12/21/2018 Forecast Update

FORECAST SUMMARY:

Friday, December 21st, 2018 through Friday, December 28th, 2018

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

FORECAST DISCUSSION

Current Air Quality is Good going into the Christmas holiday weekend.  As air and ground conditions stay moist, the opportunity of particulates running into the Low Moderate range is always a possibility.

The best chances appear to be on Sunday when we get into a southerly wind profile.  Christmas Day also looks promising with weak winds biased from the southeast.  Southeast winds look to prevail through the end of next week but appear to be strong enough to keep the atmosphere well mixed. 

With another holiday weekend (New Year’s) following Christmas, we will be updating this forecast on the Friday before that next holiday break.

EXTENDED FORECAST:

Air Quality is expected to remain mostly Good to Low Moderate going into the New Year’s holiday weekend.

Forecast updated by Jim Haywood: Friday, December 21st, 2018

Next forecast update: Friday, December 28th, 2018

12/17/2018 Forecast Update

FORECAST SUMMARY:

Monday, December 17th, 2018 through Friday, December 21st, 2018

PM-2.5:  24-hour Fine Particulate concentrations will be generally Good except for Wednesday and Thursday when widespread Moderates are expected.

FORECAST DISCUSSION

A weak front will pass through Michigan during Monday with little fanfare.  The primary result of this passage will be a wind shift to the northwest which will help clean out the higher particulate numbers we observed, last week.  With that frontal passage, I expect mostly Good to Low Moderate concentrations through Tuesday.

As high pressure drifts over the region during mid-week, winds will return to a southerly direction and a short warming trend.  This will likely push PM-2.5 concentrations back into the Moderate range.  I expect this to last Wednesday into Thursday. 

Another cold front should pass through the state later Thursday.  This should push winds back to a northwesterly direction and clean out any residual Moderates.  Mostly Good conditions should persist Friday through the weekend.

Since the State offices will be closed Christmas Eve and Christmas Day, a short update will be issued on Friday.

EXTENDED FORECAST:

Air Quality is expected to remain mostly Good going into the Christmas holiday week.

Forecast updated by Jim Haywood: Monday, December 17th, 2018

Next forecast update: Friday, December 21st, 2018

12/10/2018 Forecast Update

FORECAST SUMMARY:

Monday, December 10th, 2018 through Monday, December 17th, 2018

PM-2.5: 24-hour Fine Particulate concentrations will range between middle Good and middle Moderate through the forecast period.

FORECAST DISCUSSION:

Quiet conditions, for the most part, will be experienced over the next week. A system moving through late Wednesday/early Thursday brings snow into the forecast. After that, the next system Friday into Saturday looks to track south of the state, but a disturbance further north may bring some precipitation to the area. Before and after these systems, high pressure keeps precipitation out of the forecast and seasonable to a little slightly above normal temperatures are anticipated.

As for air quality through the period, fine particulate will range from middle Good to middle Moderate through Wednesday thanks to weaker winds, especially during the morning hours. The highest fine particulate levels will be seen in the more urban parts of the state with mostly Moderates prevailing. There isn’t much of a wind-shift with the mid-week system and winds go light, and then south early Friday. Fine particulate during this period will continue to range from middle Good to middle Moderate. East to northeast winds develop early in the weekend as the storm system tracks south of the state. Fine particulate may improve towards the Good range; however, a few Moderates may linger.

EXTENDED FORECAST:

Extended models show an upper level trough dropping in early next week bringing northwest winds. This flow will clean out any lingering Moderates of fine particulate; generally Good levels expected early next week.

Next forecast update: Monday, December 17th, 2018

12/03/2018 Forecast Update

FORECAST SUMMARY:

Monday, December 3rd, 2018 through Monday, December 10th, 2018

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

FORECAST DISCUSSION

A slight warming trend, during the weekend, melted most of the snow pack associated with the storm experienced early last week.  Warming air over a snow pack has the tendency to spurn particulate growth in the atmosphere and we saw that trend develop, especially during last Friday.  In the Detroit area, we saw hourly spikes of PM-2.5 causing the 24-hour average to settle around the 35 ug/m3 threshold between Moderate and USG.  Fortunately, that was a short-lived episode and early week readings are back into the Good category.

I anticipate this week’s forecast to yield mostly Good readings.  A weak front will pass through Michigan on Monday followed by northerly winds.  A period of calm weather should persist until Thursday when the next weak front is projected to pass.  There are no indications that Air Quality should exceed the Good to Low Moderate range

High pressure and rare sunny skies should prevail during the weekend.  Air Quality should be generally Good but light winds may allow some stagnation into the 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, December 3rd, 2018

Next forecast update: Monday, December 10th, 2018

11/26/2018 Forecast Update

FORECAST SUMMARY:

Monday, November 26th, 2018 through Monday, December 3rd, 2018

PM-2.5: 24-hour Fine Particulate concentrations will be mostly Good, but a few periods of low-Moderates are possible.

FORECAST DISCUSSION:

The snow storm which brought decent snow accumulations across much of Lower Michigan will pull away from the state as Monday progresses. Lake effect snows will then develop later Monday, possible lasting into Wednesday, due to northwest winds behind the departing storm. Fine particulate levels through Wednesday will be in the Good range.

Quiet weather is anticipated Thursday as a high-pressure area moves in. A weak system passing later Thursday into Friday could trigger some scattered precipitation. Winds will be lighter Thursday into Friday; therefore, fine particulate may reach low Moderate across parts of southern Michigan.

EXTENDED FORECAST:

Extended models show a stronger storm system coming into play Saturday and Sunday. Current models show temperatures may be warm enough for rain, especially in Lower Michigan. Regardless of what type of precipitation we end up with, stronger winds with this system should keep fine particulate generally Good.

Forecast updated by Stephanie Hengesbach: Monday, November 26th, 2018

Next forecast update: Monday, December 3rd, 2018