Mallow Posted November 12, 2014 Share Posted November 12, 2014 Because it hasn't been made yet, and because we have interesting weather to deal with. A very cold airmass has invaded east of the Cascades. There's one near-sea-level gap in the Cascades, at the Columbia River Gorge. Currently the east winds are blowing hard through the Columbia River Gorge into the Portland metropolitan area. A storm moving in from the southwest will throw moisture over this airmass tonight and tomorrow morning. Many models suggest 850mb temperatures will be +1 to +2 for the bulk of the precip, and some of the models suggest surface temperatures will warm from near freezing at the start to the mid to upper 30s by the end of the precipitation. Not all models suggest this, and for good reason. Especially the high-resolution models hint that the air coming out of the Gorge will be cold enough and deep enough to keep the precipitation frozen, largely in the form of snow. This is a borderline situation (they usually are for Portland), but right now, I'm leaning towards mostly or all snow for the Portland metro area, especially Multnomah County (Washington and northern Clackamas Counties may turn over to rain, southern Clackamas County will most certainly, but they're not really part of the metro area). If it's all snow, Portland could expect 2 to 5 inches. Given that up until this morning, the NWS was calling for POSSIBLY up to a half an inch (they have actually changed that to 1.5-2.5 inches, so they're catching on faster than the models), and that most local news outlets are still going for no accumulations, that could be a pretty big 24-hour "bust". Link to comment Share on other sites More sharing options...
Coach McGuirk Posted November 12, 2014 Share Posted November 12, 2014 NWS is saying 3-7 inches of snow/ice for Portland. Link to comment Share on other sites More sharing options...
Mallow Posted November 13, 2014 Author Share Posted November 13, 2014 NWS is saying 3-7 inches of snow/ice for Portland. Yep. It could happen, but they're probably going overboard. Link to comment Share on other sites More sharing options...
Chinook Posted November 13, 2014 Share Posted November 13, 2014 freezing rain/ sleet with nearly gale force wind gusts at Portland Conditions at: KPDX observed 13 November 2014 16:24 UTC Temperature: 34°F Dewpoint: 24°F Winds: from the E (90 degrees) at 26 MPH (23 knots) gusting to 38 MPH (33 knots) Visibility: 10 or more miles (16+ km) Present Weather: -FZRA PL (light freezing rain, ice pellets) Link to comment Share on other sites More sharing options...
Mallow Posted November 13, 2014 Author Share Posted November 13, 2014 Yep. Some snow has been mixing in from time to time, but it's looking like this is more of a zr storm. They're currently in a radar hole, but it looks like more precip is moving in from the west. Link to comment Share on other sites More sharing options...
snownut Posted November 13, 2014 Share Posted November 13, 2014 first snow in town here in Bend. 6-1/2" of fluffy powder so far. ( My first winter living here ) Link to comment Share on other sites More sharing options...
Mallow Posted November 14, 2014 Author Share Posted November 14, 2014 first snow in town here in Bend. 6-1/2" of fluffy powder so far. ( My first winter living here ) Nice! Link to comment Share on other sites More sharing options...
Coach McGuirk Posted November 14, 2014 Share Posted November 14, 2014 So Portland got .1in zr and .1in ip? Sucks. Link to comment Share on other sites More sharing options...
snownut Posted November 15, 2014 Share Posted November 15, 2014 So Portland got .1in zr and .1in ip? Sucks. Big snows all over central OR. 11" total here at my home in Bend but much more in areas around me. I just moved here in July from VA. It was so frustrating hearing locals and the local KTVZ weather "forecasters" keep talking about all the freezing rain here. It sleeted here in Bend most of Thursday night, there was little or no freezing rain. Hate it when TV weather people do not even know basic weather. Link to comment Share on other sites More sharing options...
Mallow Posted November 16, 2014 Author Share Posted November 16, 2014 So Portland got .1in zr and .1in ip? Sucks. Yep. A lot less moisture made it up to KPDX than forecast. Areas not far to the south got a lot more zr, but nobody in the Willamette Valley really got much snow. Link to comment Share on other sites More sharing options...
