10/12/2020 Forecast Update

FORECAST SUMMARY:

Monday, October 12th, 2020 through Monday, October 16th, 2020

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

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

FORECAST DISCUSSION

We will experience a series of fronts, during the week, which will keep the atmosphere well mixed.  During Monday, the state will briefly be in the warm air sector found between a warm front and a cold front that will pass Monday night.  The brisk winds should keep all Air Quality readings in the Good category.

A second front will pass late Tuesday night with little fanfare.  The third and most significant front of the week will pass early Thursday with a sharp cool-down in its wake.  All of this activity should keep Air Quality mostly Good through the work week.

The best chance of any Moderate readings for fine particulates will come early in the weekend as a large high pressure ridge slides eastward across the Midsouth states.  Calm nights will set up strong morning inversions and a good chance for widespread frost.

The fourth front of the forecast period should pass early Monday morning followed by another cool-down. 

EXTENDED FORECAST: 

Air Quality should be mostly Good going into next week.

Forecast updated by Jim Haywood: Monday, October 12th, 2020
Next forecast update: Monday, October 16th, 2020

10/5/2020 Forecast Update

FORECAST SUMMARY:

Monday, October 5th, 2020 through Monday, October 12th, 2020

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good; some low Moderates are possible late in the period.

PM-2.5: 24-hour average Fine Particulate concentrations will be Good through mid-week with a mix of Good and low-Moderates the rest of the forecast period.

FORECAST DISCUSSION:

Over the next week the only chances for precipitation come late Monday into Tuesday, then again late Tuesday into Wednesday. The first system is a weak boundary and any associated precipitation will be light and contained to the norther portion of the state. The second system is more organized and better chances for rain exist; however, the precipitation will again be more confined to northern areas. Aside from these systems, the region will be dominated with high pressure producing sunshine and dry conditions. Cooler temperatures through mid-week will moderate for the end of the week and weekend.

Last week Good air quality was seen for both ozone and fine particulate. The expected ozone forecast this next week will be a continuation of primarily Good levels. This can be attributed to cooler temperatures at both the surface and upper levels through mid-week. As high pressure builds overhead Thursday and then east Friday, warmer temperatures enter the region with the warmest reading expected Saturday. Warmer surface and upper level temperatures, coupled with plenty of sunshine, could allow for low-Moderate ozone in a few southern monitors; however, it’s too late in the season for widespread increased ozone. The threat for low-Moderates could continue into early next week, but again, most locations should remain Good.

The two systems early in the week will produce a northwesterly flow in their wake. This will help fine particulate stay generally Good through Wednesday. Lighter winds Thursday, turning southerly Friday could be a period of low-Moderate fine particulate, especially in southern portion of the state. Increased wind speeds Saturday should keep fine particulate from increasing higher than a continuation of low-Moderate.

EXTENDED FORECAST:

Extended forecast models show high pressure being reinforced early next week with a continuation of dry conditions and comfortable fall temperatures. Air quality early next week is not expected to be higher than low-Moderate for either ozone or fine particulate.

Forecast Update by Meteorologist Stephanie M. Hengesbach Monday October 5th, 2020.
Next forecast update: Monday, October 12th, 2020

9/28/2020 Forecast Update

FORECAST SUMMARY:

Monday, September 28th, 2020 through Monday, October 5th, 2020

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

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

FORECAST DISCUSSION

The warm dry weather experienced, last week, will be replaced by cooler wet weather, this week.  During Monday, areas of showers will persist between a front that passed through Sunday night and another front that will pass through Monday night.  Monday Air Quality is currently Good.

More showers are expected Wednesday as a stronger cold front passes through the region with cooler air behind it.  This will provide a good cleanout including no overhead smoke form the western fires and continued Good Air Quality.  Showers will likely persist through Thursday before a dry out period begins on Friday lasting until another weak front passes during Sunday,  All in all, Air Quality should be mostly Good through the entire forecast period.

