Overview

January was a rather wet month, though not as wet as December. What really set the month apart, however, were the mild temperatures. The entire state was well above normal, due to persistent flow of air from the southwest, bringing mild, fairly wet conditions to the entire state. Freezing levels were very high. As a result, much of the mountain snowpack melted, bringing the statewide average down to about 50% of normal.

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. Figure 1 shows the percentage of normal precipitation for the Water Year.

Basin Summary

Here is a summary of precipitation, water supply, and snow pack as of the end of the month, by river basin:

	Precipitation			Snow	Stream Flow		SWSI
BASIN	(1)	(2)	(3)	(4)	(5)	(6)	(7)
OWYHEE	98	74	71	64	36	43	-1.3
MALHEUR	126	86	77	59	17	28	-1.8
GRAND RONDE, POWDER, BURNT	120	81	79	60	102	84	-2.2
UMATILLA, WALLA WALLA, WILLOW	154	104	77	42	111	69	-1.4
UPPER JOHN DAY	125	83	77	51	54	45	-1.4
UPPER DESCHUTES, CROOKED	104	81	76	55	65	50	-0.7
LOWER DESCHUTES, HOOD RIVER	135	91	68	22	87	57	-1.5
WILLAMETTE	118	93	73	33	93	61	-0.3
ROGUE, UMPQUA	93	113	89	64	99	87	+0.2
KLAMATH	85	89	77	58	82	75	-1.8
LAKE COUNTY, GOOSE LAKE	98	93	79	62	73	58	-1.2
HARNEY	105	72	70	45	57	62	-1.5
NORTH COAST	119	87	n.a.	n.a.	116	69	-1.5
SOUTH COAST	98	99	n.a.	n.a.	118	110	-0.1

n.a. Not available

(1) Percent of normal October precipitation, from NOAA Cooperative sites
(2) Percent of normal October precipitation, from Natural Resources Conservation Service (NRCS) SNOTEL sites
(3) Percent of normal October stream flow, from U.S. Geological Survey (USGS)
(4) Surface Water Supply Index, from NRCS (-4 = very dry, 0 = normal, +4 = very wet)

Forecast

The Climate Prediction Center (CPC) predicts above-average temperatures and below-average precipitation for February and also for the three-month period ending in April. Oregon Climate Service predicts above-average temperatures and average precipitation for February, but average temperatures and above-average precipitation for the three months.

El Niño Update

CPC says: "Warm episode (El Niño) conditions continued during January 2003, as equatorial SST anomalies remained greater than +1°C in the central equatorial Pacific (175°E-125°W). In addition, enhanced precipitation and cloudiness were observed over the central tropical Pacific , and positive subsurface temperature departures and a deeper-than-average oceanic thermocline were observed throughout the equatorial Pacific east of 180°W. These conditions are consistent with mature warm episode conditions.

During January 2003 there were indications that the warm episode is beginning to weaken. Sea-surface temperature anomalies decreased throughout the eastern equatorial Pacific by as much as 1.5°C during the month, while equatorial easterly winds were near normal throughout the central and eastern equatorial Pacific. Over the past several weeks there has also been a steady eastward progression of negative subsurface temperature anomalies, indicating a gradual depletion of the excess warmth in the upper ocean of the equatorial Pacific. This evolution is typical during the mature phase of warm episodes."

Our comment: this was never much of an El Niño event, and it's been fading steadily since early December. The climate impacts this winter across the U.S. do not resemble typical El Niño impacts, as one would expect from what is at most a "weak to moderate" El Niño event. To assume that typical winter El Niño impacts will occur this spring, as CPC has done, seems incorrect. But we'll have to wait and see!

Cooling on the Horizon?

A journal article review from Center for the Study of Carbon Dioxide and Global Change (www.co2science.org)

Inclusion of this review here is not meant to be an endorsement, but we feel that the paper's conclusions are pertinent to the people of Oregon. Multidecadal cycles have often been discussed in there pages. We suggest that interested persons acquire a copy of the original article for review.

Reference
Chavez, F.P., Ryan, J., Lluch-Cota, S.E. and Niquen C., M. 2003. From anchovies to sardines and back: multidecadal change in the Pacific Ocean. Science 299: 217-221.

What was done
The authors "review physical and biological fluctuations with periods of about 50 years that are particularly prominent in the Pacific Ocean." Parameters studied include air and ocean temperatures, atmospheric CO2 concentration, landings of anchovies and sardines, and the productivity of coastal and open ocean ecosystems.

What was learned
The authors find that "sardine and anchovy fluctuations are associated with large-scale changes in ocean temperatures: for 25 years, the Pacific is warmer than average (the warm, sardine regime) and then switches to cooler than average for the next 25 years (the cool, anchovy regime)." They also report that "instrumental data provide evidence for two full cycles: cool phases from about 1900 to 1925 and 1950 to 1975 and warm phases from about 1925 to 1950 and 1975 to the mid-1990s." These warm and cool regimes, which they respectively call El Viejo (the old man) and La Vieja (the old woman), are manifest in myriad similar-scale biological fluctuations that may be even better indicators of climate change than climate data themselves, according to the authors.

What it means
The findings of this important study have many ramifications. The one that we highlight is the challenge the new results present for the detection of CO2-induced global warming. The authors correctly note, for example, that data used in climate change projections are "strongly influenced by multidecadal variability of the sort described here, creating an interpretive problem." Hence, they conclude that "these large-scale, naturally occurring variations must be taken into account when considering human-induced climate change."

In this regard, we note that the warming of the late 1970s to late 1990s, which returned much of the world to the level of warmth experienced during the 1930s and 1940s, may well be about to end. In fact, Chavez et al. cite much evidence that indicates a change from El Viejo to La Vieja conditions may already be in progress. If this is indeed true, we could well see global temperatures begin to drop in the very near future.

We also note that the authors remarks about "large-scale, naturally occurring variations" needing to be considered when looking for "human-induced climate change" apply equally well to the millennial-scale climatic oscillation that brought our planet the Roman Warm Period, the Medieval Warm Period and now, very likely, the Modern Warm Period, which is something climate alarmists seem especially loath to do.

Oregon Climate Service

George H. Taylor, Oregon State Climatologist

Wayne P. Gibson, Programmer/GIS mngr.

Mandy Matzke, Research Assistant/Manager of Data Services

Kelly Jenson, Undergraduate Assistant

Melanie Mitchell, Student Assistant

Sandra Terra, Undergraduate Assistant

Oregon Climate Service, Strand 316,                                 Phone: (541) 737-5705  
Oregon State University                                                      Fax: (541) 737-5710   
Corvallis, Oregon  97331                                                     E-mail: oregon@oce.orst.edu   
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