Classic 4th; Smoky skies add vivid sunsets; AZ fire coverage and perspective

Weather Winning Streak

Our weather luck has changed for the better in Minnesota, just in time for one of the biggest holiday weeks of the year.

This 4th of July marks the 5th day in a row without rain in most of the Upper Midwest. That hasn’t happened in about 3 months since the first days of April. In the soggy year of 2013, that’s the last time the metro was able to string together 5 straight days without “measurable” precip.

Is that a tinge of dryness I detect in my grass today?

502 amish-built-american-flag-weather-vane

In this Updraft we look at smoky skies over Minnesota that may create some additional colors at sunrise and sunset the next few days. We also highlight some remarkable “desert meteorology” that fueled the deadly Yarnell Hill Fire in Arizona, and try and add some perspective on how climate change is boosting the number of large wildfires in the American West.

In Minnesota we can celebrate this Independence Day knowing our rainy spring means full lakes and rivers, lush forests and green grass to play and picnic on, and no threat of wildfires. And did I mention the weather will be pretty close to “perfect” on the 4th?

Something to be grateful for.

Image: Twin Cities NWS

Fab 4th of July:

This is as good as it gets folks.

There’s been plenty of (justified?) weather whining and complaining of the past few months. Not this week. Minnesota’s weather has delivered for the biggest holiday week of the year.

Here’s the Euro model hour by hour breakdown for the start of the 4th of July weekend in the metro. (My forecast added in black text)

Ideal weather on the 4th of July? Image: Euro model “meteogram” from Norwegian Met Institute

Time to thank your local weatherman?

Red sky at night. Image: University of Illinois via Ron Holle

 Smoky Skies: Vivid sunrise & sunset colors this weekend?

You may have noticed a “whitish tint” to the sky lately over Minnesota.

Smoke from numerous wildfires in Canada and the West have dispersed smoke plume aloft over much of the USA this 4th of July weekend. Some of the thickest smoke plumes have settled over the Upper Midwest.

Here’s the “analyzed smoke mapper” from NOAA.

Smoke from distant fires drifts over the Upper Midwest Wednesday. Image: NOAA

Elevated smoke particles are effective at scattering out violet and blue wavelengths in the atmosphere at sunset, and that may mean some vivid reddish sunset hues the next few days over Minnesota.

Here’s a good explanation from the University of Illinois.

When there is a high concentration of particles in the atmosphere that are slightly larger than air molecules (like smoke, dust, and pollutants), shorter and intermediate wavelengths of light (violet, blue and yellow) are scattered away. Therefore, only the longer wavelengths (orange and red) reach the observer’s eyes, giving the sun a orange-red appearance.

When incoming sunlight encounters a heavy concentration of particles in the atmosphere, the shorter wavelengths of light (violet and blue) are scattered away, resulting in a red sunset. Red sunsets are often observed from a beach because of the high concentration of salt particles suspended in the air over the oceans. These particles effectively scatter shorter wavelengths of light, producing red sunsets. Dust and ash particles injected into the atmosphere by volcanic eruptions can also cause red sunsets.

Image: University of Illinois

Arizona Fires

Chasing Clues: “Monsoon Thunderstorms” may have triggered Hot Shot deaths

The news of 19 dead firefighters is a tragic way to open the 4th of July week.

The search for meteorological clues to what happened Sunday as the Yarnell Hill Fire exploded seems to point to so called “dry microbursts. As the fire flared, monsoon thunderstorms fired off Arizona’s Mogollon Rim and raced southwest toward the fire. Local meteorologists call this pattern a “rim shot” as the storms brew in the high country and race into the valleys below.

“Monsoon thunderstorms” racing southwest off Arizona’s Mogollon Rim likely produced gusty and erratic winds that caused explosive fire behavior Sunday. Image: UW Madison CIMS Satellite Blog

UW Madison’s CIMSS Satellite Blog has an excellent write up tracking satellite clues to what caused the  Yarnell Hill Fire to explode into the deadliest fire in decades.

