Climate Change in W Washington

This is from the National Weather Service

Consider this message as a heads up.....looks like we are going to get a major change in the weather pattern next week.

You are welcome to forward this message to other interested parties.

Impacts of El Nino are starting to take hold in the Pacific Ocean weather pattern. A Madden Julian Oscillation (MJO) has crossed into the western Pacific tropical region and is heading east. For you weather junkies and those who have not attended our fall media/emergency management workshops in the past, much more about the MJO is available from the NOAA/NWS Climate Prediction Center at:

http://www.cpc.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

As the MJO heads east toward central America during the next week or so, the weather pattern across the Pacific and for that matter, the northern hemisphere is forecast to shift dramatically. Bottom line for our area is that a major ridge of high pressure is forecast to set up south of Alaska with lower pressure over the western U.S., pushing the storm track south into California and the inter-mountain region.

So what does that mean? After we get by this weekend with yet another wet and windy storm, the storm track will shift from a general west to east pattern to a north-south orientation in the Mon-Wed time frame and a colder air mass from the interior of western Canada is anticipated to descend into western Washington and much of the western U.S.

The transition from our current pattern to the new weather pattern may involve some lowland snow mid-week. Temperatures will cool into the 20s and 30s in our region by Wed or Thu. In the longer term, this MJO may finally initiate the long-awaited El Nino weather pattern with the storm track predominately across the southern tier of the U.S. Until that occurs full-time, we will have to endure a period of below normal temperatures.

Bottom line - consider this message as a heads up and to watch NWS weather forecasts and any statements closely through next week via our web site at

http://www.weather.gov/seattle/

Another quite interesting feature on our web site is our area forecast discussion issued every 6 hours, where forecasters discuss the upcoming weather pattern and confidence - kind of reading between the lines of the forecast. The area forecast discussion (AFD) can be found at this link:

http://www.wrh.noaa.gov/sew/forecasts.php

The latest 6-10 day outlook is at the following link, demonstrating the confidence in colder than normal temperatures for the Pacific NW. In addition, I added what the upper level weather pattern may look like mid-week next week (flow moving from north to south into the western U.S.) at this link.

http://www.cpc.noaa.gov/products/predictions/610day/610temp.new.gif

http://www.nco.ncep.noaa.gov/pmb/nwprod/
analysis/namer/gfs/12/images/gfs_500_156s.gif