Download presentation
Presentation is loading. Please wait.
1
Seasonal outlooks for hydrology and water resources: streamflow, reservoir, and hydropower forecasts for the Pacific Northwest Andy Wood and Alan Hamlet Department of Civil and Environmental Engineering for Climate and Water Resource Forecasts for the 2007 Water Year UW Climate Impacts Group October 3, 2006, Kelso, WA
2
Part I West Wide Hydrologic Forecast System
3
Experimental W. US Hydrologic Forecast System Soil Moisture Initial Condition Snowpack Initial Condition
4
Experimental Western US Hydrologic Forecast System ESP ENSO/PDO ENSO CPC Official Outlooks NCEP CFS CAS OCN SMLR CCA CA NSIPP/GMAO dynamical model VIC Hydrolog y Model NOAA NASA UW Multiple Seasonal Climate Forecast Data Sources
5
Hydrologic Model-based Forecasting ICs Spin-upForecast obs recently observed meteorological data ensemble of met. data to generate forecast hydrologic state
6
targeted statistics e.g., runoff volumes monthly hydrographs spatial forecast maps
7
Flow location maps give access to monthly hydrograph plots, and also to raw forecast data. Clicking the stream flow forecast map also accesses current basin-averaged conditions Applications: streamflow Introduction
8
Soil Moisture for last 2 weeks The daily update of surface conditions enables animationed views of recent changes
9
Other views of changing hydrologic conditions www.hydro.washington.edu/ forecast/monitor/ Soil moisture change in last month
10
WY 2007 Forecast
11
Average annual water cycle The PNW hydrologic cycle PNW Where we are now on average soil moisture near annual low runoff near low nearly all water year precipitation yet to come snow season not really underway evaporation not a factor
12
The PNW hydrologic cycle water balance Note that there is variability in soil moisture now… current
13
Oct. 1 Soil Moisture Comparison THIS YEAR LAST YEARTHIS YEAR
14
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes Forecasts of April-September Flow Dalles: 100 / 88 ESPESP - El Nino
15
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes Forecasts of April-September Flow Snake: 96 / 83 ESPESP - El Nino
16
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes Forecasts of April-September Flow Upper Snake: 95 / 83 ESPESP - El Nino
17
Recap of WY 2006
18
Recap WY2006, Dec. 1 hydrologic conditions Soil MoistureSWE
19
Recap WY2006, Jan. 1 hydrologic conditions
20
Recap WY2006, Feb. 1 hydrologic conditions
21
Recap WY2006, Mar. 1 hydrologic conditions
22
Recap WY2006, Apr. 1 hydrologic conditions
23
Recap WY2006, May. 1 hydrologic conditions
24
Recap WY2006, Jul. 1 hydrologic conditions
25
Winter 2005-06: seasonal volume forecast for APR-SEP flow OBS Forecasts made on 1 st of Month
26
Winter 2005-06: seasonal volume forecast for APR-SEP flow OBS Forecasts made on 1 st of Month
27
Part II ENSO/PDO Forecasts
28
ENSO is typically very stable from Oct-Jan
29
Evaluation of Sept 1 ECMWF Nino3.4 Forecast for WY 2003-2005 WY 2003 WY 2004WY 2005
30
Used range: Jan3.4 >= -0.4 Jan3.4 <= 0.6 Evaluation of Aug 1 ECMWF Nino3.4 Forecast for WY 2006
31
Nino3.4 -0.4 to 0.6 Ensemble Streamflow Forecast for the Columbia River at The Dalles for WY 2006. (Nino3.4 anomalies between -0.4 and 0.6) Naturalized Flow (cfs) Black = Climatological Extremes Gray = Forecast Ensemble Members Red = Observed Blue = Ensemble Mean
32
Natural Flows at Milner 1928-1989
33
Natural Streamflow (KAF) WY 2006 Red = long term mean Blue = ensemble mean Gray = ensemble members Black = range of observations
34
October 1 Spin Up System Storage Forecast from SnakeSim: Jackson Lake Palisades Island Park Ririe American Falls Lake Walcott Nino3.4 anomaly between -0.4 and 0.6 C Demand aligned with water cond. Active Reservoir Storage (kaf) Obs. System Storage Oct 8, 2006
35
Nino3.4 0.0 to 0.6 Ensemble Streamflow Forecast for the Columbia River at The Dalles for WY 2006. (Nino3.4 anomalies between 0.0 and 0.6) Naturalized Flow (cfs) Black = Climatological Extremes Gray = Forecast Ensemble Members Red = Observed Blue = Ensemble Mean
36
WY 2007 Forecast
37
http://www.ecmwf.int/products/forecasts/d/charts/seasonal/forecast/plumes/
38
Natural Flows at Milner 1928-1989
39
Milner 2007 Nino3.4 Range 0.7 to 1.5 Natural Flow (KAF) Red = long term mean Blue = ensemble mean Gray = ensemble members Black = range of observations 2007 Forecast for Natural Flow at Milner
40
Milner 2007 Nino3.4 Range 0.7 to 1.5 Warm PDO Natural Flow (KAF) Red = long term mean Blue = ensemble mean Gray = ensemble members Black = range of observations 2007 Forecast for Natural Flow at Milner
41
Upper Snake Storage (KAF) 2007 System Storage Forecasts for the Upper Snake (Oct-Aug) Nino3.4 Range 0.7 to 1.5 Nino3.4 Range Warm PDO Full
42
Modified Flow (cfs) Ensemble Streamflow Forecast for the Columbia River at The Dalles for WY 2007. (Nino3.4 anomalies between 0.7 and 1.5) Black = Climatological Extremes Gray = Forecast Ensemble Members Red = LTM from 1950-1999 Blue = Ensemble Mean
43
All Years (‘60-’99) Nino3.4 Composite Long-Range Ensemble Forecasts of System-Wide Columbia Basin Hydropower Production for Water Year 2007.
44
Summary of Ensemble Average Hydropower Production for All Years (‘60-’99) Vs. Nino3.4 Composite Nino3.4 composite is about 7% lower
45
Regionally Averaged Cool Season Precipitation Anomalies PRECIP
46
Selected References on Compositing Techniques: Hamlet, A.F., Lettenmaier, D.P., 1999: Columbia River Streamflow Forecasting Based on ENSO and PDO Climate Signals, ASCE J. of Water Res. Planning and Mgmt., 125 (6) : 333-341 Werner, K., Brandon, D., Clark, M., et al., 2004: Climate index weighting schemes for NWS ESP-based seasonal volume forecasts, J. of Hydrometeorology, 5 (6): 1076-1090
47
Conclusions: The WY 2006 ESP forecast predicted a range of flows centered around near normal conditions. Actual flows in 2006 were towards the upper range of this forecast, probably due in part to an unusually large ENSO forecast error. A moderate warm ENSO event is expected for the winter of 2006-2007. ESP traces from 1960- 1999 associated with a forecasted range of Nino3.4 anomalies from 0.7-1.5 suggest elevated drought risks for WY 2007, and lower carryover storage in the upper Snake at the end of WY 2007.
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.