Halloween Forecast and November Weather Action

October 26, 2011

The forecast isn’t looking so bad for this weekend; that’s because our dull weather pattern continues through about the middle of next week (the next 6-7 days).  One weak weather system comes through here Friday, and another late Sunday.  That leaves Saturday and most of Sunday dry, and then just a few leftover showers on Monday.  By Monday evening we should be clearing out; the little tots might actually have dry weather!  I’ll think I’ll join my kids on Monday too…should I go as a Gangsta’ like my son?  Probably not; doesn’t seem to quite fit.

Moving on…tomorrow DOES look like a nice day to get work done outside (again!).  A foggy start, then sun in the afternoon.

I mentioned a change coming up next week.  Models seem to be keying in on stronger troughing in the Eastern Pacific and Western USA.  This is WAY out there, but in the 7-14 day period several troughs come crashing down into our region.  They each contain colder air and periods of rain.  It’s pretty obvious on these two charts:

They are the long range ensemble forecasts from the 12z ECMWF and 18z GFS runs.  Two things stick out on both.  After about November 2nd, 850mb temps (around 5,000′) drop below average for most or all of the rest of the model runs.  That implies cooler than average temperatures, and most precipitation would fall as snow at/above pass elevations in the Cascades.  The blue line is the “operational” run, the red line is the average of all the ensemble members.  The green is average.  The other item I noticed is the GFS (at least the 18z) operational is just about the coolest of all the ensemble members.  So it may be a bit cold…we’ll see.

So prepare for a change next week, but it appears we’ll end up with a drier than average October.

Chief Meteorologist Mark Nelsen


Northern Lights and Mt. Hood

October 25, 2011

Northern Lights and Mt. Hood

Gary Randall captured the Aurora Borealis, Mt. Hood, and an Orionid Meteor October 23, 2011.

First Frost Tonight in Outlying Areas

October 24, 2011

Here are a couple charts I put together with average first frost dates:

Everything is lining up well for a perfect night of radiational cooling.  Skies have cleared out, dewpoints have lowered, and we have no significant pressure gradient either up/down the Willamette Valley or east/west through the Gorge.  So no stirring of the wind.  Those dewpoints are a little higher than I’d like for low temps in outlying areas to drop into the upper 20s.  But some drier air above should work down during the night, plus some moisture will condense out as either fog or dew.  So my forecast of 37 at PDX and the coldest spots (SPB & HIO) at 28-29 SHOULD be okay.  We’ll find out in the morning.

Chief Meteorologist Mark Nelsen

Annual Winter Weather Meeting THIS Saturday

October 24, 2011

It’s time kids; the largest Oregon Chapter AMS meeting of the year.  It’s the 19th Annual Winter Weather Meeting.  Here’s a slightly edited official press release:

Regional Experts Will Once Again Descend On Portland To Predict This Coming Winter’s Weather!

Saturday, October 29th, 10:00am, OMSI Auditorium

La Nina is coming back again! Last winter saw record setting snowfall at several mountain locations across the Pacific Northwest as well as multiple snowfalls in bothPortland andSeattle. Will this winter be a repeat? TheOregon chapter of the American Meteorological Society (AMS) is proud to announce the 19th annual “Winter Weather Forecast Conference” inPortland. This year’s event will once again be held at the Oregon Museum of Science and Industry (OMSI), located at1945 S.E. Water Avenue inPortland on Saturday, October 29th 2011 from 10 AM to 3 PM inside OMSI’s auditorium. As always, the conference is free and open to the general public. The year’s meeting has been expanded to include an exciting / new afternoon session. The Oregon AMS will also be raffling off a $300Davis home weather station. You will need to be present in order to win. Raffle tickets will be on sale at the conference. Parking at OMSI will be free. Video and still cameras will be allowed, however bulky tripods are discouraged due to an expected capacity crowd. In keeping with tradition, regional news media is again encouraged to advance and cover this event.

This year’s expanded rundown is as follows:

Morning “winter weather forecast” session 10am-12pm

Opening comments / welcome – Steve Pierce, President Oregon AMS

OMSI update – Jim Todd

Last year’s weather recap – Mark Nelsen, Chief Meteorologist, KPTV Ch.12 Portland

1st Winter Forecast – Pete Parsons, Meteorologist, Oregon Department of Forestry

2nd Winter Forecast – Dave Elson, Meteorologist, NOAA / National Weather Service

3rd Winter Forecast – Kyle Dittmer, Meteorologist / Hydrologist, Columbia River Inter-Tribal Fish Commission

4th Winter Forecast – Jim Little, Meteorologist, Oregon Department of Forestry

5th Winter Forecast – George Taylor, Meteorologist / Former Oregon State Climatologist, Retired

Audience Q&A

Lunch break for all conference attendees from 12-1pm. Exact timing of the lunch break is subject to slight modification. A no host lunch is available in the OMSI food court.

*NEW* afternoon session 1-3pm

* Special AMS raffle @ 1pm. You must be present in order to win this great weather-related item, valued at nearly $300. Raffle tickets will be available during the lunch break in the OMSI auditorium.

