Weather Blog

Long range forecasts maintain generally warm pattern through February

Long range forecasts maintain generally warm pattern through February
Sen sets over Seattle on July 17, 2014. (Photo courtesy: Bruce Hogarth)

For much of late winter and spring, the message has been the same by NOAA's Climate Prediction Center: Expect a warmer than normal summer.

So far, July is delivering, with several days of 80s and 90s around the Pacific Northwest, and even a few triple digit days east of the Cascades. Seattle is just one spot in the region, but it's a whopping 3.0 degrees above normal so far and through Sunday, is tied for the third-hottest July on record at Sea-Tac Airport (Average temperpature (high+low/2) so far: 68.6° -- record is 69.5° in 2009; 2nd is 68.8°.)

And the forecast for this week brings a return of more warm-to-hot weather to finish off the month and potentially cement the month as 2nd warmest on record.

So what about August? Those same long-range forecasts suggest more of the same. And September. And October. And November. And...see a theme developing?

The forecasters who create these long-range models are still basing the short term summer/early fall warmth on a number of extended forecast models that concur with the heat.

As for late fall and winter, the orange/brown warm/dry blobs are based on the idea that a weak-to-borderline-moderate El Nino will develop this fall. The latest indications there are for a bit more uncertainty now about the El Nino's strength than in recent months, but trends are still pointing toward weak-to-moderate event.

The forecasters warm there is still a chance the event could end up stronger than predicted -- or revert back to neutral conditions like we saw in our last El Nino event, but say highest likelihood is still the weak to borderline-moderate scenario. They did say the slimmer chances of the strong event are even a little slimmer now than they have been.

El Nino's tend to make for dry and warm autumns...and especially winters around the Pacific Northwest, and that's where the forecast maps are leaning. Here it is in table format, and you can see the best odds for warm weather come in the mid-late winter months:

90 day period: % Chance above normal % Chance Normal % Chance Below Normal
Aug-Sep-Oct 2014 39 32 29
Sep-Oct-Nov 2014 39 34 27
Oct-Nov-Dec 2014 35 35 30
Nov-Dec-Jan 2014-15 37 32 29
Dec-Jan-Feb 2014-15 40 34 27
Jan-Feb-Mar 2015 44 35 23
Feb-Mar-Apr 2015 47 34 22
Mar-Apr-May 2015 34 33 32
Apr-May-June 2015 32 33 34
May-June-Jul 2015 31 31 34
June-Jul-Aug 2015 33 34 33

The models show El Nino should weaken and fizzle out by spring and thus no real signal is signified yet for next spring and beyond yet.

Remember these forecasts represent weighted odds for being cooler/warmer-drier/wetter than normal. Sort of how you can give higher odds the Mariners will win a baseball game if Felix Hernandez is pitching, but -gasp!- the Mariners do occasionally lose one. So put another way, let's just say El Nino is like having Felix on the mound for a warmer/drier winter!