Overview

April precipitation was above normal throughout the state, enabling seasonal percentages of normal to increase slightly, and greatly assisting in an easing of water supply worries. With additional wet conditions expected in May, and many of Oregon’s larger reservoirs filling significantly, things are looking much better. A number of central and eastern Oregon counties remain in drought status, but if the wet spring continues that may change.

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 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	124	99	97	87	62	43	-1.7
MALHEUR	146	92	78	6	15	28	-1.7
GRAND RONDE, POWDER, BURNT	116	83	71	36	74	65	-2.6
UMATILLA, WALLA WALLA, WILLOW	103	59	63	9	63	55	-3.0
UPPER JOHN DAY	143	76	72	16	51	42	-2.3
UPPER DESCHUTES, CROOKED	120	63	63	40	37	42	-1.7
LOWER DESCHUTES, HOOD RIVER	105	63	61	15	71	51	-3.2
WILLAMETTE	128	77	62	27	85	49	-2.6
ROGUE, UMPQUA	109	69	71	50	86	49	-1.6
KLAMATH	216	111	68	46	44	54	-1.9
LAKE COUNTY, GOOSE LAKE	127	90	85	100	54	46	-1.1
HARNEY	123	69	79	71	45	50	-1.5
NORTH COAST	124	77	57	n.a.	125	63	-1.7
SOUTH COAST	124	99	n.a	n.a.	134	66	-2.1

n.a. Not available
(1) Percent of normal April 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 snow water equivalent, from NRCS SNOTEL sites
(5) Percent of normal April stream flow, from U.S. Geological Survey (USGS)
(6) Percent of normal seasonal stream flow (since Oct. 1), from USGS
(7) Surface Water Supply Index, from NRCS (-4 = very dry, 0 = normal, +4 = very wet)

Forecasts

The Climate Prediction Center’s (CPC) forecasts for May-July appear below. Temperatures for Oregon (and all of the West) are likely to be above normal, while precipitation probabilities are near normal.

Oregon Climate Service predicts normal temperatures and above-normal precipitation for the next three months.

El Niño update
The Australian Bureau of Meteorology (BOM) suggests that the chances of an El Niño event have increased in the last month. Their May 4 update states,

“Current observations continue to show neutral ENSO conditions, however in the past fortnight there has been a warming of the eastern Pacific and the 30-day SOI value has fallen once again, to –11. Whilst cloud over the equatorial Pacific shows no clear signal or trend, the Trade Winds have weakened slightly over much of the region, more so in the west than the east. This may have contributed to a general warming trend of the ocean surface. Furthermore, the "Kelvin wave" of subsurface warming that has been tracked since February, has reached the coast of South America and warmed the far eastern Pacific - the traditional El Niño region. This warming now appears to have spread some distance westward.”

NOAA’s Climate Prediction Center reported on May 5:
“ENSO-neutral conditions are expected to prevail during the northern summer (June-August), in spite of recent increases in SST anomalies associated with strong Madden-Julian Oscillation (MJO) activity.

Surface and subsurface water temperatures increased substantially in the eastern equatorial Pacific during April, associated with the arrival of the downwelling phase of a strong oceanic Kelvin wave. A majority of the statistical and coupled model forecasts indicate that ENSO-neutral conditions will prevail during the northern summer (June-August). The spread in the forecasts indicates increasing uncertainty during the last half of 2005.

Funnel Clouds in the Valley

I love looking at clouds.

One of the really nice things about being a bicycle rider is that I always have a full view of the sky. I can look up, or around, or from side to side, with unobstructed views. Kind of like being in a convertible – except that at 15 mph I have a lot more time, and leeway, to gaze around me.

And I spend much of that gazing time looking at clouds. When conditions are stormy, I marvel at convection - vertical development of clouds due to rising air. And I watch for funnel clouds!

Back in 1976, when I lived in Santa Barbara, I saw a series of waterspouts just offshore. It was cool - and I have the pictures to prove it. But that’s the last time I saw any “twisty things.” Meanwhile, plenty of other people see them - and many of them are not even bike riders!