EXTENDED FORECAST:

Air Quality should be mostly Good going into next week.

Forecast updated by Jim Haywood: Monday, September 28th, 202
Next forecast update: Monday, October 5th, 2020

9/25/2020

FORECAST SUMMARY:

Friday, September 25th, 2020 through Monday, September 28th, 2020

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good; some Moderates are possible Friday or Saturday.

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

FORECAST DISCUSSION:

A frontal boundary lingering over the northern portion of the state keeps clouds and precipitation in the forecast. Further south, summer-like conditions are in store as we end the week. Warm southerly winds will produce above normal temperatures and partly to mostly sunny skies prevail though Saturday afternoon. A cold front approaching by Sunday brings increasing clouds late Saturday and chances for precipitation Sunday afternoon/evening. Looking at the smoke plume analysis, smoke is lingering across the southern portion of the state. Smoke will likely linger over parts of the region this weekend; however, the smoke layer will be pushed out early next week.

As for air quality, fine particulate levels have been upper Good to low Moderate since Tuesday, and ozone has been mostly Good with only one monitor in the southwest reaching just over the Moderate threshold Wednesday, and four locations in the southeast Thursday. Fine particulate mostly in the Moderate range is likely across the southern portion of the state Friday and Saturday with Good levels up north. For ozone, southerly winds and warmer temperatures are conducive for increasing levels. Plenty of sunshine Friday will provide the best chance for Moderates as increasing clouds Saturday into Sunday should hamper ozone development. Also, the earlier sunset this time of year will help as ozone will not have as much time to develop. On Sunday, Good ozone is expected while any Moderate fine particulate should improve late in the day.

EXTENDED FORECAST:

Extended forecast models show unsettled weather developing next week with chances for precipitation and a drop in temperatures. This set-up will provide Good air quality.

Forecast update by Stephanie M. Hengesbach September 25th, 2020
Next forecast update: Monday, September 28th, 2020

9/21/2020 Forecast Update

FORECAST SUMMARY:

Monday, September 21st, 2020 through Friday, September 25th, 2020

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good; some Moderates are possible late in the week.

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

FORECAST DISCUSSION:

Weak disturbances may bring a few periods of precipitation to the northern portion of the state; however, most areas will be dominated by high pressure providing dry conditions and moderating temperatures through the week. Another item to note, wildfire smoke has returned which will again provide a hazy look to the sky.

Air quality this past weekend was Good for both ozone and fine particulate aside from two monitors in the southeast that reached low Moderate for fine particulate. For Monday and Tuesday, winds will be from a southerly direction, but surface and upper level temperatures look to remain low enough (along with earlier sunset this time of year), where ozone will stay generally Good. Smoke forecast models show the plume staying “elevated” the next few days; therefore, it should not have a negative impact on fine particulate. With lighter southerly winds, fine particulate will range from upper Good to low Moderate.

By mid-week, west/southwesterly winds continue with high pressure to our east. Making the forecast a bit challenging is uncertainty on how the smoke over the region will play out as the week progresses. Models show the plume reaching closer to the ground and this is something we will keep an eye on. Considering there is no real air mass change this week, we would expect fine particulate to increase into the Moderate range, especially across the southern portion of the state. Ozone may also increase into low-Moderate.

Similar conditions continue through Friday and more widespread Moderate pollution levels are a good possibility. By Saturday, temperatures as the surface and upper levels increase and coupled with plenty of sunshine, conditions look more conducive for ozone development. While it is late in the ozone season, it’s not out of the question to see elevated ozone in September; therefore, we will be updating the forecast Friday to detail expected pollution levels for the weekend.

EXTENDED FORECAST:

Extended forecast models show the next chance for widespread precipitation comes with a storm system passing late Saturday into Sunday. Good pollution levels should return early next week.

