Weather Blog

Long range forecasts suggest more of the same through August

By Published: Jul 20, 2012 at 6:00 AM PDT
Long range forecasts suggest more of the same through August
Image Courtesy: Puget Sound Clean Air Agency Visibility Camera

I'm starting to wonder if Mother Nature is relaxing on a beach somewhere (obviously not a Washington beach) and just phoning it in. Because the long range forecasts are starting to have a certain sameness to them.

First, the new 6-10 and 8-14 day forecasts show continued expectations of cooler than normal conditions:



But what about August? NOAA just put out the fresh monthly update of its 30-day forecast Thursday and the forecast for August sure looks an awful lot like July's, which looked an awful lot like June's.



The gist: Much hotter than normal conditions are expected to persist across about 80 percent of the U.S., with one notable exception -- the extreme left corner of the Pacific Northwest, which remains painted in the refreshing blue hues signifying expected cooler than normal conditions.

There are multiple reasons for the "stuck" forecast. For the nation east of the Northwest, they are trapped in a dangerous Catch-22. It has been so hot and dry there not only this summer but last summer that they are now in the midst of a historical drought. Wet soils help to absorb some of the sun's energy and heat by triggering evaporation, but with the ground bone dry, it actually allows surface temperatures to be hotter -- as evidenced by multiple, oppressive heat waves back there. And of course, hot and dry weather continues to extract what little moisture is left, furthering the engine.

For us though, the main driving force has been much cooler than normal water temperatures in our neck of the Pacific Ocean -- partially La Nina driven -- and also a consistent pattern of "upwelling" that cools temperatures even more. (Check out Cliff Mass' excellent explanation of upwelling in his blog.)

To top it off, the ridge of high pressure over the Midwest has been so intense, it's essentially a road block to a progressive weather pattern. (Also not helping, another very stubborn ridge out in the Pacific). Put the two together, and our area remains in a general "trough by default", as Steve Pool likes to put it.

The trough has mainly been aligned to affect southern Alaska with the Pacific Northwest just on the edge -- note that Eastern Washington and Oregon, as well as California and the Desert Southwest have had no issues with lack of summer heat. For us, it's been a choice between either our natural marine air conditioning days (which, don't get me wrong, are about the most pleasant days you can have) or dealing with upper level lows that cause cooling and thunderstorms. Our heat-bringing thermal troughs have yet to be heard from -- a good thing for many.

So overall, I'd say expect a lot of 70s again in August, with perhaps a few 80s snuck in there for good measure. (Cheers? Or groans?)

A big change coming this winter

However, those persistent blues over the Northwest make a significant change to the opposite end of the field by winter time. Here is the 90 day forecast for January through March:



If you were to look up "El Nino" in the dictionary, this is the photo you would see -- obviously NOAA is trending their forecasts now toward an expected El Nino event.

This is the classic pattern that shows above normal temperatures and below normal rainfall across the Northwest (across the entire northern tier, actually) with a very wet winter forecast for California, Texas and the South. That's because El Nino years typically focus the jet stream across I-40 instead of I-90.

So if you're up for a quiet winter and figure skiing is not your thing, odds are in your favor.