Cold Rivers Plus A Warm Weekend

May 15, 2009
Watch Out If You're On The Rivers!
Watch Out If You’re On The Rivers!

Of course anyone who has lived in this area long knows that at the first onset of warm and sunny weather, folks will be jumping into local rivers.  Watch out if you do that this weekend;  the big rivers are about as cold as the Pacific Ocean.  The rivers draining the Cascades are swollen with ice-cold snowmelt, running at only 40-45 degrees or so.  You may remember when I did the Polar Bear Jump back on New Year’s Day 2008?  Everything pretty much seized up at 48 degrees that day when we jumped in the water, and within one minute I was feeling quite a bit weaker.  Imagine fighting a current at the same time.  Definitely don’t do it if you’ve been drinking either.   Of course these are things your mother should have taught you, but they always bear repeating right?

Moving on…the weather forecast shows a taste of summer the next 3 days.  High 500mb heights combined with very weak onshore flow means warm, but not hot weather.  This is not a set up where we get the hot east wind and temps in the 90s like we saw last year.  The reason is that the upper level ridge is quite flat, as opposed to a sharp ridge with the upper level high centered closer to us.

Last night’s change with the 00z GFS (see previous post) was correct apparently.  The following runs have continued that idea.  I think we have to give the ECMWF kudos for forecasting this warm spell while the GFS spent days waffling around with the details.

I’ll be participating in Solv’s Down By the Riverside event tomorrow morning from 9am-Noon.  There are something like 350 projects spread across the state.  Me and several others from my church will be helping out at Beaver Creek near the Sandy River in Troutdale.  Looks like plenty of sun and no rain…good news there.

Mark Nelsen

The GFS giving it up a bit…

May 14, 2009

A very short post because I took a nice long bike ride, then ended up on the phone discussing some possible big changes in the Portland TV weather people “scene”.  How’s that for a tease?  Basically I was doing some weather gossip.  Don’t worry, it doesn’t affect anyone here at FOX-12.

Well, the 00z GFS has suddenly veered towards the ECMWF solution for Monday-Tuesday, keeping upper-level heights much higher, 850mb temps warmer, and digging an approaching trough much farther offshore.  It’s really obvious when you look at the 12z, 18z, 00z 500mb height comparison for Monday afternoon.  This link is a good place to view it.  I notice the 850 mb temp over PDX is 15-16 now compared to 5 Monday afternoon on the new GFS.  So I bumped Monday back up to 80, which could be low.  We’ll see.  Okay, time to slather the makeup on again…Mark Nelsen

Big Warm Up On Track

May 13, 2009

A brief post tonight due to working on some graphics, plus making vacation plans.  Very important stuff.

Well, the ECMWF came a bit towards the GFS today, so we got rid of the 85 degree temp on Monday.  But the GFS also seems to be a bit unsure about the Sunday outlook too.  Right now I’d figure about 77 based on the GFS.  The ECMWF has been slower with the breakdown of the ridging, so we’ll leave the 7 Day forecast as it is for now.

AMS Meeting Thursday

May 12, 2009

We have an Oregon Chapter AMS meeting this Thursday.  Anyone is welcome for good food and weather chat.  Dinner generally seems to cost $10-$20 if my memory is correct.  Remember that you don’t actually have to eat, you could just come and have a drink, socialize, and steal someone else’s cup of spumoni ice cream…just not mine.  Actually I don’t think I’ll make it to this meeting since it’s so far from work, so grab some from someone else.


May AMS Meeting – “Rose Festival Weather”

Date: Thursday, May 14th
Time:  6:00-9:00pm (Dinner at 6:00pm)
Location: Old Spaghetti Factory in Clackamas 12725 SE 93rd Ave Clackamas, OR 97015

George Miller… meteorologist, writer, historian and college instructor… will share his interesting findings upon review of 100+ years of Rose Festival weather records!

For complete meeting details and driving directions, please see —

TONIGHT’S WEATHER:  Easy forecast through about Sunday, but the last two days of the extended forecast are messy.  Warm up still looks great Friday through Sunday, but the last few runs of the GFS have shown a deep and fast moving upper-level trough swinging through the Pacific Northwest Monday.  Meanwhile, the 12z ECMWF went the other direction.  It has the energy digging far offshore pumping up a hot ridge over us.  It doesn’t get much more extreme than this:  00z GFS has 850 mb temp Monday afternoon over PDX of -1!  The 12z ECMWF has about 21!  So…it’s either going to be 93 or 60 for a high in Portland on Monday!  Now that’s some fun forecasting.  We decided to leave the two 85 degree temps in the forecast until things flesh out tomorrow.  I have a gut feeling that tonight’s 00z ECMWF will make a dramatic change towards the GFS solution.  I do notice that both models keep us relatively dry next week.

