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Great earthquake rocks Chile; NYC gets 4th greatest snow ever; Xynthia batters Europe

By: Dr. Jeff Masters, 5:26 PM GMT on February 27, 2010

A great earthquake with magnitude 8.8 rocked the coast of Chile at 6:34 GMT this morning, generating a potentially dangerous tsunami that is racing across the Pacific Ocean. The great quake is the 7th most powerful tremor in world history (Figure 1). Preliminary tsunami wave heights for the California coast near Santa Barbara are 2 - 2.5 feet. The wave is expected to arrive between 12:15 - 12:35 pm PST. The tsunami is expected to arrive in Hawaii between 11:05 - 11:42am HST, with a wave 8.2 feet high expected in Hilo, on the Big Island. A tsunami from the 9.5 Magnitude 1960 earthquake in Chile killed 61 people in Hilo. Today's quake was so strong, that it triggered a seiche in Lake Pontchartrain, Louisiana, over 4,500 miles (7,000 km) away. The lake sloshed back and forth, creating a wave 0.4 - 0.51 feet on either side of the lake.

Figure 1. Wikipedia's list of strongest earthquakes of all-time.

Preliminary tsunami amplitude forecasts:

La Jolla, CA 2.3 ft
Los Angeles, CA 2.0 ft
Malibu, CA 2.6 ft
Pt. San Luis, CA 2.3 ft
Half Moon Bay, CA 2.6 ft
Crescent City, CA 1.7 ft
Morro Bay, CA 2.2 ft
Santa Monica, CA 3.3 ft
San Francisco, CA 0.7 ft
Pismo Beach, CA 4.6 ft

Hilo, HI 8.2 feet 11:5am HST
Honolulu, HI 1.6 ft 11:37am HST
Kahului, HI 7.2 ft 11:26am HST
Nawiliwili, HI 3.0 ft 11:42am HST
Haleiwa 1.6 ft
Kawaihae 2.0 ft

Port Orford, OR 0.7 ft

Moclip, WA 1.3 ft

Seward, AK 1.3 ft
Stika, AK 1.3 ft
Kodiak, AK 2.3 ft

Tofino, British Columbia 1.7 ft

Today's great quake occurred at the boundary between the Nazca and South American plates about 325 km southwest of the capital Santiago (population 5.3 million). The depth was estimated at 35 km. At least four aftershocks of magnitude 6 or higher have occurred, the largest being a 6.9 aftershock. Fortunately, the area close to the epicenter is relatively sparsely populated, but there may be heavy damage in Concepción (est. pop. 300,000) and Chillan (est. pop. 170,000), which lie 115 km and 100 km to the south of the epicenter, respectively.

Figure 2. NOAA's preliminary forecast of tsunami wave energy for today's earthquake. Image credit: NOAA Tsunami Warning Center.

New York City slammed with its 4th largest snowstorm on record
The snow from the fourth extreme snowstorm to wallop the Northeast U.S. this winter dumped a remarkable 20.9" of snow on New York City's Central Park yesterday and Thursday. This is the 4th largest snowstorm for the city in recorded history. According to the National Weather Service, the top ten snowstorms on record for New York City's Central Park are:

26.9" Feb 11-12, 2006
26.4" Dec 26-27, 1947
21.0" Mar 12-14, 1888
20.9" Feb 25-26, 2010
20.2" Jan 7-8, 1996
19.8" Feb 16-17, 2003
18.1" Mar 7-8, 1941
17.7" Feb 5-7, 1978
17.6" Feb 11-12, 1983
17.5" Feb 4-7, 1920

The storm also helped New York City set a new all-time snowfall record for the most snow ever recorded in a month--36.9". The old record was 30.5", set in March 1896. However, the old Lower Manhattan WB Station recorded 37.9" in February 1894. Yesterday's snowstorm puts New York City's snow for the 2009 - 2010 season at 51.4", making it the 11th snowiest winter since 1869. Chris Burt, author of Extreme Weather, lists the city's all-time seasonal snowfall record at 81.5", set in the winter of 1867 - 1868. This measurement came before official records began in Central Park, and were done be the NY Park Commissioners (see "Annual Report NY Park Commissioners", 1868, by John B. Marie). The second snowiest winter in NYC occurred during the winter of 1995 - 1996, when 75.6" fell.

Destructive Winter Storm Xynthia battering Portugal and Spain
A powerful 969 mb low pressure system named "Xynthia" is rapidly intensifying of the coast of Spain, and stands poised to deliver a devastating blow to Portugal, Spain, and France today and tomorrow as it powers through Europe. Sustained winds of 60 mph (96 km/hr) were reported today at a Personal Weather Station in Costa del Morte, Spain. The pressure fell to 969 mb as Xynthia passed overhead. For comparison, Winter Storm Klaus had a minimum pressure of 967 mb. Klaus, which hit northern Spain and southwest France January 23 - 25, was Earth's most costly natural disaster of 2009, causing $5.1 billion in damage and killing 26. Models predict that Xynthia will continue to intensify today, reaching 962 mb as it moves into the west coast of France Sunday morning. Sustained winds of 50 - 65 mph (80 - 105 km/hr) with hurricane-force gusts up to 100 mph (160 km/hr) are possible along the north coast of Spain tonight and the west coast of France on Sunday as Xynthia barrels through. The storm is also bringing an exceptionally moist plume of tropical moisture ashore, as seen in precipitable water imagery from NOAA (Figure 4). This moisture is likely to cause moderate to severe flooding in portions of Europe over the weekend.

Figure 3. Visible satellite image at 12 GMT of Xynthia.

Figure 4. Satellite measurements show a region of extremely high atmospheric moisture is associated with Winter Storm Xynthia. This moisture will surge over Portugal and Spain today, potentially creating serious flooding. Image credit: Sheldon Kusselson, NOAA/NESDIS.

Links to follow:
Wundermap for Northwest Spain
Spanish radar
Portugese radar

Jeff Masters
Central Park 26Feb10
Central Park 26Feb10
the BIG one Taken in Manhattan
Tree 1, House 0
Tree 1, House 0
This cottage was no match for 65 mph wind and an old pine tree.

Winter Weather

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.