Wildfire potential, November through February

November wildfire outlook weather

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

If their analysis is correct, the only areas with above normal wildfire activity during the period will be Southern California in November and December, and Hawaii December through February.

Below:

  • An excerpt from the NIFC narrative report for the next several months;
  • More of NIFC’s monthly graphical outlooks;
  • NOAA’s three-month temperature and precipitation forecasts; and,
  • Drought Monitor.

“Much of the West exited fire season by early October as the frequency of wet systems moving across the country increased. Cooler temperatures brought higher humidity levels and good overnight recoveries which also reduced large fire potential. As anticipated, the frequency of Santa Ana and North Wind events across California was lower than average, so critical fire weather periods were infrequent and of short duration. Nevertheless, fire activity was observed in isolated locations across the region in the remaining pockets where fuels remained critically dry. The Klondike fire made large runs mid-month. In the East, fire activity was also less active than average. This was due to the onset of a weak El Niño which promoted wetter than average conditions. The primary draw on resources was in response to Hurricane Michael which made landfall at Mexico Beach, Florida, with 155 mph winds.

“While most regions of the country are out of fire season during November, varying levels of activity are observed across California and the Southeast. The onset of El Niño should allow for a continuance of wetter than average conditions across the Southeast which should limit fire activity. However, pockets of critically dry fuels will persist across California, especially along coastal areas and along the front of the Southern Sierra. These areas will remain susceptible during wind events.

“Climatologically speaking, fire activity during the winter months, December through February, is at a minimum. Areas most susceptible to activity are generally restricted to the southeastern states where periodic increases in fire activity are possible during dry periods until spring greenup begins. However, current data and expected trends in precipitation suggest that large fire potential will be Below Normal in this region. The abundance of moisture should keep fuels in most areas from becoming critically dry. Drought forecasts project that the region should remain mostly free of drought.

“Across the West, overall warmer and drier than average conditions are expected. This should lead to below average snowpack in most mountain locations across the northern tier of the country. Snowpack should trend toward average levels moving south along the Continental Divide as the impacts of the El Niño begin to produce a positive effect on precipitation amounts received.”


December wildfire outlook weather
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Precipitation hits some areas in Western U.S.

(Originally published at 2:40 p.m. MDT October 3, 2018)

Precipitation last 72 hours
Precipitation 3 p.m. Sept. 30 to 3 p.m. Oct. 3. NWS. Click to enlarge.

(Originally published at 2:40 p.m. MDT October 3, 2018)

Quite a number of areas in the Western United States have received significant precipitation over the last 72 hours. The green, yellow, and red areas in the map above represent locations with more than one-third of an inch, which should impede the ignition or growth of wildfires.

The data in southern Arizona that shows two to four inches explains why rescues like the ones below were occurring in Phoenix.

Wildfire potential October through January

(Originally published at 4:48 p.m. MDT October 1, 2018)

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

If their analysis is correct, the only areas with above normal wildfire activity in October will be California, Southern Idaho, and Northern Nevada. Those areas will shrink in November to just Central and Southern California, and in December to just Southern California and the Central Coast. In January only Hawaii will have above normal potential.

Below:

  • An excerpt from the NIFC narrative report for the next several months;
  • More of NIFC’s monthly graphical outlooks;
  • NOAA’s three-month temperature and precipitation forecasts; and,
  • Drought Monitor.

“October and November mark another transition in the western fire season as the focus typically shifts to California as occasional Foehn wind events develop. The Southeast also typically experiences a fall peak during this period. The fall season this year might not follow the traditional script, however. Expected long-range weather patterns for at least October do not support the development of a significant number of wind events. While they may occur, the total number of events should be less than average. Considering that expected precipitation will be below average during this period, this could be a big factor in keeping some of the impacts from having an elevated potential at bay. Across the Southeast, conditions have been very wet over the past several months. With the potential development of an El Niño, the wet pattern is not likely to change. This should result in overall Normal to Below Normal significant wildland fire potential throughout the remainder of the fall.

“Transitioning from November into December and January, all regions are expected to experience reduced fire activity with the arrival of winter. Brief periods of critical fire weather conditions could elevate fire potential during occasional wind events over areas that are not snow covered. Events such as this are generally short in duration. Areas to monitor are along the Rocky Mountain Front, the Great Basin, the Southwest, and the southern Great Plains (during January.) All of these areas were experiencing some measure of drought at the end of September though some improvement is expected along the Rocky Mountain Front in southern Colorado and New Mexico.”

wildfire potential september through January

Continue reading “Wildfire potential October through January”

Most of U.S. predicted to have above normal temperatures the rest of the year

temperature precipitation outlook

Today the National Weather service issued their long range temperature and precipitation outlooks for October through December. If their forecast is correct almost all of the United States is likely to have higher than normal temperatures the rest of this year. The precipitation outlook is more varied, with the Northwest expecting below normal amounts, while the Southwest, Southern Plains, the Gulf Coast and East Coast should receive above normal precip.

