The orange ball of the sun shines through smoke layers late in the day on Monday, June 5, over the Roanoke Valley. Courtesy of Chris White.
The orange ball of the sun shines through smoke layers late in the day on Monday, June 5, over the Roanoke Valley. Courtesy of Chris White.

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Cool June mornings this week aren’t just smoke and mirrors, but there is a lot of smoke.

A cold front arriving Wednesday evening from the north will renew an unseasonably cool and dry air mass from Canada, leading to widespread 40s lows along and west of the Blue Ridge on Thursday and Friday mornings, even in some rural valleys east of the Blue Ridge.

Highs will be mostly in the 70s, even in lower-elevation locations like the Roanoke Valley and areas east of the Blue Ridge that normally see 80s regularly in early June. Dew points will be low so it will be quite comfortable, not sticky.

·        See last section of today’s weather column for how to enter the Cardinal Weather heat prediction contest.

Morning chill may feel a bit like fall, but don’t expect crisp blue skies, sharp visibility or clean, fresh air. Also wafting south behind the cold front will be more waves of smoke arising from wildfires mostly in Quebec.

A NOAA weather model shows where the densest smoke was located on Tuesday evening, with continued waves of it expected to move south over the next few days. Courtesy of NOAA.
A NOAA weather model shows where the densest smoke was located on Tuesday evening, with continued waves of it expected to move south over the next few days. Courtesy of NOAA.

We’ve already been experiencing smoky days, with red sunrises and sunsets, whitened skies and grayish haze across the landscape. Air quality levels have worsened into the moderate to unhealthy categories across much of Virginia, causing some breathing issues for people with health sensitivities to air pollution. Air quality is even worse in many states to our north, sometimes at unprecedented levels.

The morning sun glows red over the Blue Ridge in southern Roanoke County on Tuesday morning, June 6. Photo by Kevin Myatt.
The morning sun glows red over the Blue Ridge in southern Roanoke County on Tuesday morning, June 6. Photo by Kevin Myatt.

Unlike with wildfire smoke that sometimes filters through high in our skies from western North America wildfires (and there are several of those ongoing in western Canada), much more of this smoke has been blowing in near the surface, circulated by low pressure off the Northeast U.S. coast. That’s why we are seeing more of it graying out the views of our Southwest and Southside Virginia terrain and even being a detectable odor at times.

It is unclear yet when we’ll see full relief from the smoke, but the atmospheric pattern may start to shift to more westerly flow rather than northerly vectors next week. That would carry more of the smoke eastward well north of us. Conditions that sparked the fires may also start to ease over eastern Canada, though many fires are likely to continue, as they also are from earlier in western Canada.

Sun shining through smoke cast an orange pall even on inside walls. Photo by Kevin Myatt.
Sun shining through smoke cast an orange pall even on inside walls. Photo by Kevin Myatt.

Wildfires in Canada have occurred because of anomalously early and intense high-pressure “heat domes” that have, especially over western Canada, brought extreme and sometimes unprecedented warm temperatures relative to the season.  Wildfires in eastern Canada were further stoked by the circulation around the upper-low off the Northeast U.S/southeast Canadian coast.

The unseasonably early and in some cases unprecedented hot, dry weather over much of Canada generally follows what is expected to occur more frequently and intensely with global climate change.

Thus far, the heat domes have not formed over our region and have in fact helped deflect and circulate cooler air masses toward Virginia.  We’ll follow that thought below.

This map shows average May temperatures relative to how they're ranked historically, with a wide swath of western Canada seeing its warmest on record, while temperatures slightly below the long-term median were seen near the East Coast of the U.S. Courtesy of Brian Brettschneider, climatologist.
This map shows average May temperatures relative to how they’re ranked historically, with a wide swath of western Canada seeing its warmest on record, while temperatures slightly below the long-term median were seen near the East Coast of the U.S. Courtesy of Brian Brettschneider, climatologist.

Elusive 90-degree highs

Weather statistics can be wonky and wacky.

Consider: One of the warmest years to date through the end of May at multiple locations in Southwest and Southside is now weeks past the average date for the first 90-degree temperature at quite a few of those places.

Danville has yet to hit 90 degrees. If it were to hit 90 on Thursday – which it won’t – it would be tied for 11th latest first 90-degree day in over 100 years of weather records. By Friday it will already be a full month past the average date for the first 90-degree high.

Roanoke has yet to hit 90 degrees, scraping close on April 20 and June 3 at 89. The average date for first 90-degree high is May 19. There is good reason now to think 90 degrees won’t happen until sometime after June 15. If that’s the case, it would be among the top 14 or so latest dates for first 90-degree high in 111 years of weather records.

