Tuesday’s weather in Fort McMurray was 8 degrees above record high for the date

Hot weather Alberta

“#ymmfire” refers to the airport code for the Fort McMurray International Airport in Alberta. The entire population of the city, more than 80,000, was ordered to evacuate when it became obvious it was going to be overrun by the fire.

More information about the fire.

Below is an excerpt from a May 4, 2016 article at Slate about the weather in Canada:

…Canada’s northern forests have been burning more frequently over recent decades as temperatures there are rising at twice the rate of the global average. A 2013 analysis showed that the boreal forests of Alaska and northern Canada are now burning at a rate unseen in at least the past 10,000 years. The extreme weather of recent months is also closely linked with the ongoing record-setting El Niño conditions in the Pacific Ocean, which tends to bring a warmer and drier winter to this part of Canada. Last month, Canadian officials mentioned the possibility of “large fires” after over-winter snowpack was 60 to 85 percent below normal and drought conditions worsened.

This week, a strong atmospheric blocking pattern—a semi-stable extreme arrangement of the jet stream—reinforced an unseasonable heat wave and helped temperatures reach 90 degrees Fahrenheit (32.2 degrees Celsius) on Tuesday in Fort McMurray, 40 degrees Fahrenheit above normal, eight degrees above the daily record high, 15 degrees warmer than Houston, and the same temperature as Miami. While fleeing, some evacuees had to turn on their air conditioners…

Wildfire potential, May through July

On May 1 the Predictive Services section at the National Interagency Fire Center issued their Wildland Fire Potential Outlook for May through August, 2016. The data represents the cumulative forecasts of the ten Geographic Area Predictive Services Units and the National Predictive Services Unit.

If their forecast is correct, the Northwest and Rocky Mountain areas will avoid unusually high wildfire activity while Hawaii and some locations in the Southwest, California, Nevada and southern Idaho could be busy in June, July, and August.

UPDATE May 2, 2016. NIFC took the unusual step of producing a video version of the outlook. It was released today.

Here are the highlights of the written report issued May 1. Following that are maps for June through August.

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“Conditions in the mid-Atlantic and Appalachian region were dry enough through April to see increased fire activity at the end of the month. Greenup and increases in precipitation will decrease much potential through May.

“Heavy fine fuel loadings are expected across the Southwest and Great Basin, and lower elevation areas of southern and central California. This will likely increase fire activity in these areas throughout fire season especially when associated with dry and windy periods.  Fire activity will begin in May and June across the Southwest and transition northward as usual throughout the June and July.

“Warm April conditions depleted some of the mountain snowpack. Remaining snowpack should continue to melt off but remain long enough for a normal to slightly delayed onset of higher elevation fire activity. Nearly all higher elevation timbered areas are expected to see normal fire activity throughout the Outlook period.

“Poor seasonal snowpack and early snowmelt in South Central Alaska will likely to lead to above normal conditions in May, especially in the populated corridors.

“Significant moisture across the Central U.S. is expected to produce below normal significant fire potential, especially coupled with green-up occurring throughout this area.

“Most other areas of the U.S. are expected to see normal significant fire potential throughout the summer fire season. It is important to note that normal fire activity still represents a number of significant fires occurring and acres burned.”

Outlook-June

Outlook_July-Aug

Wind map, April 5, 2016

The image above is a screen grab from an animated graphic showing the wind speed and direction in the United States at 1:35 p.m MDT today. This image does not do it justice. Go to the Wind Map site and become mesmerized by the animation.

The map gives us a clue that firefighters working on the fire in Woodward County in northwest Oklahoma might be challenged to keep up with it.

Wildfire potential for April through July

On April 1 the Predictive Services section at the National Interagency Fire Center issued their Wildland Fire Potential Outlook for April through July, 2016. The data represents the cumulative forecasts of the ten Geographic Area Predictive Services Units and the National Predictive Services Unit.

If their predictions are correct, elevated wildfire potential will be migrating toward the southwest during the four-month period, while it is expected to remain above normal in Hawaii through July.

Here are the highlights from their outlook. Click on the images to see larger versions.

April
wildfire potential April 2016

  • Above normal significant fire potential continues across the southern Plains to the Upper Midwest; the mountains of Virginia and North Carolina; the Hawaiian Islands; and will develop in south central Alaska.
  • Below normal significant fire potential will remain across the central Gulf Coast and Puerto Rico.
  • Significant fire potential is normal across the remainder of the U.S., though the potential for pre-greenup fire activity increases through early spring.

May
wildfire potential May 2016

  • Above normal significant fire potential will return to normal across the southern Plains through the Upper Midwest.
  • Above normal potential will develop in the fine fuel areas of the southern Southwest. Above normal fire potential will continue across the Hawaiian Islands and south central Alaska.
  • Below normal significant fire potential will continue across the central Gulf Coast, central Georgia, upstate South Carolina, and eastern Puerto Rico.
  • Significant fire potential will remain normal across the remainder of the U.S.

