday, winds at the surface and upper levels turn more southwesterly and warmer temperatures move in. This is more conducive for ozone, but a warm front will also be tracking up from the south bringing with it clouds and scattered storms. Ozone may reach Moderate in areas with more hours of sunshine but levels higher than Moderate are not expected; more widespread Moderate fine particulate can be expected. Forecast maps will be evaluated again Friday morning and this forecast will be updated if we feel pollution levels will increase higher than what is currently anticipated.

EXTENDED FORECAST:

The warm front, followed by an associated cold front, will keep storm chances through Monday. Ozone may reach Moderate in a few locations if the sun breaks out, otherwise levels should be Good. Fine particulate through early next week will range from upper Good to low Moderate.

Next forecast update: Monday, June 24th, 2019
Update by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy

06/17/2019 Forecast Update

FORECAST SUMMARY:

Monday, June 17th, 2019 through Thursday, June 20th, 2019

Ozone: 8-hour Ozone concentrations will be mostly Good with scattered Moderates possible Tuesday.

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

FORECAST DISCUSSION:

Generally quiet conditions start the week with high pressure in place. Clouds and cooler temperatures Monday will keep ozone generally Good; however, weaker winds may allow for Moderate fine particulate in the southeastern portion of the state. More sunshine is expected Tuesday as winds remaining light and upper level temperatures cool. Ozone may increase into the Moderate range and scattered Moderate fine particulate may linger as well. The next weather system approaches Wednesday bringing in clouds and chances for precipitation. The heaviest rainfall looks to occur across the southern portion of the state. A few Moderates for fine particulate may continue; Good ozone is expected. Northerly winds develop Thursday after the Wednesday system passes. Both ozone and fine particulate will be Good.

High pressure settles over the state Friday with temperatures warming at the surface. Plenty of sunshine is anticipated which could allow for increased ozone, but cooler upper level temperatures may hamper ozone development. There is enough risk for increased readings; therefore, we will be evaluating weather conditions Thursday to get a better handle on expected pollution levels for Friday.

EXTENDED FORECAST:

Extended models show more summer-like temperatures for the coming weekend, but it also comes with storm chances. It may be a set-up where ozone will quickly develop in areas with only a few hours on sunshine. Updated information on the extended forecast can also be expected Thursday.

Next forecast update: Thursday, June 20th, 2019
Update by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy

06/10/2019 Forecast Update

FORECAST SUMMARY:

Monday, June 10th, 2019 through Monday, June 17th, 2019

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

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

FORECAST DISCUSSION 

Rain will move out of the area, Monday morning, as a front migrates across the state.  Brisk northwest winds will push dry air into the region during the afternoon and skies should be generally clear by sunset.  Air Quality issues will be small as the incoming air will be clean.

Clear skies should persist through Tuesday as high pressure rapidly pushes through the upper Midwest.  Highs should reach the mid-70’s with comfortable humidity borne on light westerly winds.  Air Quality should remain Good.

The Wednesday/Thursday time frame shows another chance of rain, albeit not as much as we saw during Sunday and early Monday.  I expect shower activity to start Wednesday afternoon and linger into Thursday morning.  Cooler temperatures on Thursday will struggle to reach the low 60’s with Good Air Quality.

Surface high pressure will nudge its way into the lower Great Lakes region during Friday providing a pleasant day with westerly winds and continued Good Air Quality.

More unsettled weather will likely return to the region during the weekend.  The models are not totally certain on the nature of the precipitation potential but overcast skies and mostly southeast winds in advance of another low pressure system should keep ozone levels low and fine particulates in the Good to Low Moderate range. 

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Monday, June 10th, 2019
Next forecast update: Monday, June 17th, 2019

06/07/2019 Forecast Update

FORECAST SUMMARY:

Friday, June 7th, 2019 through Monday, June 10th, 2019

Ozone: 8-hour Ozone concentrations will range from Good to Moderate.

