Almost of the western United States, except for Washington and the northern Rockies, is experiencing “moderate” to “exceptional” drought, according to the Drought Monitor released June 27, 2013.
The West is dry
Dry thunderstorms predicted for CO, NM, and NV
The National Weather Service still has not fixed their web site that shows Red Flag Warnings, so we are again substituting this image from today’s NWS Fire Weather Outlook page.
The “DRY-TSTMs” indicated on the map mean there is a possibility for thunderstorms with lightning but little or no rain, creating the possibility for multiple new wildfires in Nevada, Colorado, and New Mexico.
Southern California fuels and fire behavior advisory
One of the Predictive Services offices issued a Fuels and Fire Behavior Advisory for southern California. In this new one, most of Northern California has been temporarily removed due to the unseasonably cool and wet weather pattern. With the forecast for the weather pattern to make a dramatic change mid-week with strong high pressure developing over California for rapid drying/warming into the weekend, they anticipate Northern CA will once again warrant an advisory in the next 1-2 weeks.
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“Fuels and Fire Behavior Advisory
Southern California
June 25, 2013
Subject: Low live and dead fuel moistures, along with persistent drought have created the potential for active to extreme fire behavior in Southern California.
Discussion: All of California is experiencing drought conditions. Effects of lower than normal live and dead fuel moistures and observed fire behavior for 2013 are the focus of this advisory. Note that most of Northern CA was included in the previous advisory but has been temporarily removed due to forecasted widespread wetting rain. It is anticipated that area will warrant an advisory in the next couple weeks.
Difference From Normal Conditions: Drought conditions ranging from abnormally dry to severe exist and are expected to persist or intensify. The entire area is deficient in rainfall and snow pack, resulting in fuels that are 4-8 weeks ahead of normal drying/curing rates.
Concerns to Firefighters:
- Energy Release Component (ERC) values at numerous weather stations are well above normal and many are at record maximums. Expect increased fire intensity and spread rates in these areas. Early season extreme fire behavior has been observed especially in brush fuel types. Anticipate increased spread rates, spotting, and active night time burning.
- The combination of persistent drought and record-low rainfall and snowpack amounts has led to very low live and dead fuel moistures. Low 1000-hour fuel moistures have been evidenced by complete consumption of dead fuels on recent fires. Live fuel moistures for Chamise have already reached critical levels of 60% or less in many areas. Expect fires to ignite easier and spread faster. Anticipate higher resistance to control in all fuel types.
- Active fire behavior can extend well into the night and early morning hours even with moderate RH recovery. Already this year, Southern California has experienced large fire activity and multiple team deployments. It is important to be mindful of and manage fatigue for all resources. Everyone, every day, returns home safely.
Mitigation Measures:
- Local and inbound fire personnel need to be aware that fire behavior is exceeding normal expectations for this time of the year. Local briefings need to be thorough and highlight specific fire environment conditions. These include but are not limited to local weather forecasts, Pocket Cards, ERC’s, live and dead fuel moistures, and special fuel conditions such as mortality, Sudden Oak Death and frost killed brush, etc.
- Suppression actions need to be based on good anchor points, escape routes, and safety zones. Remember LCES. Experienced lookouts are essential under these conditions.
- Base all actions on current and expected behavior of the fire. Augment initial attack resources as incident activity dictates.
- Review the most current Southern California 7-day Significant Fire Potential along with Daily, Monthly and Seasonal Outlooks at: http://www.predictiveservices.nifc.gov/outlooks/outlooks.htm
Area of Concern: The area of concern is the Southern California geographic area with the exception of 4 PSA’s: Central Valley, Central Mojave, Eastern Desert, and Lower Deserts. A map showing the areas of concern described in this advisory can be found at: National Fuel Advisories
Issued: June 25, 2013 (Note this advisory will be in effect for 14 days and will be reviewed/updated at that time.)”
Red Flag Warnings, June 22, 2013
Red Flag Warnings and Fire Weather Watches for enhanced wildfire danger have been issued by the National Weather Service for areas in Colorado, New Mexico, Kansas, Utah, Arizona, and Nevada.
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The Red Flag Warning map above was current as of 11:50 a.m. MDT on Saturday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts. For the most current data, visit this NWS site.
