Midday Update: More of the Same

I hate to nag about it again this winter, but this morning is an excellent example of why I DON’T THINK WE SHOULD FORECAST SPECIFIC SNOW LEVELS (other than 1,000′ increments) IN MOST SITUATIONS!  I know that all caps is annoying, but I’ve really come to that conclusion the last 3-4 winters.  As such, I don’t think you’ll ever see me forecast a specific snow elevation below 1,000′ .  I haven’t done that for a year or two.  One okay situation might be with a stratiform snow event where it’s just solid rain/snow coming down.

This morning reminded me of the La Nina winter 2007-2008.  This situation occurred several times in January and February.  An organized area of heavy showers move through middle of the Metro area and up into Clark County during the coolest part of the day (6-9am).  We also lost the mixing south wind overnight.  It was down to less than 2 millibars southerly gradient between Eugene and Olympia.  The two combined allowed sticking snow (and decent totals too!) down to sea level (Columbia River).  So we ended up with 2.5″ at Battleground Brian’s place at 500′, and 1/2″ totals at 200-300′ westside, while at 1,000′ in Corbett, Sandy, Brightwood and other spots had bare ground.  So WE ARE MISLEADING THE PUBLIC by giving such specific elevations.  By the way, I’m not really cranky, but hoping other forecasters would clue in to this as well.  This morning my wife heard someone on the radio saying something like “they’ve decided to lower the snow level down to 500′ now”  Ugghhh!

Last night on-air we said the morning commute would probably not be affected by snowfall except in the hills.  That was true, but of course where more than 1/2″ fell there were definitely slippery spots (in Clark County for sure).  In my snow graphic we also said “Anyone Could See Sticking Snow” the next few mornings.  That was okay too.  Although I’d sure like to see some in MY yard!

So what changes the next 24 hours?  Not much, except slightly colder airmass tomorrow morning.  There’s no reason we couldn’t see a repeat of this morning, but it’s going to all be about the shower placement.  I do note the experimental 1 1/3 km WRF-GFS has wind going calm again late tonight and in the morning.  So sticking is possible anywhere for the Thursday morning commute again, with more roads (than today) seeing white briefly IF showers show up in your neighborhood.  If you commute before 9am, I’d get up a little early and see what’s going on.  There does seem to be a bit less moisture to work with, but just one batch of showers could drop a quick inch easily.

Friday morning is dry on the GFS and NAM, but still a little moisture for early snow on our RPM (not much).

Beyond that, the big question mark on the 7 Day forecast is still Sunday and President’s Day.  The models are very stubborn with their solutions.  The ECMWF for 2-3 runs now has given us dry and mild conditions Sunday and Monday with temps maybe 45-50 both afternoons.  The GFS is still drilling a cold front down over us with sticking snow to low elevations.  The disparity is due to the ECMWF splitting energy with a deep trough dropping south well offshore.  The 12z GFS has a much shorter period of precipitation I notice with a mainly daytime Sunday event and then precipitation is gone by early Monday.  If so, it could just be a few hours of wet snow in PDX (no east wind) with a nice 3-4″ dump on the hills and foothills (reminds me of 2007-2008 again).  Then real cold (especially for the last week of February!) Tuesday-Thursday.

Chief Meteorologist Mark Nelsen

374 Responses to Midday Update: More of the Same

  1. Karl Bonner says:

    Looked at data for The Dalles for the second half of February the past 20 years (1991-2010):

    Feb 2006, Week 3:

    Two nights in low teens, highs in 30s and 40s

    Feb 2005 Week 4:

    Highs 55-61, lows 23-27 same days! Very contrasty!

    Feb 2003 Week 4:

    Highs in 40s couples with lows of 19-28

    Feb 2002 midmonth:

    Two fairly contrasty days, 55/24 and 53/25, straddled Valentine’s on both sides.

    Feb 2001 last 5 days:

    Five sunny days with highs 52-57, lows 23-28. Diurnal swings were 28-29 degrees F.

    Feb 2000:

    Data missing for last 7 days of month; nothing interesting first 22 days.