 

Wildfire potential September through December

Originally published at 10 p.m. MDT September 1, 2018)

wildfire potential September OctoberOn September 1 the Predictive Services section at the National Interagency Fire Center issued their Wildland Fire Potential Outlook for September through December. The data represents the cumulative forecasts of the ten Geographic Area Predictive Services Units and the National Predictive Services Unit.

If their analysis is correct, in September the wildfire potential will decrease in the Northern Rockies, which is not unusual for this time of the year, but remain elevated in Central Texas, California, Nevada, and the Cascades. For October through December the potential should remain high in Southern California, with no sign of a busier than usual fall fire season in the Southern Great Plains or the Southeast.

Below:

  • An excerpt from the NIFC narrative report for the next several months;
  • NIFC’s monthly graphical outlooks;
  • NOAA’s three-month temperature and precipitation forecasts; and,
  • Drought Monitor.

“The significant wildland fire potential forecasts included in this outlook represent the cumulative forecasts of the ten Geographic Area Predictive Services units and the National Predictive Services unit.

“The western fire season peaked in August as very hot and dry conditions continued under the presence of a very strong, persistent high pressure ridge during the first three weeks of the month. Many approached or broke all-time record highs during the second week of the month. Not surprisingly, many fires became quite large including the Mendocino Complex which burned more than 420,000 acres making it the largest fire on record in California. Most fires observed were in areas of preexisting or developing drought.

“Along the West Coast, drought intensification and expansion was observed across Oregon and Washington. Further inland, abnormally dry conditions developed across Nevada, Idaho, and western Montana. Drought intensification and expansion was also observed across the Great Lakes region. While pockets of extreme to exceptional drought continued across the Four Corner states, the active monsoon was allowing for some improvement to occur. Nearly the entire West Coast received less than 25% of average precipitation. Significant deficits extended inland into the Great Basin and the Northern Rockies where large areas received less than 50% of average precipitation.

“Most of Texas and the central Great Plains received above average precipitation in August. Amounts across Oklahoma, Kansas, and Arkansas received 200% to 400% of average precipitation. The East Coast received similar amounts. Temperatures nationwide were generally near to slightly above average except across the central Great Plains where they were a few degrees below average. Alaska fully exited the season mid-month as a wet and cool patter took hold across the Interior. Hawaii experienced large fire activity as well; however, the heavy rains from Hurricane Lane quickly reduced fire potential across the state.

“September is a transitional month for the West. Critical fire weather periods become increasingly driven by occasional wind events resulting from passing cold fronts or by a strong westerly flow. The transition this year began a few weeks early. A shift to a fall-like pattern began the last week of August. Overall normal significant large fire potential is expected in most areas across the West except along the Canadian border with northeastern Washington, extreme northern Idaho, and northwestern Montana where above normal potential is expected. Debris from Hurricane Lane may produce heavy dead fuel loadings across Hawaii which could become receptive should abnormally dry conditions develop. Portions of northwestern Nevada and northeastern California could remain elevated as well given continued fuel dryness and a propensity for wind events.

“In October, the continued seasonal transition into fall will allow for colder air to become entrenched across the Great Basin thus creating a high pressure ridge that should periodically induce Foehn Wind events across both Northern and Southern California. Other regions across the Westshould fully exit fire season. In the East, preexisting drought conditions across the Great Lakes Region cloud promote wind-driven events should the fuels remain dry after leaf drop. The remainder of the East is largely free of drought entering late fall.

“November and December are traditionally months where fire activity is reduced. The focus during this period generally shifts from California to the Southeast where during dry years, significant fire activity can be observed. Latest data suggests that the late fall period will experience at least average conditions if not wetter than average conditions in some locations. So, Normal Significant Large Fire Potential is expected across most of country during the remainder of the outlook period.”

wildfire potential November December

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Fall-like weather could slow wildfires in Northern Rockies

The trend could last into next week

weather forecast northern rockies
Graphic produced by the National Weather Service office in Missoula, Montana August 21, 2018 at 8:30 p.m. MDT.

(Originally published at 9:12 a.m. MDT August 22, 2018)

When I saw the prediction from the Missoula National Weather Service office above, it got me thinking about how this cooler, possibly wetter weather is going to affect the dozens of large wildfires currently burning in the northwest United States. Two of the fires we have written about over the last couple of days, Watson Creek in Oregon and Howe Ridge in Montana, recently had small amounts of precipitation, certainly not enough to put them out, but it will absolutely slow their spread for a day or two.

No doubt other fires were also were affected, as you can see in the map below showing precipitation over the last 48 hours. But it looks like Washington, western Oregon, and most of northern California remained dry.

weather 48-hour precipitation map
Estimated precipitation for the 48-hour period ending at 8 a.m. CDT August 22, 2018.

More rain is expected in the Northern Rockies into next week. Below is the forecast for precipitation on Monday afternoon, August 27. The “haze” shown in California and Oregon is presumably smoke from the Mendocino Complex of Fires.

precipitation August 27 2018
Predicted precipitation for August 27, 2018.

Next are the predictions for precipitation and temperature August 27 through 31.

Continue reading “Fall-like weather could slow wildfires in Northern Rockies”