A few years ago my wife Cindy saw a funnel cloud from our living room. It appeared to be over Lincoln School, or thereabouts. Richard Halter found a video which verified Cindy’s sighting. But as she would say, “after 30 years of marriage to a meteorologist I know a funnel cloud when I see one!” Amen!
Richard himself has seen more than a few. And this includes tornadoes in the Midwest. He’s such a storm fan that he has spent several vacations with “tornado chasers,” with some success.

There was even a funnel cloud spotted during a Beaver football game a few years ago. Thousands of people saw it, and some even recognized it. I saw it, too – but only on the film replay.

And then a few weeks ago my friend and colleague, Wolf Read, saw a funnel cloud that may have touched the ground, making it a tornado. It was near Wilsonville on a stormy afternoon.

Wolf was driving to Portland on I-5, and was near milepost 274. Ahead, he could see a “deep, dark cumulonimbus to the northwest.” The official definition of a cumulonimbus is “a big honkin’ rain cloud.” Wolf said the cloud “reminded me of East Texas thunderstorms, without the lightning.” Mind you, this wasn’t the first Big Honker he’d seen that day – they had appeared here and there since he left Albany, so he was alert to the possibility of severe weather.
As Wolf neared Wilsonville, he spotted the funnel off to the west-northwest. Over the next several minutes, he watched it (when there were no trees to obstruct the view). He described it as “a long column, wrapped in clouds at the top and bottom.” It looked like it was touching the ground, but it was hard to verify that. The funnel cloud was on the southwest side of the cumulonimbus, which is where one might expect to see it.

Shortly thereafter, he lost sight of the funnel and drove into the cloud itself. The rain was very intense, with the wipers unable to keep up, even at full speed. When he reached the back edge of the cloud, he noticed that the wind direction was very different than it had been on the south side.

Several other spotters saw the funnel that Wolf saw, but chances are nobody else drew an “artist’s rendition” of it - in addition to being a scientist, Wolf is a talented artist.

So there you go - everyone sees those things except me. But that just makes me more determined. I’ll keep my eyes on the sky until I see one of those things!

On a sad note, David Apple, former TV meteorologist for several Portland TV stations, died last week of a heart attack. David was truly a kind, gracious man. He was sitting next to me in 1997 when the KXL engineer played the “el Nino” song, which I learned and have performed in public on numerous occasions. David also encouraged me to go into TV broadcasting, but I told him I like my current job too much - and besides, I didn’t want to move to Portland.
Bless you, David. You’ll be missed.

In February I stuck my neck out and suggested a wet spring. Following the near-record dry winter, I stated:

“Our saving grace in situations like this is a wet spring. If we get abundant (or even average) spring rain, we are much less likely to experience summer water problems. But how likely is that? I looked back at other dry winters too see what happened in the following spring.

“The six winters that were drier than this winter, and their October-January totals, were 1977 (5.10 inches), 1891 (9.42”), 1979 (10.92”), 2001 (11.75”), 1931 (11.81”), and 1960 (11.88”). In five of the six years, spring was near average or well above; the only exception was 2001, which had a really dry spring. The next four years in the “dry winter” list, all slightly wetter than this year, were 1926, 1945, 1944 and 1937. Only one of the four (1944) had a truly dry spring.

“The other clue here is the wet late summer-early fall we had. The dry winters that were preceded by a wet fall were very likely to be followed by wet springs.

“The federal Climate Prediction Center doesn’t think that will happen, however. Their February-March-April forecast is for above average temperatures and below average precipitation. If that happens, this place will be dry as a bone, come summer!”

I’m truly glad my prediction was correct. Of course, everyone like to be right! But more importantly, our water situation has greatly improved.

Our web site (www.ocs.oregonstate.edu) has a page of drought links (see Drought Links) on the main page) that gives regular updates on water supply in the state.

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

Kelsey Kuykendall, Undergraduate Assistant

Sara Joos, Student Assistant

Sean Daly, Student Assistant

Kirk Borgerding, 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