Forecast Update By: Stephanie M. Hengesbach September 21, 2020.
Next forecast update: Friday, September 25th, 2020

9/14/2020 Forecast Update

FORECAST SUMMARY:

Monday, September 14th, 2020 through Monday, September 21st, 2020

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.

FORECAST DISCUSSION

The forecast week looks to be mostly sunny, dry and comfortable with Good Air Quality.  During Monday, a high pressure ridge slides eastward putting the Midwest under warm and dry southwest winds.  At the same time, westerly winds aloft are bringing in smoke from the western fires.  Skies will be noticeably less blue with colorful sunrise and sunsets.  Fortunately, the high level of smoke plume should not filter down to the surface in amounts that could significantly affect our Air Quality.

Southwest winds, behind the high pressure will drive temperatures to near 80 degrees, by Wednesday afternoon.  As such, Wednesday looks to be the best chance for any Moderate ozone levels.

The passage of a cold front, Wednesday, will place the region into a cooler air mass and Good Air Quality.  Night-time temperatures, Thursday and Friday, could drop as low as the mid-30’s.  By Sunday and Monday, surface winds shifting from southeast to southwest will provide another warming trend, but I expect Air Quality to remain Good.

EXTENDED FORECAST:

Air Quality should be mostly Good going into next week.

Forecast updated by Jim Haywood: Monday, September 14th, 2020
Next forecast update: Monday, September 21st, 2020

9/8/2020 Forecast Update

FORECAST SUMMARY:

Tuesday, September 8th, 2020 through Monday, September 14th, 2020

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

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

FORECAST DISCUSSION:

A frontal boundary stalled south of the state will keep cool temperatures and showers/storms in the forecast through mid-week. High pressure sinking in from the north Thursday should dry conditions out, lasting through part of Saturday. However, another system brings precipitation back in the forecast late in the weekend.

With a primarily cool/cloudy pattern this week, and northeasterly winds, air quality is anticipated to be Good for both ozone and fine particulate. As high-pressure slides in Thursday, clouds will decrease during the day with more in the way of sunshine Friday and early Saturday. Temperatures at the surface and upper levels, though, should keep ozone generally Good while fine particulate may reach low Moderate in the southeastern part of the state.

EXTENDED FORECAST:

Extended forecast models show a system moving through late Saturday into Sunday with high pressure returning Monday. Clouds/precipitation should keep air quality Good Sunday and northerly winds by Monday will continue the Good air quality trend into early next week.

Forecast Updated By Stephanie M. Hengesbach September 8th, 2020
Next forecast update: Monday, September 14th, 2020

8/31/2020 Forecast Upadate

FORECAST SUMMARY:

Monday, August 31st, 2020 through Tuesday, September 8th, 2020

OZONE: 8-Hour average Ozone concentrations will be a mixture of Good and Moderate through the forecast period.  

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

FORECAST DISCUSSION:

Last week, we issued what we optimistically hope to be the last Action Day Advisory for 2020.  That forecast, for Wednesday, proved to be accurate as four monitors on the West Side did cross into the USG range.

This week should be cleaner and easier to forecast as we head into the Labor Day weekend.  Temperatures will be more typical for this time of year with daily highs around 80 degrees. 

During Monday, high pressure will exit the area with a frontal passage expected Tuesday morning.  Clouds and precipitation are expected Tuesday and Wednesday as a result of this passage.  Thursday is showing strong southwest winds in advance of another front.  But the short duration of these winds and daytime high temperatures only around 80 should keep things no worse than Moderate.

The holiday weekend looks mostly dry with seasonal temperatures until a strong front pushes through during Sunday afternoon.  Cooler temperatures are expected for the beginning of next week.

Right now, it looks safe to forecast through the weekend and Monday holiday.  However, if conditions change, we will revise this forecast, as necessary.

EXTENDED FORECAST:

Air Quality should be mostly Good going into next week.