The Yarnell Hill Fire (InciWeb) was a relatively small wildfire that was started by lightning from a dry thunderstorm southwest of Prescott, Arizona on 28 June 2013. However, fire conditions became more favorable for growth on 30 June, as surface air  temperatures rose above 100 F across the area with low relative humidity values. During the afternoon hours, GOES-15 0.63 µm visible channel images (above; click image to play animation; also available as a QuickTime movie) showed that a line of thunderstorms developed over northwestern Arizona, and moved toward the southwest (the red circle highlights the general area of the Yarnell fire). It is likely that strong surface winds associated with a thunderstorm outflow boundary (nearby surface mesonet data) caused rapid growth and an abrupt change in direction of the fire, which tragically killed 19 firefighters who attempted to shelter in place (for additional details, see the Wildfire Today site).

On the GOES-15 visible imagery, a smoke plume became more obvious after 16:45 UTC, with the first formation of pyrocumulus clouds evident at 21:00 and 21:30 UTC. As the cloud shield of the thunderstorm line moved over the fire, the images revealed the development of a pyrocumulonimbus (pyroCb) cloud which exhibited a pronounced overshooting top at 23:45 UTC.

Meteorologists on the Fire Lines: Would early deployment of NWS “Incident Meteorologists” have saved lives Sunday?

You probably think of the” meteorologist” you see on TV or hear on the radio first when somebody uses the term. But did you know that 85 trained NWS “Incident Mets” staff the fireline in harms way in the big “Type I” fires?

Call them the “Weather Hot Shots”…their critical “micro forecasts” can save lives on the fireline.

A NOAA “incident meteorologist” at the scene of a wildfire.
Image: NOAA.

Here’s a good look at a slice of weather life from Andrew Freedman of Climate Central.

On Monday night, Jim Wallmann drove north from broiling Phoenix toward a bustling command post for the Yarnell Hill fire near Prescott, Ariz. The blaze had killed 19 of the 20-member crew of elite “Hotshots” a day earlier in the worst loss of firefighters in a single wildfire in 80 years. With erratic weather conditions viewed as the primary suspect behind the tragedy, Wallman had been called to the blaze specifically to prevent a repeat incident by keeping firefighters informed of changing weather conditions.

Heat, drought and climate change a deadly combination?

We know it gets hot in the Southwest. We also know that western wildfires are part of the natural cycle.

But there is a growing body of evidence that bigger, more dangerous wildfires are on the increase out west.

Trends in large wildfires (greater than 1,000 acres) in Arizona, between 1970-2011.
Click image to enlarge. Image: Climate Central.

Climate change is producing less winter snowpack in the mountains where massive stands of Ponderosa Pine and other trees living in this “marginal climate zone” get just enough snow, rainfall and coolness to thrive.

It makes sense. Change the climate balance with less winter snow, an earlier spring melt, hotter summers, prolonged drought and you have a recipe for disaster…and massive “landscape changing” fires out west.

Image: Climate Central

In my 9 years in Arizona I watched millions of acres of forests go up in flames.

Ten years ago this week, I was on the air live as the mountain town of Summerhaven near Tucson burned to the ground in a wind whipped firestorm.

I watched shocked Arizonans, many of whom had never seen anything like the increase in fires in half a century, try and cope with the unprecedented changes. It was clear to me that something had changed.

So is climate change a factor in the increase in large western fires?

The science increasingly says yes.

Climate Central’s Andrew Freedman has some great perspective on why.

The Yarnell Hill fire, like other wildfires in the West right now, is taking place in the context of one of the most extreme heat waves on record in the region, as well as a long-running drought. While the contributors to specific fires are varied and include natural weather and climate variability as well as human factors, such as arson, a draft federal climate report released in January found that manmade climate change, along with other factors, has already increased the overall risk of wildfires in the Southwest.

And projections show that the West may be in for more large wildfires in the future. Climate models show an alarming increase in large wildfires in the West in coming years, as spring snowpack melts earlier, summer temperatures increase, and droughts occur more frequently or with greater severity.

Paul Huttner