Overview

Fall weather prevailed in Oregon during September. It was a delightfully mild and dry month, with generally below-average temperature and precipitation. The only really significant storm occurred on the last day of the month, and it was a big one: northwestern Oregon picked up 1-2 inches of rain. Portland Airport, which had only seen .03 inches all month, recorded 1.68” on the 30th, putting it above normal for the month.

Table 1 is a summary of monthly averages and totals at selected stations throughout the state. Table 2 lists daily temperatures and precipitation for most of the locations listed in Table 1. In Table 3, monthly and seasonal precipitation totals throughout the state are listed.

Basin Summary

Here is a summary of water indicators at the end of the month, by river basin:

n.a. Not available
(1) Percent of normal September precipitation, from NOAA Cooperative sites
(2) Percent of normal seasonal precipitation (since Oct. 1), from NOAA Cooperative sites
(3) Percent of normal seasonal precipitation, from Natural Resources Conservation Service (NRCS) SNOTEL sites
(4) Percent of normal September stream flow, from U.S. Geological Survey (USGS)
(5) Percent of normal seasonal stream flow (since Oct. 1), from USGS
(6) Surface Water Supply Index, from NRCS (-4 = very dry, 0 = normal, +4 = very wet)

Forecasts
The Climate Prediction Center’s (CPC) forecasts for October-December appear below. Temperatures for western Oregon are likely to be above normal. Precipitation probabilities suggest an equal chance of below-, near-, and above-normal rainfall.

Oregon Climate Service predicts slightly above-normal temperatures and normal precipitation for the same three-month period.

Blogs, Podcasts, and Googles

" The way we practice journalism has changed significantly when what in the past would have been a private exchange between an annoyed source and a reporter is part of the public record. This is the 'transparency' that we so often talk about as being a hallmark of journalism in the Internet era."
— Steve Outing, New York Times

Science has changed. Journalism has changed. And the relationship between science and journalism will never be the same.

Roger Pielke, Sr. is the State Climatologist for Colorado and a professor at Colorado State University. He was a member of a climate committee reporting to the federal government and resigned from the committee because of a disagreement over policy. His resignation was the subject of a lengthy New York Time article by Andrew Revkin which “badly mischaracterized my perspective,” according to Pielke. Rather than write to the Times’ editorial page, Pielke began a lengthy conversation on his blog, http://climatesci.atmos.colostate.edu, in which Revkin participated.

Blogs are all the rage now on the Internet. By definition, a “blog” is “a frequent, chronological publication of personal thoughts and Web links.” Some blogs are simply online diaries (with links, pictures, and sound recordings added). My colleague Matt Doggett, who’s been in Iraq with the Air Force Reserve for several months, keeps a blog to share his thoughts and experiences, and to make it easy for folks to correspond with him (http://www.oregonstate.edu/~doggettm). Other blogs are more like fascinating conversations among many people, sometimes degenerating into heated arguments. You can find blogs popping up everywhere, covering just about any subject.

Weather and climate blogs have become numerous, and the list is growing every day. Here are a few that I recommend (and be warned: this list may be obsolete in a month as new blogs are added):

www.climateaudit.org – Steve McIntyre and Ross McKitrick are two Canadians who have spent a lot of time doing statistical analyses of climate and “paleoclimate” data used in journal articles and other publications. This is McIntyre’s blog.

http://realclimate.org/ - This is “the other side” of the debate on historical climate records and publications. Many of the scientists whose work is being scrutinized by McIntyre and McKitrick submit pieces to this blog, including Michael Mann of “Hockey Stick” fame. It’s quite interesting to read about the same event from the two very different perspectives that characterize the two blogs.

http://sciencepolicy.colorado.edu/prometheus/ Roger Pielke’s son, Roger Pielke, Jr., is a University of Colorado professor who specializes in science policy. Whereas his dad studies “what is happening in the world?” Pielke Jr. discusses “what should we do about it?”

http://www.FLHurricane.com Central Florida hurricane center; includes news and a Met blog. During the two recent hurricanes (Katrina and Rita), this blog was very busy, providing very timely information on the storms and the on-the-ground conditions. One advantage of a blog is that items can be posted almost immediately, so when conditions are changing quickly one can keep up with news in a very timely manner.

The Houston Chronicle. http://blogs.chron.com/rita/

From an AP article: “As Hurricane Rita approached, editors at the Houston Chronicle decided to experiment: They hand-picked about a dozen Web diarists and asked them to post regular dispatches on the newspaper's online blog -- all without any editorial intervention. The Chronicle set up a second blog for its own staff writers -- this one edited -- to post anecdotes and other info before they appeared in any stories, print or online. And science writer Eric Berger devoted his regular blog, SciGuy, to the storm.

“ Besides the Chronicle's blogs, Web surfers were able to get firsthand accounts Friday through podcasts and photographs. They could track the storm using Google-powered maps. And they could find housing and other emergency information from government and private Web sites.”

