Wildland fire potential, September through December

On September 1 the Predictive Services section at the National Interagency Fire Center issued their Wildland Fire Potential Outlook for September through December, 2016. The data represents the cumulative forecasts of the ten Geographic Area Predictive Services Units and the National Predictive Services Unit. Below are highlights from the outlook.

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September is typically a month of significant change in fire conditions, especially across the northern tier of the United States. Days shorten, lessening available solar radiation to dry and heat fuels; longer nights are cooler with generally higher humidity. These conditions slowly reduce fire activity and typically end normal fire season activity throughout the month. This is expected to be the trend this season as well.

Throughout the northern portions of the Great Basin including portions of the Northwest, Northern Rockies and Rocky Mountain Areas above normal conditions will transition through the month to normal conditions and by the end of September normal conditions indicate minimal fire activity throughout this area. Occasional dry cold fronts during September and possibly October will present the potential for large fires on the landscape to grow rapidly; however, these conditions will be short in duration followed by opportunities for successful firefighting efforts. California will remain at above normal levels of fire activity throughout much of the state as dry conditions will continue and fall will bring the increased potential for offshore flow events.

wildfire potential

In October, November and December diminishing activity in the northern tier will transition to heightened activity across the southern tier; especially in central and southernCalifornia and the Southeast. California is not expected to see any significant events that will alleviate long term drought and very dry fuels. This will come with enhanced potential for offshore flow, increasing the potential for very dry and windy conditions. The southeastern United States is a significant wildcard moving into the fall months.

Tropical systems the Atlantic Ocean and Gulf of Mexico could provide substantial relief to some if not all of the area.

If this dry area remains, fall fire activity in the Southeast will be amplified and could become significant throughout the fall and winter. It is possible significant changes will occur, but the current conditions dictate elevated potential is likely.

wildfire potential

Wildland fire potential in the lower 48 states

The U.S. Forest Service produced this map showing wildfire potential in the lower 48 states. Higher resolution versions are available.

Here is how the USFS describes this map:

“The wildland fire potential (WFP) map is a raster geospatial product produced by the USDA Forest Service, Fire Modeling Institute that is intended to be used in analyses of wildfire risk or hazardous fuels prioritization at large landscapes (100s of square miles) up through regional or national scales. The WFP map builds upon, and integrates, estimates of burn probability (BP) and conditional probabilities of fire intensity levels (FILs) generated for the national interagency Fire Program Analysis system (FPA) using a simulation modeling system called the Large Fire Simulator (FSim; Finney et al. 2011).

The specific objective of the 2012 WFP map is to depict the relative potential for wildfire that would be difficult for suppression resources to contain, based on past fire occurrence, 2008 fuels data from LANDFIRE, and 2012 estimates of wildfire likelihood and intensity from FSim. Areas with higher WFP values, therefore, represent fuels with a higher probability of experiencing high-intensity fire with torching, crowning, and other forms of extreme fire behavior under conducive weather conditions.

Using the FPA FSim products as inputs, as well as spatial data for vegetation and fuels characteristics from LANDFIRE and point locations of fire occurrence from FPA (ca. 1992 – 2010), we used a logical series of geospatial processing steps to produce an index of WFP for all of the conterminous United States at 270 meter resolution.”

Wildland fire potential, August through November

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

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“For August, significant wildland fire potential will continue to be focused in the finer fuel and brush areas of California and the Great Basin with some expansion into Oregon, Montana and Wyoming. Primary concerns continue to focus on the abundant fine fuels and their ability to carry fires more effectively than in a typical year. Additionally significant mortality will increase heavy fuel availability throughout the mountains of California, while typical summer dryness will bring fire activity in the heavier fuels of the Northwest, Northern Rockies, Rocky Mountains and Great Basin up to normal levels. Furthermore, the Southwest, Rocky Mountains and southern Great Basin will see an intermittent monsoon which will continue some level of fire activity in those areas.