Forecast updated by Jim Haywood: Monday, August 31st, 2020
Next forecast update: Tuesday, September 8th, 2020

8/26/2020 Forecast Update

FORECAST SUMMARY:

Wednesday, August 26th, 2020 through Monday, August 31st, 2020

OZONE: 8-hour average Ozone concentrations will be Good to Moderate with a chance for USG along the southern tier counties of Lake Michigan on Wednesday.

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

AN ACTION DAY ADVISORY IS ISSUED FOR WEDNESDAY FOR THE FOLLOWING MICHIGAN COUNTIES...

WEST MICHIGAN

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

FORECAST DISCUSSION:

A warm front lifting southwest to northeast Wednesday will end precipitation across much of the state while showers/storms may linger north closer to the boundary. This boundary will be the focus of storms the next few days, but the best chance for precipitation comes late Thursday into Friday as a low develops along the boundary, just north of Lake Superior, which will push a cold front through.

As expected from Tuesday’s forecast, clouds early Wednesday were cleaning out across the western/southwestern portions of the Lower Peninsula. With sunny skies and a warm southwesterly wind, temperatures will increase quickly as the day progresses. Conditions remain conducive for ozone development along the west/southwest Michigan lakeshore and the threat for USG readings in that portion of the state is covered in the Action Day we have in place for Wednesday. Across the rest of the state, ozone should be Moderate and Good closer to the front where clouds will linger. As another note, there is a plume of smoke over our region from western fires. If the plume makes it to ground level, this could also contribute to increased ozone in the west/southwest.

By Thursday, the boundary will slowly make its way south with clouds and chances for precipitation increasing. While conditions remain warm and winds from the west/southwest, we feel increased clouds in the afternoon will keep ozone from reaching higher than Moderate. In the extreme southwest corner (South Haven/Benton Harbor areas), if clouds are slower to reach there, then a monitor or two may reach low-end USG late in the day, but the threat at this time isn’t high enough to warrant the continuation of the Action Day. We anticipate ozone Thursday will range from Good to Moderate in the south.

Friday will be another warm/humid day; however, clouds and higher precipitation chances will keep ozone in the Good to low Moderate range. With high pressure moving in Saturday into Sunday, along with a northwesterly wind, Good air quality levels are expected for the weekend. Fine particulate through Friday will be a mix of upper Good to Moderate with readings improving to Good Saturday.

EXTENDED FORECAST:

High pressure and cooler conditions linger through the weekend into early next week. Mostly Good air quality is expected.

Next forecast update: Monday, August 31st, 2020

8/25/2020 Forecast Update

FORECAST SUMMARY:

Tuesday, August 25th, 2020 through Wednesday, August 26th, 2020

OZONE: 8-Hour average Ozone concentrations will be Good to Moderate with a chance of USG along the southern tier counties of Lake Michigan.

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

AN ACTION DAY ADVISORY IS ISSUED FOR WEDNESDAY FOR THE FOLLOWING MICHIGAN COUNTIES...

WEST MICHIGAN

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

FORECAST DISCUSSION:

A warm front will lift northward through Michigan tonight into Wednesday.  During Wednesday, clouds and showers are expected in the northern and eastern areas, however, southwestern counties should be cloud free, hot and humid.  Add the atmospheric smoke from the western fires and those southwestern counties are prime for elevated ozone.

As a result, an air quality advisory has been issued in West Michigan from the Indiana border up to Muskegon. 

Thursday could be a continuation of elevated ozone, the forecast will be revisited Wednesday morning to make that determination.

EXTENDED FORECAST:

Air Quality will stay mostly Good to Moderate with USG possible in West Michigan.

Forecast updated by Jim Haywood: Tuesday, August 25th, 2020
Next forecast update: Wednesday, August 26th, 2020

8/24/2020 Forecast Update

FORECAST SUMMARY: Monday, August 24th, 2020 through Tuesday, August 25th, 2020

OZONE: 8-Hour average Ozone concentrations will be a mix of Good and Moderate through Tuesday.  

