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NOAA: Storms and Drought: Climate Change Impacts on the West
Presented by Eric Boldt
November 14, 2011 CLIMATE CHANGE IMPACTS ON THE WEST My story You were thinking this? Poll Question
The diverse climate and terrain in the Western U.S. results in annual rainfall of less than 5 inches in the deserts to more than 200 inches per year in the mountains.
√ True or X False? Diverse Climate & Terrain in the West Wettest in the mountains
Driest in the deserts Los Angeles County in Southern CA
Mountains 6000-10000 ft
LA
Coast-Valleys 0-1500 ft Winter Storms floods Western Storm Impacts
Heavy Precipitation
Strong Winds
Small Tornadoes and waterspouts
High Surf and rip currents
Large Waves December 21, 2010 Poll Question
“Atmospheric Rivers” are known as…
a. A little known rock band from the Midwest b. Rivers that flood when it rains c. Plumes of tropical moisture in the atmosphere d. Jet streams Atmospheric Rivers associated with heavy precipitation events
Wetter
Amount of water vapor in the atmosphere to generate precipitation December 17-22, 2010
Atmospheric River brings 15-25 inches of rain to southern CA in 5 days. ARkStorm is a USGS led project to model the impacts of a catastrophic flood event in California.
The term “Atmospheric River” is used to explain the moist conveyor belt associated with Pacific storms. Also known as the “pineapple express.” http://pubs.usgs.gov/of/2010/1312/ NASA/NOAA project to measure Atmospheric Rivers
Aircraft drone
NASA’s Global Hawk launched from Edward’s AFB in February 2011 Flight path of NASA’s Global Hawk for a mission in February 2011
WISPAR – Winter Storms and Pacific Atmospheric Rivers project measured water vapor content from approaching storms during February 2011. Poll Question
What severe weather phenomenon results in the most annual fatalities in the U.S.?
a. Tornadoes b. Lightning c. Flash floods d. Hurricanes Heavy precipitation days have increased (measurable trend) Increase in precipitation intensity is consistent with the observed increases in atmospheric water vapor
Increase in the amount of daily precipitation over North America that falls in heavy events Precipitation intensity is a key component of severe weather.
Flash floods, debris flows, and snowfall intensity can be very destructive and life-threatening. Winter storm tracks are shifting northward and the strongest storms are likely to become stronger and more frequent, with greater wind speeds and more extreme wave heights.
Source – www.globalchange.gov More powerful storms will increase threats to life… …and property Time For Questions
??? Drought heat waves wildfires Poll Question
How important is mountain snowpack for water supply in the Western U.S.?
a. Not that important b. Somewhat important c. Important d. Very important WOW! Nearly 75% of the water supply in the Western U.S. comes from mountain snowpack
65% in California – source Dept. Water Resources Departure from normal snow depth for February 27, 2011
Drought seriously depletes water resources
Lake Oroville, CA – Feb. 2008 Winter Summer Winter January 2011
When the West would normally get precipitation it was abnormally dry.
Annual Precipitation - % Change
Drier
Drier Heat waves impact health mainly due to..... [place clip art on a box below]
High humidity Warm nights Existing health issue Heat Waves • warm overnight temperatures • prolonged temperatures 15-20 degrees above normal • combination heat and humidity makes it feel hotter • poor air quality and smoke compounds health impacts Warm night temperatures will increase
Increase in the percentage of very warm nights over North America ...On average excessive heat claims more lives each year than floods, lightning, tornadoes and hurricanes combined...
Source –NWS Temperature Change Wildfires Are fires becoming more frequent?
Are they more severe? Poll Question
What do you think? Are wildfires more severe than in the past? [place clip art on a box below]
Yes
No
Don’t know More acres burned per fire
National Interagency Fire Center – wildland fire statistics More total acres burned annually
Other factors are involved like disease, forest age, politics, causes, or is it climate change? Time For Questions
??? Monsoon flash floods Most areas of Northwest Mexico and the Southwest U.S. receive over half their annual precipitation from the monsoon
Source – NWS Tucson, AZ Winter Summer Winter Monsoon depends on winds and heat to transport moisture from the Gulf of California Monsoon moisture brings summer thunderstorms to much of the Rockies. Flash floods, and in some cases, wildfires, are caused by these storms. Will climate change impact the monsoon? ...possibly
Average monsoon start dates by decade
1950s July 1 1960s July 2 1970s July 2 1980s July 6 Latest on record (7/25/1987) 1990s July 3 2000s July 7 Earliest on record (6/17/2000) Other Severe Weather
tornadoes hurricanes Poll Question
Do tornadoes occur in California?
a. Yes b. No c. Don’t know Pt. Mugu, CA 2008 Long Beach, CA 2009
Riverside, CA 2008 Sacramento, CA 2005 In southern California – this 1200 sq. mile area has the highest frequency of tornadoes west of the Continental Divide
J. Hales study 1997-1998 El Niño (32 events in 21 days) Tornado history across the United States – since 1950 There is no clear trend in the frequency or strength of tornadoes since the 1950s for the United States as a whole...
...however, the frequency of favorable conditions for severe thunderstorms is likely to increase.
Source – www.globalchange.gov Poll Question
Have tropical cyclones occurred in California?
a. Yes b. No c. Don’t know 1858 Hurricane – San Diego 1939 Tropical Storm – Long Beach
3 other known tropical cyclones have impacted the SW – California, Arizona
Hurricane Linda 1997 Tropical Cyclone Storm Tracks As ocean temperatures rise, the strongest hurricanes are likely to increase in both the eastern Pacific and the Atlantic.
Source – www.globalchange.gov Time For Questions
??? Climate observations resources More than 11,000 volunteers take observations on farms, in urban and suburban areas, National Parks, seashores, and mountaintops.
COOP – Cooperative Observer Program CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation (rain, hail, and snow) in their local communities. NOAA Global Monitoring Exhibit NWS Los Angeles/Oxnard, CA www.weather.gov RECAP
9 Winter storms bring many types of severe weather to the West
9 Drought severely impacts water resources
9 Heat waves and wildfires may get worse
9 The monsoon is critical for desert Southwest precip
9 Tornadoes and hurricanes do occur in California
9 Opportunities for climate observing and NWS resources FOR LISTENING!
Eric Boldt Warning Coordination Meteorologist National Weather Service Los Angeles/Oxnard [email protected] Thank you to the sponsor of tonight's Web Seminar:
This web seminar contains information about programs, products, and services offered by third parties, as well as links to third-party websites. The presence of a listing or such information does not constitute an endorsement by NSTA of a particular company or organization, or its programs, products, or services. http://learningcenter.nsta.org National Science Teachers Association Dr. Francis Q. Eberle, Executive Director Zipporah Miller, Associate Executive Director Conferences and Programs Al Byers, Assistant Executive Director e-Learning
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