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

FORECAST DISCUSSION:

High pressure dominating will keep sunny and warm conditions in place Friday and Saturday. This forecast changes Sunday as a low-pressure area tracks north into the state bringing with it chances for precipitation. Precipitation could linger Monday into Tuesday, and cooler conditions are expected to move in.

As for air quality, plenty of sunshine will be in place through Saturday along with warmer surface temperatures. These are conditions conducive for ozone development; however, upper level temperatures remaining lower and easterly surface winds will hamper ozone from significantly increasing. An isolated monitor or two may reach low-end USG, but readings will mostly remain Moderate both Friday and Saturday. Clouds and chances for precipitation on Sunday should allow for generally Good ozone, with Good readings continuing Monday.

Fine particulate has generally been Good, except for some scattered Moderates in the southern part of the state. This trend is expected to continue Friday and Saturday with a mix of Good and low Moderate levels. Any Moderate fine particulate will improve into the Good range Monday after the low/front tracks east of the state and northerly winds develop.

EXTENDED FORECAST:

Extended models show cooler conditions prevailing into mid-week. This will keep air quality at Good levels.

Next forecast update: Monday, June 10th, 2019
Update by: Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy

06/03/2019 Forecast Update

FORECAST SUMMARY:

Monday, June 3rd, 2019 through Friday, June 7th, 2019

Ozone: 8-hour Ozone concentrations will be mostly Good with a few low-Moderates.

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

FORECAST DISCUSSION:

High pressure Monday is producing dry, cool conditions and allowing for Good air quality. By Tuesday, warm air moves in as the high tracks east bringing more of a southerly wind. A shortwave dropping in Tuesday will produce clouds and scattered precipitation which could last through Wednesday. High pressure is then forecast to move back in for the end of the workweek.

As for air quality, both ozone and fine particulate will range Good Monday. Increased clouds and chances for precipitation should keep ozone Good Tuesday; however, areas that break into more sunshine could reach into the Moderate range. Clouds linger Wednesday keeping ozone generally Good. Conditions dry out Thursday and more in the way of sunshine is expected. Temperatures increase both at the surface and upper levels, but winds remain southeasterly. This should keep ozone from increasing higher than low Moderate. Similar weather conditions are expected Friday and ozone should range from Good to Moderate.

Without a good period of stagnation during the week, fine particulate is expected to range between Good and low Moderate.

EXTENDED FORECAST:

Extended models show a possible upper low moving in for the weekend; however, there is a bit of uncertainty in its development. If the low does not pan out, dry conditions and good amounts of sunshine could be in place. This forecast will be updated Friday to detail expected air quality conditions for the coming weekend.

Next forecast update: Friday, June 7th, 2019
Stephanie M. Hengesbach, Meteorologist, Air Quality Division. Michigan Department of Environment, Great Lakes, and Energy

05/28/2019 Forecast Update

FORECAST SUMMARY:

Tuesday, May 28th, 2019 through Monday, June 3rd, 2019

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

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

FORECAST DISCUSSION

Cooler, cloudy weather will persist through much of the work week as a stationary front lingers in the northernIllinois/Indiana area. This combination of fronts and associated low pressure cells will likely cause outbreaks of nasty weather to our south but Michigan should only experience clouds and showers. Air Quality should remain mostly in the Good range.

We finally begin to dry out on Friday as high pressure begins pushing in from the northwest. Calm winds on Friday may allow some creep in Fine Particulates but Ozone does not appear to be an issue, at this time.

During Saturday, southwest air flow should change over to west/northwest winds later in the day as clockwise winds around the center of high pressure define our weekend wind pattern. These winds should be clean and provide Good Air Quality. Sunday and Monday’s winds should be light but predominantly northerly keeping our weather pleasant and our Air Quality Good.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Tuesday, May 28th, 2019

Next forecast update: Monday, June 3rd, 2019

05/24/2019 Forecast Update

FORECAST SUMMARY:

Friday, May 24th, 2019 through Tuesday, May 28th, 2019

Ozone: 8-hour Ozone concentrations will be mostly Good through the forecast period.