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

FORECAST DISCUSSION

Summer is not quite ready to give up its influence over the Midwest.  During the weekend, our New Haven monitor, northeast of Detroit, had peak 8-hour average concentrations just above the 70 ppb threshold on both Friday and Saturday.  Southwest winds, hot temperatures and plentiful sun was enough to push it over despite the lateness of the ozone season.

This week is also showing a possibility of continued high ozone around the state.  Monday and Tuesday are not high risk days, Wednesday and Thursday are raising some concerns.  Coupled with high temperatures and plentiful sun, there is thick atmospheric smoke from the west coast fires moving eastward across the continent.  Earlier in the year, we were caught by surprise when we had high ozone without the usual precursors.  Smoke in the atmosphere provided many of the pollutants necessary for the photochemical process which triggered that occurrence.

With that knowledge and the triple threat of sun, temperature and smoke, a forecast update, tomorrow, will be warranted for the mid-week.

EXTENDED FORECAST:

Air Quality should be Good to Moderate with a potential for USG, going into mid-week.

Forecast updated by Jim Haywood: Monday, August 24th, 2020
Next forecast update: Tuesday, August 25th, 2020

8/17/2020 Forecast Update

FORECAST SUMMARY:

Monday, August 17th, 2020 through Monday, August 24th, 2020

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

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

FORECAST DISCUSSION:

Scattered precipitation could develop Monday afternoon, otherwise, generally dry, and comfortable conditions are in store most of the workweek. This will be attributed to surface high pressure and a northwesterly upper level flow. A system further north could bring precipitation past mid-week up north, however, the next decent chance for precipitation looks to hold off until the weekend.

Sunday started the week with Good levels of both ozone and fine particulate. Surface high pressure and northwesterly winds should keep Good pollution through mid-week. As the high drifts east, winds change to a more southerly direction late Thursday into Friday. Plenty of sunshine is expected during this time and temperatures should increase a bit both at the surface and upper levels which could bring in some Moderate ozone by Friday. Fine particulate may also increase with readings between upper Good and low Moderate.

Ahead of the next weather system, dew points increase Saturday along with cloud cover over the region. Temperatures and wind flow may be more conducive for ozone development, but clouds and chances for precipitation should keep ozone from reaching higher than Moderate. Fine particulate may increase with more widespread low-Moderate readings.

EXTENDED FORECAST:

Depending on the timing of the weekend front, precipitation may linger into Sunday. Extended forecast models show another boundary coming through in the Monday/Tuesday time frame. Since there does not seem to be a period of stagnation in the long-term forecast, pollution levels higher than low-Moderate are not expected early next week.

Forecast Updated by Stephanie M. Hengesbach August 17th, 2020.
Next forecast update: Monday, August 24th, 2020

8/14/2020 Forecast Update

FORECAST SUMMARY:

Friday, August 14th, 2020 through Monday, August 17th, 2020

OZONE: 8-Hour average Ozone concentrations will be a mix of Good and Moderate through Saturday, then Good though Monday.  

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

FORECAST DISCUSSION

The ridge of high pressure that has brought us sun and warm temperatures during the week will finally break down and shift eastward Friday afternoon.  In its wake will be a weak low pressure trough moving through the Ohio Valley and a stronger front projected Saturday night.

The weaker of the two systems could bring some convective activity, later Friday afternoon, but residual atmospheric stability from the exiting high pressure, plus the lateness of the day, will likely keep that to a minimum.

The stronger system, Saturday night, could also kick off some convective activity but likely not widespread.

Air Quality during Friday and Saturday should remain in the Good to Moderate range with the mixture of broken clouds and potential shower activity.

A good clean-out will occur behind the front, on Sunday, and the new week should start in the Good category.

EXTENDED FORECAST:

Air Quality should be Good going into next week.