1st Speakers – Jeremiah Pyle and Shawn Weagle – Meteorologists, NOAA / National Weather Service. Topic: Introduction to the exciting / new dual-polarization technology upgrade to our local radars in Southwest Washington (new coastal radar) and Northwest Oregon (Portland radar).

2nd Speaker – Wolf Read – PhD candidate, Forest Science, University of British Columbia. Topic: Diminished windstorm frequency and possible association with the Pacific Decadal Oscillation (PDO) regime shift of 1976-77.

3rd Speaker – Thyra Bishop – Meteorologist / Lieutenant Colonel, Oregon National Guard. Topic: Combat meteorology. An overview of the Air Force weather career field and how combat meteorologists impact the military decision making process.

4th Speaker – Chuck Wiese – Meteorologist. Topic: Human caused climate change? A real look at the physics and evidence. A demonstration of the lack of evidence both empirically and physically, of human caused climate change.

Weather Related Vendors

George Miller – Author, retired meteorologist and Oregon AMS executive councilor; “Pacific Northwest Weather: But My Barometer Says Fair” and “Lewis andClark’s Northwest Journey: Weather Disagreeable.”

Columbia Weather Systems – Weather Equipment and Software Sales – Martha Khoury, Oregon AMS member

2012 Weather Photography Calendars – Tyler Mode, Oregon AMS member

“Depiction” GIS Mapping Software – Tim Goddard

Conference adjourns @ 3pm

Oregon AMS web site: http://www.ametsoc.org/chapters/oregon
Oregon AMS on Facebook: http://www.facebook.com/OregonAMS
Oregon AMS on Twitter: http://twitter.com/oregonams
OMSI web site: http://www.omsi.edu/

As you can see, I don’t forecast (do you think I’m nuts???), but like to look back at the past year.  I just finished that presentation over the weekend and one of the “slides” is above.  Hopefully I’ll see a bunch of you there; I’ll be in the back most of the time selling the weather system raffle tickets.

Chief Meteorologist Mark Nelsen

The Berkeley Earth Project; The Warming is Real

October 22, 2011

I rarely discuss Anthropogenic (Human-Caused) Global Warming on-air or even in this blog for two reasons:

1. The issue has become politicised so badly that you can’t have a scientific discussion about it before someone brings up Al Gore, Big Oil, Socialists, Far Right Wackos, or something similar that should have nothing to do with the discussion.

2. I have not been convinced over the years that it’s a “pressing” issue.  On the other hand, I’m do not believe there is a “scientific conspiracy” out there pushing it on us.  Plus, let’s be honest, China and India’s rising emissions of CO2 are going to totally dwarf any cutbacks we make to our CO2 output in the developed world anyway.  We’ve already made our CO2 “bed” for better or worse.  Let’s see how we can deal with the warming the next 100 years if that indeed is going to happen.

But I’m a bit more convinced our planet has been warming after a big ripple in the debate showed up this week.  A team of climate skeptics (physics professors and Ph.Ds)  from California took on the global land temperature datasets.  This time they used far more data and included far more stations that has been used in the past by other organizations. 

The summary is only two pages…pretty easy to read.  They have submitted now to the usual peer-review process.


Here are the basic findings:

– The warming is almost the same as reported by the much smaller studies used in the past (NOAA, NASA, HADLEY CENTER).

– The urban heating effect is large and real, but does not contribute signficantly to the rise in land temps because only 1% of the earth’s surface is urban.

– 1/3 of sites show cooling in the last 70 years, 2/3 show warming.

– There has been a great study by Anthony Watts showing extremely poor (check out the pictures!) weather station siting all across the USA.  But this study points out that Anthony’s “poor” stations warmed similarly to “OK” stations.  The stations might be too hot, but they warmed, or cooled, along with other stations nearby. 

– The data and methods is available for others to check as well; they want it all to be transparent with an open discussion of the study.

– They did not make an assessment of “how much of the observed warming is due to humans”.

The Berkeley Earth Temperature Project now plans to do something similar for oceans, which other data sources say have not warmed as much.

As a former co-worker once said “I guess we’ll know for sure in 100 years!”.

Go ahead and discuss below, but I’ll delete any political comments.  And yes, I’m fully aware that even this BEST study shows a decline in land temperatures the past 7 years.  It did that in the 1970s too.

By the way, a great site and easy to read is here:  http://www.skepticalscience.com/

Chief Meteorologist Mark Nelsen

Fresh Podcast Just Posted

October 21, 2011

Brian and I just finished another podcast and it’s ready for your listening pleasure.

Episode 17: Fall’s Peak Week, Mark’s Angry Email and Super Typhoon Tip

This week the guys talk about fall colors and where the best spots are around the area to catch some picturesque views.  Plus, we break down an angry email sent to Mark and look back this month in history at Super Typhoon Tip.

Click on the link above to listen to this week’s episode.

No Sunshine Today

October 19, 2011

A huge change the last 6 hours…


24 hours ago it was gusting over 70 mph at Vista House in the Gorge with easterly wind; now it’s light westerly.  We’ve had a massive push of ocean air inland since midnight, triggered by a passing upper-level trough.  Suddenly we have a 4,000′ deep marine layer in late October.  It should go without saying that we probably won’t see any sun today and high temps will be 15 degrees cooler.  But hey, at least no wind?