Morning Snow Flurries; But a Slow Week Otherwise

9:30am Monday…

If we can’t get “real” snow, this morning’s flakes are the next best thing!

After a very cold weekend, temps have warmed (slightly) here in the metro area a bit this morning; most of us are right around 30 degrees.  The fog layer has lifted up into a low cloud (stratus) layer around 1,500′ at the base of the clouds.  Radar just barely shows a little lifting of the low cloud layer has allowed flurries to develop and drop right over us.  Here’s a link to the radar loop, but by 10am you probably won’t be able to see anything.  In some spots it’s been enough to turn the ground white, not much different from a heavy frost, but it’s sure fun to watch it fall!  Here’s a pic from Rian Muleback in Gresham:

photosnow

The one thing that has changed this morning can be seen on the visible image,

VIS1PDX

the low cloud deck has lifted up and the top is now over 2,000′ ; that’s part of the reason temps are a little warmer at the lowest elevations and a little cooler higher up in our little “westside cold pool”.  It’s really cold up on the TV tower, around 22 degrees at 1800, just about the coldest I’ve seen without arctic air or a cold air mass coming through the Gorge.  The past few days have sure been interesting for the weather geeks with regard to the air mass temp!  As a result today should just be gray and a couple of degrees warmer than the last few days.  Maybe a high around 35-36 at PDX.

Check out what happens in the next 36 hours.  Our 850mb temps go from this morning’s -5 to a +11 overhead!  That means at 4,000′, temperatures which are in the mid 20s right now soar to 50 or so by Tuesday evening.  Even a little warmer Wednesday.  And the warming doesn’t really “move in” from anywhere, it is from subsidence.  That’s subsiding warmer and very dry air as a strong upper-level ridge builds right over us.   It’s a little tricky for forecasting, but here’s what I see happening…  The subsidence warm and dry air will “dry up” the 1500-3000′ low cloud layer sometime later Tuesday (maybe not until after dark) and then a new much stronger inversion forms much closer to the surface.  I could see the low clouds dissipating and then a new fog layer developing in the lowest 1,000′ of the atmosphere by Wednesday morning.  If so, the foothills should be dramatically warmer Wednesday but we stay below 40 degrees here in the lowest elevations.  This would be our more typical inversion setup.  I think I’ve decided to call this the STRATUS REPLACEMENT CYCLE; inspired by the eyewall replacement cycle.  There is no help from dry east wind the next 3 days, so if we stay clouded up or fogged in Wednesday, then we’re stuck in the muck.   For several days, the WRF-GFS has shown this whole process quite nicely:

kpdx_th

The green is relative humidity, and time goes from right to left.  Look how the dry air works down later tomorrow and by Wednesday morning it’s extremely dry except right at the surface.  SUPPOSEDLY it makes it all the way to the surface, or within a few hundred feet, but I’m assuming that will be wrong.  And look at all the beautiful dry and warm air up above 1,000’…Spring skiing time!

What about the next 7 days and beyond?  A snoozer…  Next chance for real precipitation is still over a week away…

Chief Meteorologist Mark Nelsen

 

 

160 Responses to Morning Snow Flurries; But a Slow Week Otherwise

  1. runrain says:

    With all this liquid on the ground and impending freezing temperatures, I think it’s time to pull out the GOLD model:

    Go Outside Look DOWN!

  2. W7ENK says:

    SPSPQR – but no mention of snow or ice? Bad ju-ju!!

    http://inws.wrh.noaa.gov/weather/alertinfo/8677002

  3. KPTV Tower Temps
    http://www.wrh.noaa.gov/pqr/tower_temps/tower_temps.php?&units=F
    As of 2 PM (1 hour lag. Updates every :15 after the hour)
    Upper Sensor(1818′) 26.8 (26.6 at 1:00 PM)
    Middle Sensor(1473′) 26.2 (25.3 at 1:00 PM)
    Lower Sensor(1043′) 27.7 (27.3 at 1:00 PM)
    Still remain well below freezing.

    23z(3 PM) Upper Air Analysis(Observed over PDX)
    http://www.spc.noaa.gov/exper/mesoanalysis/new/viewsector.php?sector=11
    925mb: -2.2c
    850mb: -3.2c
    700mb: +2.8c
    500mb: -16.8c

  4. runrain says:

    Uh oh… Sleet now, and temp is dropping…

  5. AREA FORECAST DISCUSSION
    NATIONAL WEATHER SERVICE PORTLAND OR
    300 PM PST MON JAN 14 2013

    .SHORT TERM…LOW CONFIDENCE SHORT TERM FORECAST IN THE WORKS FOR THIS EVENING AND TONIGHT. THE LARGELY UNANTICIPATED FLURRIES AND LIGHT SNOW HAVE CONTINUED FOR MUCH OF THE DAY ACROSS NORTHWEST OREGON AND SOUTHWEST WASHINGTON. HOWEVER…LITTLE MORE THAN A DUSTING HAS BEEN REPORTED. THERE HAS BEEN SOME DEBATE IN THE OFFICE WHETHER THIS WAS A SEEDER FEEDER SNOW EVENT OR IF THIS SNOW HAS BEEN GENERATED IN THE LOWER LEVELS OF THE ATMOSPHERE WHERE TEMPERATURES ARE GENERALLY -5C OR WARMER. BASED ON THE 12Z SLE SOUNDING…AIRCRAFT SOUNDINGS… MOUNTAIN CAMS…AND RADAR AND SATELLITE IMAGERY…IT SEEMS THE LATTER IS LIKELY THE CULPRIT. THIS APPEARS TO BE AT LEAST IN PART DUE TO WEAK ISENTROPIC LIFT NEAR 280K. MODELS CONTINUE TO SUGGEST LOW LEVEL OMEGA FIELDS WILL FADE THIS EVENING SO KEPT FLURRIES LIKELY THROUGH 7 PM BEFORE DECREASING IT TO CHANCE WORDING BETWEEN 7PM AND 10PM…AND SLIGHT CHANCE WORDING AFTER 10PM. IT SEEMS SNOW CHANCES WILL BE HIGHEST ACROSS THE LOWER COLUMBIA RIVER AND LOWER WILLAMETTE VALLEY AREA WITH LITTLE TO NO THREAT OF SNOW TOWARDS EUGENE.

    LATEST AIRCRAFT SOUNDING INDICATES THE SUBSIDENCE INVERSION IS BEGINNING TO DEVELOP OVER THE PACIFIC NORTHWEST. EXPECT THIS INVERSION TO LOWER OVERNIGHT…SLOWLY COMPRESSING THE LOW LEVEL
    MOISTURE IN PLACE. THIS SHOULD MAKE IT INCREASINGLY HARD FOR ICE CRYSTALS TO FORM…AND THUS PRECIPITATION WILL HAVE A CHANCE TO FALL MORE IN THE FORM OF FREEZING DRIZZLE. MOISTURE MAY BE TO SHALLOW TO ACTUALLY FORM DRIZZLE BY THAT POINT THOUGH. AS A RESULT…JUST PUT IN A SLIGHT CHANCE MENTION OF FREEZING DRIZZLE ALONG THE LOWER COLUMBIA RIVER AND LOWER WILLAMETTE VALLEYS FROM 7PM THIS EVENING THROUGH 4 AM IN ORDER TO ACCOUNT FOR THE UNCERTAINTY OF WHEN OR IF ANY WILL FALL. IT WILL NOT TAKE MUCH FREEZING DRIZZLE TO MAKE A MESS OF THE ROADS SO TUESDAY MORNING COULD BE HAZARDOUS FOR THOSE COMMUTING.

    A THERMAL SURFACE TROUGH WILL STRENGTHEN OVER CALIFORNIA ON TUESDAY…WHICH WILL INCREASE THE PRESSURE GRADIENT ACROSS WESTERN OREGON. INCREASING NORTHERLY WINDS SHOULD HELP TO MIX SOME OF THE GUNK AND MOISTURE OUT OF THE WILLAMETTE VALLEY. MODELS SUGGEST THE SUBSIDENCE INVERSION WILL LOWER TO THE VALLEY FLOOR WEDNESDAY AND THURSDAY…BUT STILL THINK SOME MOISTURE AND COLD AIR WILL LINGER SO KEPT A MENTION OF VALLEY FOG AND TEMPERATURES COOLER THAN NEARBY FOOTHILLS DURING THIS TIME. /NEUMAN

    .LONG TERM…THURSDAY EVENING THROUGH MONDAY…THE LONG TERM FORECAST IS BEGINNING TO RESEMBLE A BROKEN RECORD…MODELS CONTINUE OVERWHELMING AGREEMENT IN AN EXTENDED PERIOD OF COOL DRY WEATHER ACROSS THE PACIFIC NORTHWEST. WEAK SURFACE FLOW AND CLEAR SKIES DURING THE DAY WILL ALLOW OVERNIGHT TEMPERATURES TO PLUMMET NEAR
    FREEZING OR BELOW…SO ANY FOG THAT DOES DEVELOP WILL LIKELY BE FREEZING FOG. THE RIDGE BEGINS TO AMPLIFY OVER THE WEEKEND…WITH THE AXIS SLOWLY SHIFTING MORE EASTERLY EARLY NEXT WEEK. BROWN

  6. Miguel says:

    There is snow when there is NO snow in the forecast. What do you know? :)

  7. W7ENK says:

    Just received word that tonight’s rehearsal at Clackamas Community College — top of the hill in Oregon City — has been canceled. Is it really that bad up there?!?