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

FORECAST DISCUSSION:

An active weather pattern continues as we move into the Memorial Day weekend. The weekend won’t be a complete washout, but periods of showers and storms exist through Tuesday. Sunday into Monday afternoon looks to be the driest period.

Clouds and precipitation chances keep ozone Good Friday and Saturday. A frontal boundary settles near the state border Sunday. Clouds and precipitation may linger in the south with mostly dry conditions further north. Winds will have a northerly component keeping ozone mostly Good even in areas that break into some afternoon sunshine. The boundary tracks back north Monday causing clouds to increase and precipitation to move back in during the afternoon. Chances for showers and storms continue Tuesday. Generally Good ozone is expected both Monday and Tuesday.

Increased moisture near the frontal boundary on Sunday may allow for some increased fine particulate into the Moderate range across the southern portion of the state. Otherwise, the active pattern keeps the air well-mixed and fine particulate is expected to be mostly Good.

EXTENDED FORECAST:

Extended models show precipitation remaining in the forecast through mid-week. Air pollution during this time will be generally Good.

Next forecast update: Tuesday, May 28th, 2019
Update by: Stephanie M. Hengesbach

05/20/2019 Forecast Update

FORECAST SUMMARY:

Monday, May 20th, 2019 through Friday, May 24th, 2019

Ozone: 8-hour Ozone concentrations will be mostly Good with a few Moderates possible Thursday and/or Friday.

PM-2.5: 24-hour Fine Particulate concentrations are expected to range from middle Good to low Moderate through the week.

FORECAST DISCUSSION:

Cool, cloudy conditions on Monday turn warmer as the week progresses; however, a more active pattern will also develop. After a mostly dry Tuesday, precipitation comes in the forecast through Wednesday as a low-pressure area tracks north of the region. Past mid-week an upper level ridge builds across the southeast, but a surface boundary lingers further north across our region through the weekend. Disturbances moving across this boundary will keep scattered showers and storms in the forecast as temperatures and humidity levels increase.

Ozone is expected to remain Good through Wednesday, but readings could reach Moderate Thursday and/or Friday if precipitation remains at bay and afternoon sunshine breaks out for a few hours. Fine particulate may also increase into the Moderate range starting Wednesday, especially in the southeast.

EXTENDED FORECAST:

Extended models show the boundary possibly lingering through the Memorial Day holiday. Since the placement of this boundary is important in determining air quality levels, we will be having another regional forecast call Friday to better evaluate expected conditions through the holiday weekend.

Next forecast update: Friday, May 24th, 2019
Update by: Stephanie M. Hengesbach

05/13/2019 Forecast Update

FORECAST SUMMARY:

Monday, May13th, 2019 through Monday, May 20th, 2019

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

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

FORECAST DISCUSSION

The cloudy, cool and wet weather observed on Monday will give way to clear skies on Tuesday as high pressure moves into the region.  Winds through Tuesday will vary north to west and Air Quality should be Good.

During Wednesday, a weak front will drop down through the state.  Winds will be generally southeast until the front passes then turn briefly to the northwest. 

During Thursday, we will see the start of a slow warm up as winds become predominantly southwest in advance of a front over the Plaines states.  Ozone will not be an issue as temperatures will not get warm enough and cloud cover will happen more often than clear skies.  But Fine Particulates could creep into the Low Moderate range. 

Southwest winds will persist, along with the possibility of Low Moderates, until a frontal passage late Sunday night.  Rain chances increase as the front draws closer during the weekend.

