Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Tracking an Uncertain Climate for Water Supply Phillip Pasteris Natural Resources Conservation Service National Water and Climate Center Portland, Oregon

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA WY One for the Books! Lowest Columbia streamflow since 1977 Lowest snowpacks since 1977 Record peak power prices Record drought in many areas Significant forest fires in CA, WA, MT

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA The Dalles Hydrograph

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Columbia Snowpack

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Columbia Snowpack

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Record Drought

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA WY Uncertainty Summary provided by George Taylor, Oregon State Climatologist - National Centers for Environmental Prediction (NCEP) coupled ocean/atmosphere model shows a weak El Nino developing in the next six months.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA WY Uncertainty The Scripps / Max Planck Institute (MPI) hybrid coupled model include a moderate El Nino developing this fall, followed by a return to near-normal conditions in mid- winter.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA WY Uncertainty The Climate Diagnostics Center (CDC) predictive model takes a contrary viewpoint, indicating the development of much stronger La Nina conditions in the next several months, continuing throughout the winter.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA WY Where Are We Now?

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA WY Tracking Uncertainty Real-time climate data from SNOTEL Real-time climate data from BC network NWS COOP climate data through UCAN Streamflow from the USGS Reservoir data from operators

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA The SNOTEL Network - OR

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA The SNOTEL Network - WA

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA The SNOTEL Network - ID

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA The SNOTEL Network - MT

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Snow Network in BC

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Snow Plots In British Columbia Molson Creek - Upper Columbia

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Snow Plots In British Columbia East Creek - W. Kootenay R.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Snow Plots In British Columbia Morrissey Ridge - E. Kootenay R.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Typical SNOTEL Data Plot

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Typical SNOTEL Data Plot

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Typical SNOTEL Data Plot

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Typical SNOTEL Data Plot

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Typical SNOTEL Data Plot

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Sub-Monthly Water Supply Forecasts Production of sub-monthly water supply forecasts (WSFs) is driven by user needs for more frequent assessments of water supply availability based on real- time SNOTEL information. Users include NRCS Water Supply Specialists; private, state, and federal reservoir owners/operators; dam safety engineers and hydrologists; Montana Fish Wildlife and Parks; Montana Power; irrigation companies; and NRCS field offices that distribute our streamflow forecasts to local irrigators, reservoir operators, and conservation district boards.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Sub-Monthly Water Supply Forecasts The concept is to “capture the trend” using daily SNOTEL data and provide users with more frequent forecasts that reduce risk. Because the WSF procedures selected for this process primarily use SNOTEL data, we can use the current SNOTEL observations and project forward to the 1st of the month. The only "unknown" in these procedures is the next month's SNOTEL snow water equivalent value; the only other data in these procedures (until June 1) is fall precipitation, which is already known.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Sub-Monthly Water Supply Forecasts Flat-line scenario: We can simply take the value from SNOTEL today and use it as is, thus assuming no additional accumulation for the rest of the month.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Sub-Monthly Water Supply Forecasts Add/subtract some portion of a normal (average) increment: If we think the precipitation during the remaining period of the month is going to be below normal, then we could add, say, 75% of a normal increase (prorated for the days left until the first of the month) to the current observed value. Likewise, we could add, say, 125% of the normal increase if we saw that the weather forecasts called for major storms in the coming days or weeks.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Sub-Monthly Water Supply Forecasts Use the same rate of change that has occurred so far this month. For example, if the February 1 snow water equivalent was 10" and the value on February 22 was 12", that is a 2" increase over the first 22 days of the month, or 2/22 = or " per day. The process would then add * 7 (days left in the month [leap year]) = 0.6 to obtain 12.6" as the estimated value for March 1.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA Preliminary Results Montana responses were very favorable. Recognized the deteriorating snowpack conditions. Captured the trend on a weekly basis. Provided opportunities to ingest late season snowfalls and reduce hope for drought reduction. Further analysis underway.

Long-range Forecasting of Climate and Water Resources in the Pacific Northwest, October 2001, Kelso, WA In Summary Climate trends and variability are something we need to learn to live with. Using climate networks, like SNOTEL, on a daily basis helps all resource managers and the public cope. “The future ain’t what it used to be.” - Yogi Berra