Lynchburg – you get the point by now – has yet to hit 90 degrees, even though the average first 90-degree high happens on May 21 over more than 130 years of records.

Yet, through May 31, it’s still the warmest year on record through the first five months at Lynchburg, second warmest at Roanoke, and sixth warmest at Danville.

(Locations like Blacksburg and Galax and Wytheville and Bristol and westward haven’t typically hit 90 by now, so that part isn’t unusual. But it is among the warmest years on record through the first five months at many of those sites also.)

The reason the year is still on track to be among the warmest on record and yet 90 has been such a struggle to hit is that the atmospheric patterns that propelled extreme winter warmth relative to normal broke down rapidly during the spring, replaced by patterns that have repeatedly brought cool air masses south from Canada.

As already noted, hot high pressure has staked its tent in western Canada with extraordinary heat. Downstream from the clockwise rotation of that high over the Eastern U.S., cold fronts push through, cool air wedges back in against the mountains from New England, and chilly damp upper-level lows get stuck.

We have a couple of warmer days with widespread 80s now and then, such as late last week and Monday and Tuesday, but those periods get truncated, as will happen Wednesday with a cold front that leads to cooler weather with comfortably low dew points to end this work week.

It will be interesting to see if these kinds of cooler patterns persist or recur for our region in the summer ahead, or if sooner or later we get scorched underneath a heat dome.

This map of air pressure at mid-levels of the atmosphere shows intense levels of high pressure occurred over western Canada in May while some slight low pressure nosed down the East Coast. Courtesy of Brian Brettschneider, climatologist.
This map of air pressure at mid-levels of the atmosphere shows intense levels of high pressure occurred over western Canada in May while some slight low pressure nosed down the East Coast. Courtesy of Brian Brettschneider, climatologist.

Heat prediction contest

This contest is so simple to enter, it can be summarized in a paragraph: 

Email weather@cardinalnews.org with your name, where you live (city, town or county), and your pick for the hottest temperatures between June 20 and Aug. 31 at ONE LOCATION chosen from the 12 towns and cities spread across our region listed below. It’s OK for couples or families to put more than one entry on an email – and no age limit.

Whoever is closest gets a $25 gift card and notoriety in this space for summer forecasting prowess (or a lucky guess — it is truly better to be lucky than good). I’ll take entries through Sunday, June 18, at midnight. I will only be giving out one gift card, so the tiebreaker if two entries are equally close will be whose entry I received first. About 20 folks entered last week (I introduced the contest at the end of that column) so they have a leg up.

The list of towns and cities you can choose to pick from also includes what the historic range for coolest to hottest peak summer temperatures going back 50-130 years (except for Clarksville and Galax, where consistent records go back only 20-25 years).  It’s always possible the warmest temperature between June 20 and August 31 could end slightly below or above these ranges, but this is what the range has been in the past for the hottest day of the summer.

·        Abingdon: 87 to 100

·        Appomattox: 90 to 103

·        Blacksburg: 86 to 100

·        Clarksville: 95 to 107

·        Danville: 92 to 107

·        Galax: 86 to 97

·        Lexington: 89 to 105

·        Lynchburg:  91 to 106

·        Martinsville: 90 to 105

·        Roanoke: 90 to 105

·        Wise: 82 to 95

·        Wytheville: 85 to 98

Journalist Kevin Myatt has been writing about weather for 19 years. His weekly column is sponsored by Oakey’s, a family-run, locally-owned funeral home with locations throughout the Roanoke Valley.

Low clouds stretch across the sky on Sunday, June 4, at Raphine in Rockbridge County, as a wedge of cool, damp air parked against the mountains and kept temperatures mostly in the 60s. Not far south of this location on Sunday, a Cessna Citation jet crashed into the mountains near Montebello, an incident that resulted in scrambled fighter jets and a sonic boom over the Washington, D.C. area. Photo by Dwayne Yancey.
Low clouds stretch across the sky on Sunday, June 4, at Raphine in Rockbridge County, as a wedge of cool, damp air parked against the mountains and kept temperatures mostly in the 60s. Not far south of this location on Sunday, a Cessna Citation jet crashed into the mountains near Montebello, an incident that resulted in scrambled fighter jets and a sonic boom over the Washington, D.C. area. Photo by Dwayne Yancey.

Kevin Myatt has written about Southwest and Southside Virginia weather for the past two decades, previously...