Wind, Wildflowers and Warmth

During the spring, the eastern slopes of the Cascades offer a wonderful refuge from the clouds and precipitation west of the Cascade crest, and this time of the year there is a special bonus: amazing wildflower displays. But this ideal escape is tempered by one "issue"--at least in some locations: strong winds.

Yesterday, in search of warmth, sun, and wildflowers I headed with some friends to the hills near Vantage, Washington (see map). Vantage is probably the most dependably warm, sunny location within two hours drive of Seattle during the spring.

During this season, winds aloft are often from the west or northwest, with clouds west and over the Cascades. Air descends and warms east of the main Cascade crest and then sinks again as it drops down over the final hills west of Vantage. Descent causes warming and the evaporation of any clouds...and yesterday (Saturday) was a perfect example. To illustrate, here are two satellite images from about 3 PM Saturday, one from the NWS geostationary satellite and the second from the NASA MODIS high-resolution satellite.

Classic spring satellite image. Western Washington engulfed in clouds except for two clear zones downstream of Vancouver Is and the Olympics. But cross the Cascade crest and descend the slopes and the skies opened up. You can see low -evel lee wave clouds just east of the Cascades crest (those north-south linear features) and if you look carefully you will see streams of high level clouds stretching to the SE away from the Cascades....they are associated with high level mountain waves produced by the Cascades.

Driving across the Cascades around 10 AM we hit a wall of clouds, fog, and rain, which began to lessen east of the crest around Easton. By Cle Elum the rain was over and the skies brightened, while by Ellensburg sun was starting to break through. But it was the descent along the terrain down to Vantage that brought what we were looking for: bright sun and temperatures that climbed into the lower to mid 60s.

As we unloaded our mountain bikes at a location a few miles north of Vantage, it became apparent that the sun had some competition for our attention: strong winds. Spring is the windy season east of the Cascade crest, particularly in situation like Saturday's, with cooler air and high pressure west of the Cascades and lower pressure to the east. This pressure difference can produce strong westerly winds particularly downwind of weaknesses or gaps in the Cascades, such as the "Stampede Gap" west of Ellensburg. The UW high-resolution model forecast for 11 AM on Saturday showed such strong winds, particularly over the hills NW of Vantage (see graphic). In fact, the predicted winds were REALLY strong (gusts to 50 knots), but I chose to go anyway....a Northwest version of storm chasing!

As we ascended the rough dirt road, the winds increased, particularly when we were downstream of westward, directed canyons. Biking was difficult at times--our bikes were being pushed over by the winds and sometimes we had to walk. I estimated that we had sustained 30-40 mph, with gusts to 50+ in places. It got pretty wild. Here is a video that gives you a taste of what it was like:

But then there were the wildflowers, which my friend Wendell Brown tells me peak in that area during late April. Fields of white and yellow flowers. And best of all, perhaps, was a flowering cactus (see photo at top of blog).