Snow on March 28th?

SnapshotI feel like it’s time for one of those "sample" tests.  The ones that don’t really count, but you take them to see how your skills are coming along.  Why the heck am I wound up about snow or a surprise snowstorm in Portland, Oregon on March 28th???  That thought actually makes the forecasting easier, thinking that 7 days from now we could hit 75 or 80 degrees (first week of April).  But, back to reality.

Very complex and messy forecast with a high potential for being wrong some areas and right on others in the morning.  So the 00z runs are out and STILL in some reasonable disagreement tonight.  Both GFS and NAM take a low across Southern Oregon tomorrow, of course the NAM continues to be significantly deeper.  But there is a 2nd, weaker low that approaches the Washington Coast at the same time late tonight and tomorrow.  In reality it’s almost more like a negative tilt front with a wind swith line from easterly to gusty westerly.  It passes through the metro area about midday tomorrow.  From now until midday, we have light or calm wind.  No significant east or southerly wind (plus there is no cold air to our east in late March, so the easterly wouldn’t help anyway).  A cold atmosphere modifies only slightly the next 12 hours, so all we need is steady, heavy precipitation to drag a very wet snow level down to sea level in the first few hours of daylight.  The MM5-GFS is more impressive with precipitation, bringing snow down to the Valley floor, the NAM a bit slower, which would say no snow anywhere below 1,000′.  I’m leaning more towards the GFS with it’s track record.  You see my forecast above, it applies to all areas West of the Cascades, including the Coastline, in Northwest Oregon and S.W. Washington.

As I’ve mentioned in the last few months, I’m done with that 200′, 500′, 700′ snow level crap that was so useless this winter for many.  I just think we’ll have heavy, wet snowflakes from 5-9am, with some sticking possible, but temps bottoming out near 35 in the city and 32 at the top of the West Hills.  The North Coast is in a very interesting spot with light morning wind and even heavier precip. right under the front.  Could it be a widespread 2-4" even to the beaches out there?  Tough call.  If the northern low is slightly too strong, then a weak onshore breeze will be present all night and through the heavy precip.  No snow in that case.  But I’ll stick with the Trace-1" forecast out there in the end.

Saturday and Sunday look far more showery, so it should be like this morning, with random spots each morning getting a dusting.  Amazing how strong the sun is.  An airmass cold enough to bring a dusting to the lowest elevations at night, but a high of 50 by late afternoon, then back to snow the next night.  What a battle between solar insolation and the very cold upper-level airmass.  If today was a winter day, we would have had a 38-40 degree high at PDX, even with the sun.

A bit more reasonable next week with temps recovering to near normal…which is about 58 for the first few days of April in Portland…Mark Nelsen

212 Responses to Snow on March 28th?

  1. 32 here & just started snowing

  2. Ryan (Walnut Grove) says:

    I wonder if that cell in noted as “intensifying” is just being hidden by the Coastal Mountains & Hills?

  3. Jesse-Orchards says:

    Snow had been reported in Eugene, Salem, Olympia, Seattle and Bellingham this evening.
    What an incredible event for late March.
    You are right, Ryan, it looks as if our turn may be coming soon. I was noticing a little piece of energy offshore on IR earlier, looks like it rotated right toward the Portland/Vancouver area.

  4. Ryan (Walnut Grove) says:

    I’m noticing that cell to the NNW of Vancouver/Portland is really starting to blow up. Looks like a line of showers is getting ready to roll in.

  5. wendy-silverlake,wa says:

    Got cells that keep popping up to my west. Ground is more covered now than it has been in two days, and it’s not letting up.

  6. Ryan (Walnut Grove) says:

    I’m just waiting for a cell to target my house. It will fall as snow I just need the moisture!

  7. mark says:

    Anyone remmeber this? ^^^

  8. mark says:

    Things got pretty quiet here all the sudden..
    I think we need a FAB 5 Forecast to cheer us up!

  9. Tyler Mode in NW Vancouver (Hazel Dell) says:

    I’m guessing anyone who experienced “sleet” today was actually having hail/graupel.
    Btw…if anyone needs to know…graupel is basically like hail, but its surrounded by snow. Its like mini snowballs falling from the sky.

