Warmest La Nina Year

January 23, 2012

I just found this little chart (I really like charts and graphs) on the NCDC site.  It shows global land/ocean temps since 1950, so obviously a relatively short record.  BUT, what’s most interesting is how this past year’s La Nina had little effect on global temps, or at least less effect than in the past.  In fact, 2011 was the warmest La Nina year during that period of time.  Interesting eh?  Of course we’re talking about all of 1/2 degree difference, but interesting nonetheless.


One Last Wet Storm System

January 23, 2012

This one comes in late tonight and tomorrow morning…but it won’t be nearly as wet as last week’s deluge.  Check out our RPM rain forecast.   Luckily just an inch or so here in the Valleys tomorrow and Wednesday.  Heavier amounts in the Coast and Cascade Ranges could set off minor river flooding on either of the usual North Coast Range rivers (Wilson & Nehalem).

No signficiant wind coming up with this system other than the usual gusts 50-65 mph on the coastline, much lighter here in the Valleys.

There WILL be another shot of snow in the central/eastern Columbia River Gorge.  Plenty of snow cover to the east, a cold night, then precipitation moves in over the cool air around 8am.  Model soundings say snow is possibly from start to early afternoon.  POSSIBLY a period of freezing rain in the late afternoon; no dramatic warming until late tomorrow night with a return of the west wind.  So I see 3-5″ possible for Cascade Locks to The Dalles from 8am-3pm.

Starting Thursday, it appears we are headed for a big slowdown in the weather again, similar to what we saw for the 7 weeks before mid January.  A few weak systems for very light rain here or there, but that’s it. 

The GFS (a bit unreliable this winter in my view) shows strong ridging off and on over the next 2 weeks.  The ECMWF isn’t quite as much a “blowtorch”, showing occasional systems moving inland and no real strong ridging.  Both say little or no chance for lower elevation snow, no arctic blasts, and no windstorm/flooding events.

Here are the two 850mb ensemble temp charts for the next two weeks from both the GFS:

and the ECMWF, note they both have some sort of chilly troughing (briefly) about 8 days from now, around the 31st.:

Chief Meteorologist Mark Nelsen


Rescheduled Global Warming Meeting Is This Week

January 23, 2012

In case you were wondering, our local chapter of the AMS (American Meteorological Society) rescheduled the OMSI Global Warming Meeting for this week.  It’ll be coming up this Wednesday at the Airport Shilo Inn. 

The point of this meeting was to offer the other side (those that are unconvinced humans are the cause of global warming) a chance to be heard.  I am on the executive board of our local chapter and while I don’t necessarily agree with their views, I did want to hear what they have to say and thought they should be heard.  As with any other topic we cover at AMS meetings, we are expecting the speakers to stick to science; this isn’t a political meeting. 

Here are the details:

WHAT:  Come take a look at the science, both the logic and the evidence. Is human caused global warming the greatest scientific myth of our generation?

WHEN: Wednesday, January 25th 2012 from 7-9 PM. Please plan to arrive early. A large turnout is expected. There will be a no-host social hour in the Shilo restaurant from 5-7pm. Come eat dinner and/or have a beverage. Catch up with friends and colleagues!

WHERE: Portland Airport Shilo Inn Convention Center Ballroom 11707 NE Airport Way, Portland, OR 97220. Hotel directions: http://www.shiloinns.com/hotel_details.asp?PI=PASOR

COST: Free and open to the general public.

GUEST SPEAKERS: Former Oregon State Climatologist George Taylor, Meteorologist Chuck Wiese and Physicist Gordon Fulks, PhD.

AGENDA: Come hear Mr. Taylor, Mr. Wiese and Dr. Fulks explore what they consider to be the many problems with the theory of catastrophic human-caused climate change. They will also present their own forecasts for the next decade, century, millennium and beyond. There will also be a public Q & A session at the conclusion of the meeting.

CONTACT: Oregon AMS President, Steve Pierce at: stevejpierce@comcast.net or 503-504-2075. Oregon AMS web site: http://www.ametsoc.org/chapters/oregon

The Oregon Chapter of the American Meteorological Society has no formal position on the subject matter of climate change. Our society is committed to our mission statement which reads: The purpose of this society shall be to advance professional ideals in the science of meteorology and to promote the development, exchange, and application of meteorological knowledge. To that end, we are planning to host a future meeting with the opposing side of this subject matter. Please stay tuned for additional details.

I will not be able to attend this meeting because of my schedule, I’ll be on the 6, 8, 10, & 11pm newscasts that night.