Forecast updated by Jim Haywood: Friday, August 14th, 2020
Next forecast update: Monday, August 17th, 2020

8/10/2020 Forecast Update

FORECAST SUMMARY:

Monday, August 10th, 2020 through Friday, August 14th, 2020

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

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

FORECAST DISCUSSION:

Warm conditions are in store this week. A cold front later Monday/early Tuesday will bring storms in the forecast. Precipitation should exit early Tuesday, but northerly winds will not significantly drop temperatures; highs in the 80s can be expected through the rest of the week under generally sunny skies.

As for air quality, several monitors reached Moderate for ozone Sunday and that trend will likely continue Monday. After the boundary moves through, high pressure both at the surface and upper levels will dominate the rest of the workweek. A northerly component to the wind should keep ozone Good Tuesday. Winds are light at mid-week then turn east/southeast as ridging moves east of the region. The expected wind flow this week is not conduce for ozone development; however, warmer surface and upper level temperatures, coupled with no airmass change, could cause Moderate ozone to develop by Thursday or Friday.

Fine particulate has been between upper Good and low Moderate since Sunday and levels in that range will persist until the boundary passes Tuesday. Like ozone, Good fine particulate levels at mid-week could increase back to low Moderate by Thursday or Friday.

EXTENDED FORECAST:

There is some uncertainty on when the next chance for precipitation moves into the region. Extended models are showing chances for storms during the weekend, but there is enough uncertainty in the forecast that we will issue an update Friday to detail anticipated air quality conditions for the weekend, into next week.

Forecast Updated by: Stephanie M. Hengesbach August 10th, 2020.
Next forecast update: Friday, August 14th, 2020

8/7/2020 Forecast Update

FORECAST SUMMARY:

Friday, August 7th, 2020 through Monday, August 10th, 2020

OZONE: 8-Hour average Ozone concentrations will be mostly Moderate through the weekend period with a slight chance of isolated USG during Saturday and Monday.  

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

FORECAST DISCUSSION

The weekend weather will be a return to more typical summer weather with temperatures rising back into the upper 80’s with increasing humidity. With this shift, Air Quality will likely begin slowly degrading.  The question will be if we could reach the USG levels.

The past two weeks have yielded Good Air Quality.  As the current high pressure system moves off to the east during Friday, winds will begin a shift to the south and southwest.  With that shift, air pollutants from Illinois and Indiana will drift over Lake Michigan and can impact the lake shores.  Current ozone models are keeping the highest concentrations over the lake and more towards the Wisconsin shore.

The Saturday forecast is pretty straight-forward with a mix of Good and Moderate.  Sunday and Monday have increasing temperatures and humidity, but chances also increase for shower activity as a short-wave of low pressure passes through Sunday morning with a stronger front projected to pass Monday night.

With the potential clouds and shower activity, ozone production should be reduced enough to ward off any widespread USG.  As such, I anticipate this forecast should be sufficient to get us through Monday morning.  However, if conditions do deteriorate enough, we will update this weekend forecast, as necessary.

EXTENDED FORECAST:

Air Quality should be a mix of Good and Moderate going into next week.

Forecast updated by Jim Haywood: Friday, August 7th, 2020
Next forecast update: Monday, August 10th, 2020

8/3/2020 Forecast Update

FORECAST SUMMARY:

Monday, August 3rd, 2020 through Friday, August 7th, 2020

OZONE: 8-hour average Ozone concentrations will be mostly Good with Moderates possible Friday.

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

FORECAST DISCUSSION:

Clouds and chances for precipitation are in the forecast Monday and Tuesday thanks to upper level disturbances moving through the region. High pressure at mid-week will dry conditions and provide cooler than normal temperatures for a couple days. Warmer conditions look to move in for the end of the week and into the weekend.