  8. LIVE REPORT from Southeast Portland!
    Dangerous conditions unfolding with untold consequences beginning to emerge across PDX metro!
    https://www.facebook.com/photo.php?v=4820384999224&set=o.158533057538771&type=2&theater

    Just trying to bring some humor along with my analysis. :D

  9. Full Frontal Boundary says:

    And you think Portland news outlets oversell cold weather, check out the craziness going down on the airwaves down in LaLa Land!

    http://v.iheart.com/2SnX

  10. ocpaul says:

    animated infrared shows lots of moisture from the north:

    http://wwwghcc.msfc.nasa.gov/cgi-bin/post-goes

    big flakes falling at 286′ in Oregon City-32.4 temp

    a nice, steady drop- surprise snows are the best!!

  11. runrain says:

    Looks like a break in the weather now and then perhaps something else moving in later tonight from Eastern Washington? Friend in Spokane says it’s freezing rain there right now.

  12. KPTV Tower Temps
    http://www.wrh.noaa.gov/pqr/tower_temps/tower_temps.php?&units=F
    As of 1 PM (1 hour lag. Updates every :15 after the hour)
    Upper Sensor(1818′) 26.6 (26.1 at 12:00 PM)
    Middle Sensor(1473′) 25.3 (25.2 at 12:00 PM)
    Lower Sensor(1043′) 27.3 (26.4 at 12:00 PM)
    *Slight warming, but still remain well below freezing.

    22z(2 PM) Upper Air Analysis(Observed over PDX)
    http://www.spc.noaa.gov/exper/mesoanalysis/new/viewsector.php?sector=11
    925mb: -2.2c
    850mb: -3.5c
    700mb: +2.6c
    500mb: -16.5c
    *Slow warming aloft underway

  13. Tyler Mode in Battle Ground says:

    Looks like a coating of ice at KM Mountain.

    http://www.wsdot.com/traffic/swcam.aspx?cam=1251

  14. Jordan (Raleigh Hills, 420') says:

    Been snizzling and light snowing for a couple hours now in Raleigh Hills. Got some white stuff on the trees and some grassy spots, not too much though. temp 32F, dew point 30F. Hope to see some more later tonight. Maybe some of that BC moisture will makes it way down into the Willamette valley later this evening and tonight.

  15. PDX-DLS now +6.5mb …. strong marine push and onshore flow.

  16. Mike Brightwood says:

    It is currently snowing in Brightwood and points east. 27 degrees. Your buddy Andy Carson read from his telestrator this morning that it would be 36 degrees with no precip of any kind. Mr. Nelsen, would please take Mr. Carson and his people, that apparently put false information for him to read on the telestrator under you wing and instruct them. You concentrate on the Gorge area and get it pretty much correct. Please pass your expertise to Mr. Carson and his producers.

    • runrain says:

      I think they just do weather for the marketing aspect of it.

    • Ben T says:

      It was coming down with big flakes a little bit ago. They definitely weren’t flurries.

    • Ron says:

      These little snow events are very very difficult to forecast. There are wrinkles in the atmosphere that many times we just cannot accurately predict other than “a chance of. . .Forecasting is just not that precise yet. The Gorge is more predictable for the most part. Less variables.. The dynamics that occur in the atmosphere here in the valley are just too chaotic to pin things down like this. It just isn’t that simple. Its part of the Chaos theory. Small things in the atmosphere interact in ways we cannot plan for and then things like this happen. Part of the amazing wonder of Nature.

    • Mike Brightwood says:

      Who the Hell is “Ron”? My comment was sent to Mark So, Ron is now making excuses for the lack of definitive “guess estimates” by the staff at KPTV-12. Is metreology an “inexact science”, which is an oxymoron. I have lived up here for over twenty years and I am flat out tired of flat-lander city folks reading telestrators when they have no clue as to what is happening outside the concrete box they work in, let alone a neighborhood 35 miles east of them. Then these same people use the excuse over and over again “That this is the Northwest, the weather changes quickly” Go to Arizona!!. Stop not taking responsibility about your mistakes. Have some personal courage.

    • PDX Weather Nut says:

      Hard to call snow flurries a “snow event”. Sure was a nice change over our usual dismal cold rain. PDX area is way overdue for a real snowfall. Doesn’t look like that’ll happen in the next 10 days or so though. Gotta get the bad air out of here once the pollution starts to gather soon!

    • PDX Weather Nut says:

      Only “sure” bet for snow in PDX seems to be when an entrenched cold pocket of air drops directly south and precip comes in. Everything else is guesstimation.

