Why So Much Smoke From Canada This Summer?

The air quality across the Great Lakes, Ohio Valley and much of New England recently has been very poor due to the smoke from Canadian fires in eastern Ontario and portions of Quebec.  

June 28 Air Quality Levels

June 28 Air Quality Over Great Lakes

Earlier in the week, smoke from the fires in western Canada were the culprit. 

Current Conditions in Canada

Area Burned vs All Years Since 1980

Fire Stars Since 1980

Why has smoke from the north impacted our air quality and sky condition this summer?  Has this happened before?  Is this low air quality unprecedented? 

The smoke movement has to do with the overall weather pattern across North America. In late May and June the pattern featured an abnormally strong and stagnant ridge of high pressure over central Canada and high pressure over Texas. The flow is clockwise so the winds steered the smoke from Quebec south into the Great Lakes. Now in July the ridge over Canada has weakened. A trough has replaced the ridge. The dominant flow has been northwesterly bring in fast moving cold fronts from the west and northwest recently. The flow steered smoke from the fires in western Canada into the upper mid-west and Great Lakes. 

Watch how the high pressure ridge (warmer colors) developed in May across Canada.  Also notice how the ridge faded and emerged further east then central Canada by early June. Also notice how there was little southern high pressure. Pockets of blue indicate low pressure.  No sign of the Bermuda high to establish a southwesterly wind across the central US keeping the smoke north.

Upper Level Pattern (3 day periods) - Early May thru June 24-26

This abnormally strong Canadian ridge created record setting temperatures in May and June across western Canada

Soil moisture dropped both in western and eastern Canada.  Dry conditions began to spread across the Great Lakes.

When we look at the air pollution data since 1980 for Cleveland and surrounding locations, the time of year where pollution becomes more of a problem is summer.  Warm and often times stagnant air creates conditions that keep pollution from dissipating.  What really stands out on this graphic is the frequency of low air quality in the 1980s and 1990s between May and August. Look at the summer of 1988. 36 days with highs in the 90s with a few 100 degree days and little wind. Compare this to early summer of 2023 (bottom of graphic - red arrow). Only a few days in late May, June 28 and July 17-18 air quality was considered poor.

This was the same pattern that kept the humidity in northern Ohio at decades low levels in May and most of June although the recently higher July humidity brought up the seasonal average.

Both summer time high pressure ridges are not linked. Often times they will merge briefly. That has not happened this summer.  Below is a long range forecast for July 31, 2023.  Notice both ridges are distant.

This is also the same pattern that has kept most of the extreme heat in the deep south and away from the Ohio Valley. 

If this were a typical late spring and summer with the Bermuda High establishing itself over the southeastern US, the dominant flow would be southwesterly keeping the smoke up north. Look for this pattern to continue from time to time in August and September. The developing El Nino is probably a contributor.

July 3rd Warmest on Record GLOBLLY. Here is the Breakdown

According to NCEP (National Center for Environmental Prediction), July 3rd was the warmest day on record GLOBALLY.  Note this is not for one city, one state, one region or one country.  It's the entire planet. 

Global Temperatures vs Normal 18z July 3rd

The average global temperature reached 17.01 degrees Celsius (62.62 Fahrenheit), surpassing the August 2016 record of 16.92C (62.46F).   

The largest warmer anomalies are located near Antarctica.

I broke down the globe into 9 different locations. The break down is done to show how the temperature anomalies vary within each region. Each image shows the locations with above normal (warmer colors) temperatures and below normal (cooler colors) temperatures on July 3rd.  The global average takes into account ALL of these regions below.

First North America. I labeled regions that are above normal with "AN" and below normal with "BN"

Now the lower 48 states:

The Caribbean and Mexico:

Canada:

South America:

Europe:

Asia:

Middle East:

Africa:

Australia:

Tornado Recap

For the first time since early September last year, northern Ohio saw it's first tornado warnings June 15.  Not the latest on record but close. 

Latest first tornado warning in order (after June 1st):

July 24, 2005

June 24, 1999

June 22, 1990

June 19, 2021

June 15, 2023

June 5, 2016

June 3, 1989

June 1, 1987

Not every tornado warning means there were actual touchdowns.  In most instances (75% of the time approximately) the warning is issued due to doppler radar indicated rotation within the storm.  Last Thursday, not only did we have multiple tornado warnings, we had multiple tornadoes!  Here is the list: (h/t Mackenzie Bart and Dontae Jones for the graphic)

NWS statement here

Red dots indicate the approximate location of each tornado

Here is a nice video of a constructed powerpoint of the entire severe storm event via the Iowa State University - Mesonet Site (IEM Raccoon).  88 slides total. 5 seconds per slide. Well worth it.

Video format from youtube

Little Humidity. Little Rainfall. The Complete May 2023 Recap

Lots of colorful  👇   charts here so be prepared!  

We were coming off of an extremely wet April. Temperatures were slightly above normal.  7 of the last 10 days had measurable rainfall.  Back in late April the changes in the tropical Pacific (SOI drop), northern Atlantic (negative NAO) and Bering Sea Low pressure were strongly pointing to a cooler than normal start to May.

Early May Outlook posted back on April 21

The upper level pattern in 7 day increments:  500mB (18,000 feet on left)  Jet stream on the right featured an active west-to-east storm track left over from late April.

May 1 to May 7

By the second week of April, the ridge over central Canada shifts west and south.

May 8 to May 14

Notice the split flow which emerged in the middle of the month. Storm track along the southern border and west to east through central Canada and into New England.

May 15 to May 21

By the final week of May, two pronounced jet stream tracks kept storm systems away from the central keeping the mid-west and corn belt very dry.

Overall temperatures west of the Mississippi and in the upper mid-west were above normal.

The center of the heat was in western Canada.

The split flow kept a large portion of the central US, deep south and Great Lakes extremely dry.

In northern Ohio, we had rain to start the month which skewed the overall totals. 25 of the 31 days were dry.

Temperatures in northern Ohio were slightly below average.  We had more days below than above.  Days in grey were a degree to either side of average.

By far the biggest element was the lack of humidity.  

In fact, April had more humid periods than May. 

We average more than 105 total hours of high humidity in May.  We ONLY had ONE HOUR!  Only 1966, 67, 68 and 1971 compare.

April and May high humidity periods (total hours) compared to past years.

The average northern Ohio humidity in May was the 3rd lowest since the last 1940s.

Severe storm warnings were non-existent in Ohio and surrounding states compared to April.

What about June?  On May 22nd, the tropical Pacific indicated a HUGE drop in the SOI.  Using the historical analogs, the "less humid & dry" pattern looks to continue through the middle of the month.  The projections on June 2 were latching onto this idea bigtime.

What we will watch during the second half of June/early July is how much the severe dry conditions will persist.  If they do, the dry ground could feed the central US ridge further enhancing the heat. More on this in the weeks ahead.