Podcast? There’s another new term! According to wikipedia, Podcasting is “making audio files (most commonly in MP3 format) available online in a way that allows software to automatically download the files for listening at the user's convenience.” It’s a great way to listen to testimonies, interviews, musical performances, and conversations on your MP3 player or computer, whenever you want. Last week I listened to a U.S. Senate subcommittee hearing and a poet reading her own material.

What an amazing time it is!

Hurricanes and Climate Change

The devastating effects of hurricane Katrina have gotten everyone’s attention, and among the questions being asked are “is this due to climate change?” and “are we likely to see more storms like this in the future?”

According to a release from the National Center for Atmospheric Research (NCAR), “The number of Category 4 and 5 hurricanes worldwide has nearly doubled over the past 35 years, even though the total number of hurricanes has dropped since the 1990s, according to a study by researchers at the Georgia Institute of Technology and the NCAR. The shift occurred as global sea surface temperatures have increased over the same period. The research appears in the September 16 issue of Science.

“ A study published in July in the journal Nature came to a similar conclusion. Focusing on North Atlantic and North Pacific hurricanes, Kerry Emanuel (Massachusetts Institute of Technology) found an increase in their duration and power, although his study used a different measurement to determine a storm's power.”

Dr. Bill Gray of Colorado State University is a noted hurricane expert, and is most famous for his annual forecasts of the number and strength of tropical storms in the Atlantic. Recently Gray was asked to comment on this, and he said:

“ We have had global warming. That’s not a question. The globe has warmed the last 30 years, and the last 10 years in particular. And we’ve had, at least the last 10 years, we’ve had a pick up in the Atlantic basin major storms. But in the earlier period, if we go back from 1970 through the middle ‘90s, that 25 year period – even though the globe was warming slightly, the number of major storms was down, quite a bit down.
“ Another feature of this is that the Atlantic operates differently. The Atlantic only has about 12 percent of the global storms. And even though the Atlantic major storm activity has gone up greatly the last 10 years. In the other global basins, it’s slightly gone down. You know, both frequency and strength of storms have not changed in these other basins. If anything, they’ve slightly gone down.

“ All my colleagues that have been around a long time – I think if you go to ask the last four or five directors of the national hurricane center – we all don’t think [the increase in hurricanes is due to] human-induced global warming.”

Dr. Jim O’Brien is Director of the Florida Climate Center and the Center for Ocean-Atmospheric Prediction Studies at Florida State University. He has spent many years studying hurricane behavior. Following Katrina’s appearance, he said:

“ If you take the strength of the hurricanes at landfall from 1851 to 2004 and plot it up, you’ll see this remarkable semi-periodic thing come out with about 15 years or so of many storms, strong storms and then 15 years or so with much reduced storms and then 15 years… and it just keeps going like that over the 150 years we have records of. And so if you look at this long record, you’ll see that there’s absolutely no evidence of any increase in strength. Of course, in the periods when we have a lot of storms, you’re likely to have stronger storms; and in the periods where you have less storms, you’re likely not to have strong storms.”

Most hurricane experts would agree that there is much to learn about these storms. Satellite data, which are invaluable for assessing tropical storms, are only available for a few decades, so the long-term cycles O’Brien mentions are not well understood. And day-to-day forecasts can go awry as well.

Beyond the science of hurricane analysis and forecasting, however, there are human decisions to be made. One of those is “to evacuate or not?” Roy Spencer of the University of Alabama brought up a very interesting point:

“ [Katrina] was well predicted. The problem we have though is that people get used to getting warnings about hurricane hits. And this is because hurricane prediction, just like tornado prediction, is not perfect. People need at least two days notice in order to evacuate and the forecasts just aren’t good enough yet – even as good as Katrina was – to be able to forecast every one.

“ So the tendency is to over-forecast these situations so that people then have some complacency. They say, ‘Well, the last three times we’ve been told to evacuate and nothing happened, so I’m going to stay here this time.’ And that’s understandable. That’s human nature. And there’s really nothing we can do about that because the science of forecasting is not perfect.”

And even though forecasts have gotten better, we all know they have a long way to go! As research continues (including lots of exciting work by my colleagues in the College of Oceanic and Atmospheric Sciences at OSU) our forecasts and understanding will continue to improve.

Oregon Climate Service

George H. Taylor, Oregon State Climatologist

Wayne P. Gibson, Programmer/GIS mngr.

Eileen Kaspar, Research Assistant/Manager of Data Services

Melanie Mitchell, Undergraduate Assistant

Wolf Read, Undergraduate Assistant

Emily Gibson, Student Assistant

Cadee Hale, Publications Assistant

Sara Joos, Student Assistant

Sean Daly, Student Assistant

Kirk Borgerding, Undergraduate Assistant

Kelsey Kuykendall, Undergraduate Assistant

Oregon Climate Service, Strand 326,                             	     Phone: (541) 737-5705  
Oregon State University                                                      Fax: (541) 737-5710   
Corvallis, Oregon  97331                                                     E-mail: oregon@coas.orst.edu   
                                                                             Web: http://www.ocs.oregonstate.edu