Tuesday, January 11, 2011

10:30 PM Nowcast

Based on the reports you have provided, right now there is roughly 1-2 inches over much of the area, with substantially more over Kitsap and SE of the Olympics and less near the Cascade foothills. As shown by the radar, precipitation is still occurring over much of the region:
Well I hate to be a party pooper, but the warming is occurring aloft and the snow is fated to turn to rain. Here is the latest vertical sounding (10 PM) of temperature at Seattle. The temperature structure aloft is shown every hour (1206 is ten pm, time is in GMT)
The temperature has warmed up considerably above 800 meters (around 2500 ft). You notice that the temperature is nearly constant in the lowest portion of the atmosphere..that is not a coincidence...it is very close to 32F all the way down since the precipitation is melting as it falls.

Here are the winds in the lowest 400o meters of the atmosphere from ten pm yesterday to 10 PM today. Strong southwesterly flow is found aloft (50 kts!) and the SW flow is moving down. SW flow is warm and moist.


You get the picture...this pretty snow is not going to last...it will turn to wet snow and then rain over the next 2-6 hours over most of the lowlands, depending where you are.

The other interesting story are the winds. There is a huge pressure difference the Cascades and some locations on the east side of the Sound and in the foothills are getting 40-50 mph gusts--like North Bend, Snoqualmie Ridge, and some locations near Enumclaw.

69 comments:

  1. Close to 3.5 inches on Silverdale Ridge! Coming down hard! I think we'll get close to 5! One more NOWCAST! Woo Hoo!

    ReplyDelete
  2. I so appreciate your attention to the weather! Thanks for all that you do.

    ReplyDelete
  3. 2.1 " of snow here in Normandy park 128', 2 Miles SW of SEATAC.

    Temp 30.5
    DP 27.4
    Wind gusting 15-20mph out of the ENE

    Seems like a little more than I expected here. There is a police cruiser in the ditch on hwy509

    Some Ice pellets have mixed in, or as most know them: sleet.

    ReplyDelete
  4. Poulsbo, still snowing steady at 9:48pm. Total since 7:30 pm 2 1/2 inch.
    Temp 31.5 F
    Baro 29.89 falling
    Wind SSE 2mph gusts to 6mph
    Altitude: 270 feet

    ReplyDelete
  5. Sequim. Wind blowing 25-30 mph with gusts to 40. Temp at 34 with only a scattering of driven flakes and graupel. 9:55PM

    ReplyDelete
  6. Still snowing hard in North Tacoma. Three days of this would have been amazing! Hard to believe this will be a rainy mess by 6am, what a waste!

    ReplyDelete
  7. Snow has turned over to rain north of Hoquiam. 34.5 degees. Almost 2 inches on the ground.

    ReplyDelete
  8. This comment has been removed by the author.

    ReplyDelete
  9. Port Angeles right now -- snowed steadily from about 7pm till maybe 10:50. Now it's more like graupel at 10pm. About two inches on the ground; wish we'd get more!

    ReplyDelete
  10. I don't know the most accurate way to measure precipitation of the frozen variety (do I just stick a ruler through the snow built up on my deck?) but it appears to be about 2-3" of accumulation here in the Phinney Greenwood area at the top of the ridge. Wondering if my kids' school will be cancelled in the morning or if the temps will warm and wash it all away.

    ReplyDelete
  11. Still strong NE winds at Hoquiam (at 10pm)...which means snow for awhile more, I guess.

    ReplyDelete
  12. close to 3 inch in NE Seattle Wedgwood.
    Temp.: 32

    ReplyDelete
  13. Drove 15th Ave. NE between Shorline and Seattle at 9:00. About 1.5"-2" of accumulation. Between 175th and 125th saw three plows, one Shoreline plow coming off a minor arterial to hit 15th, WSDOT plowing 145th, and a SDOT plow on 15th. I suppose I should go walk the dogs and enjoy the snow while it is still here.

    ReplyDelete
  14. More than 2.5 inches and still falling at 10:05 in NW Olympia - just 1/2 mile from the Sound.

    ReplyDelete
  15. 2 inches in North Ballard. Nice steady snow.

    ReplyDelete
  16. South Tacoma - we have about 1.5 to 2 inches of accumulation and it is snowing again.

    ReplyDelete
  17. 3.25 inches right at sea level on the water in Shelton and still with moderate snow.
    Temp: 31.6
    D.P. 29
    Light NNE wind 4mph

    ReplyDelete
  18. 3.5 inches in Mill Creek, still 29 degrees, and still snowing heavily. If it snows 2-6 more hours at this rate, we'll end up with quite a bit.

    ReplyDelete
  19. 10:40pm Woodinville, 4 inches of snow and still coming down lightly.

    ReplyDelete
  20. Just went to the 8:00 showing of True Grit here in Bellingham. no snow when we went in, came oot to 4".

    Had to leave the car at the bottom of the south hill and walk up. Should have taken the 4x4 truck. Live and learn........

    Still snowing hard.

    ReplyDelete
  21. Duvall, 420' 3.5" and still snowing. May end up with 4-5"

    ReplyDelete
  22. Just went to the 8:00 showing of True Grit here in Bellingham. No snow when I went in, 4" when we came out.