As for air quality, weather conditions will not be conducive for ozone development through Wednesday; therefore, mostly Good ozone is expected. High pressure overhead will produce plenty of sunshine by Thursday and temperatures warm closer to 80 on Friday. Lighter winds turning southerly could allow for Moderate ozone in some locations Thursday and/or Friday.

By Saturday, winds pick up from a southerly direction and both surface and upper level temperatures increase. Weather conditions turn more conducive for ozone development by the weekend so we will update the forecast Friday to detail any potential increase for the weekend into early next week.

Fine particulate through mid-week will continue mostly Good with only a few locations in the southeast possibly averaging low-Moderate for the day. Like ozone, by the end of the week a few more Moderate levels are possible.

EXTENDED FORECAST:

Extended forecast maps show warmer temperatures into early next week, but what is uncertain is a possibility of storm activity. More details on the extended forecast will be posted Friday.

Forecast updated by Meteorologist Stephanie M. Hengesbach August 3rd, 2020.
Next forecast update: Friday, August 7th, 2020

7/27/2020 Forecast Update

FORECAST SUMMARY:

Monday, July 27th, 2020 through Monday, August 3rd, 2020

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

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

FORECAST DISCUSSION:

The work week starts with a slow-moving cold front which could kick off shower activity during Monday.  The clouds and shower activity will keep Air Quality in the Good range through the day.

The remainder of the forecast period should be the closest thing to a ‘normal’ summer weather week that we have seen in a while.  Temperatures should stay in the lower 80’s, dew points comfortably dryer, and skies mostly rain-free.  The wind patterns for the week will not feature any southwest winds, which can be so damaging to our Lake Michigan shoreline, and mostly clean-source wind directions to help Southeast Michigan.  Winds do go calm, at the end of the work week, so we may see a brief period of stagnation creep in the urban areas but that should be short-lived. 

So, for the first time in many weeks, I think we are comfortable going until Monday for our next forecast update.

EXTENDED FORECAST:

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

Forecast updated by Jim Haywood: Monday, July 27th, 2020
Next forecast update: Monday, August 3rd, 2020

7/24/2020 Forecast Update

FORECAST SUMMARY:

Friday, July 24th, 2020 through Monday, July 27th, 2020

OZONE: 8-hour average Ozone concentrations will range from Good to Moderate through Sunday, with Good readings Monday.

PM-2.5: 24-hour average Fine Particulate concentrations will range from upper Good to low Moderate through the forecast period.

FORECAST DISCUSSION:

Sunny conditions Friday will make a pleasant day, and easterly winds hamper any pollution build up. On Saturday, southwesterly winds develop as high pressure moves east of the region. Temperatures at the surface and upper levels will increase, along with humidity levels. A frontal boundary moves in Sunday bringing chances for precipitation from northwest to southeast as the day progresses. Precipitation chances linger into Monday as the boundary sinks southeast.

As for air quality, Good conditions have been in place and we are starting Friday with a clean background. Easterly winds at the surface and upper levels should keep ozone from increasing much; readings will range from Good to low Moderate. Winds become more conducive for ozone development Saturday, but with coming off such a low background we do not expect levels higher than upper Moderate.

While we don’t feel the threat for elevated ozone is high enough this weekend to warrant Action Days, there is a small chance that a monitor or two Saturday will increase faster than anticipated reaching low-end USG. If this happens it would most likely be along the lakeshore of west Michigan and/or in the southeast upwind of the Detroit area.

With the current timing of the front, increasing clouds Sunday and precipitation moving in as the day progresses should keep ozone from reaching higher than Moderate. If the front slows down keeping mostly sunny skies during the day, then there is a possibility for isolated USG readings in the southwest and/or southeast. Even without an Action Day, we will update the AirNow forecast to USG Saturday or Sunday mornings if we feel the USG threat becomes higher than anticipated.

Fine particulate has been Good most of this week. Good levels will linger Friday with a mix of Good to low Moderate expected until the front passes Monday.

