2009 2009 Winter in review: Winter in review:

El Nino, US drought and global El Nino, US drought and global

HazardsHazards

April 2010April 2010

University of CaliforniaUniversity of California

Santa BarbaraSanta Barbara

Acknowledgements: most graphics from Climate Prediction Center

(CPC/NCEP/NOAA)

OUTLINE

ENSO evolution and current conditions

Winter precipitation and US Drought conditions

Global Hazards during winter 2009

Summary

• El Niño is present across the equatorial Pacific Ocean.

• Sea surface temperatures (SST) are more than 1.0ºC above-average across much of the central and eastern equatorial Pacific.

• Based on current observations and dynamical model forecasts, El Niño is expected to continue at least through the Northern Hemisphere spring 2010.

Recent Evolution of Equatorial Pacific SST Departures (oC)

Longitude

Time

Since the beginning of June 2009, SST anomalies have been at least +0.5°C across most of the equatorial Pacific.

During December 2009, positive SST anomalies increased across much of the equatorial Pacific.

From late December 2009 to mid-February 2010, positive SST anomalies decreased across portions of the central and east-central Pacific.

Recently, positive SST anomalies have decreased over the central Pacific.

Niño Region SST Departures (oC) Recent Evolution

The latest weekly SST departures are:

Niño 4 1.0ºC

Niño 3.4 1.1ºC

Niño 3 0.7ºC

Niño 1+2 0.1ºC

SST Departures (oC) in the Tropical Pacific During the Last 4 Weeks

During the last 4-weeks, equatorial SSTs were more than 1.0°C above average between 165°E and 120°W and near the western S. American coast.

Global SST Departures (oC)

During the last four weeks, equatorial SSTs were above-average across the Pacific, Indian, and Atlantic Oceans.

Weekly SST Departures (oC) for the Last Four Weeks

• During the last four weeks, positive SST anomalies have persisted across the central, east-central, and far eastern Pacific.

• During the last 30 days, equatorial SST anomalies are nearly unchanged across much of the Pacific.

• Since mid-February 2010, the positive subsurface temperature anomalies increased in association with the downwelling phase of an oceanic Kelvin wave

• Recently, the Kelvin wave has increased temperatures in the east-central equatorial Pacific Ocean.

Sub-Surface Temperature Departures (oC) in the Equatorial Pacific

Most recent pentad analysisLongitude

Time

U.S. Temperature and Precipitation Departures During the Last 30 and 90 Days

30-day (ending 27 Mar 2010) temperature departures (degree C)

90-day (ending 28 Mar 2010) % of average precipitation

90-day (ending 27 Mar 2010) temperature departures (degree C)

Last 30 Days

Last 90 Days

30-day (ending 28 Mar 2010) % of average precipitation

US Drought Conditions

Current US Drought Conditions

NCEP CPC Temperature

& Precipitation

Outlooks

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Global Weather Hazards – December 2009

Devastating drought was the most costly weather disaster in the U.S in 2009, causing nearly $4 billion in crop losses

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Two significant rainfall events on December 4th and 9th caused widespread

flooding and induced mudslides in southern Brazil

•26 people dead • On the night of December 8th, the Sao Paulo city received half of its total average December precipitation (7.5” = 19 cm). •Along the southern border with Uruguay and Argentina, in the Rio Grande do Sul state, rivers swelled to 10 meters (33 feet) above normal levels and 18,000 people were forced from their homes. A state of emergency was declared in over 130 towns and cities in the area.

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18-20 December

•Over two feet (61 cm) of snow accumulation in North Carolina, Virginia, West Virginia, Maryland, New Jersey, and New York. •heaviest snow event to ever affect Washington, D.C. in December; 16 inches (41 cm) of accumulation•6th greatest snow storm in D.C. history. •23.2 inches (59 cm) of accumulation in Philadelphia; 2nd highest snowfall ever for a single event.

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Global Weather Hazards – January 2010

Floods and over 80 different mudslides on January 1st and 2nd in southeast Brazil killed at least 76 people in the Sao Paulo, Rio De Janeiro, and Minas Gerais states. Over 200 houses at Angra dos Reis were deemed uninhabitable by local authorities, leaving 125 homeless and leading to the evacuation of another 238. The direct losses were estimated to be up to 145 million U.S. dollars

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•Series of intense extratropical cyclones affected the west coast and southwest region of the United States 17-23 January Rainfall amounts over 12 inches (30 cm) and snow accumulations over four feet (122 cm)

•Severe thunderstorms; seven tornadoes being reported in California

•The third and last storm of the series broke numerous records across the West, including all-time record low pressures over roughly 10–15 percent of the United States

•Record low pressures: LA (983.3 mb), San Diego (987.0 mb), Salt Lake City (979.9 mb), Las Vegas (983.0 mb), and Phoenix (983.0 mb)

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Ventura Tornado InformationAt approximately 12:20pm on Thursday, January 21st, a small EF-0 tornado touched down on the east side of Ventura. The damage path was approximately 1.5 miles in length, and 200 feet wide at times.Damage consisted of:•Large trees blown over or snapped above the ground•Asphalt shingles blown off roofs•Dented garage doors•One car tipped on its side against a tree•Damaged crop shelters•One metal roof lifted off a small outbuilding

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Global Weather Hazards – February 2010

5-6 February 'Snowmageddon' •Snow storm dumped more than 16”•Colesville Maryland—suburb of Washington D.C.—received the most snowfall, with 40 inches (102 cm)•Preliminary all-time records reported: state record of 26.5 inches (65.3 cm) in Wilmington, Delaware•Washington Dulles Airport received 32.4 inches (82.3 cm), its largest two-day snowfall total on record

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State of the ClimateGlobal Hazards

National Oceanic and Atmospheric AdministrationNational Climatic Data Center