Revisions to the National Fire Danger Rating System

fire dangerThe National Fire Danger Rating System tracks weather events through their effects on live and dead fuels and adjusts them accordingly based on forecasted weather. The most visible product of the system, which is used by most large land management agencies in the United States, is the predicted fire danger, often expressed as adjectives ranging from Low to Extreme.

The NFDRS was first released for general use in 1972 and was subsequently revised in 1978 and 1988. Work on another revision began in 2000 and is nearing completion. Reportedly this next version is much simpler and more automated than its predecessors and it represents a vast improvement in fire potential assessment capabilities.

Three major changes will be:

  • The Fosberg Dead Fuel Moisture Model will be replaced with the Nelson Dead Fuel Moisture Model.
  • The Burgan Live Fuel Moisture Model will be replaced with the Growing Season Index-based live fuel moistures.
  • The number of fuel models in the NFDRS will be reduced from 40 to 5.

Jon Wallace, a member of the team rolling out and implementing the new system described the transition in an email today:

“The system is expected to be back from contracting and thus complete on November 1st of 2016. After the first of the year we’re going to begin training of Subject Matter Expert groups located within each geographic area, and when that training is complete we will open the system up for all users.  We had to wait to conduct this training until the system was fully functional.

“As you can imagine, there is going to be a learning curve for the user community and these Subject Matter Expert groups are going to help us get through that curve within their respective geographic area.

“All members of the user community will be able to see the new NFDRS2016, as well as the 1978 and 1988 NFDRS models during the spring of 2017.  This will allow them to work with the subject matter expert groups to set up NFDRS parameters prior to the Summer of 2017 fire season.  They will then be able to compare the outputs of the new system to what they are used to seeing in the older versions of NFDRS.

“This side by side comparison will be available to users through the 2018 fire season, at which time we will re-evaluate the need to continue support of the old systems.”

Linking wildfires to climate change — it’s complicated

This is a rather surprising 2-minute video about attributing wildfires to climate change. It was produced by the National Center for Atmospheric Research and the University Corporation for Atmospheric Research.

Dry thunderstorms possible in Montana and Wyoming

Friday’s weather includes Red Flag Warnings in the west and a hurricane on the east coast

Above: Weather forecast, current at 9 a.m. MDT September 2, 2016. Weatherunderground. Black text added by WildfireToday.

The weather map for the United States today has quite a range of conditions across the country. While Hurricane Hermine, now downgraded to a tropical storm, batters the southeast, a cold front is bringing strong winds and low humidities to some areas in the west. There is a chance of isolated dry thunderstorms in northwest Wyoming and eastern Montana.

Fire weather, September 2, 2016
Fire weather, September 2, 2016.

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.


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

Wildfire smoke and fire danger, August 31 and September 1, 2016

wildfire  smoke forecast
Wildfire smoke forecast for 5 p.m. MDT August 31, 2016.

NOAA’s Earth System Research Laboratory, as part of an experimental program (above), has produced a smoke forecast for 5 p.m. on Wednesday, August 31, showing that many areas in the western U.S. are affected by smoke from wildfires.

Below is their forecast for 5 p.m. MDT on Thursday, September 1, 2016.

Wildfire smoke forecast
Wildfire smoke forecast for 5 p.m. MDT September 1, 2016.

The last map, below, predicts elevated wildfire danger on September 1 in parts of California, Nevada, Utah, Idaho, and Montana. Isolated dry thunderstorms could be in the cards for areas in Nevada, Idaho, Montana, Utah, and Wyoming.

Wildfire danger for September 1
Wildfire danger for September 1, 2016.

Impressive convection column on Pioneer Fire is being studied by researchers

Above: The photo above was taken from the research aircraft August 30 by Nick Guy of the University of Wyoming’s Atmospheric Science department.

The Fire Weather Research Laboratory from San Jose State University is conducting research from an aircraft flying over the Pioneer Fire in central Idaho. Today using N2UW, a twin engine 1977 Beech 200T King Air, they flew for over three hours at 27,000 feet studying the fire for the RaDFire project.

The aircraft is outfitted with a ton of instruments including Doppler radar. Craig Clements, Associate Professor in the Meteorology Dept. at SJSU, described it for us:

The radar is called the Wyoming Cloud Radar (WCR). It’s on the aircraft, points up, down, and down-forward to get horizontal winds and vertical winds. The goal of the RadFIRE (Rapid Deployments to Wildfires Campaign) is to get data on plume dynamics from ground based mobile Doppler Lidar. But we were awarded 10 flight hours to test the WCR to see if it works in smoke plumes. And it does so well, more than we can imagine!

The group has been known to fly through the convection column. I’ve done that a few times and it’s an interesting experience — it can get a little turbulent, as you might expect.

On Monday they said the top of the pyrocumulus cloud over the fire topped out above 30,000 feet. In Tuesday’s photos it was at about 25,000 feet but toward the end of the day the top got up to at least 32,000 feet, Mr. Clements said.

The project is sponsored by the National Science Foundation and it’s being led by San Jose State University. Other collaborators on the project are David Kingsmill at the University of Colorado Boulder, and the University of Wyoming King Air team.

Since it started on July 18 the Pioneer Fire has burned over 140,000 acres.

This last photo of the convection column was not taken by the researchers. It was shot by Steve Botti in Stanley on August 29, more than 20 miles away from the fire.

Pioneer Fire
Pioneer Fire, as seen from Stanley August 29, 2016. Via Mike Warren.