Weather Discussion January 4. Year in Review SEATAC HAD THE WARMEST AVERAGE January TEMPERATURE EVER WITH 47.0 DEGREES BREAKING THE PREVIOUS RECORD.

Weather DiscussionJanuary 4

Year in Review

• SEATAC HAD THE WARMEST AVERAGE January TEMPERATURE EVER WITH 47.0 DEGREES BREAKING THE PREVIOUS RECORD IN 2006 OF 46.6 DEGREES. OLYMPIA HAD THE SECOND WARMEST JANUARY EVER AT 43.7 DEGREES AND QUILLAYUTE NEAR FORKS ALSO HAD THE SECOND WARMEST JANUARY EVER AT 46.3 DEGREES.

Year in Review

• SPRING...COOL AND WET. AVERAGE WESTERN WASHINGTON TEMPERATURES IN MAY AND JUNE RANGED BETWEEN 1 AND 3 DEGREES BELOW NORMAL WHILE PRECIPITATION WAS ONE TO 2.5 INCHES ABOVE AVERAGE. SEATAC AIRPORT DID NOT REACH 75 DEGREES OR GREATER UNTIL JUNE 23RD...THE LATEST EVER.

Year in Review

• TWO HEAT SUMMER WAVES WITH HIGH TEMPERATURES IN THE 90S...ONE IN JULY AND THE OTHER IN AUGUST. SEATAC AIRPORT

AVERAGES ONLY THREE DAYS PER YEAR OF 90 DEGREES OR ABOVE - 2010 HAD SIX DAYS IN THE 90S AND 21 DAYS OF 80 OR BETTER WITH AN AVERAGE OF 25 DAYS PER YEAR.

• SEATAC AIRPORT HAD ITS THIRD WETTEST SEPTEMBER EVER WITH 4.80 INCHES - JUST OVER THREE INCHES ABOVE NORMAL.

• In NOVEMBER SEATAC AIRPORT HIT 74 DEGREES ON THE 3RD AND THEN ON THE 24TH PLUNGED TO 14 - A 60 DEGREE RANGE IN ONE MONTH - THE GREATEST EVER ON RECORD

Last Five Days: Low Dewpoints and Lots of Frost

Dewpoint

Recent Evolution of Equatorial Pacific SST Departures (oC)

Longitude

Time

Niño Region SST Departures (oC) Recent Evolution

The latest weekly SST departures are:

Niño 4 -1.5ºC

Niño 3.4 -1.5ºC

Niño 3 -1.5ºC

Niño 1+2 -0.6ºC

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

During the last 4-weeks, SSTs were at least 1.0°C below average between 160°E and the South American coast, with departures more than 2.0°C below average in some areas.

Pacific Niño 3.4 SST Outlook

Figure provided by the International Research Institute (IRI) for Climate and Society (updated 14 December 2010).

• Nearly all models indicate that La Niña (Niño-3.4 SST anomalies -0.5°C or less) will peak during the Northern Hemisphere Winter 2010-11. • La Niña is expected to last at least into the Northern Hemisphere spring 2011.

The seasonal outlooks combine the effects of long-term trends, soil moisture, and, when appropriate, the ENSO cycle.

Temperature Precipitation

U. S. Seasonal OutlooksJanuary - March 2011

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

30-day (ending 1 Jan 2011) temperature departures (degree C)

90-day (ending 2 Jan 2011) % of average precipitation

90-day (ending 1 Jan 2011) temperature departures (degree C)

Last 30 Days

Last 90 Days

30-day (ending 2 Jan 2011) % of average precipitation