Two fuels and fire behavior advisories for Colorado
The Rocky Mountain Geographic Area and the Upper Colorado River Fire Management Unit on the Colorado Western Slope issued two Fuels and Fire Behavior Advisories today. Below are the complete texts of both:
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“Fuels and Fire Behavior Advisory
Western Slope of Colorado
06/21/2013
Subject: Western Colorado is in the third year of drought. The situation is predicted to persist or intensify through July. There is increased risk of large fire development and intense fire behavior. Dry, heavy fuels at higher elevations could pose a greater risk of active fire behavior.
Discussion: The wet spring pattern that occurred during April and May has provided a brief reprieve. Live and dead fuel moistures are quickly returning to a condition that will support large fire growth.
Forecasts do not offer the prospect of live or dead fuels conditions improving through July.
Difference from normal conditions: Fuels are described by fire managers as being deceptively green. The visual greenness being observed can lessen the sense of fire potential. Live fuels, which had shown some improvement from late spring precipitation, are drying. On the Western Slope of Colorado, 100FM fuels are setting historically low values for the date, nearing the 3rd percentile, and moving into the range associated with historic large fires. Long-term drying has made large, higher elevation fuels, available as well.
Concerns to Firefighters and the Public:
- Recent large fires on the Front Range and Western Slope have displayed intense and/or extreme fire behavior.
- Long-range spotting, fire whorls, extreme fireline intensity and high winds have been observed and will continue to be control problems on both wildland and urban interface incidents.
- Local preparedness planning and cooperation should be on-going.
- Management of suppression resources rest and recovery as activity increases.
Mitigation Measures: Strategies for dealing with each of the specific circumstances listed above include using Predictive Service¡¦s forecasts of higher potential for large fire occurrence, rapid initial attack in those high risk areas, and daily fire and fuels briefings to suppression personnel.
Continue reading
Red Flag Warnings, June 21, 2013
Red Flag Warnings and Fire Weather Watches for enhanced wildfire danger have been issued by the National Weather Service for areas in California, Arizona, New Mexico, Utah, and Colorado.
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The Red Flag Warning map above was current as of 9:38 a.m. MDT on Friday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts. For the most current data, visit this NWS site.
Red Flag Warnings, June 20, 2013
Red Flag Warnings and Fire Weather Watches for enhanced wildfire danger have been issued by the National Weather Service for areas in California, Arizona, New Mexico, Utah, Colorado, and Wyoming.
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The Red Flag Warning map above was current as of 9:08 a.m. MDT on Thursday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts. For the most current data, visit this NWS site.
Studying pyrocumulus
You may be familiar with pyrocumulus (pyroCb) clouds that form over intensely burning vegetation fires. They can be a combination of smoke and condensation. Some firefighters call this “ice capping”.
Chuck Bushey, a Fire Behavior Analyst and former President of the International Association of Wildland Fire, is a member of a small group studying pyroCb led by Mike Fromm of the US Naval Observatory.
Chuck sent me a link to an animation of pyroCb forming over the Silver Fire recently in southern New Mexico, and explained:
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“…this is one recent example of the sort of products our small global pryoCb group watch. The group also examines lots of particulate and atmospheric information (some from ground based instrumentation such as Lidar, as well as from other satellite channels) to make sure it’s a real fire event or something else. There are other events that may look similar from orbit and some of the more remote incidents that this group sees we may be the first observers.
We can sometimes track these major upper atmospheric (stratospheric) events multiple times around the globe mixing with other weather systems. The most global round-trips I have observed has been four in the northern hemisphere.
We can only speculate on what the input of the volatile elemental and organic chemicals and other pyrolyized materials (such as soil and ash) are having on the cold, upper atmosphere and our climate. We also guess that these events may be more frequent now and maybe more intense than in the recent past but we really don’t know because no one was watching and our capabilities were limited.”
Huge smoke plume attacks thunderstorm cell
Originally published at 10:09 p.m. MDT, JUne 19, 2013
The photo above got my attention. It was posted on Twitter and Instagram by Chris Bronson, aka @cgb777.
My view from the plane of the Colorado wildfires. #colorado #wildfire http://t.co/yAHwRkZMP4
— Chris Bronson (@cgb777) June 20, 2013
It’s a very impressive smoke plume. Since he said it was in Colorado I guessed that it was the West Fork Complex in south-central Colorado 14 miles north of Pagosa Springs, which was listed on InciWeb (when it was working – don’t get me started) at 8,000+ acres. So I fired up Google Earth and confirmed that the geography matched. Then I visited the NASA site for viewing GOES images and found the series of photos below that show primarily the southeast corner of Colorado, and also portions of NM, OK, TX, and KS.
