Contact: Stephanie Kenitzer FOR IMMEDIATE RELEASE
(301) 713-0622 2/10/95
The extreme warmth over eastern North America and the heavy precipitation in California are linked to an overall atmospheric pattern that typically accompanies El Nino, a disruptive ocean current, according to a report released today by the National Weather Service's Climate Analysis Center in Camp Springs, Md.
El Nino conditions are characterized by the warming of sea surface temperatures in the Pacific Ocean and changes in weather patterns in many locations around the world.
"A southward shift of the jet stream off the California coast along with a strong northward shift of the jet stream over eastern North America is a common feature of the December/January circulation during El Nino," said David Rodenhuis, director of the Climate Analysis Center. "It was these extreme jet stream conditions that were primarily responsible for the unusual temperature and rainfall we experienced from mid-December 1994 through January 1995."
More than 250 record high temperatures were established across the northern and eastern sections of the United States during the November 1994-January 1995 time period. Statewide- average temperatures for the three-month period were the highest on record in New Hampshire and Vermont. Furthermore, this was one of the five warmest three-month periods since 1895 in 14 other states including Maryland, New Jersey, New York, Pennsylvania, Rhode Island, Connecticut, Ohio, Massachusetts, Michigan, Wisconsin, Kentucky, Minnesota, Virginia and West Virginia.
In addition to the extremely warm conditions, the eastern United States did not receive much snow in the months of November, December and January. By late January, much of the Northeast had recorded snowfall deficits exceeding 12 inches, while some regions of central New York and southwestern New England recorded 2.5 to 4 feet less than normal, according to the NWS Northeast Regional Climate Center, Cornell University, Ithaca, New York.
While it was warm in the Northeast, much of California observed record or near-record precipitation in January. The heaviest precipitation in California fell on Jan. 8-10, 1995, when new all-time 24-hour rainfall records were established at Sacramento (4.47 inches) and Santa Barbara (7.45 inches). Overall, January was the wettest month on record at the Los Angeles International Airport (12.74 inches).
Much of the observed temperature and rainfall departures were associated with a extremely-pronounced jet stream pattern across the country. The abnormal northward shifts in the jet stream over eastern North America and the southward migration of the jet stream near the West Coast signify a negative phase of the Tropical/Northern Hemisphere (TNH) pattern, common during El Nino events. The TNH pattern reached record strength in December and was even stronger in January, contributing to the extreme warmth to the eastern half of the United States and the severe rainfall in California.
The ENSO Winter Impact report is available through the Internet on the Climate Analysis Center's World Wide Web Home Page, http://nic.fb4.noaa.gov. It is also available over National Weather Service media including Automation of Field Operations Services (AFOS) and Family of Services.
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Editor's Note: For a hard copy of the report, contact the NWS Public Affairs office at (301) 713-0622 or Rich Tinker at the Climate Analysis Center at (301) 763-4670.