    Feb 1997:

    2/22 to 2/24 was sunny and contrasty, lows 26-30 and highs 53-59.

    Feb 1996 midmonth (after Great Flood):

    Five days with highs 50-55 and lows 25-28

    Feb 1995 late month:

    The “Great February Heat Wave of ’95”: from 2/19 to 2/25, seven days with highs 60+ (warmest was 68 on the 24th!) and three contrasty days (about 30 degrees diurnal from 2/22 to 2/24).

    Feb 1994 last week:

    Three days with highs in mid 30s and snow.

    Second half of Feb 1993:

    Only one day 40 or higher (it was 41). Six days with highs in 20s, five of them in the last week. Nine days with lows in teens, coldest was 14 on 2/26 and 2/28.

    Feb 1991 final week:

    Every day was 60 or above (warmest 62 and it happened on 4 of the 7 days). Lows ranged from 27 to 34. Diurnal swings ranged from 28 to 33. More clouds than sun.

    Feb 1988, the 19th to 29th:

    Seven days with highs in the 60s. No recorded precip, and apparently more sun than clouds. Diurnal swings were all between 28 and 33, except for the 29th when it was only 22.

    ===============

    So it CAN get cold in late February here, as evidenced by 2006 and 1993. And in the latter case it was bitterly cold for a prolonged period!

    But it doesn’t happen very often. Only three years since I was born (1983-2010) have seen temps below 20, and one of them just barely so. And in 2006, we had only one day that never rose above freezing, and only one other day failed to hit 40. So serious cold after Valentine’s is somewhat more likely here than in Portland, but still very unlikely.

    Far more common are contrasty days with diurnal swings of 30+ degrees F, and sunny springlike afternoons (highs of 55+).

  2. snodaze says:

    We had a “winter blast”… Anyone know when and where that happened? Was there any damage from the ‘blast’? KPTV is reporting a blast…

  3. Rob "Wrath" S.E. Portland says:

    Next cold system is dropping down the British Columbia Coast developing west of northern Vancouver Island. http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?ir4km_enhanced+12

  4. Rob "Wrath" S.E. Portland says:

    I liked the 00Z GFS. The trough isn’t that much further offshore and there would be strong east winds this weekend.

  5. bgb41 says:

    00Z GFS @ Troutdale

    Well looking at IR loops, looks like current upper low is weakening off Astoria. GFS is picking up on this and now showing no measurable precip at KTTD until monday when there is only 0.03 QPF. This is following the trend of the ECMWF dropping our anticipated sun/mon storm well offshore. Tues/Wed precip returns with probably another similar scenario like todays with snow in some areas but not everywhere. Tuesday morning looks like our best show now but since that is 5 days away that system too may drop down into California also. Amazing how la la land is calling for the northerly flow all the way through the end of the run. Early March still has some potential.

  6. Bishoy says:

    Well, if anyone cares, the 00Z GFS is still showing a decent snow event later in the run towards next Tuesday.

  7. Yevpolo1990 says:

    5th place guys!!!! nobody ever thought we could have done that, well nothing is stopping Lamarcus 😀

    36 here with DP at 34

  8. stilllearning says:

    We’re heading down to Rockaway Beach for the weekend and I know that Ben keeps saying it looks good for the coast, but I am curious what others are seeing?? We’re taking our son down for the first time and would love if he could play in the sand and snow!!

    • timmy - scappoose says:

      its the coast in late feb… if it snows, it will be under a shower, it wont likely mess up driving too much. the passes are another story, definitely expect snow covered roads on the drive there at least briefly.

  9. Curtis Salem says:

    I have been following the blog for awhile now but I am still confused on what the deal is for sunday and monday?. Is the low going to be too far offshore or are temps going to be too warm or is it still way up in the air?

    • marinersfan85 says:

      Everyone else is just as confused. We probably won’t really know what will happen until about 24-48 hours before the “event”

    • Mike near Clackamas Town Center says:

      Because of the disagreement with the ECMWF and GFS, the track of the lows Friday and sunday could go just about anywhere. If it tracks ever so slightly to the east Areas in W. Washington and/or W. Oregon could have a surprise snow event.

  10. snodaze says:

    Just saw that police are about to shoot and kill someone at the Vancouver hospital scroll across my TV…

    What’s up in the Van tonight? Radar go down?

    Hey, radar is weather related, so stick it.:-)) kidding of course

  11. .SHORT TERM…SHOWERS CONTINUE TO ROLL IN FROM THE PACIFIC AS WEAK
    DISTURBANCES CONTINUE TO ROTATE THROUGH THE COLD UPPER LEVEL TROUGH
    OVER THE NE PACIFIC AND INTO THE PACIFIC NORTHWEST. DOPPLER RADAR
    REMAINS SPECKLED WITH SHOWERS…ESPECIALLY NEAR THE COAST. OVERNIGHT
    SHOWER ACTIVITY WILL FAVOR THE COAST…AS THE INTERIOR COOLS AND
    BECOMES SLIGHTLY MORE STABLE. COLD AIR ALOFT CONTINUES TO RESULT IN
    LOW FREEZING LEVELS AND MIXED PRECIPITATION AS LOW AS SEA LEVEL.

    LITTLE CHANGE IN THE FORECAST FOR THE NEXT 36 HOURS WITH OCCASIONAL
    SHOWERS…ISOLATED THUNDERSTORMS NEAR THE COAST…AND SNOW POSSIBLE
    DOWN TO THE LOWEST OF ELEVATIONS. HEAVIER SHOWERS MAY LOCALLY PRODUCE
    A QUICK INCH OR TWO OF SNOW AS THEY DID EARLIER THIS MORNING. THE
    BEST CHANCE FOR THIS IS THURSDAY MORNING AS A WEAK VORT AND SFC
    TROUGH NEAR NEWPORT SLOWLY TRAVELS E-NE ACROSS THE DISTRICT. AGAIN
    THE 00Z NAM SHOWS CONVECTIVE BULLSEYES MOVING THROUGH FOREST PARK AND
    INTO CLARK COUNTY…BRINGING THE POTENTIAL FOR A FEW INCHES OF SNOW.
    AS MENTIONED IN LAST NIGHTS DISCUSSION…THE NAM MODEL PHYSICS CAN
    FALL VICTIM TO CONVECTIVE FEEDBACK WHICH CAUSES IT TO GET CARRIED
    AWAY WITH CONVECTIVE PRECIPITATION. WILL STICK WITH GENERIC RAIN AND
    SNOW SHOWERS FOR THE LOWLANDS…WITH ACCUMULATIONS OF UP TO 1 INCH IN
    HEAVIER SHOWERS. REMOVED MENTION OF SNOW LEVEL THROUGH FRI
    MORNING…AS SNOW WILL BE POSSIBLE AT ANY ELEVATION. SOME AREAS AT
    1000 FT ELEVATION MAY SEE NO NEW SNOW WHILE OTHERS AT THE VALLEY
    FLOOR GET A QUICK INCH FROM A HEAVY SHOWER. LIGHTER SHOWERS WILL
    GENERALLY FALL IN THE FORM OF RAIN ANYWHERE BELOW 1000 FT IN
    ELEVATION.

    THE FORECAST FOR FRIDAY WILL BE AN INTERESTING ONE TO WATCH AS A
    REINFORCING SHOT OF COLD AIR COMES DOWN FROM THE SE ALASKA PANHANDLE.
    LATEST NAM/GFS/ECMWF/CANADIAN ALL BRING AN UPPER LOW SOUTHWARD OFF
    THE WA/OR COAST FRIDAY. WHILE THE 00Z GFS TAKES THIS LOW TOO FAR
    OFFSHORE TO PROVIDE A MAJOR IMPACT TO THE COAST…THE 00Z NAM AND 12Z
    CANADIAN BOTH KEEP IT CLOSE ENOUGH TO PRODUCE SIGNIFICANT
    PRECIPITATION ALONG THE COAST. 00Z NAM BUFR SOUNDINGS ARE VERY CLOSE
    TO SUGGESTING SNOW FOR AT LEAST PART OF THE EVENT. WILL HAVE TO WATCH
    THIS FOR POSSIBLE INCREASED SNOW ALONG THE COAST FRIDAY.

    THE SHORTWAVE WILL MOVE INLAND OVER NORTHERN/CENTRAL CALIFORNIA
    SATURDAY WITH MOST ACCOMPANYING PRECIPITATION SOUTH OF OUR AREA BY
    THEN…POSSIBLY JUST BRUSHING OUR SOUTHERN ZONES. WEAGLE

  12. CrazeyCritter (Brightwood) says:

    I want some snow 😦

  13. Tyler Mode in Battle Ground says:

    Looks like the moisture Sunday night/Monday may stay off of the coast altogether…and we stay dry!

  14. geo says:

    Urban heat island effect?

  15. goducks09 says:

    Ugh…so close on Monday.

  16. Josh "The Snowman" From Everett, WA says:

    00z shows Tomorrow’s and Sat/Sundays’s lows hugging the coast almost immediate.

    What does this mean? Snow, and at least a few inches of it. Disregard what the precip output is with these models as they tend to underestimate overwater trajectory and how these lows tend to develop with their cold core.

    What 00z looks like to me is game on.

  17. Bishoy says:

    Uh oh…

  18. kcteach-Gresham-500' says:

    Grass is still white here. Down to 33.3.

  19. Here is the new 24 hour RPM SNOW Fall

  20. muxpux says:

    well the radar seems to have died. now what? haha. had a couple snow showers (no sticking) and a hail shower today here in longview.

    should i expecvt anything overnight? doesnt look all that promising to my eyes…

    • Wendy-Silverlake,WA says:

      I was just walking out of Lowe’s when that hit today. It was nasty! I don’t think I’ve seen sideways hail like that in a long time.

  21. SilentReader says:

    last two mornings woke up to snow and some sticking snow. But all was melted by noon. I see today it was much cooler, only about 38 for a high. currently 33F and can’t tell if it’s snowing or not but I am sure what ever we get tonight will be here for me in the morning.
    Location: Scappoose Hills at about 1000FT.

  22. camas mom says:

    Snowing again up here – probably 1/2-1″ on the ground

  23. jlsc says:

    In downtown Gresham (I don’t know the elevation here), the awesome flakes came for a few minutes, but we’re back to the wimpy mostly rain flakes.

  24. Diana - Mt. Scott says:

    I guess I wasn’t paying attention for awhile! Just measured a fresh 1/2 inch covering everything. I didn’t see it falling, and it’s stopped now, but everythings white! Temp is 32.7

  25. PaulB/Eugene says:

    In Eugene we have not had any snow today (at least did not see any at the office). If it gets a bit colder as expected, may squeeze some snow showers out of the sky in the next day.

    WRF extended MM5 had significant snows once again for SW OR, with Eugene getting clipped by snows…1-3 inches in town, as much as five inches if one gains any elevation above the valley floor….will wait and see

  26. Rob "Wrath" S.E. Portland says:

    A pretty decent snow shower here. I’ve picked up a very wet, sloppy dusting….

    35.2

  27. Yevpolo1990 says:

    Looks like I can get some clearing tonight to lower the temp more, another round tomorrow?

  28. Yevpolo1990 says:

    00z nam shows us switching to light easterly flow on hour 39

    Shows about an inch of snow Friday morning:
    http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?mm5d2_e_snow3+//72/3

  29. kcteach-Gresham-500' says:

    Huge snowflakes right now.

    • kcteach-Gresham-500' says:

      We’re talking silver dollar sized flakes. Awesome to see.

    • TAGinGresham says:

      Yep, same thing at my house! It is really coming down!

    • Yevpolo1990 says:

      had my fun earlier today 🙂 hope you enjoy it!

    • TAGinGresham says:

      They are huge and floppy! So pretty, I just wish the ground wasn’t so wet and “warm” :(. Also, it would be nice if it happened during the day so you could really see it, but beggers can’t be choosers I guess.

    • TAGinGresham says:

      Well now it is beginning to stick on the cars, deck rails, and grass. I’m sure it is only a matter of time though, and it will be done.

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