Precipitation slows fire season in the Northwest

Precipitation in the northwest one-quarter of the United States received over the last 72 hours will slow if not end the wildland fire season in some areas. The map shows precipitation detected by weather radar, which means there are gaps in areas with poor radar coverage.

According to the data, many areas received more than half an inch which will definitely have an effect lasting more than a few days.

You might notice that the rainfall in southeast Texas is completely off the chart, showing more than 15 inches. As this is written Thursday afternoon the Houston area is in the middle of the fifth 500+ year rainstorm in the last five years.


What has the weather been like in your area over the last week?

The maps below show the precipitation and  temperature outlooks for September 25 through 29.

temperature outlook 6-10 days precipitation outlook 6-10 days

Portions of California expected to see above average wildfire activity

September 2019 wildfire outlook

On 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 NIFC’s analysis is correct, California will be one of two states expected to have areas with above average potential for wildfires, and those sections of California will shrink through December until the only areas remaining are the mountains and coasts from Santa Barbara south to the Mexican border. Southern Alaska could also have above normal fire activity in September.

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;
  • Vegetation greenness map;
  • Keetch-Byram Drought Index.

From NIFC:

“Due to the recent lack of rainfall, areas of concern have emerged and are expanding to include Texas, California, Nevada, Utah and southwestern Wyoming – all of which have generally seen less than 25% of average precipitation during the past month. Extended periods of dry conditions across New Mexico and the southern Great Plains are also leading to the development and intensification of drought conditions.

“Entering September, warmer and drier than average conditions are expected to occur along the West Coast, which may persist well into fall. However, the passage of periodic wet systems should gradually end the fire season from north to south across the Northern Rockies, Central Rockies and Great Basin. Texas is expected to remain warmer and drier than average, which may, in turn prolong their season well into fall. Warmer and drier than average conditions are expected across the piedmont of the southern Appalachians, but wet antecedent conditions should preclude fire activity there.

“As the fall progresses, fire activity should relent over the Pacific Northwest and eventually Northern California during October. Southern California will likely be the last area to see fire activity conclude in 2019 as offshore winds and dry fuels may keep fire activity going south of Pt. Conception into December. In Alaska, overall warmer and wetter than average conditions are expected until the state enters winter.”


October 2019 wildfire outlook

November 2019 wildfire outlook

Continue reading “Portions of California expected to see above average wildfire activity”

Elevated wildfire potential expected in Washington, Oregon, Nevada, and California

August wildfire outlook

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

If NIFC’s analysis is correct, areas in Washington, Oregon, Nevada, and California will have elevated potential for wildfires in August and September. With the monsoons moving into the Southwest there are no areas east of those four states that NIFC identified as having high wildfire potential between August and November.

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;
  • Vegetation greenness map.From NIFC:

“Moderate to severe drought conditions exist across portions of northern Oregon, Washington, northern Idaho and western Montana. However, a recent extended period of cool and periodically moist conditions has lessened the drought stress in the vegetation. Moderate drought has emerged across the northeastern Interior of Alaska and on the Kenai Peninsula. Puerto Rico is also showing developing drought across the southern portion of the island.

“Looking forward, an active but compressed season is expected across the West as the southwestern monsoon becomes more active in August. While this will effectively end the season across the Southwest, lightning-induced fire activity is expected to increase elsewhere. Wind events, which have been largely absent thus far, will increase in frequency by mid to late month as dry frontal passages become a more common occurrence. The occurrence of both wind events and low humidities will influence an increase in fire behavior and growth. Activity in Alaska will continue to diminish as the frequency of frontal passages increases and as temperatures begin to cool. By mid-September the seasonal transition out of the core fire season will be underway as the seasonal transition begins to bring wetting systems to most regions.

“By October and November, however, California will reenter the fire season as Foehn Wind events begin to develop. Concerns this year are higher than average due to the presence of an abundant crop of fine fuels in the lower to middle elevations.”


September wildfire outlook

Continue reading “Elevated wildfire potential expected in Washington, Oregon, Nevada, and California”

Excessive Heat Warnings in parts of Central and Eastern U.S.

Excessive Heat Warnings and Heat Advisories
Excessive Heat Warnings (red) and Heat Advisories (orange) in effect July 21, 2019. NWS.