Mallow Posted November 16, 2014 Author Share Posted November 16, 2014 Big snows all over central OR. 11" total here at my home in Bend but much more in areas around me. I just moved here in July from VA. It was so frustrating hearing locals and the local KTVZ weather "forecasters" keep talking about all the freezing rain here. It sleeted here in Bend most of Thursday night, there was little or no freezing rain. Hate it when TV weather people do not even know basic weather. It's possible it was freezing rain in other parts of town, but ya, it's also possible they just don't know the difference. Link to comment Share on other sites More sharing options...
Chinook Posted November 28, 2014 Share Posted November 28, 2014 This is a 7.5 day storm total from Seattle ATX radar, showing 12-18" of rain (or perhaps snow) east of Everett. 18" is higher than the annual precipitation in my backyard!! Link to comment Share on other sites More sharing options...
andyhb Posted November 29, 2014 Share Posted November 29, 2014 First snowfall of the season up here tonight. Link to comment Share on other sites More sharing options...
Chinook Posted December 8, 2014 Share Posted December 8, 2014 There are 966mb and 962mb lows in the northeast Pacific, as analyzed by the GFS this afternoon. Look at these huge arms of clouds connected to the swirls, with lots of details in the cloud features. The SLP values are around 2-3 standard deviations below normal, at about 45N/150W (the location of the 966mb low) Link to comment Share on other sites More sharing options...
Mallow Posted December 9, 2014 Author Share Posted December 9, 2014 The models are spinning up a small, potent surface low rotating around that larger trough on Thursday. There's quite a bit of variability on the strength of the storm as it moves northward along the Oregon coast, but it's looking quite possible that the Willamette Valley, including Portland, could be in for a brief, major wind storm on Thursday. The GFS has consistently shown a sub-980mb low riding up the coast with very tight gradients extending into the Willamette Valley, funneling wind northward down the valley. The latest 4km WRF run with GFS boundary conditions produces sustained winds over 50kts and gusts over 70kts in the Valley. If this were to happen, it would rival some of the other great wind storms in the region, perhaps even approaching (but almost definitely not actually reaching or exceeding) the intensity of the infamous Columbus Day Storm of October 1962. Link to comment Share on other sites More sharing options...
andyhb Posted December 10, 2014 Share Posted December 10, 2014 The models are spinning up a small, potent surface low rotating around that larger trough on Thursday. There's quite a bit of variability on the strength of the storm as it moves northward along the Oregon coast, but it's looking quite possible that the Willamette Valley, including Portland, could be in for a brief, major wind storm on Thursday. The GFS has consistently shown a sub-980mb low riding up the coast with very tight gradients extending into the Willamette Valley, funneling wind northward down the valley. The latest 4km WRF run with GFS boundary conditions produces sustained winds over 50kts and gusts over 70kts in the Valley. If this were to happen, it would rival some of the other great wind storms in the region, perhaps even approaching (but almost definitely not actually reaching or exceeding) the intensity of the infamous Columbus Day Storm of October 1962. Looks somewhat reminiscent of the South Valley Surprise on Feb 7th, 2002 in terms of how tightly wound it is, although this system appears stronger and is on a different track. The intense winds with that were entirely driven by the gradient given that the system overall was not excessively deep. That said, it experienced a very rapid cyclogenesis/pressure falls/rises. These tight, small cyclones have produced, as you say, some of the more impressive wind events in the region. Wouldn't be surprised to see some damaging winds further north into WA/perhaps SW BC given the progged track (especially if it moves a bit further west). Link to comment Share on other sites More sharing options...
1900hurricane Posted December 10, 2014 Share Posted December 10, 2014 Here come the impulse that might spin up the tight little surface low. Link to comment Share on other sites More sharing options...
Mallow Posted December 10, 2014 Author Share Posted December 10, 2014 Here come the impulse that might spin up the tight little surface low. Yep! In fact, I think you can see the 500mb vort max associated with it as that feature due west of San Francisco. Link to comment Share on other sites More sharing options...
1900hurricane Posted December 10, 2014 Share Posted December 10, 2014 This thing looks like it's about ready to go boom. http://rammb.cira.colostate.edu/wmovl/vrl/tutorials/satmanu-eumetsat/SatManu/CMs/RaCy/backgr.htm Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
andyhb Posted December 10, 2014 Share Posted December 10, 2014 This thing looks like it's about ready to go boom. http://rammb.cira.colostate.edu/wmovl/vrl/tutorials/satmanu-eumetsat/SatManu/CMs/RaCy/backgr.htm That is nasty looking. This probably will be the most significant wind storm in several years up here. Wouldn't be too surprised if it ends up deeper than forecast given the intensity of the divergence aloft in the left exit region of that jet. Given the rather small size of the system, that could translate to some rather extreme cyclogenesis/frontogenesis. Haven't seen one on this track in awhile. CIPS analogs have both November 1981 and December 1995 among them for 12z. Link to comment Share on other sites More sharing options...