    Had to leave the car at the bottom of the south hill and walk up.

    Should have taken the 4x4 truck.

    Live and learn.....

    Still snowing hard.

    ReplyDelete
  23. About 3" here in Kingston and still snowing.

    ReplyDelete
  24. Guessing 5 inches in Bellingham, including the snow from last week. Winds picking up and temps around 30 degrees.

    Looking very pretty outside, but I guess it won't be here in the morning - shame.

    ReplyDelete
  25. It's 2245 in Lower Queen Anne, calm and steady snow fall of small light flakes. My deck rail has almost 1" (not quite) of accumalation.
    It still seems cold out but could hear something dripping off the roof.
    It would be nice to see the pretty snow in the morning but I won't count on it.

    ReplyDelete
  26. 3 miles NNE of Monroe @ 380' - Snow falling moderately, wind blowing from east. During the bigger gusts it starts looking like a white out. Near as I can tell there's about 1.5" of snow. Temp got as low as 29 but is now 30. Hope I wake up in the morning to lots of snow on the ground, but I recognize that's highly unlikely.

    Thanks for the blog... you do a great job!

    ReplyDelete
  27. 3.25 inches in 3 hours at the heart of Bainbridge Island as of 10:51 with temperature holding steady at 32.7F.

    Small flakes and due to the glightly > freezing temp it's perfect snowball snow :)

    ReplyDelete
  28. 3 miles NNE of Monroe @ 380' - Snow falling moderately, wind blowing from east. During the bigger gusts it starts looking like a white out. Near as I can tell there's about 1.5" of snow. Temp got as low as 29 but is now 30. Hope I wake up in the morning to lots of snow on the ground, but I recognize that's highly unlikely.

    Thanks for the blog... you do a great job!

    ReplyDelete
  29. East Magnolia. Snow started at 8 PM and is now pretty much rain. 2" on cartop. 32 degrees, 70% humidity. Made a 5' snowman. Vive le nowcast!

    ReplyDelete
  30. About 2 to 2.5 inches of snow up the hill from Fremont in Seattle. still snowing steadily at 11:05pm.

    ReplyDelete
  31. 11pm here in Portland and we are still @ 30* and steady freezing rain is still falling. If its not snow, its just not the same. Will be glad to see this gone tomorrow morning when I have to go to work in Vancouver.

    ReplyDelete
  32. Just measured 3.5 inches on the south end of Bainbridge Island at 11:06pm. Still coming down hard, no rain yet! Wish it would stick around!

    ReplyDelete
  33. Bothell, 720ft elevation. Light snow, 2.75" of snow on the ground. 33.1F, no wind.

    ReplyDelete
  34. Steady snow in Marysville 29 deg. and 2+ inches of snow. Great for making snowballs.

    ReplyDelete
  35. Bothell, 720ft elevation. Light snow, 33.1F, 2.75" of snow on the ground. No wind.

    ReplyDelete
  36. Love the Nowcasts!!!! Thank you for keeping us big weather fans informed!! About 3" here in Brier. Exciting, even if it will all be gone by morning.

    ReplyDelete
  37. Loving the "nowcasts" - we are at 4 inches of new snow in Bellingham. NWS says it stays snow here until 10 AM. Sounds different than what you are saying. Is that wrong or is it is Fraser outflow situation? Or what?

    ReplyDelete
  38. Only 2 inches so far in Van BC at 11:30 pm. They predicted 10-25 cm so we will see.

    ReplyDelete
  39. Several inches of snow in Bellingham since 8pm. Woohoo! I just got back from an invigorating ski through the neighborhood. Winter Storm Warning in effect until 7pm, changing to rain by 10pm. Finally, we got the best end of the snow stick!

    ReplyDelete
  40. We have 5" in Silverdale on the Ridge!! And still snowing HARD! 32F.

    This is 2" more than the models ever showed!!

    What a snow storm!

    We weren't even in the Heavy Snow Warning but we've passed the 4" amount needed to verify a Heavy Snow Warning. Wow.

    ReplyDelete
  41. I love your blog. I am still hoping that before the winter is over, we have a snopocolypse.

    Shoreline, about 2 inches and still coming down nicely.

    ReplyDelete
  42. 3" here in Redmond Ridge. It's a blizzard out there!

    ReplyDelete
  43. About 2.5" 5 miles ESE of North Bend, 784'. Still coming down, wind still blowing, but not gusting as hard here. Temperature still around 29F.

    ReplyDelete
  44. 3inches in north Bellingham now and still snowing. I'd say .5 inches and hour

    ReplyDelete
  45. King 5 showed Kyle Moore on Snoqualmie ridge at 11:00 and the wind was really blowing. The snow was horizontal.

    ReplyDelete
  46. Poulsbo, midnight, total of 5 inches and still snowing. It's beautiful!

    temp. 32.4
    Baro 29.80 falling
    wind SSE 2mph gusts to 8 mph.
    Altitude 270 feet
    Station info:
    http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KWAPOULS11

    ReplyDelete
  47. We're up to 33F at 12:20 am and whatever you'd call it falling from the sky (sleet?), it is very wet. Bellevue weather 01/11/11

    ReplyDelete
  48. Duvall, 372ft, 12:20am, still snowing, 6 inches, 33 degrees

    ReplyDelete
  49. 12:30 AM, Seattle, Wedgwood, snow still falling pretty fast. About 2-3 inches on the ground. Are the roads going to be clear by the morning commute? Hmm.