Air Quality will return to Good on Monday on the back side of the front and the return of northwest winds.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Monday, May 13th, 2019
Next forecast update: Monday, May 20th, 2019

05/06/2019 Forecast Update

FORECAST SUMMARY: Monday, May 6th, 2019 through Monday, May 13th, 2019

Ozone: 8-hour Ozone concentrations will be Good.

PM-2.5: 24-hour Fine Particulate concentrations are expected to be mostly Good with only a few periods of possible low Moderates.

FORECAST DISCUSSION:

Precipitation is in the forecast Monday/early Tuesday as a cold front move through.  This boundary stalls south of the state before moving back north Wednesday bringing precipitation back in the forecast.  Precipitation chances linger Thursday as a low develops along this boundary and tracks northeast across the state.  High pressure builds in Friday drying conditions out for the end of the week.

As for air quality, fine particulate levels early Monday were ranging between upper Good and low Moderate.  Readings will improve as the front passes with mostly Good averages for the day; however, the southeast may remain low Moderate.  Northeast/easterly winds Tuesday into Wednesday will keep fine particulate in the Good range.  Weaker winds for a time Thursday may allow for a few low-Moderate fine particulate readings, otherwise levels will be Good through Friday.

Clouds, precipitation chances, and lower temperatures will keep ozone Good through the workweek.

EXTENDED FORECAST:

Extended models show high pressure in place most of Saturday but a front passes during the night bringing chances for rain.  High pressure builds back in early next week with cooler temperatures expected.  Low-Moderate fine particulate is possible, mostly in the southeast, on Saturday; otherwise both fine particulate and ozone will be Good.

Next forecast update: Monday, May 13th, 2019
Updated by: Stephanie M. Hengesbach, Meteorologist, Michigan Department of Environment, Great Lakes, and Energy

04/29/2019 Forecast Update

FORECAST SUMMARY:

Monday, April 29th, 2019 through Monday, May 6th, 2019

PM-2.5: 24-hour Fine Particulate concentrations are expected to be Good through much of the week with Moderates possible by the weekend.

FORECAST DISCUSSION:

A wet period is expected between Monday and Thursday with chances for showers and/or storms as three systems pass through. Monday should be mostly rain but chances for storms arrives later Tuesday through Thursday. Cooler temperatures start the period; however, southerly winds by mid-week will bring in seasonable temperatures. A dry out is expected Friday as high pressure moves in.

As for air quality, levels are low early Monday and readings are expected to average Good for the day. Easterly/southeasterly winds into Wednesday will keep air quality mostly Good; however, southerly winds later Wednesday into Thursday could allow for low-Moderates to mix in. Winds turn back northerly as high pressure builds in Friday and air quality is expected to be Good.

EXTENDED FORECAST:

Extended models show high pressure remaining in control until Monday when precipitation returns ahead of a frontal boundary. Lighter winds turn southwesterly Sunday and temperatures should be warmer, in the 60s. Weather conditions will be more conducive for Moderate air quality early next week with levels ranging from upper Good to middle Moderate.

Next forecast update: Monday, May 6th, 2019
FORECAST UPDATED BY Stephanie M. Hengesbach, Meteorologist, Air Quality Division, Michigan Department of Environment, Great Lakes, and Energy

04/22/2019 Forecast Update

FORECAST SUMMARY:

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

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

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

FORECAST DISCUSSION

Monday will give us a taste of the upcoming summer with afternoon temperatures approaching 80 degrees.  These warm temperatures will be courtesy of a tight low pressure system over the Plaines states causing brisk southerly winds.  The winds will provide enough mixing such that Air Quality should remain Good. 

When the associated front passes Thursday morning, shifting winds to the northwest will provide clean air and cooler temperatures.

The best chance of Low Moderates, during the forecast period, will likely be Thursday when another weak front pushes across the state.  Southwest winds with temperatures in the upper 60’s could yield a creep in fine particulates concentrations. 

Temperatures look to be cooler during the weekend with Good Air Quality.

EXTENDED FORECAST:

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

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