Precipitation January through March was record lowest in some Western areas

100-year records were set in areas of Northern California, Southern Oregon, Central Idaho, and Northern Nevada

Western US precipitation, Jan-Mar, 2022 record setting dry drought

Precipitation from January through March in the 11 Western states was below normal in many locations, but record driest amounts were recorded in areas of Northern California, Southern Oregon, Central Idaho, Northern Nevada, and scattered sections of Montana, Colorado, and Utah. This is based on more than 100 years of data from the WestWide Drought Tracker at the University of Idaho.

The dry weather is already affecting live fuel moisture of the brush in the Santa Cruz Mountains south of San Francisco. On April 1 it was near the lowest ever measured on that date, about 30 percent below average.

low live fuel moisture, Santa Cruz Mountains, California
Live fuel moisture, Santa Cruz Mountains, California. San José State University.

Of course there is a temptation to conclude that extremely dry soils and vegetation in April will lead to more acres burned than average, but the reality is that the weather in the summer has veto power. If conditions during the peak of the western wildfire season are cooler, wetter, more humid, and less windy than typical, it will not necessarily be a busier than average fire season.

However (there is always a “however”) if this dry trend continues through June, and if the weather in the following three months is close to normal, the effects of the current shortages of wildland firefighters are going to be even more noticeable and far-reaching than we saw during the last two years.

And the three-month forecast for much of the West predicts below normal precipitation.

90-day Precipitation Outlook, March 17, 2022

Seasonal Drought Outlook

Precipitation anomaly Jan-Mar, 2022

Soil moisture anomaly April 2, 2022
NWS, Climate Prediction Center

In Northern California the snowpack on April 1 was 28 percent of normal for the date; statewide it was 38 percent.

California Sierra snowpack, April 1, 2022
California Sierra snowpack, April 1, 2022.

Western drought expected to continue through June

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Affecting parts of 23 states

Drought tendency, March 17 - June 30, 2022
The drought is expected to continue in the brown areas. (NOAA. Updated March 17, 2022)

In an analysis updated March 17 by NOAA, the drought in the western half of the United States is expected continue at least through June 30, 2022, affecting parts of 23 states.

And in most of those areas the temperatures will be higher than average and there will be less than average precipitation.

Three-month precipitation and temperature outlook, updated March 17, 2022.
Three-month precipitation and temperature outlook, updated March 17, 2022. NOAA.

NIFC’s forecast for wildfire potential this summer

It is influenced by the fact that more than 87% of the West is now categorized in drought.

Drought year to year

The forecast for wildland fire potential issued June 1 by the National Interagency Fire Center for June through September predicts wildfire potential will be higher than normal in the Southwest until the monsoons arrive in July. For the rest of the period, fire potential will be increasing in the Great Basin and the Pacific Coast states. From July through September nearly all of the mountainous areas of California, Oregon, and Washington are in the above normal category.

NIFC has modified their prediction for the Northern Rockies to show higher than normal fire potential in August for Idaho, Montana,  and most of Wyoming.

The entire eastern half of the U.S. is not expected to have any areas with above normal potential through September.

The data from NIFC shown here represents the cumulative forecasts of the ten Geographic Area Predictive Services Units and the National Predictive Services Unit.

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;
  • Drought Monitor;
  • Keetch-Byram Drought Index.

    “The year-to-date acres burned remains well below the 10-year average and significant fire activity was also limited during May. The absence of critical fire weather patterns in areas with very dry fuels helped limit significant fire activity in May. Fuels remain very dry across large swaths of the Southwest, Great Basin, and California with fuel dryness in much of the West two to four weeks ahead of schedule.

“Drought expanded and intensified over the West, especially in California. More than 87% of the West is now categorized in drought and over half the West in the highest two categories of drought. Snowpack set new record lows in parts of the West, including the Sierra, in May.

“Climate outlooks indicate warmer and drier than normal conditions are likely for much of the High Plains and West through summer continuing and exacerbating drought there. Near normal timing and precipitation is likely with the Southwest Monsoon in July, which should help alleviate drought conditions and significant fire activity, at least temporarily.

“Southern Area is likely to have near normal fire potential through the summer with below normal potential across the southern Plains in June. Near normal significant fire potential is also likely for Eastern Area and Alaska through the summer, although elevated periods of activity are possible during short-term drying episodes.

“The Southwest is forecast to have above normal significant fire potential through June before the Southwest Monsoon arrives.

“Above normal significant fire potential will expand northward into the Great Basin and Rocky Mountain Geographic Areas through August with areas closer to the monsoon likely returning to near normal significant fire potential in July and August.

“Central Oregon into southeast Washington is likely to have above normal significant fire potential beginning in June with portions of the Coast Ranges, Sierra, and Cascades in California increasing to above normal in June and July and continuing through September.

“West of the Continental Divide in the Northern Rockies is expected to have above normal significant fire potential in July before spreading across the entire geographic area during August, then likely returning to normal in September.

“Leeside locations of Hawaii are likely to have above normal significant fire potential into September due to heavier fuel loading and forecast warm and dry conditions.”


Wildfire potential Wildfire potential Wildfire potential Wildfire potential

Continue reading “NIFC’s forecast for wildfire potential this summer”

Drought has killed junipers in Arizona and blue oaks in the San Francisco Bay Area

Soil moisture is very low across much of the West and Upper Midwest

Soil Moisture, May 24, 2021
Soil Moisture, May 24, 2021. NOAA.
Drought Monitor, May 18, 2021
Drought Monitor, May 18, 2021. NOAA.

