Warmth obliterates records in Washington state; Unsettled pattern in the West through early next week
March 20, 2019; 6:46 AM
What a turnaround it has been in the Pacific Northwest. After a cold and snowy February/early March, temperatures surged again in many areas on Tuesday, especially west of the Cascades, where a strong easterly wind developed.
When air flows down from a higher elevation to a lower elevation (this is called downsloping), it dries out and warms. It also takes any marine influence out of play, so when there is a strong wind blowing down the mountains like yesterday, it can really magnify the warmth in areas downwind.
Seattle reached a stunning high of 79 degrees on Tuesday, which absolutely obliterated the daily record, which was 63.
*Warmest March Day on Record*
Observed temperature of 79° in Seattle makes today the warmest March day on record since 1894 (includes both Sea-Tac and Federal Building data). Previous record was 78° on March 29, 2004. #WAwx
— NWS Seattle (@NWSSeattle) March 19, 2019
Also, in Washington, Olympia (78) and Bellingham (74) also broke their daily records by more than 10 degrees Fahrenheit.
Perhaps the biggest anomaly was Quillayute on the Olympic Peninsula, where the high temperature reached 81 degrees, breaking the old daily record by 15 degrees. Places like Forks and Quillayute, where it typically only hits 80 a handful of times a year, really had that downsloping at work, as the gusty wind out of the east and southeast was coming down off the Olympics.
Farther south across Oregon, it was a warm day in Portland, but not quite a record breaker. Highs did get to record levels in Eugene and Salem.
With low pressure to the south, Wednesday will be another very warm day across Washington and northern Oregon as that offshore flow persists. By Thursday and beyond though, as the flow gradually turns more onshore, temperatures will come down.
This storm will bring some rain and mountain snow to the northern half of California on Wednesday before shifting into Nevada and the Four Corners region Wednesday night into Thursday.
With the cold air aloft, some of this precipitation will be convective, which will lead to the potential for heavy downpours, thunder and even small hail in some spots.
After a brief break, a weak storm heading into British Columbia will drag a cold front through the West on Friday night, bringing some showers and some mountain snow. This will be a pretty fast mover and won't produce too much in the way of rain or snow.
Another storm looks to move northward off the Northwest coast by early next week. Depending on the exact track and strength of the system, that could be a more significant round of rain and mountain snow, especially across Northern California.
Both the GFS and European models show a more potent storm system sitting off the West Coast early next week, which would likely bring a few rounds of rain into Oregon and Northern California.
We'll take a closer look at that system over the weekend.
The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com