    ReplyDelete
  50. Edmonds, 360', 4.5" just stopped snowing

    ReplyDelete
  51. The sound of rain falling on top of the snow covering my skylight up here in Maple Leaf is fascinating.

    ReplyDelete
  52. Hardly any snow in Ravensdale. Wind was howling most of the night. This morning finds everything encased in ice. Waiting for the warm up!

    ReplyDelete
  53. We have about 6 inches here in Maple Falls, in the Mt. Baker foothills. Started to change to light rain now...sigh

    Love the nowcast!

    ReplyDelete
  54. Birch Bay: We left the house at about 7:00 - it was 34 degrees, 4.5" of snow, and still mixed precip coming down. It's melting fast where I work in the Cordata area of Bellingham. Roads are relatively good in both areas.

    ReplyDelete
  55. We measured our Ravenna snow this morning and it is 2.6 inches deep with heavy icy rain failling.

    ReplyDelete
  56. Woke up at 2:00am and through one calibrated eyeball.... I measured 5.1 inches on the top of my deck rail :)... It was still snowing hard, so I'd say we got 5-6 inches here overnight (sea level Hansville). Absolutely calm all night with no winds. Temperature is 39 right now and the wind is just starting to pick up. We just had a 25 mph gust. We have accumulated .36 of precip so far today. Current conditions @ www.SkunkBayWeather.com

    ReplyDelete
  57. Here in the Methow at 8am we've gotten 9 inches overnight. What I don't get is that it's snowing like mad but the radar images show that there's no precip. Precip shows in Seattle and Spokane but not here. What gives?

    ReplyDelete
  58. Oops. In my last post I wrote pm's where I meant am's.

    At 7am the snow was substantially gone in Bellingham with strong wind gusts and rain. Icy slushy roads and I live at the bottom of a hill so my commute will be delayed.

    ReplyDelete
  59. First big gusts hit the western shores of the Key Peninsula at about 4:00 am and its been gusty since then. The ~4 inches is now awful slush. Schools are closed here, too. 42 deg F. The rain gauge says 1.07 inches for last 24 hrs.

    ReplyDelete
  60. Just buy eyeing it from inside I'm guessing we may have actually gotten 3" in Ballard by about 3:30am (when I woke up briefly) although it may have just turned to rain about them because it was lightly raining.

    I am sad that Snowpocalypse for today and tomorrow will not be happening ... possibly the only person I know over ten years old who feels that way.

    ReplyDelete
  61. For Mark in the Methow--you can find a coverage map, google for Spokane OTX 88d coverage blocking mountains or something like that. Here is one I see...
    http://www.nws.noaa.gov/oh/hrl/papers/2000mou/Jay/Fig30.gif

    The short answer is of course the mountains block the beams.

    ReplyDelete
  62. We ended up with about 6 inches here 5 miles ESE of North Bend. Wind was howling off and on during the night. Changed to rain at some point and the snow is sliding off our metal roof, but temp is still hovering around 30. Just the occasional breeze.

    Temp last night was the same and we got snow, now it's rain. There's a lot about this weather stuff I just don't get, obviously :( Better read Cliff's book....got it for Christmas.....

    Kids got a 2 hour delayed opening at school in Seattle. Better than nothing, like they said! They were so hoping for an epic storm....

    ReplyDelete
  63. Please do more of the NowCasts. I loved being informed on what was happening!

    ReplyDelete
  64. couple of inches in port townsend last night, gone this morning.

    ReplyDelete
  65. I woke at 4 am and measure almost exactly 6" here a couple miles North of Mill Creek. 7 hours later it's almost all gone with the temp having risen to 47 degrees!

    ReplyDelete
  66. Cliff:

    What are the odds of getting a real snow event this winter? Say, a widesread 8-10 inches that lasts for at least a few days...

    ReplyDelete
  67. Out here in Eatonville we started out as light snow around 6:30 pm....changed to sleet by 9:00 pm.....just rain by 10:00 pm. The winds really picked up overnight gusting to 48 mph at around 4:00 am. It's been a blustery, wet day out here all day. Like "dimension38" said...hoping to get a widespread 8 - 10 inches event that sticks around for a few days! Maybe later this month or in February? I think our chances get pretty slim after that.....Oh well! We can always hope for next year! Nuetral years are supposed to be almost as bad as La Nina years aren't they?

    ReplyDelete
  68. I am curious about Dimension38's question about snow as well. Can you explain this warming trend that is forecasted for the next week? Will it continue or should we get some more winter storms?

    ReplyDelete
  69. It's a bit late for a Nowcast, but I created a time-lapse video with annotated temperature of snow falling and then melting in University Park neighborhood (just north of UW):
    http://www.youtube.com/watch?v=7V8Kc7ExAPs

    ReplyDelete