Weather Blog

Newest summer outlook for Portland: Hot and dry

Newest summer outlook for Portland: Hot and dry
Sun rises by Mt. Hood over downtown Portland. (Photo courtesy YouNews contributor: BigMike58)

We've been celebrating this week the jump in our mountain snowpack after a fairly wet February -- now up to 58-73 percent across the northern Oregon Cascades-- but new forecast data out by long range climate computer models suggests the rally in snowpack may be even more important than you might think.

Fresh data released a few days ago is now suggesting there are significantly higher chances of a warmer and drier than normal spring and summer across the West, including the Pacific Northwest.

The warmer than normal forecast begins with the April-May-June 90 day forecast and continues through its August-September-October forecast, with a significant signal coming in for the July-August-September period being warmer than normal.

And in what would be a significant change from past years, models suggest the April-May-June and May-June-July periods will be drier than normal. (See photo gallery to step through the forecasted maps.)

To localize this for the Portland area, NOAA recently has been translating these maps into exact percentages for individual cities. Here is the temperature anomaly for Portland:

90 day period: % Chance above normal % Chance Normal % Chance Below Normal
Mar-Apr-May 2014 40% 33% 27%
Apr-May-Jun 2014 49% 31% 20%
May-Jun-Jul 2014 50% 31% 19%
Jun-Jul-Aug 2014 53% 29% 18%
Jul-Aug-Sep 2014 54% 30% 16%
Aug-Sep-Oct 2014 41% 34% 25%
Sep-Oct-Nov 2014 35% 33% 32%
Oct-Nov-Dec 2014 34% 34% 32%

The forecasters cite a blend of climate models for the increasing confidence in a toasty West, plus a 50/50 shot that current neutral conditions may trend into warming El Nino conditions by summertime. If that were to hold into autumn and winter, that would not bode well for winter fans next year. Then again, a big bad feared El Nino last winter didn't pan out.

Suffice to say, if the forecasts are correct, it would mean a greater reliance on water for irrigation and, sadly, likely wildfire fighting so that fresh batch of snow the past few weeks up in our mountains should help combat those challenges.