EXTENDED FORECAST:

Northwesterly winds develop Monday after the cold front passes. The cooler, cleaner air will produce Good air quality early next week.

Forecast updated by Stephanie M. Hengesbach
Next forecast update: Monday, July 27th, 2020

7/20/2020 Forecast Update

FORECAST SUMMARY:

Monday, July 20th, 2020 through Friday, July 24th, 2020

OZONE: 8-Hour average Ozone concentrations will be Good to Low Moderate through the work week.  

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

FORECAST DISCUSSION

Nobody will deny that this has been a very active summer, both in extreme temperatures and Air Quality.  Fortunately, it looks like this week will be a break in the action.

Looking at the monitor readings, Monday morning, we are seeing low readings which should stay low through the early part of the week.  Mid-week looks to stay low, as well, as a result of a warm front moving through late Tuesday and an associated cold front during Wednesday.  Northwest winds behind the front will provide another clean-out on Thursday.

The warmer temperatures start moving back in during Friday to set up a toasty weekend.  Friday should stay within the Good to Moderate range, so I am not anticipating another forecast update until Friday morning.

EXTENDED FORECAST:

Air Quality should be mostly Good to Low Moderate going into the weekend.  We could see a rise in ozone during the weekend.

Forecast updated by Jim Haywood: Monday, July 20th, 2020
Next forecast update: Friday, July 24th, 2020

7/17/2020 Forecast Update

FORECAST SUMMARY:

Friday, July 17th, 2020 through Monday, July 20th, 2020

OZONE: 8-hour average Ozone concentrations will be mostly Moderate Friday and Saturday with a chance for USG, especially Saturday. Levels will be Good to Moderate Sunday and Monday.

PM-2.5: 24-hour average Fine Particulate concentrations will range from upper Good to low Moderate Friday and Saturday with mostly Good concentrations Sunday and Monday.

AN AIR QUALITY ACTION DAY ADVISORY IS ISSUED FOR SATURDAY JULY 18th FOR THE FOLLOWING COUNTIES:

IN WEST MICHIGAN:

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

IN Southeast MICHIGAN:

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

FORECAST DISCUSSION:

Hot, sunny conditions are expected as we come to the end of the week, and humidity levels will be quite high Saturday. A cold front passes the state Sunday with associated showers and storms expected late Saturday and Sunday ahead of and along the boundary. Conditions dry out Sunday behind the front and northerly winds should produce Good air quality early next week.

Until then, sunny skies coupled with south/southwesterly winds and warm temperatures both at the surface and upper levels will allow ozone to climb Friday. We are coming off a low background, so we are expecting most locations to be Moderate for ozone. But there is a chance a monitor or two could rise faster than anticipated reaching low-end USG along the western shore of Lake Michigan and/or in the southeast.

On Saturday, south/southwest winds increase in speed bringing in higher humidity; heat indices will approach 100 degrees across parts of the state. Mostly sunny skies continue, especially in the southeastern portion of the state. We will have another day of warm surface and upper level temperatures and ozone is expected to reach higher than the Friday increase. With the projected forecast, we feel there is enough threat for USG ozone Saturday to warrant issuing an Air Quality Action Day across the western lakeshore and in the southeast. What could prevent elevated ozone Saturday would be a very small chance for afternoon storm development, especially in the west. We do not feel this risk is high enough to not issue the action day, but any storm development would likely keep ozone from reaching USG.

Fine particulate may increase into the Moderate range Friday and/or Saturday with generally Good concentrations Sunday and Monday.

EXTENDED FORECAST:

Air Quality readings improve Sunday behind the front. Good ozone Sunday could reach into the Moderate range on Monday, but we do not anticipate elevated ozone early next week. If our thoughts on that changes, we will send a forecast update.

Forecast Updated by Stephanie M. Hengesbach July 17th, 2020.
Next forecast update: Monday, July 20th, 2020