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:
Oregon AMS on Facebook:
Oregon AMS on Twitter:
OMSI web site:

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