Guess who's back. Yes, that's right. Your best friend the Upper Level Low is living in our backyard and doesn't want to leave. That's what you get for inviting stray weather systems over for dinner. A quick refresher for the new people: an upper level low is a centralized area of low pressure. We're mostly concerned with ULLs lurking off the Pacific coast. ULLs diminish pressure gradients (because they're low pressure to our west) and send disorganized high clouds over the Gorge. In addition, the ULL turns upper level flow southerly, making Hatchery winds gusty and sending the Wall into gusty madness. We don't like upper level lows unless they are centered over Idaho, giving low pressure to our east.
Point being? Despite dense marine clouds west of the Spring Creek National Fish Hatchery and Lower Columbia Fish Counting Station, winds will only be thermal today. That limits wind development; we really need high pressure over Portland to send wind speeds into the nuclear range. So... With Portland stuck at 70 degrees and The Dalles headed for 85, watch for 15-18 by early afternoon and 22-25 at Doug's/Rowena in the late afternoon. Don't forget to check Mosier, as it's made peace with the ULL. Southerly upper flow tends to favor Mosier and Bingen.
Sunday brings a confusing picture. Clouds pour into Portland overnight, bringing liquid sunshine and weekend woes for the city crowd. Hood River stands guard with a sentence of 40% rain chance hanging over the town. With this setup, we'd normally see nuking winds, but with the ULL pushing inland, pressure gradients get squashed. Cloud penetration does not present a nice picture for the sailboat race from Cascade Locks to Hood River tomorrow. It does present a nice picture for kiteboarding at Roosevelt. Sorry kids, but I can only give you 19-22 tomorrow from Doug's eastward. However, uncertainty rules the models (when will a front arrive and when will the ULL cross the state), so things could change dramatically by tomorrow.
Monday brings another front and the probable eastward movement of the ULL. If the low crosses early, we could see good winds in the evening. If a quick-moving front passes, as expected, we could see sailable winds ahead of it. If, if, if. Monday is more complicated even than Sunday. For now, I'll say glass or east winds in the morning, with clouds, and light west in the afternoon. However, this is subject to change at any time.
Some weather forecast that was.
Okay. I have a couple of houses to do today, so I'll see you guys at Rowena this afternoon. If not, I'll see you on Hospital Hill for a ride later.
PSA: I still have one harness and helmet combo that I picked up at Arlington on Thursday. If it is yours, please claim it so I don't have to live with it in my tiny car. =)
Have an awesome day doing whatever toots your horn!
Print | posted @ Saturday, August 18, 2007 7:42 AM