wildfire potential September 2016

“As fall begins, days shorten, temperatures cool and frontal systems become more common. This typical transition will return much of the Northwest, Northern Rockies, Rocky Mountains and Great Basin to normal fire activity through September. California will continue to see elevated potential due to long term dryness. This will occasionally be amplified through the fall and early winter as offshore flow events become more common. The southern U.S. will also see an increase to above normal significant fire potential as long term dryness couples with leaf drop and dormancy of live fuels to create a receptive environment for fall fire activity.

wildfire potential October November

“By October and November much of central California will transition to normal fire potential as is seasonally expected. Southern California will continue to see elevated significant fire potential and will also see the persistent threat of offshore wind events. The southeastern states will see a broad area of increased potential as a result of long term dryness and the introduction of La Niña conditions which typically bring warmer and drier-than-normal conditions to the southern tier of states.”

Wildland fire potential, July through October

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

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“During late June and July significant wildland fire potential usually transitions from the Southwest and southern California northward into the remainder of the western United States. The timing of this transition should be near normal; however, some areas will experience an increased potential for significant fires due in large part to high fine fuel loading. These areas include the northern and western Great Basin, northern California and some of the finer fuel regime areas of Montana, Wyoming and the Dakotas. Additionally the Southwest will continue to see elevated significant wildland fire potential through July as monsoonal rainfall may not be as consistent as usual. Southern California also will continue to have elevated significant fire potential throughout the period driven by long term drought and vegetation mortality. Alaska fire potential will remain near normal with the northern portions of the state below normal. Alaska usually begins to transition to late season conditions in July and August.

wildfire potential August 2016

The same heavy fine fuel crops that are driving the above normal forecast for July will continue to present above normal potential into August. Forecasted normal conditions in the higher elevations for August, however, mean that a number of significant wildland fires are likely to develop in these areas throughout the West. Fire season in the western U.S. is typically at its peak in July and August and this year should be no different with the potential for significant fires across the spectrum of fuel regimes all indicating at least normal levels of fire activity.

wildfire potential Sept and Oct 2016

In September and October the northern tier of states should see a rapid return to normal wildfire potential. The focus for activity should transition to California. Long term drought is expected to remain in place and fall conditions typically bring an increase in offshore wind events that often drive fire activity for the state.”

Wildfire potential, June through September

On June 1 the Predictive Services section at the National Interagency Fire Center issued their Wildland Fire Potential Outlook for June through September, 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, Alaska, the Northwest, the East, the Central states, and Rocky Mountain areas will avoid unusually high wildfire activity. Over the four-month period above normal wildfire potential should move from Arizona and New Mexico into California, Nevada, and southwest Idaho, and remain high in Hawaii for the entire period.

Wildfire Potential July 2016 Wildfire Potential Aug-Sep 2016

Here are the highlights of the written report issued May 1 (which we have reformatted a little for easier reading). More details are available at the link above.

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Eastern States

“Conditions across the Eastern States have mitigated enough thanks to timely moisture and the onset of green-up that these areas no longer present a concern for above normal significant wildland fire potential.

Alaska

For June and early July two primary areas of fire activity are the focus. First, Alaska has begun to see significant fire activity. Recent moisture over the state has dried out, triggering an increase in fire activity. Some of these fires are holdover fires from the 2015 fire season. Alaska will continue to see normal levels of significant fire activity into July.

Southwest Area

Second, the Southwest Area enters its primary fire season in June and July. This area has a robust fine fuel crop; however, lingering moisture has largely kept significant fires at bay. As seasonal drying progresses south of the Mogollon Rim, expect above normal levels of significant fire potential to remain dominant through at least early July, especially in fine fuel regimes.

Great Basin and California

Heavy and continuous fine fuel loadings are expected across the Great Basin and lower elevation areas of southern and central California. Dry and windy periods will increase fire activity and the potential for fires to become large and grow rapidly. Fire activity will begin in June and July and transition northward throughout the Outlook period. Warm conditions have depleted much 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.

Other areas

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.”


As a bonus, here is some additional weather data:

Continue reading “Wildfire potential, June through September”

Wildfire potential, May through August

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