Chief Meteorologist Mark Nelsen


Gorge Ice Storm Update: More Damaging Ice Through Tonight

January 20, 2012

One more weather development this morning, that approaching low pressure center is pulling quite a bit of cold air through the Gorge, more than I expected. In fact it’s deepening east of the Cascade Crest.  Auspurger Mountain (~3000′), was 38 degrees at 4am but is now down to 21!  The cold air is banking up against the east side of the Cascades.  Same thing with a dropping temperature across the river at Greenpoint SNOTEL site at about the same elevation.  So the cold airmass over there is around 3,000′ thick.  With such thick cold air, temps are now at/below freezing at the west end of the Gorge above about 1,000′ with a strong east wind.  Vista House wind sensor froze up around 10am…you can see it here.  And at my home I have ice starting to form on trees, but not on the road/pavement.  Seems like it needs to be about 30 degrees with freezing rain to get ice on pavement during the day.  It’s interesting in situations like this where the temp goes from 34 to 33 to 32 etc…; it’s just raining like normal, and then all of a sudden you notice ice is forming on objects while it continues to rain at exactly the same rate.

If you’ve lived in the Columbia River Gorge long, you know that to get the cold air out, the wind needs to switch to west.   There is good and bad news on that front:

Bad:  There will be no wind switch and thus no warmup until the very early morning hoursThe Ice Storm will continue until that time.  Anything that falls will fall as freezing rain or possibly sleet (ice pellets);  more thick ice building up on all objects.   That could easily add another 1/2″ ice accumulation.  There are already trees and powerlines down all over the place out there in the Hood River Valley and east to The Dalles, Lyle etc…; it’ll get worse before it gets better.

Good:  Sometime between 4am and daybreak a good surge of 45 degree westerly wind will punch through the east end of the Gorge, aided by a much cooler airmass moving in above too (sounds strange, but this helps mix out the cooler air at the lowest elevations).  That breaks the inversion currently in place with below freezing air below but mild temps in the mountains.  So tomorrow will be MUCH warmer for storm cleanup.

By the way, if you have good ice storm pictures, send them to photos@kptv.com and we may be able to get them on-air to show others.

Chief Meteorologist Mark Nelsen


11am: Quick Update

January 20, 2012

Pretty quiet this morning with light rain picking up across the area.  Here in the Portland Metro area we have a mainly uneventful weather weekend on the way (including today):

FLOODING:  All rivers continuing to recede today since we had almost 24 hours with no rain in the central Willamette Valley.   The rain the next 3 days will be light enough that none are forecast will return to flooding. 

 ICE STORM:  The Columbia River Gorge has an Ice Storm Warning.  All of today’s rain will fall as glaze ice east of Cascade Locks.    What a mess developing in the Hood River Valley and in The Dalles too.  I see slightly colder air moved in overnight in that area.  Middle Mtn (in the MIDDLE of the Hood River Valley…hmmm…) went from low 30s last night down into the mid 20s now.  So it’s a good 2,000′ layer of chilly air stuck.  That won’t get dislodged until the wave (related to wind westside) comes through late tonight.  Could see another 1/2″ ice easily.

WIND:  Model are noticeably weaker this morning with the wave coming through tonight.  Still windy along the Coast, gusts up around 70 mph for a brief period 11pm-3am there.  But nothing too unusual.  Here in the Valley, only the MM5-NAM is holding onto a strong southerly gradient (18mb OLM-EUG).  The WRF-GFS and our RPM have 13-16mb gradient OLM-EUG.  That would be more of a “wind advisory” event with gusts around 40 mph.  Once again, nothing unusual there.  So as of now, I don’t see a windstorm overnight.  Hopefully the 00z model runs are weak as well.

And now…I…am… “checking out” of any weather activities until I get to work around 2pm…not even going to think WEATHER for the first time in a week…

Chief Meteorologist Mark Nelsen

 


Possible Windstorm Friday Night

January 19, 2012

A disturbing (or exciting) convergence of mesoscale models suddenly occurred this evening; they all show the potential for a signficant windstorm on the coast and possibly a windstorm in the western Valleys late tomorrow night.

The WRF-GFS and our RPM both show almost exactly the same thing.  A deep low tracking to about Astoria and then moving inland over SW Washington.  Timing is the same too, with strongest wind here in the Northern Willamette Valley sometime between Midnight-3am.  How strong could the wind be based on these models?  The WRF-GFS shows 17 millibars from Olympia to Eugene!  A common calculation for a possible peak gust at PDX is about 3.15×17 in this case.  That would be between 50-60 mph, maybe similar to the Hannukah Eve storm in December 2006 (for Portland).  Our RPM is slightly farther south with the low, showing 16 millibars from just Kelso to Eugene!  That’s real impressive. 