June and July
wildfire potential June-July 2016

  • Above normal significant fire potential will continue across the southern Southwest and expand into Texas and southern Nevada. Above normal potential will also develop in northwestern Nevada and northeastern California as well as the fine fuel areas of southern California. An area of above normal potential will develop in Florida.
  • Significant fire potential will remain normal across the remainder of the U.S.

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A bonus: the drought monitor, temperature/precipitation outlooks, and the southern California outlook.

Continue reading “Wildfire potential for April through July”

Wildland fire management in Wyoming

The University of Wyoming has issued a publication about the patterns, influences, and effects of wildland fire in the state.

The University of Wyoming paper covers basic facts about fire, weather, intensity, severity, prescribed burning, as well as fire effects and interactions with soils, plants, livestock, wildlife, and bark beetle outbreaks. The document is 16 pages long with an additional 8 pages of references and a glossary. It was written by Derek Scasta, Assistant Professor and Extension Rangeland Specialist.

A couple of items attracted my attention. One is the graphic at the top of this article, the mean fire return interval for Wyoming. If you’re familiar with the geography of an area, data like this can absorb your interest for a while. The map appears to be a section taken out of the whole country map.

Another topic covered in the publication is the relationship between precipitation and acres burned.

Wyoming precipitation acres burned

The chart above from the paper uses the total Wyoming statewide annual precipitation compared with the total number of acres burned in wildfires each year. We have been thinking that the weather in the summer has a greater effect on acres burned than weather throughout the year. Those weather factors include temperature, relative humidity, wind, and precipitation, and a few others used by the National Fire Danger Rating System. It’s beyond our capacity to analyze all of those, unless we use an index that takes multiple parameters into account, such as the Burning Index or the Energy Release Component.

Wyoming precipitation acres burned, WildfireToday

But what we did (immediately above) was to take one weather parameter from the summer and plotted it on a chart similar to the UofW chart– average monthly precipitation each year for June, July, and August. The weather data came from NOAA, and the acres burned was extracted from the University of Wyoming chart.

Included among the disclaimers is that average precipitation across the state does not apply to every square mile. Thunderstorms in the summer could be hammering one area, while a major fire is burning somewhere else. And, using only precipitation does not take into account temperature, relative humidity, and wind, which are all very important.

If anyone is interested in analyzing the Wyoming fire occurrence data using another weather factor or NFDRS Index (from the summer months), below are the numbers I used. Or, if you’d like to look at another state or geographic area, that would be fine. It’s important to analyze the acres burned and the weather observations for a large area in order get a sample of sufficient size to make it statistically significant. For example, use 15 to 20 years of information from a large national forest with multiple weather stations to reduce the data-skewing impact of a gully-washer thunderstorm at one location.

wyoming acres burned precipitation

Winter weather — precursor to the 2016 wildfire season

Above: precipitation last 90 days, percent departure from normal. Click to see larger version.

There are three main factors that influence the behavior of a wildland fire: weather, fuel, and topography. Thankfully topography does not change from year to year in any significant manner. If it did, the job of wildland firefighters would be incredibly more difficult. Weather and fuels (vegetation) do change, not only from year to year from but from day to day — even hour to hour as the fine fuels absorb moisture out of the air. The weather is infinitely variable and has a huge effect on fires and fuels. This turns many firefighters into amateur meteorologists in an effort to master their craft and keep themselves and their colleagues safe.

Often at this time of the year as preparations are under way for the western wildfire season we look back at the winter weather.

There is little doubt that precipitation and temperature over the last 90 days will have an effect on summer fires. Many media outlets find it hard to resist the temptation on a slow news day to exaggerate how, for example, a dry winter might lead to disastrous wildfires. But the fact is summer weather has a greater effect on the number of acres burned than the conditions six months before. Hot, dry, and windy conditions in the summer are usually associated with a busy fire season.

Precipitation

As you can see in the map above, large sections of the forested areas in the northwest had above normal precipitation over the last 90 days. There are regions in Montana, Washington, and Oregon that had 150 to 200 percent of average. However, much of the southwest, southern California, and areas within the states of Colorado, Utah, Nevada, and Wyoming were below normal.

CA reservoir levels 3-14-2016
Water levels at selected California reservoirs, March 14, 2016. California Dept. of Water Resources.

Heavy rain this winter in northern California, 110 to 150 percent of normal, has been adding a lot of water to the reservoirs that have been in pretty bad shape for the last couple of years. The two largest reservoirs in the state, Lake Shasta and Lake Oroville, have both refilled to levels above the historical average and are 81 and 73 percent full. Most of the lakes farther south have some serious catching up to do.

Snow Cover

Snow Cover 3-15-2016
Snow cover on March 15, 2016. Rutgers.

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Snowpack, March 1, 2016
Snowpack, March 1, 2016