Mallow Posted December 10, 2014 Author Share Posted December 10, 2014 That is nasty looking. This probably will be the most significant wind storm in several years up here. Wouldn't be too surprised if it ends up deeper than forecast given the intensity of the divergence aloft in the left exit region of that jet. Given the rather small size of the system, that could translate to some rather extreme cyclogenesis/frontogenesis. Haven't seen one on this track in awhile. CIPS analogs have both November 1981 and December 1995 among them for 12z. Link to comment Share on other sites More sharing options...
andyhb Posted December 10, 2014 Share Posted December 10, 2014 The November 1981 double windstorms are the #2 and #3 analogs on that set (although one of them is Nov 17th at 06z which falls a bit outside the timeframe of the storms). Link to comment Share on other sites More sharing options...
ice1972 Posted December 10, 2014 Share Posted December 10, 2014 Bay Area school districts are canceling schools tomorrow....this is a relatively new policy as I do not recall "rain days" growing up in the East Bay.....1972 to 2004.....never ever did this happen....is this one forecast to be especially bad? High wind? Anyway I wish I was home to witness....CA has great weather but can rock in the winter sometimes.....1997 for instance....epic.... Link to comment Share on other sites More sharing options...
Mallow Posted December 11, 2014 Author Share Posted December 11, 2014 Bay Area school districts are canceling schools tomorrow....this is a relatively new policy as I do not recall "rain days" growing up in the East Bay.....1972 to 2004.....never ever did this happen....is this one forecast to be especially bad? High wind? Anyway I wish I was home to witness....CA has great weather but can rock in the winter sometimes.....1997 for instance....epic.... Probably the high wind. Link to comment Share on other sites More sharing options...
ice1972 Posted December 11, 2014 Share Posted December 11, 2014 Probably the high wind. Still I don't recall ever canceling classes for weather in the Bay Area.....1981, 1997 for instance.....sure there's a few other bad ones... Link to comment Share on other sites More sharing options...
andyhb Posted December 11, 2014 Share Posted December 11, 2014 Had lightning and thunder up here the past few minutes, might be the first time I've ever seen it in December up here. Link to comment Share on other sites More sharing options...
andyhb Posted December 11, 2014 Share Posted December 11, 2014 00z Euro has it at 976.7 mb SW of Astoria (mouth of the Columbia River for those unfamiliar) by 00z Friday. 60-80 kt winds at H85 on the east side of it. I kinda figured some of the models might be occluding it too quickly. Link to comment Share on other sites More sharing options...
Mallow Posted December 11, 2014 Author Share Posted December 11, 2014 Looks like it's probably going to be stronger, but further west, than modeled... which is common with these things. That probably means the inland locations like Portland and Seattle will have more of a "once every few winters" type windstorm rather than a "once every few decades" one. Gusts of 45-60 or so. Link to comment Share on other sites More sharing options...
ice1972 Posted December 11, 2014 Share Posted December 11, 2014 Tracking Bay Area impact from SNE......looks like a doozy.....>100,000 without power......flash flood warnings most Bay Area counties......Embarcadero shut down from AT&T Park north to Pier 39 due to sea water overtopping sea wall.....and found this lol pic on twitter....looks like it could be somewhere in Oakland before you get on the Bay Bridge.... Link to comment Share on other sites More sharing options...
andyhb Posted December 11, 2014 Share Posted December 11, 2014 Looks like it's probably going to be stronger, but further west, than modeled... which is common with these things. That probably means the inland locations like Portland and Seattle will have more of a "once every few winters" type windstorm rather than a "once every few decades" one. Gusts of 45-60 or so. Agreed with this. Traditionally, these years that have had a number of storms already (as we have) tend to lead up to something bigger. It's been over seven years since the Great Gale of 2007, and nearly eight years since the Hanukkah Eve Storm of 2006 and it seems like we're overdue for another major one. Link to comment Share on other sites More sharing options...
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