This is the forecast for the foothills of the Northern Blue Mountains of Oregon, including the cities of Athena, Pendleton, and Pilot Rock issued from KPDT at 8:53 AM on May 19, 2017:
Today will be mostly sunny. Highs 71° to 76°. West wind 5 to 10 mph. Tonight will be mostly clear. Lows 48° to 53°. West wind 5 to 10 mph shifting to the south overnight. Tomorrow will be partly cloudy in the morning, then mostly cloudy with a 20 percent chance of showers and thunderstorms in the afternoon. Highs 68° to 73°. South wind 5 to 10 mph shifting to the west in the afternoon.
3 a.m. Area Forecast Discussion:
An offshore ridge will be expanding over the area today and fair and sunny weather is expected. Winds will be generally light though the Columbia Gorge and Kittitas Valley will reach 10 to 25 mph this afternoon. With the ridge bringing higher 500 mb heights to the area, temperatures will be 3 to 5 degrees warmer than yesterday with highs in the lower to mid 70s and in the mid 60s to lower 70s in the mountains. Tonight will be quiet as well though cloud cover will increase overnight in the north as a wave slides over the ridge to the Washington/Canadian border overnight. The cloud cover will help keep the Columbia Basin in the upper 40s to mid 50s while the rest of the area will be in the upper 30s and 40s. The wave will move into our area in the afternoon and will bring moisture and unstable conditions to the eastern half of the area. A chance of showers and a slight chance of thunderstorms will be possible in the eastern Oregon mountains Saturday afternoon. The Blue mountain foothills will have a slight chance of showers and thunderstorms as well. The thunderstorms should not be strong and do not anticipate any severe weather. Rain amounts will be less than a tenth of an inch except under the heaviest showers. Showers will taper off and end in the evening. Temperatures will cool a few degrees on Saturday to the upper 60s to mid 70s with 60s in the mountains.
8:25 a.m. Regional Weather Observations:
Pendleton Airport: Sunny, temperature 54°, dewpoint 45°, relative humidity 71%, south wind 7 mph, air pressure 30.10 inches rising.
Adams: Temperature 55°, dewpoint 49°, relative humidity 80%, calm, air pressure 30.08 inches steady.
Athena: Temperature 578:25 a.m., dewpoint 498:25 a.m., relative humidity 75%, calm, air pressure 30.11 inches steady.
Helix: Temperature 55°, dewpoint 47°, relative humidity 74%, south wind 7 mph, air pressure 30.07 inches rising.
Milton-Freewater: Temperature 58°, dewpoint 47°, relative humidity 67%, calm, air pressure 30.08 inches steady.
Pilot Rock: Temperature 59°, dewpoint 48°, relative humidity 67%, southwest wind 1 mph, air pressure 30.11 inches steady.
Tutuilla: Temperature 55°, dewpoint 49°, relative humidity 80%, calm, air pressure 30.11 inches rising.
Umapine: Temperature 60°, dewpoint 52°, relative humidity 75%, calm, air pressure 30.06 inches rising.
Weston School: Temperature 57°, dewpoint 41°, relative humidity 55%, southwest wind 3 mph, air pressure 30.06 inches steady.