    • Ron says:

      Hey Mike, lived here for 62 years, retired science teacher. Doesn’t matter if you sent it to Mark or anyone else. If you put it out there be ready for a response. People often seem to think meteorologists can predict everything and with exact scientific methodology. Weather and climate just isn’t that simple. Looks to me that the NWS, Mark Nelsen, and others didn’t make the call on this either. Nothin’ wrong with that. No one made the right call. Relax.

    • Mike Brightwood says:

      Ron, the point that I was trying to make (and maybe I was obsure aboutt it), Like you said, they have all the state-of the-art equuipment and they don’t get it right. There is no such thing as an “inexact science” That’s an oxymoron. Weather guessers NEVER apologize. Perhaps they don’t apologize in the NW because the weather can change very quickly and that makes the weather guessers wrong so often.

    • W7ENK says:

      Good Lord, someone’s cranky! Time for a diapie change???

    • Mike Brightwood says:

      Another example of a person not getting the point!!Pay Attention.

    • Tyler Mode in Battle Ground says:

      My best advice for those who think all these weather forecasters are unreliable? DON’T WATCH THEM! Make your own forecast!

      For everyone else, if yesterday was 2-3 degrees warmer, it would have all been regular old drizzle and this blog would have been dead.

  17. It is going to be very icy overnight and into tomorrow morning..

  18. Matt says:

    Pretty legit snow shower in Milwaukie for the last 30 mins. Big flakes but not sticking as easily as it was this morning.

  19. alohabb says:

    Drizzle/spizzle/snow…roads all over covered with moisture. If it starts to freeze, oh boy what a commuting mess!

  20. WEATHERDAN says:

    31 and snowing lightly in South Salem at 1:17PM. RadSat image from UW has area of snow moving Southward from British Columbia into Eastern Washington. Seems to be holding together nicely. Vort max seems to be over southern BC this PM. Should be over us later tonight. Very interesting. It’s cold enough for snow. And if we get some decent moisture dropping down from the North we may see more than just a few flurries. After this little system it looks like cold but dry conditions continuing for the valley.

  21. Teresa says:

    Steady light snow in Orchards, trying to stick, but not quite there.

  22. Still got the snowflakes here in Kelso Longview! The ground is white but not the roads! Local temp 32-34! Not liking thought about the drive to work at 3:30p & not liking thought going home at 8:30p! Freeze is the thought there! Surgery Tuesday morning 11am in Tumwater! A hour drive up I-5! Thinking we be ok on freeway it’s getting on & off it that’s the issue!

  23. Muxpux (Castle Rock 175') says:

    Been snowing here for a few hours now. Deck is white, and the grass has that seafoam green look to it. Radar looks like we’re pretty well under the bullseye

  24. EA_TTD says:

    Spitting flakes again in Troutdale. Round one had an easterly drift to the flakes while this one has a westerly drift. Not near hard enough to stick but nice to look at.

  25. ErinK says:

    Anymore flurries on the way for the west side? Maybe…. Possibly…..

  26. JKM says:

    It’s been snowing on and off since about Noon, in Brush Prairie, WA @ Prairie High School. Big flakes then little flakes, then big again!

  27. Holly in Eastmoreland says:

    Snow flurries in the Milwaulkie area near Bob’s Red Mill for the last 25 minutes. Still coming down although no real accumulation so far.

  28. No Snow says:

    Hey Germantown summit, I’m coming over skyline tonight with my ruler so don’t be exaggerating your snow depth. :-)

  29. W7ENK says:

    Still snowing lightly in Downtown, the streets are getting damp — I’d hesitate to actually call it “wet” — but could become a slick mess in short order, 32 degrees currently.

  30. Mr. Donut says:

    Did someone call for warming up above?

    Mt. Hood Meadows Base Area Weather Station @ 5250′
    Monday, Jan. 14 at 12:35 PM
    Temperature: 24° F (-4° C)

    Top of Mt. Hood Express Weather Station @ 6600′
    Monday, Jan. 14 at 12:35 PM
    Temperature: 46° F (8° C)
    Wind: North at 29 mph (48 km/h)

  31. runrain says:

    Going to be treacherous on the streets in about 4 hours when this all freezes.

  32. Marc (East Vancouver) says:

    Was it KOIN predicting flurries for today? I thought I saw someone laugh at their forecast on Saturday which included flurries for today. Time to enjoy it while while we can! It’s gorgeous outside.

  33. runrain says:

    Mount Washington New Hampshire recorded a record January high temperature of 48° yesterday.

  34. Marc (East Vancouver) says:

    Biggest snowfall of the winter so far! What a surprise!

  35. Sifton says:

    well what ya know, SNOW!!

  36. Oregon Foto says:

    Cool…legit snow flakes downtown PDX!

  37. EY (Oak Grove) says:

    Sticking on bark dust and plants here.

Follow

Get every new post delivered to your Inbox.

Join 286 other followers

%d bloggers like this: