A Brief Post

January 22, 2009

I'm ashamed to admit I forgot to post this evening, and I really want to get out of here right after the weathercast.  So it'll be a short post.

In general, I don't see any changes from last night's thinking, except that most models are pretty dry for Sunday.  Now our RPM model we get here in the station indicates .30"!  It shows an organized wave moving down the coastline on Sunday morning.  I don't really see any other model showing that, so let's assume it's out to lunch.  We have leaned our forecast towards dry, but turning windy and chilly Sunday.  So the numbers on the 7 Day forecast haven't changed.  It is going to be a very brief cold snap.  The cold air gets wiped out of here quickly on Tuesday as a front moves in with low pressure up to the north.  A decent southerly flow up the valley warms us well above freezing that day.

Not much else going on beyond Tuesday either…Mark

Sun Dogs and Cold Temps

January 21, 2009

IMG_3612  A nice picture of a sun dog from Tim in Cedar Mill today.  I have a link on my weather page to the Atmospheric Optics page.  Or you can just click on that link to find our FAR more than you want to know about different visual phenomena in the atmosphere.

Okay, moving on to the weather…east wind TRYING to die down again this evening.  We've gone all the way down to a 6.5 mb. PDX-DLS gradient…I see TTD has only gusted to 33 mph the last 6 hours, and Corbett has stayed below 60 degrees.  The process continues tomorrow, so gusts should be below 40 mph even in the Gorge.

There are some echoes showing up on radar offshore this evening as a dying system moves onshore.  A sprinkle wouldn't surprise me, but we have a very dry airmass down at the surface, so freezing rain seems unlikely.  There's no chance for snow with temps in the 30s and 40s up at 4-6,000'!

For those of you out on the eastside wanting to get rid of the wind completely?  Hmmm, that's a problem.  Cooler air starts pouring back into Eastern Washington Friday, allowing the surface high east of the Cascades to "reload", which means easterly flow through the Gorge strengthens again.  That will be with us then through the middle of next week…sorry folks, no big warmup is coming for the frozen Gorge (or nearly frozen).

Some changes in our forecast this evening.  Those of you who watch the maps closely probably know what I mean.  18z and 00z GFS and now the 00z NAM have some moisture over us Sunday.  It is "spun up" by an upper level trough passing overhead at the same time a modified arctic front passes south at the surface.  Precipitation Sunday morning is accompanied by increasing easterly flow (30kts at 2,000'!) bringing in dry and cold air from the east.  Seems a bit like December 14th, when we had little or no snow in spots, but more in others.  One thing that is different is the airmass is not nearly as cold.  We are saying temps stay in the mid-upper 30s Sunday and Monday.  If current trends continue, those still need to come down by about 5 degrees for Sunday and Monday.  But that's still 3-4 days away…plenty of time to "fine-tune" the forecast.

This appears to be a one-shot deal for cold air…it's back to some sort of mild westerly flow or ridgy conditions Tuesday and beyond…Mark Nelsen


Another Chilly (& Windy) Night

January 20, 2009

Picture 002  Doug Jacobs sent in this nice looking picture from Grass Valley.  The picture was taken today, and he wondered how I possibly could call for a 10,000' freezing level.  Of course if you are reading this blog you probably know the answer.  First you need to know where he is.  Grass Valley is on Highway 97, maybe 25 miles south of Biggs Jct. near Maryhill.  It's at about 2,400'.  That puts them at the "intersection" of the low clouds and land over there in Eastern Oregon.  They have been in/out of the top of the fog layer much of the last week.  When the layer is deeper, they just see low clouds there, when thinner, they get fog.  In fact the temperature there has been between 20 and 25 degrees for the past 5 days!  Now that's REALLY boring weather, but it does make for a frosty scene doesn't it?

Back here west of the Cascades, nothing has changed dramatically in the last 24 hours.  The airmass coming through the Gorge has cooled though.  Troutdale is running 3 degrees cooler, Corbett is 2 degrees down.  This also dropped the high temperature at PDX 6 degrees from yesterday!  Since Saturday, it seems like PDX has been getting a bit warmer than I would have expected based on the airmass pouring out of the Gorge…the strong offshore gradient must have allowed some slight mixing of the warmer air above.  Weakening gradient has now kept the airmass more homogeneous, so I went only for a high of 45 again tomorrow.

Speaking of gradient, it's been a slow and painful process the last 24 hours.  We've gone from 10 millibars PDX-DLS easterly gradient down to 7.2 right now.  I expect a drop to 4-6 mb. by tomorrow at this time.  The wind has sure been slow to respond.  Gusts are still reaching around 60 mph at Corbett and 30-40 mph at TTD.  I notice we haven't seen a gust over 40 at Troutdale since 6am though, so progress is being made for those of you that are REALLY sick of the wind.  Today is day #6 of strong easterly flow…just one more to go!  I think Thursday will just see gusts 30-40 mph at the west end of the Gorge as the surface high continues to weaken.

Looks like a significant pattern change coming up this weekend, but to what?  What a tremendous mess in models beginning this weekend and continuing next week.  The general idea SEEMS to be for a longwave trough to become established along the West Coast, similar to what we saw in December.  However, model runs are all over the place…which makes me want to curl up in a fetal position, cry and murmur…ecmwf…ecmwf.  The GFS as of 00z suddenly now seems to want to be ridgy next week, a huge change.  The ECMWF sure looks similar to last winter, with cool storms coming at us from the west.  It also isn't quite as cold/deep with an initial shot of modified arctic air dropping over us Sunday though.  The GFS is definitely colder, in fact I realize our 7 Day forecast doesn't represent an airmass that cold (highs 35-40).  But Drew and I decided with model uncertainty that our current weekend forecast is a good blend.  As for snow, from what I see now, there's no moisture around since the cold air just "drops in" Sunday and Monday.  The ECMWF would have a big snowstorm by Tuesday as a surface low approaches the cold air over us, but the GFS is just plain dry.  I assume both of these will change with future model runs…it's only Tuesday!  Mark Nelsen

Extra: I've updated some of the peak wind gusts from the weekend storm down below.  The NWS reported 77 on their "Rooster Rock" sensor (which is 3 miles west at the Corbett exit).  Also a 67 in SE Troutdale.   Small town rumor says someone in Corbett measured 92 mph, but I haven't tracked that one down yet.

Still Blowing, but Weaker

January 19, 2009

Troutdale wind 03  Keith Biggs sent us this picture from Troutdale…one of many trees that fell the last few days.  Good news this evening as the wind has definitely ramped back down to "normal" at Troutdale.  Of course the gusts to around 60 mph might be considered "normal" up at Corbett, or at least generally not damaging.  The 9pm update from PGE says only 100 customers are out of power, so clearly there aren't many new outages.  My power at home came on soon after noon, so we were out about 38 hours.  That generator was worth EVERY penny!

Cold air is still streaming through the Gorge, but the cold air pool appears to be slightly shallower, evidenced by some clearing at Redmond and Bend today.  The thinner pool of cold air gives us a lighter pressure gradient through the Gorge…it's now around 10 millibars instead of 14+ over the weekend.  I think we'll see the gradient continue to gradually slacken the next 3 days…probably down to just 2-4 mb. by Thursday.

Not much to talk about through the weekend…except a sharp little drop of cooler air sometime Sunday, or Monday, depending on which model you choose to look at.  We (Drew and I) chose to not show anything dramatic either of those days since there are serious model differences. I did notice that the 12z WRF-GFS actually generates snow over us Monday morning as moisture from the west runs over colder air in place.  But once again, fun to look at but who knows what models will show tomorrow…Mark Nelsen

Peak Gusts: The Gorge Windstorm of ’09

January 18, 2009

(Wednesday 2pm)

I've updated a few windspeeds from the weekend storm here…I found a battery in the Corbett sensor today at the grade school.  Someone was thinking ahead.  So it recorded peak gusts during the entire storm, just couldn't send to a powerless computer.  Now I'm not getting paid for this, but the Davis Vantage Pro installed up there is a heck of an instrument.  It just keeps going and going and going…

(Previous post here)

From what I can tell, this has been the strongest easterly windstorm in the eastern Portland/Vancouver metro area since at least February 1996 (just before the flood) or more likely sometime before that.  That's based on the amount of damage seen out there and the actual recorded speeds.  This is the first time I've seen a peak gust around 60 mph at Troutdale (easterly) since the mid 90s when 24 hour a day observations began.  I think it's also safe to say that from the amount of downed trees, the period from Saturday midday to midday Sunday must have seen gusts of 80-90 mph in the Corbett area as well, the strongest since 1996 when several anemometers recorded gusts of 90-100 mph.  Unfortunately, the power went out during the windiest period!  I'm on hour 15 of no power here…posting via generator…Mark

So…if you have an anemometer and MEASURED a peak gust, put it here, keep discussing weather in other posts please:

1. Peak gust (mph)

2. Location

3. Time (if you know)

This is what I have so far:

Crown Point: 105 Noon Sunday (hand held), 92 3:30pm Saturday (hand held Tyler Mode)
Cape Horn, WA: 86 Sunday Night
Corbett (Menucha): 87 Sunday AM 
Corbett Elementary: 79 10:00pm Saturday 
Rooster Rock (NWS – Corbett Exit I-84): 77 Sunday Evening
Troutdale (SE):67 Saturday PM
Troutdale (Cherry Park): 63 5am Sunday
Troutdale Airport (KTTD): 59 6:30am Sunday
Troutdale (ODOT): 54 6:43am Sunday
West Orient Elementary: 54 Early Sunday AM
East Portland (ODOT-I205/Division): 49 5:22am Sunday
East Portland (160/Burnside): 58 10:30am Sunday
Portland Airport (KPDX): 44 11:35am Sunday
Parkrose: 42 11:00pm Sunday
SE Portland: 36 8pm Saturday
Beaverton (Cedar Mill): 44 4pm Saturday
Beaverton (SW): 33
East Vancouver: 38 10:30am Sunday
Skamania, WA: 56 10:30am Sunday

Crown Point Report

January 17, 2009

I was just up there for about an hour, standing in the lee of Vista House with Tyler Mode, Jesse from Orchards (and his brother), "Sandman" from Aloha, and Dr. J from Vancouver.

I hadn't done that for several years…here are the highlights:

1. Tyler recorded a peak gust of 92 mph.

2. 3 (or was it 4 or 5) car doors broken as folks parked facing away from the wind.  You open the door and it snaps well beyond the normal opening, bending the metal…one couple had two doors busted on the same car!  Good times…as the car hobbled back the scenic highway towards Corbett.  They won't ever be back.

3. One woman was tossed head first into the pavement and appeared stunned.  It's okay, the First Live Local weather blog team rushed in to help out.  A bit of blood here and there, but she made it back to her car.

4. Lots of flying hats, kleenex etc…

5. I had almost forgotten this one.  When in the middle of a windstorm, don't ask a guy that walks up to you "hey, you're Sandman right?".  He'll think you're nuts, or worse, working a drug deal as Fox12's Most Wanted.  I did that today…had the wrong person.  Real classy, right on the steps of one of Oregon's most famous tourist spots.  Could have caused an incident.

If you've never experienced 80-100 mph wind, this is the place to do it.  Just be very careful, walk low/close to the ground, and park facing into the wind.  And it's windy enough that I would not allow children out of the vehicle that are under 10 or so.

I'm attempting to warm up now…Mark Nelsen

Wind “Meeting” Today

January 17, 2009

If you want to feel 70-90 mph wind gusts just for fun, a few of us are getting together to "feel the wind" out at Crown Point near Corbett at 3pm today.  I have a feeling we won't last long with a windchill in the teens.  But anyone else is invited.  It'll be a beautiful, but brutal afternoon out there.  Just get off exit #22 at Corbett, head up the hill to the old highway, then go east about 2 miles.  I'll be in a Prius or 4Runner.  I doubt many other humans will be there, so it shouldn't be hard to find us.