When it comes to precipitation along the West Coast, there are always winners and losers.
Sometimes the jet stream, the conduit of storm systems, heads north into Washington and BC, and we are wet, while California is dry.
At other times, the jet stream heads southward to California, and they get the precipitation, and we are dry.
On relatively rare occasions, a huge ridge of high pressure covers the entire West Coast, so everyone is dry.
Over the past 60 days, we have generally had a pattern of dry north and wet south (see below).
This pattern has been particularly apparent over the past week, with central California getting hit particularly hard.
Thus, California has enjoyed the precipitation it needs to sustain agriculture and its large population... a very good thing. For example, all of California's reservoirs are all running above normal (see below), and the state's overall snowpack has increased substantially during the past month.
Why this recent precipitation distribution with wet California and a dry Northwest?
Mainly, because we have recently seen a repeated pattern of a deep upper-level trough extending southward down the Coast, as shown by the upper-level flow pattern below (for Tuesday morning).
I should note that there is no reason to suggest that such patterns have anything to do with global warming. The research is clear on this. It is natural variability.
It is also clear that we expect the jet stream to move northward during late winter, and the atmospheric "fire hose" will return to our area.
What about the next few weeks?
The forecast precipitation total through next Wednesday, which I have some confidence in, shows moderately wet conditions from central CA to British Columbia, with the heaviest precipitation over southern Oregon.
Ensemble (many forecasts) from the US systems suggests around 30 inches of snowfall at Stampede Pass in the WA Cascades over the next week:
Beyond that period, forecast skill declines, but the major forecasting systems bring heavy precipitation into our region, so that the totals through early March get impressive over WA and BC (see below).
That also means a lot of snow in our mountains.
It's colder than a witch's tittie out
ReplyDeleteAs a long time resident (over 60 years) and skier, recent weather seems reminiscent of much of what I've experienced - frustrating ski seasons with little snow accumulation and super long seasons with snow accumulation and a season ending in May. The NOAA funded (partially) drought monitor is a particularly frustrating piece of political nonsense that puts itself out there as "science". Politics should have no part in science; but seems to insert its nose into as many areas of our life as it possibly can whether invited or not. I expect politics when I read the Seattle Times; but for something partially funded by NOAA; I expect more honesty.
ReplyDeleteIt's not uncommon for Mach to get more precipitation than February as the jet stream moves back north.
ReplyDeleteIt should be clear by now that we have a lot less snow than we usually have this time of year. This is despite early season predictions to the contrary. Now it looks like the "Cold, Wet, and Snowy Period" predicted on February 13th won't be that cold and snowy. It will help -- a little -- but it just isn't enough. As someone who really enjoys the snow (in the mountains) I now know what if must have felt like to be a Patriot fan at the Super Bowl. You keep looking up at the score board thinking there is still time. Maybe next drive. Or the drive after. Eventually you get some points, but by then the game is over. Unless we have a really unusual late Winter and Spring (and there is no reason to believe we will) the snow lovers will have lost. Big time.
ReplyDeleteOh well. There is always next year.
Not sure we should put much faith in the long range forecast for plentiful snow in the Cascades in the near future. The European snow forecast issued about February 7 predicted 35 to 50 inches near the Cascade crest by February 22. There was only about 10 inches in the passes during this period. The snowpack has been especially scant at the low and mid elevations, with several Snotel sites reporting near record low amounts for this time of the year. It is getting pretty late in the season to expect these lower elevation sites to build a decent snowpack.
ReplyDeleteIts currently pooring rain with thunder along the Grays Harbor coast. There has been more dry time this winter, but we're making up for some of that now.
ReplyDeleteI know! I was shooting on Ruby Beach the previous day when a front came through, covered the beach in hail and dumped solid sheets of rain for at least an hour. Makes for some amazing photos! But I swear, "Idiocracy" is looking more like a documentary with each passing day: Several groups on the beach looked at me like I was wrong in the head when I showed up dressed for bad weather, and then they just looked confused and miserable trudging back to their cars in a hailstorm.
DeleteWeather changes frequently, the SF Bay Area must have been a lot wetter in the past with giant Redwood trees: Henry Cowell Redwoods State Park with giants over 50 feet around.
ReplyDeleteNot saying you're wrong about that (I don't know one way or the other), but the redwoods on the Central Coast get a lot of their water from fog and mist condensing on the needles and then falling to the ground. It's a big reason why those trees thrive in climate where there's often little or no measurable rainfall from June to October, but the Central Coast is often locked into low stratus and fog for days at a time.
ReplyDelete(See "June Gloom" and "Fogust"; also see the thousands of tourists we must have watched when we lived in SF, turning blue and looking thoroughly befuddled Sn their flip-flops and Fisherman's Wharf tshirts when that surge of stratus poured through the Golden Gate every afternoon and dumped the wind chill into the 40s in the space of 10 or 15 miinutes. Only the most perceptive noticed that the locals were all carrying fleece and hats on even the warmest of mornings :-)