In some areas of the Western states the 20-year long drought has reduced moisture content in plants to the lowest levels scientists have seen. Soil moisture is very low — at or near record lows across much of California. Particularly hard hit are locations in Colorado, Utah, Nevada, New Mexico, Arizona, and California.

Junipers are dying in Arizona from a lack of water. The East Bay Times reports that drought is likely responsible for dead or dying acacia, eucalyptus, and Monterey pines in East Bay Regional Parks near San Francisco.

From the an Associated Press article by Seth Borenstein:

In Arizona, junipers are succumbing to the 20-year drought and its two-year intensification, said Joel McMillin, a forest health zone leader for the U.S. Forest Service there. Officials haven’t done a precise count but anecdotally the die-off is 5% to 30% with some patches up to 60%.

Until the dead needles drop to the ground, which takes a year or so, the fire hazard increases, fire manager Steinhardt said. “So you have something that’s highly flammable and it’s … 20-, 30-, 40-foot tall and every single one of those needles on there now becomes an ember that can be launched.”

“This is probably one of the driest and potentially most challenging situations I’ve been in,” said the veteran of 32 fire seasons.

In California, normally drought-tolerant blue oaks are dying around the San Francisco Bay Area, said Scott Stephens, a fire science professor at the University of California, Berkeley. “They don’t have access to water. Soil moisture is so low. When you start to see blue oak dying, that gets your attention.”

Human-caused climate change and decades of fire suppression that increases fuel loads are aggravating fire conditions across the West, scientists said.

Global warming has contributed to the megadrought and is making plants more prone to burning.

Vegetation with a low moisture content is easier to ignite in a wildfire and contributes to a rapid rate rate of spread that is more difficult for firefighters to suppress. Dead or dying trees that still have leaves attached during the first year or so after their decline can also enhance the spread and intensity of a fire and adds to the number of burning embers lofted into the air that can ignite spot fires ahead of the blaze, putting structures at risk that are distant from the fire.

Extremely dry soil and vegetation in May does not guarantee a busier than average summer fire season in the West — the weather in the coming months is the primary factor. If it turns relatively cool and wet, the number of acres burned is not likely to be extreme. But if the drought continues into June, July, and August, normal weather, or especially warmer and drier than normal weather, could produce a busier than average Western fire season.

Precip & Temp outlook for May 1-7, 2021
Precip & Temp outlook for May 1-7, 2021. Made May 24, 2021.
Precip & Temp outlook for June, July, & August
Precip & Temp outlook for June, July, & August, 2021. Made May 20, 2021.

Progression of the drought during a 35-day period

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Drought worsens in California

Drought Monitor, May 4, 2021
Drought Monitor, May 4, 2021. NOAA.

A Drought Monitor update:  During the 5-week period between March 31 and May 4, the “Extreme Drought” areas grew in California, Oregon, Montana, Wyoming, and North Dakota.

Drought Monitor, created March 31, 2021
Drought Monitor, March 31, 2021. NOAA.

Below are the temperature and precipitation outlooks for May, 2021.

Temperature and precipitation outlook for May
Temperature and precipitation outlooks for May, created April 30, 2021.

Wildfire potential in the Southwest expected to remain above normal through June

It is also predicted to be above normal in much of the Great Basin through August

May wildfire outlook

The forecasts for wildland fire potential issued May 1 by the National Interagency Fire Center for May through August predict wildfire potential will be higher than normal in the Southwest until the monsoons arrive in July. Fire potential is also expected to be high in much of the Great Basin for the entire period and will be increasing in the mountains of California from June through August.

The Great Plains and Northern Rockies are slated for normal conditions but Central Oregon and Southeast Washington will be above normal beginning in June.

The data from NIFC shown here represents the cumulative forecasts of the ten Geographic Area Predictive Services Units and the National Predictive Services Unit.

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;
  • Drought Monitor;
  • Keetch-Byram Drought Index.

    “Climate outlooks indicate warmer and drier than normal conditions are likely for much of the Plains and West into summer continuing and exacerbating drought there. A Fuels and Fire Behavior Advisory is in effect for North Dakota, eastern Montana, and northwest South Dakota due to drought and continuous fine fuels. Near normal timing and precipitation are expected with the Southwest Monsoon in July, which will help alleviate drought and significant fire activity.

“Near normal significant fire potential is forecast across the northern Plains into the Great Lakes for May, but dry periods followed by strong winds could increase fire activity above normal. Outside of increased fire potential in western Oklahoma and west Texas, Southern area is likely to have near normal fire potential with elevated activity possible in and around northern Florida in May.

“The Southwest is forecast to have above normal significant fire potential through June before the Southwest Monsoon arrives. Above normal significant fire potential will expand northward into the Great Basin and Rocky Mountain Geographic Areas through August with areas closer to the monsoon likely returning to near normal significant fire potential in July and August. Central Oregon into southeast Washington are likely to have above normal significant fire potential beginning in June with portions of the Coast Ranges, Sierra, and Cascades in California increasing to above normal in June and July and continuing through August. Leeside locations of Hawaii are likely to have above normal significant fire potential in July and August due to heavier fuel loading and forecast warm and dry conditions, while Alaska should have near normal significant fire potential through summer.”


June wildfire outlook July wildfire outlook August wildfire outlook

Temperature outlook May-July, 2021
Temperature outlook May-July, 2021
Precipitation outlook May-July, 2021
Precipitation outlook May-July, 2021

Drought Monitor April 27, 2021 Keetch-Byram Drought Index