After this last image at 0200 UTC (8 p.m. MDT) the later images are too dark to see anything.
Chuck Bushey sent me this link to an animated GOES 13 Rapid Scan Operations visible and 3.9 µm shortwave Infrared images for the same two fires and the same period of time. With the IR in the lower frame you can easily tell when the second, more southern, fire gets going.
I thought it was interesting how the smoke plume in the four photographs above moved into space occupied by the large thunderstorm cell and appeared to force it to partially or mostly dissipate. Meteorologists out there can feel free to correct me if I’m wrong, but I’m thinking that there were at least two or three factors that caused it to happen.
- Warmer air in the plume lowered the relative humidity, reducing the condensation which formed the cloud; (I’m not too sure about this one; traveling over 200 miles, the plume probably cooled close to ambient temperature)
- The plume shaded the ground at the base of the thunderstorm cell, turning off its heat engine — less heated air rising = less condensation = less cloud;
- And this one I’m not too sure about either. Particulates in the plume served as condensation nuclei in the cloud. Moisture condensed on the particles, which then fell out as rain, dissipating the cloud.
- Or, heck, since the sun was setting, THAT turned off the heat engine, causing the thunderstorm cell to break up.
- Or all of the above?
It was also interesting how the scattered cumulus clouds on the Colorado/New Mexico state line in the span of 45 minutes formed into a large cumulonimbus cloud, which then seemed to merge or grow into the other one farther north near the smoke plume.
And then to make the photos even more interesting, a new smoke plume popped up in the last two photos between the West Fork Complex and the thunderstorms in the southeast corner of Colorado. As this is written at 10 p.m. Wednesday, this newer plume and fire does not show up on the Rocky Mountain Coordination Center map of current fires.
Another Fuels and Fire Behavior Advisory — this time, Arizona and New Mexico
One of the Predictive Services offices has issued another Fuels and Fire Behavior Advisory. The last one, issued June 10, was for California. This new one, dated June 16, is for portions of Arizona and New Mexico.
The advisory does not mention the “Southwest Monsoon,” an event that typically starts in early July and generally begins to draw the curtain on the fire season in Arizona, New Mexico, West Texas, southern Utah and southwestern Colorado.
Below is the full text of the advisory.
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“Fuels and Fire Behavior Advisory
Arizona and New Mexico
June 16, 2013
Subject: Persistent multi-year drought across much of New Mexico and Arizona has dropped fuel moistures to critically low levels in the large dead and live foliar fuels. These critically low fuel moistures increase available fuel loading which contributes to and supports active crown fire in timber fuels when critical fire weather is present.
Discussion: The multi-year drought has reduced the fine fuel loading across most of the region so the focus for this advisory will be the timber fuels within the region.
Difference from normal conditions: Drought creates more available fuel in timber fuel types which will increase fire intensities, crown fire potential and difficulty of control for fire suppression resources. Short duration rain events provide only short term fuel moisture improvement in timber litter fuels (1, 10, and 100 hour dead fuels). Fuels rebound quickly to previous dryness levels. Short duration rain events provide no fuel moisture recovery in large dead and live foliar fuels.
Concerns to Firefighters and the Public:
- Surface fire will quickly transition to crown fire and only requires low to moderate surface fire intensity to transition.
- Active/running crown fire has produced long range spotting up to one mile under the influence of an unstable atmosphere.
- Active fire behavior can extend well into night and early morning hours even with moderate RH recovery.
- Thunderstorm activity will create a mosaic pattern of surface fuel moistures. Surface fire intensity and fire behavior may change abruptly when fires cross these boundaries of moist and dry surface fuels.
Mitigation Measures:
- Local briefings need to be thorough and highlight specific fire environment conditions. These include but are not limited to local weather forecasts, Pocket Cards, ERC’s, live and dead fuel moistures, and special fuel conditions such as drought and insect mortality
- Lookouts, both on the ground and in the air, can help identify the initiation and location of crown fire. They can also provide the location of resultant spot fires from active crown fire.
- Firefighters should acknowledge that fire growth and fire behavior they encounter this year may exceed anything they have experienced before due to the drought factor. Normal strategies and tactics may need to be adjusted to account for the drought factor.
Area of Concern: Please reference the map posted on the National Fuel Advisory Page.
http://www.predictiveservices.nifc.gov/fuels_fire-danger/fuels_fire-danger.htm
The timber fuels within this area of concern are the target for this fire behavior advisory.”
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Thanks go out to Ken