Now the MM5-NAM is a bit different, more of an open wave (not a closed area of low pressure), but it’s farther south.  I’d put the strong winds somewhere down in the Valley, more like Salem and Eugene.  It shows 11 millibars just from Portland to Eugene with a strong surge from the southwest behind the wave.  It’s just slightly later too, closer to 3-4am.

So the possibility of a significant windstorm is definitely there; I’ll get more excited about it if the 12z runs all come in similar or stronger.

Other than that, today has been consumed by flood coverage.  It has been the biggest flood since 1996 in the central valley.  In some areas worse than 1996.  Here are the 3 day rain totals:

Chief Meteorologist Mark Nelsen


Flood Update: La Nina Making Up for Lost Time?

January 19, 2012

What a mess this morning, not here in the metro area, but down in the Willamette Valley, here are the highlights:

  1. Heavy rain is ending west of the Cascades, now it’s light showers through tomorrow afternoon
  2. It doesn’t matter, the damage has already been done rain-wise
  3. A few rivers have major flooding, most have minor
  4. The smaller creeks and streams and localized flooding are a much larger issue today

Check out the 3-day rain totals:

Portland: 2.61″
Salem: 6.71″
Corvallis: 5.93″
Eugene: 5.00″

Now you can see why almost all the flooding issues are down in the valley!

Here are the rivers with MAJOR flood warnings from the Northwest River Forecast Center:

ALSEA RIVER
LUCKIAMUTE RIVER
MARYS RIVER (Record Flooding)

Rivers with MINOR flood warnings

JOHNSON CREEK
CLACKAMAS RIVER
MOLALLA RIVER
S. YAMHILL RIVER
PUDDING RIVER
SANTIAM RIVER

Something that sticks out here, all the rivers draining the Cascades either have no flooding or minor flooding.  Minor flooding means just a foot or so above flood stage by the way.  There’s a good reason for that.  The flood control reservoirs (Detroit, Green Peter, Cougar etc…) are all less than one quarter of capacity!  Some have very little in them.  Check out the reservoir “teacup” diagram:

So no major flooding expected on the Willamette River itself.  I see Detroit Dam and Fern Ridge are holding back about 90% of their river’s flow…pretty impressive!  So where is all the water coming from?  It’s from the Coast Range (no dams there) and the water falling in the foothills and valley itself.  6″ of rain falling over the wide, flat expanse of the Willamette Valley plus the foothills (dams don’t capture that water) is enough to cause the widespread flooding down there.  So yes, it’s possible to have 1996 style flooding in Willamette Valley towns but not have major river flooding at the same time.

Up here in the Portland Metro Area, other than ares of water from this morning’s downpour, I don’t foresee any signficant flooding issues showing up in the next 24-36 hours.  But we are still under a Flood Watch.

Meteorologically interesting this morning as a surface low has moved onshore a bit north of the forecast.  It’s moving right into the Portland Metro right now and will just die overhead!  Strong south wind to the south of it over Salem  just compounding the flooding.  To the east, a very thin layer of that cold arctic air is bringing mainly freezing rain to the central and eastern Gorge.  That will come to an end only with the precipitation tapering off.  The cold air isn’t going anywhere this evening; no west wind to scour it out.

Two more things to talk about:

1. Possible strong south wind tomorrow night.  A deep low tracks towards SE Alaska tomorrow evening, but models are definitely hinting at a secondary low or at least “triple point” moving by just to our north.  Interesting to note that both MM5-NAM, WRF-GFS, and our RPM show the tightest southerly gradient right around midnight-2am tomorrow night.   The WRF-GFS would suggest gusts 40-50 mph since it shows 60 mph wind just a thousand feet or two above the surface.

2. Long range:  Possible heavy rain on snow event next Tuesday-Thursday, timing and amount of rain uncertain.  Not good of course.

3. Longer range: Models have definitely been trending towards colder flow/troughing over the West Coast about one week from now onwards:  Check out the last two ensemble 850mb charts from GFS and ECMWF. 

The signal is there, especially on the GFS.  But they both have us back in the “close to arctic blast, low elevation snow possible” pattern.  We’ll keep an eye on it.

Chief Meteorologist Mark Nelsen