I’ve turned off the “Gravatars” (the pictures) in the comments for now, let me know (in the comments) what you think.  Seems like only some of us were using them and maybe a few were annoyed by them.

Cooler Air Moving In

May 11, 2009

First a poll, for fun:


I thought of this today as I came outside to get in the car and drive to work.  It was breezy, comfortable, and just refreshing in general.  I thought “what a perfectly normal spring day in Western Oregon”.  It seems like it’s been a very nice spring so far to me.  A warm spell about every week and a half, followed by cooler weather and showers.  We haven’t seen any long spells of wet weather, and no constant cold like last year.  Remember last year?  I think almost the entire Spring was chilly (through mid June!) minus that 95 degree heat wave in mid-May.  That was sure strange.  Anyway, looks like quite a few of you are happy with this Spring so far as well.  Of course most of us here would probably like to see lots more hail and thunderstorms every few days, but this is about reality here in the poll.

Moving on, a nice pool of cool air beginning to arrive now.  A radar on the South Washington Coast would be nice in a situation like tonight’s.  IR satellite shows a nice band or two of what are probably heavy showers moving towards the Coastline.  Maybe a flash of lightning on the beaches overnight?  Maybe not.  In fact Drew and I discussed the possibility of a thunderstorm Tuesday afternoon inland.  Looks like the main dynamics and coldest air has moved off to our east during the peak afternoon heating.  We’ll see if the strong sunshine can do the trick.  I left thundershowers out of the forecast in the end.

Models are agreeing well on a nice ridge developing over us Saturday through Monday.  In fact the ECMWF and GFS hint that it’ll be the beginning of a longer period of much drier and mild weather.  The maps definitely have that “late May-early June” look with higher 500mb heights even after the weekend…Mark Nelsen

A New Radar?

May 8, 2009

radarThe news came out yesterday that the Pacific Northwest MAY soon get a new weather surveillance radar!  Any new weather tools are welcome of course…but it’s always about the $$$ isn’t it?  Here’s the deal.  President Obama’s budget proposal includes funding for the first Pacific Northwest coastal radar.  Cliff Mass (a tireless promoter of the idea and a professor at the UW in Seattle) puts it this way in his Weather BlogThe implications of this inclusion are substantial…the National Weather Service is now supporting the radar and if the requested funding is approved by Congress (about 7 million dollars), the radar will become a reality.

So where might the new radar go?  Lots of thought has been put into it and it appears the plan is to put it near Westport, WA.  That’s maybe 40 miles north of Astoria.  It would be nice to get a 2nd one on the Central Oregon Coast since we have the worst coastal radar coverage in the nation, but once again…it’s all about the $$$!  Here is a great Powerpoint presentation on the whole subject:  Northwest Coastal Radar Proposal

Enjoy the sunny weekend!


1. Any and all are welcome to comment.  This is an open discussion.  However, to avoid abuse, the VERY FIRST TIME you post a comment, we must approve it manually.  So if it’s your first time commenting, be patient, especially over the weekends!

2. Signing up is easy, just go to, click SIGN ME UP, then click USERNAME ONLY PLEASE.  Want to add a picture of yourself?  Go to EDIT PROFILE once you are logged in and on the right side will be a neat little tool to change your “Gravatar”.  As for logging in or out, I notice that each time I come back I’m logged in, both at home and work.  So unless you dump your “cookies” regularly you’ll probably always be logged in for commenting.

Mark Nelsen

An Oregon Tornado

May 7, 2009

snapshotThe storm report came out from the Pendleton Forecast Office today.  Looks like an EF1 tornado popped out of that severe thunderstorm just northeast of Pendleton yesterday.  Pretty impressive for the Pacific Northwest.  It’s all about location though as always…imagine if that would have moved through the Metro Area.  Wait, that did happen last January…in Vancouver.

The weather looks very quiet the next few days…nice and warmer with plenty of sunshine.  Mark Nelsen