Hopefully firefighters will not have to spend much time battling fires in the areas where Excessive Heat Warnings and Heat Advisories have been issued by the National Weather Service.

On Sunday, July 21 most of the areas identified on the map will experience  heat indexes or actual temperatures around 105 or 110 degrees.

Here is a typical passage in the NWS forecasts for the affected areas:

IMPACTS…THE DANGEROUS HEAT AND HUMIDITY COULD QUICKLY CAUSE HEAT STRESS OR HEAT STROKE IF PRECAUTIONS ARE NOT TAKEN. THE VERY YOUNG, THE ELDERLY, THOSE WITHOUT AIR CONDITIONING, AND THOSE PARTICIPATING IN STRENUOUS OUTDOOR ACTIVITIES ARE THE MOST SUSCEPTIBLE. ALSO, CAR INTERIORS CAN REACH LETHAL TEMPERATURES IN A MATTER OF MINUTES.

The West had below normal precipitation in June

Precipitation during June in the West,
Precipitation during June in the West, compared to normal.

Most of the Western United States, in this case west of the 100th meridian, had below normal precipitation in the month of June. And, the area was cooler than normal, except for California, Oregon, Northern Idaho, and Washington.

Temperature during June in the West,
Temperature during June in the West, compared to normal.

Below are more details from the Western Regional Climate Center:


June in the West
“June, 2019
“Precipitation was below normal across much of the West; however, June is typically one of the driest months of the year for some parts of the region. Temperatures were above normal in coastal states and near to slightly below normal elsewhere in the region.

“Scattered areas of the West observed above normal June precipitation, generally associated with isolated thunderstorm events for locations west of the Rockies. Owyhee Dam in eastern Oregon logged 2.38 in (60 mm) in June, 259% of normal. Nearly all of this precipitation (2.27 in/58 mm) fell in one day on June 13. Some areas east of the Rocky Mountains saw persistent precipitation throughout the month. Fort Collins, Colorado, reported 2.59 in (66 mm) for June, 119% of normal and saw at least trace amounts of precipitation on 22 days of the month. Wolf Point, Montana reported 4.49 in (114 mm), 165% of normal, the 3rd wettest in a relatively short record beginning in 1998 and had at least trace precipitation on 17 days in June.

“Much of the Pacific Northwest and Intermountain West observed drier than normal conditions this month. Missoula, Montana recorded 0.66 in (17 mm), 32% of normal and the 6th driest June since records began in 1948. Portland, Oregon, observed 0.45 in (11 mm) of precipitation, 26% of normal and the 10th driest June in an 82-year record. In the US Drought Monitor, some areas of improvement were seen along the northern border of New Mexico and Arizona. Western Oregon, western Washington, and several areas along the northern border of the western states saw expansion of drought conditions this month.

“California saw the greatest departures above normal temperature for June. In northern California, Ukiah reported an average temperature of 72 °F (22.2 °C), 4.4 °F (2.4 °C) above normal and the third warmest June since records began in 1949. In the southern Central Valley, Bakersfield logged an average temperature of 81.9 °F (27.7 °C), also 4.4 °F (2.4 °C) above normal and the 10th warmest June in a record that began in 1937. Some areas of Oregon and Washington also saw temperatures several degrees above normal. Temperatures in Roseburg, southern Oregon, averaged to 67.7 °F (19.8 °C), 3.8 °F (2.1 °C) above normal. Elsewhere, temperatures were near to slightly below normal. For example, in eastern Nevada, Ely reported an average temperature of 58.6 °F (14.8 °C), 1.4 °F (0.8 °C) below normal. In Albuquerque, New Mexico, temperatures averaged to 73.8 °F (23.2 °C), 1.1 °F (0.6 °C) below normal. Phoenix, Arizona, reported a June average temperature of 91.1 °F (32.8 °C), 0.3 °F (0.2 °C) above normal.