  10. TheTriforce Silverton Or 360ft says:

    B1900pilot? It’s 36 here so it’s dropping fast. DP is below 32 since my station does not register DP while it’s below 32F

  11. mark says:

    Well, you may be right, but when I check temps around the area, I’m always the warmest one, and I’m actually at a higher elevation on Sexton Mounain at about 350 feet.
    Oh yeah, and some light snow outside right now..

  12. Ryan (Walnut Grove) says:

    Almost forgot… 35 at my house in the Couve.

  13. gratefulduck (weather blog lurker) says:

    Mark.. I have noticed that this paritcular spot seems to be bit cooler for some reason… I am right behind (on the hall side) of Highland park middle school. the intersection of Murray and allen is probably not quite a mile away.

  14. Ryan (Walnut Grove) says:

    A couple hours ago on St. Johns in the Couve I got caught in an intense hail/graupel/snow storm that laid a good 1/4″ on the street in just a few minutes. I nearly lost my car make a turn! Exciting stuff.

  15. Tyler Mode in NW Vancouver (Hazel Dell) says:

    Check out the obs for Astoria…8 pm and thunder reported, winds gusting to 28 mph.

  16. mark says:

    Oh…Well Im an idiot….Gratefulduck, I think my thermometer is just off because mine says 41 degrees right now.

  17. mark says:

    Does anyone live near the intersection of Allen and Murray in Beaverton?

  18. gratefulduck (weather blog lurker) says:

    oh..yeah.. that is in beaverton.. near Murray and allen.

  19. gratefulduck (weather blog lurker) says:

    38.5 with a DP of 29.5
    Hmmm… bring on the moisture!!!!!!

  20. mark says:

    40 degrees at Beaverton as of 7:40.

  21. Camas~Mom says:

    Oh, sorry, forgot our total. So far today 3.5 inches, that is not including the melting we had going on during the sun breaks. Could’ve been more like 5 inches total. I think Kirk said today puts us up over 40″ for this winter. But we both agree, this last cell to go through that made it so pretty is the best snow we’ve seen. Unreal, eh?!

  22. B1900 Pilot -- Bethany, OR (400') says:

    Temp dropping rapidly here in the Beaverton area. I’ve got 36 with a DP of 30. Any other temps out there as of 7:30?

  23. Camas~Mom says:

    We had a really cool windy blizzardish type of cell go through where the snow was perfect powder snow. It coated the trees in snow over the whole tree – inside the branches all the way to the trunk and to the tip of the trees. I have two large hemlock trees that look like they were professionally flocked. Gorgeous!
    I wonder if we’ll get that dump of moisture around 11:00 or not? Only time will tell….

  24. Tyler Mode in NW Vancouver (Hazel Dell) says:

    Hit a nice heavy shower on the way home near Kalama, complete with a flash of lightning!
    Totaled an inch so far today, which makes it the biggest snowfall of the 07/08 “winter”

  25. Mark Nelsen says:

    I might post about this tonight; NWS recorded only a trace today, so still no measurable snow at PQR (122nd & Sandy) for this cold season.
    Portland has recorded traces of snow later than this date though.

  26. Max-Fairview says:

    What a crazy day!

  27. Jesse-Orchards says:

    Had a “mini-blizzard” here about a half hour ago. A strong shower moved in from the WNW, started out as hail, then graupel, then fine, powdery snow. Dropped the temperature from 40 to 35 in about 15 minutes, and coated the grass, cars and rooftops. Picked up about 2/10ths of an inch of snow.
    Very gusty winds with the cell as well. Have been seeing some extreme downdrafts underneath showers today.

  28. What a neat trip to town today. No snow on the roads so i could actually enjoy what was falling. Saw something new today. 1/2 way between Hillsboro & North Plains….the sun was shining & I kept driving in & out of snow flurries. As I came around a curve….there it was…..a “Snowbow”. Snowing to beat the band & contained a bright rainbow. Sure wish my camera had been handy.
    Blizzard type snow on & off all day up here……….but still in the “stick & melt” zone. Wonder what tonight will bring??

  29. it is snowing so beautifully right now; slow moving quarter size flakes, ….35.6

  30. holy crap sez Nelsen
    crazy intense wonderful
    joyful record break

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