Nation Braces for More Severe Storms

Another Severe Storm on Deck

As much of the United States is still feeling the effects of the severe storms that distressed the country last week, the nation braces for another round of severe weather.  Quick on Winter Storm Jupiter’s coattails is another severe storm, which already has a name.  Winter Storm “Kori” is forecast to hit the west coast by mid-week, establishing yet another atmospheric river over the region. Multiple weather warnings have been issued well ahead of this storm as most of the Pacific Northwest prepares for flooding, ice, freezing rain, and high winds. Parts of the Portland metro area along with the Washington Cascades and the Columbia River Gorge will have the greatest chance for damaging ice accumulations as cold air and precipitation will linger in those areas the longest.

severe storms

Precipitation Forecast for the Next 7 Days.

The storm is expected to persist through the weekend as the front plows eastward. Meanwhile, a concurrent storm will have the Southeast experiencing waves of heavy rain.  Two converging fronts will cause warm, tropical air to be pulled up from the south bringing unseasonably warm temperatures and heavy rainfall over the majority of Appalachia. Severe thunderstorms and tornadoes are possible. It appears 2017 will start off the year with the vengeance that was expected–but didn’t materialize–from last year’s El Nino weather pattern.

Earlier Severe Storms

In previous weeks, western states received much needed rain, helping to alleviate concerns due to record warmth and prolonged drought. Parts of the Sierra Mountain range, under drought since December of 2011, are now buried under as much as 10 feet and have already doubled the average snow-pack for this time of year.  Similarly, the State of Colorado has already received 75% of its annual snow-pack and a staggering 400 avalanches have been recorded to date. Down in Texas, heavy rains drenched the state and at least four tornadoes were spotted late Sunday.

The Midwest, however, seems to have taken the brunt of the recent bad weather.  The ice storm pushed eastward leaving a swath of downed trees, power outages and traffic accidents in its wake. Freezing rain and ice accumulated on trees and powerlines across the heartland, causing them to collapse under the added weight. Multiple Midwest states reported power outages leaving thousands of customers without electricity.  According to the Associated Press, Oklahoma was especially hard hit with “tens of thousands of Oklahoma homes and businesses (reporting a loss of) power during Jupiter.”

severe storms

Over an Inch of Ice Accumulation Causes Widespread Power Outages.

The swift and frigid storm also made for extremely hazardous driving conditions which resulted in several road closures and numerous auto accidents.  Hundreds of injuries and sadly 7 fatalities were caused by the slippery surfaces.

 

Sources:

https://weather.com/forecast/regional/news/winter-storm-kori-snow-ice-atmospheric-river-west-northwest-california-oregon

http://www.wfaa.com/weather/storms-combine-to-create-tornadoes-home-damage-in-dfw-and-beyond/386368403

http://www.aol.com/article/weather/2017/01/16/deadly-ice-storm-spreads-into-midwest-targets-new-england/21655905/

https://weather.com/news/weather/news/winter-storm-jupiter-ice-storm-plains-midwest-latest-news

Winter Storms Continue to Improve Drought Conditions

Drought conditions across California were steadily improving as we closed out 2016. This past week has further weakened the drought’s stranglehold on the state. A series of severe winter storms continue to saturate the state and, as of this week, more than 40% of the state is now considered by officials to be drought free. The severely drought-stricken areas of Southern California have diminished by 41% and the Sierra snowpack is now at 160% of normal levels.

California Drought

Drought Snapshot – Source: Los Angeles Times

Storms Fueling Drought Recovery

Since December 1, the storms have brought snow and heavy rainfall to much of the state. Northern California, especially, has seen precipitation levels that rival some of the wettest years on record.

City Rainfall (in) Since Dec 1 Average Annual Rainfall (in) % of Annual
Fresno 5.14 11.5 44.70%
Monterey 6.84 19.5 35.08%
Redding 10.56 34.61 30.51%
Sacramento 10.82 18.51 58.45%
San Francisco 7.81 23.64 33.04%
Santa Rosa 18.29 36.28 50.41%
South Lake Tahoe 14.88 52.45 28.37%

 

According to UC Davis water expert Jay Lund, “In terms of surface water, most of California is no longer in drought”.  Many of the state’s reservoirs are nearing capacity and now at or above historic averages.  Lake Shasta, the state’s largest reservoir, has swelled to over 80% capacity and the Bureau of Reclamation opened Shasta Dam for the first time in over 6 years. Managers at many of the state’s other reservoirs are following suit, releasing water in order to make room for future storm and mountain run-off.

Aquifers Have Not Recovered

While the state’s many reservoirs are recovering well, the groundwater aquifers could take decades to recover. Central California’s many farms have relied on groundwater to continue irrigating their farms for much of the five year drought. The result has been a depleting water table, up to fifty feet below historic levels in some areas.  For many farmers, this caused a financial burden of digging a deeper well, or many risked the well drying up entirely.

Groundwater depletion has been an ongoing problem in California’s Central Valley, even in years of normal rainfall. The extended drought has exacerbated the problem, and while these recent winter storms will help to replenish some of the groundwater resources, the water table will likely never return to historic levels.

Sources

http://www.latimes.com/local/lanow/la-me-drought-monitor-20170112-story.html

http://www.krcrtv.com/news/local/shasta/water-released-from-shasta-spillway-for-first-time-in-6-yrs/265266996

https://weather.com/news/weather/news/atmospheric-river-california-impacts

http://www.latimes.com/local/california/la-me-storms-drought-20170111-story.html

Atmospheric River Brings Heavy Snow and Rain to California

California started 2017 off with an extremely active weather pattern. Since January 3rd, an “atmospheric river” has brought heavy rain and snow to much of the state. Ski areas within the Sierra Nevada mountain range are reporting close to record snow totals (Mammoth Mountain 101″ of snowfall, Heavenly 114″ and Squaw Valley 94″).

The lower elevations are receiving significant rainfall as well, causing some rivers to overflow.  Area lakes are nearing capacity, prompting officials to expel extra water in preparation for runoff from higher elevations. Though Southern California has not received as much rainfall as the Northern portions of the state, they continue to see rainfall totals in the .5″ to 1.0″ range per storm. Winter storms have now accounted for 5 deaths in Northern California. The forecast calls for January 10th and 11th to be the heaviest snow and rainfall period of the recent storms.

atmospheric river

An atmospheric river is a narrow corridor or filament of concentrated moisture in the atmosphere.

Far-reaching Effects

Since January 1st, officials in Lake Tahoe are reporting a rise in water level of roughly 1 foot, which is equal to about 33.6 billion gallons of water. Down in the Sacramento Valley, the state Water Resources Division had to open the gates of a 100-year-old levee in order to alleviate rising water levels. This was no small task, as each of the dam’s 48 doors had to be opened up manually.

Officials are expecting numerous avalanches in prone areas due to new snowfall on an already heavy snowpack. Avalanche warnings currently extend from as far north as Mt. Shasta to as far south as Mt. Whitney.  Mammoth Mountain Ski area had to stop operations over the weekend due to blizzard conditions and thunderstorms over the ski resort which could have put patrons at risk.

What is and Atmospheric River?

Sounding like something out of a science fiction novel about time travel, an atmospheric river is a narrow corridor or filament of concentrated moisture in the atmosphere.  When these “rivers in the sky” make landfall, they often release this water vapor in the form of heavy rain or snow.  The most common of such meteorological phenomena is a Pineapple Express, the name given to the warm water vapor plumes that originate over Hawaii and follow the jet stream northeast toward California. Many of California’s major flooding events have historically been a product of an atmospheric river.

Sources:

 

2016 Fire Season in Review

Fire Season in 2016 saw no shortage of headline-filling wildfires across the US and North America.  However, 2016’s final numbers for both total starts and total acres burned actually came in below averages from the last ten years in both categories.  Data reported by the National Interagency Fire Center (NIFC) for the 2016 calendar year showed 62,864 fire starts, accumulating 5,415,121 acres (down 4.5 million acres from the year before). 

In a recent blog post, we highlighted the top ten wildfires in terms of destruction. Those ten fires alone burned over 1.7 million acres and destroyed over 6,000 structures, displacing tens of thousands of people.

2016 Wildfires in the US

Major Fires from Fire Season 2016 reported by GEOMAC and NIFC

A Look Back at 2016 Fire Danger

The record-setting year in 2015 (in terms of acreage burned) was due mostly to several large fires in Alaska which accounted for over 5 million of the 10 million total acres burned. This year, Alaska was much quieter and the rest of the country burned more or less an average amount. Like most years, 2016 saw high fire danger transition across the country (see animation below), coinciding with regional climate and conditions. High fire danger started in the Midwest in March and April, crept into the Southwest in May and June, moved into the Mountainous West by July, before finishing with the Southern Appalachians towards the end of the year.

2016 Fire Season Highlights

2016 saw the largest fire in Canadian history, the Fort McMurray Fire in May, which scorched over 1.4 million acres in Alberta. It also saw the costliest fire in California history with the Soberanes Fire which lasted 12 weeks and cost in excess of 250 million dollars to fight before being completely smothered.  Yellowstone National Park in Wyoming had its most active fire year since 1988 with 62,000 acres burned and two significant fires that closed down parts of the park. Lastly, the Southern Appalachians saw a significant period of drought through October and November, bringing the devastating Chimney Tops 2 fire and the worst overall fire season on record to that region.

 

Sources: NIFC, GEOMAC, Predictive Services

Fire Causes Evacuations in Valparaíso, Chile

Valparaíso Fire

On the afternoon of January 2nd, around 400 people were forced to evacuate Valparaíso, a coastal port city in central Chile, due to a forest fire that entered a hillside neighborhood. Local officials believe the fire began at a fisherman’s club and then traveled into the residential area.  As of Tuesday morning, January 3rd, around 100 homes were estimated destroyed with another 500 still at risk, as smoke continues to climb into the skies above the town.

Thus far, no deaths have been reported and the 19 minor injuries are thought to be mostly due to smoke inhalation. News footage shows harrowing video of citizens carrying a variety of items out of their homes, hoping some will be salvageable, including mattresses, entertainment centers, and appliances.

Valparaíso fire burns hillside of homes

Hillside of homes burned Monday, January 2nd, 2017.

Active History of Wildfires

This area of Chile is no stranger to the threat of wildfire. It regularly has an active fire season beginning in November, peaking in January or February, and then decreasing around April. Typically, nearly all wildfires in this region are caused by humans, as lightning and other traditional natural causes are not prevalent in the area.

Chile has also received significantly less rainfall in the last year due to the transition from El Niño to La Niña. The current drought (referred to as megasequía, or ‘mega-drought’) is the longest and most extensive drought in Chilean history, now spanning the past 6 years. The arid weather further dries out the fuels, making any wildland fire a potentially fast-growing danger to surrounding towns.

The 2014 Great Fire of Valparaíso

April of 2014 saw one of the more notable fires in the area’s history.  What is now commonly known as the “Great Fire of Valparaíso” burned across an unofficial landfill area into surrounding vegetation and residential areas.  Over 3 square miles (nearly 2,000 acres) burned, destroying more than 2,500 homes and leaving an estimated 11,000 people displaced.  An additional 6,000 people were forced to evacuate.  Fifteen people were killed and ten reported serious injuries.  The cause of the fire remains under investigation.

Hillside view of the Great Fire of Valparaíso, April 12th, 2014.

Hillside view of the Great Fire of Valparaíso, April 12th, 2014.

To read further details on the active wildfire history of Chile, please visit the sources below.

Sources:

California in Severe Drought!… Or is it?

It’s no secret that California has been in a major drought for the last five years.  This has resulted in larger and more aggressive wildfires during that time, keeping firefighters busy and resulting in increased levels of acreage burned.  However, the California drought conditions are actually better than some experts predicted, and metrics other than rain and snowfall levels may indicate impending recovery.

California drought 2015 vs 2016

2015 vs 2016 conditions, Source: U.S. Drought Monitor

Complex Water Resources

Most of California has a naturally dry climate, and it relies on a complex system of aqueducts, aquifers, and reservoirs to transport and store water resources. As such, the state of the drought from a human-use perspective can be gauged by how full the reservoirs are compared to historical averages.

California drought measured by Reservoir Levels

California Reservoir Levels, Source: California Department of Water Resources

As the map depicts, many California reservoirs are at or near historical average levels. Also, these levels do not yet take into account the snowpack melts during the spring season, which should increase the reservoir levels even further. While California is far from having a comfortable amount of water to survive future potential droughts, this wet season should provide at least a temporary reprieve from the drought conditions and restrictions.

La Niña Less Severe than Anticipated

The El Niño event in 2015 which was expected to be one of the strongest on record resulted in little rainfall to ease the dry conditions. An El Niño event is marked by warmer-than-usual waters in the mid-latitudes of the Pacific Ocean, and often leads to excess rainfall across the West Coast. El Niño events are often followed by La Niña events, which are very dry and lead to drought. Fortunately, 2016 is proving to be much wetter than a typical La Niña event and is even producing moisture that is helping to mitigate drought conditions rather than worsen them.

Why the California Drought Matters

The ongoing California drought has caused major ecological damage, led to severe water use restrictions, and contributed to major fire seasons. While this may seem like an issue specific only to Californians, the drought has ripple effects on the entire country.

California produces a majority of the fresh produce consumed nationwide. Seventy percent of total fruit and tree nut production and 55 percent of vegetables come from the state. Agriculture consumes 80 percent of California’s water resources on an average year, and a lack of water has led to lower crop yields and higher-priced produce nationwide.

Sources:

California’s Drought Could Upend America’s Entire Food System

California Sees Largest Drought-Free Patch Since 2013

California Drought Farm and Food Impacts

 

Sage Fire in Ventura County Determined to Be Human Caused

Sage Fire near Simi Valley

Around 2:30 pm on Tuesday, December 20th, a brush fire broke out on a neighborhood hillside in Simi Valley, California, near Los Angeles. The Sage Fire threatened homes just south of the Ronald Reagan Presidential Library, off Wood Ranch Parkway and Long Canyon Road. Several roads were closed, and the children in the nearby Wood Ranch Elementary’s after school program were bussed to another school.

Sage Fire burn scar from December 20, 2016.

Sage Fire burn scar from December 20, 2016.

Helicopters made several water drops to assist ground crews with structure protection and ground efforts toward containment. Within a couple of hours, the crews had stopped the fire’s forward progress at 61 acres, and by Wednesday the 21st, the fire was 100% contained. No structure damage or injuries were reported and the road closures had been lifted.

Investigation complete

Depending on the complexity and location of the fire, investigations into the cause can often take significant time.  The cause of the Sage Fire however was quickly determined, mainly due to an eye witness account.  Soon after the fire broke out, a nearby homeowner saw two workmen attempting to put it out, smothering it with dirt and trying to create a fire break. This witness’ statement coupled with observed fire behavior and a known starting location assisted investigators in reaching a conclusion quickly–that the fire was accidentally started by sparks from these workmen repairing a metal fence.

Rain in the forecast

The upcoming weather forecast for the days following the fire indicate high chances of rain for multiple days.  As such, several crews continued monitoring the burn area and surrounding neighborhood for the potential for mudslides and debris flows.  These crews also worked with city officials to ensure that nearby storm drains remained clear. Ventura County fire stations handed out free sandbags to homeowners to protect against potential slides, and the County made sandbags available for pickup by homeowners at a location near the burn area.

 

Ten Most Destructive Wildfires of 2016

Wildfire Season in 2016 was below average in terms of acreage with almost 62,000 fire ignitions totaling 5.3million acres (down from a record 10 million acres burned last year). But this year was especially destructive in terms of structure loss. The ten worst fires destroyed over 6,000 structures alone.