“Much of Alaska experienced warmer and drier than normal conditions during June. Anchorage reported its all-time warmest and driest June in a 68-year record. Temperatures averaged to 60.5 °F (15.8 °C), 5.2 °F (2.9 °C) above normal. Precipitation totaled 0.06 in (2 mm), 6% of normal. In the northwestern part of the state, Kotzebue reported an average temperature of 56.8 °F (13.8 °C), 11.1 °F (6.2 °C) above normal and set the record for warmest June by 3.4 °F (1.9 °C). Records for Kotzebue began in 1897. Although a few southeastern Alaska stations reported above normal precipitation this month (e.g., Ketchikan reported 7.97 in/202 mm, 120% of normal), moderate to extreme drought conditions persist in this region. Roughly 3% of the state is experiencing drought conditions, all in the Panhandle. Ketchikan anticipates needing backup generators through at least October as reservoirs remain too low to generate hydropower.

“Above normal temperatures dominated in Hawaii, driven primarily by above normal sea surface temperatures in the Central Pacific. Kahului, Maui, logged an average temperature of 80.9 °F (27.2 °C), 2.9 °F (1.6 °C) above normal and the warmest June since records began in 1954. Many areas of the state observed above normal precipitation. Honolulu recorded 5.68 in (144 mm), more than 2000% of normal. A large portion of this, 4.2 in (107 mm) fell during intense thunderstorms associated with an upper-level low-pressure system that drew moist air into the region on June 25. The storm also caused downed trees, flooding, and several injuries due to lightning strikes on Oahu. In contrast, the windward side of the Big Island reported well below normal precipitation, Hilo observed 3.90 in (99 mm), 53% of normal. Drought improvement occurred on the windward sides of the islands in Hawaii and Maui Counties, with more island-wide improvement for Oahu and Kauai. Moderate to extreme drought conditions remain to some degree on the leeward sides of all islands.”

 

July could bring elevated wildfire potential to parts of the west coast, Alaska, Arizona, and the Southeast

Moderate to severe drought conditions exist in western Oregon and Washington

wildfire outlook 2019 July

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

If NIFC’s analysis is correct, areas in California, Washington, Oregon, Arizona, Alaska, and California will have elevated potential for wildfires at times during the four month period. Forecasters predict portions of Florida, Georgia, and the Carolinas will have enhanced potential in July.

The areas affected by the multi-year drought in the West have greatly decreased to the point where there are no locations with extreme or exceptional drought. No areas in California are listed as being in drought status, which is a major change from five or six months ago.

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;
  • Vegetation greenness map.

From NIFC:

“Moderate to severe drought conditions exist across Washington and Oregon, especially across western portions of both states. Soil moisture levels are drier than average and drought stress exists. Another area of concern is southern Arizona. While fuel conditions across most of the Southwest exhibit above average fuel moisture and greenness, the southern third of the state is the anomaly. Areas along and north of the Mexican Border remain persistently dry. Periodic wind events have led to critical periods with above normal activity observed. This area will remain a concern until the monsoon arrives in July.

“Alaska experienced a slow entry into its season. By mid-June fire activity increased significantly as fuels continued dried. Numerous lightning events produced a significant number of fire starts. The consistent warm and dry pattern observed at month’s end suggested that the state will continue to be active well into July before the season begins to wind down with the arrival of late summer rains in August.

“In California, robust crop of grasses has grown. The fuel beds have become more continuous than what is typically seen. When the hot, dry, and windy patterns develop during the middle to late summer months, the large fire potential in these areas will elevate. In the higher elevations, the abundant moisture received translated into historic snowfall. This and slow melting rates will translate into a delayed entry into the fire season. To the east, concerns across the Great Basin are rising due to heavy fuel loading and an expected long-duration heat event in early July that should propel the region into fire season.

“With fine fuels fully cured across the West and high elevation larger fuels becoming adequately dry in August, fire season 2019 will peak in August across much of the West. Exceptions to this will be the Southwest where an ongoing monsoon reduced fire activity and the central Rockies, which may not have enough time to fully dry and cure before monsoonal moisture, begins to affect the region.

“A gradual decrease in fire activity is expected to begin by mid-September as the seasonal transition begins and as shortening days translate to shorter burn periods and better overall humidity recoveries overnight. California will begin to reenter fire season in October as East and North wind events begin to occur.”


wildfire outlook 2019 August
Continue reading “July could bring elevated wildfire potential to parts of the west coast, Alaska, Arizona, and the Southeast”