Not much rain out of last night’s system. Here are the rain totals since midnight; but you have to add .05 to .11″ to these to get the “big storm total
High pressure settles in east of the Cascades for our first strong east wind we’ve seen in many weeks. WRF-GFS and our RPM show 3-5 millibars easterly gradient Saturday, then a big ramp up Saturday night through Monday morning with 8-10 mb gradient. What does that mean? The larger the pressure difference between The Dalles and Troutdale or Portland (east of Cascades to west side), the stronger the wind blows through the exit region of the Columbia River Gorge. That’s the western half of the Gorge. This means Sunday is the day if you are starved for weather action and want to get blown around out at Vista House. I also replace the anemometer out at Corbett a couple of weeks ago too so now it’ll be working.
The east wind dies off quickly later Monday and Tuesday as we get into a split-flow pattern most of next week. That means weather systems will be coming at us from the west, but they will be weak and not contain all that much moisture for valley rain or mountain snow. That said, it’ll still be the wettest pattern we’ve seen in a solid 3-4 weeks…it’s been dry! I could see a total of 8-12″ in the Cascades above 4,000′ one week from today. That’ll help out the higher resorts and higher parts of the lower resorts, but at best we’ll see 8-12″ on the ground at Government Camp next Friday evening. We’ll take whatever we can get this winter!
Beyond that, models all push strong upper-level ridging back up over us about 10 days from now. The sequence of a brief wet period and then strong ridging coming back the first half of January has been well forecast for several days in the long-range models. Most striking is the 15 day ensemble forecast from the GEM, GFS, and ECMWF valid Saturday the 18th. They all look almost the same for the same date! All were initialized at 12z today.
This all says to me that we’ll see some much-needed snow in the Cascades over the next week, but for the next two weeks (or beyond) we don’t see a sudden change to a snowy and rainy pattern. No hint that we’ll be seeing things going back to normal in the next two weeks. But like I said…we’ll take whatever we can get this winter…baby steps…
Chief Meteorologist Mark Nelsen