Unfortunately, every year a significant amount of such damage is due to human-caused fires which often spread quickly to structures along the wildland urban interface.  This year as many as 1 in 5 fires were intentionally set.  The deadliest fire of 2016, Chimney Tops 2, was started in Tennessee by two teenage boys and was ultimately responsible for 14 fatalities and at least 160 injuries.

Canada also saw its worst disaster on record with May’s Fort McMurray Fire, which cost 3.58 billion (Canadian dollars) and burned 1.46 million acres in Alberta.  The cause of the fire is still unknown, but lightning has been ruled out as the source of ignition, and human activity is strongly suspected.

destructive wildfires

Ten Most Destructive Wildfires of 2016

For further details on the 10 most destructive wildfires of 2016, see the ESRI Story Map embedded below (best viewed in Chrome or Internet Explorer):

Wildfire 101: Dead Fuel Moisture

What is Dead Fuel Moisture?

A recent lack of significant rainfall has kept Southern California in extreme drought, which means there is increased potential for significant wildfire due to dangerous levels of dead fuel moisture. As explained by NOAA, fuel moisture is a measure of the amount of water in a potential fuel, and is expressed as a percentage of the dry weight of that fuel.  So if leaves and downed trees were completely dry in a given area, the fuel moisture level would be 0%.

When fuel moisture content is high, fires do not ignite readily, or at all, because most of the fire’s heat energy is used up trying to evaporate and drive water from the plant in order for it to burn. When the fuel moisture content is low (like in drought-stricken Southern California), fires start more easily and can spread rapidly as all of the heat energy goes directly into the burning flame itself. When drought is extreme and the fuel moisture content is less than 30%, that fuel is considered to be dead, giving us the “dead fuel moisture” designation.

The United States Forest Service which manages a nationwide fuel moisture index, classifies fuel moisture based on two metrics:  fuel size and time lag.

  • Fuel size refers to the actual physical dimensions of the fuel (i.e. the diameter of downed logs or branches).
  • A fuel’s time lag classification is proportional to its diameter and is loosely defined as the time it would take for 2/3 of the dead fuel to respond to atmospheric moisture.  For example, if a fuel had a “1-hour” time lag, one could expect its wildfire susceptibility to change after only 1 hour of humid weather.  Fuels with 100- or 1000-hour time lags would be expected to be much less resistant to humidity.

Fuel moisture is dependent upon both environmental conditions (such as weather, local topography, and length of day) and vegetation characteristics.  The smallest fuels most often take the least time to respond to atmospheric moisture, whereas larger fuels lose or gain moisture slowly over time.

The classifications of the Forest Services’s index (also known as NFDRS) are as follows:

Dead Fuel Moisture

The Dead Fuel Moisture Time Lag Classes as defined by the United States Forest Service

Drought Conditions Improving in California

According to the weather almanac, San Diego–home to RedZone’s intelligence team–had received a minuscule .7 inches of rain since June 1st.  Luckily, a significant rain event entered the southern California region on Thursday evening, adding wetness to the low fuel moisture readings around the region.

Since late Thursday night (12/15), significant rains have finally fallen across the area. The gusty winds and showers are expected to begin tapering off late Friday as the moisture exits to the east, but a long-awaited significant wetting event has been left behind. Early reports on Friday (12/16) have measured up to 3.3 inches in the East County Mountains and greater than 1 inch along the San Diego Coast, far exceeding the cumulative totals since June.

As we discussed a few weeks ago, the drought situation in Northern California had already improved earlier this year, and now the dry weather in Southern California appears to be coming to an end.


Source(s):

http://patch.com/california/ranchobernardo-4sranch/storm-moves-through-san-diego-region

https://www.ncdc.noaa.gov/monitoring-references/dyk/deadfuelmoisture

http://www.nwcg.gov/glossary/a-z

http://www.wfas.net/index.php/dead-fuel-moisture-moisture–drought-38