seasonal outlooks for hydrology and water resources: streamflow, reservoir, and hydropower forecasts...
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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
Presentation Outline
1. Introduction: UW Experimental Hydrologic
Forecasting System
2. Water Year 2007 Outlook
3. Water Year 2006 Assessment
Introduction
UW Forecast System
www.hydro.washington.edu/forecast/westwide/
Developing “focus regions”
-- Klamath R. basin-- Yakima R. basin-- Feather R. basin-- WA State 1/16
Experimental W. US Hydrologic Forecast System
Soil MoistureInitial
Condition
SnowpackInitial Condition
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 Hydrology Model
NOAA
NASA
UW
Multiple Seasonal Climate Forecast Data Sources
Hydrologic Model-based Forecasting
ICsSpin-up Forecast
obs
recently observedmeteorological data
ensemble of met. datato generate forecast
hydrologicstate
targeted statisticse.g., runoff volumes
monthly hydrographs
spatial forecast maps
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: streamflowIntroduction
Presentation Outline
1. Introduction: UW Experimental Hydrologic Forecasting
System
2. Water Year 2007 Outlook
3. Water Year 2006 Assessment
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
The PNW hydrologic cycle
water balance
Note that there is variability insoil moisture now…
current
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Forecasts of April-September Flow
Dalles: 100 / 88
ESP ESP - El Nino
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Forecasts of April-September Flow
Priest Rapids: 101 / 89
ESP ESP - El Nino
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Forecasts of April-September Flow
Snake: 96 / 83
ESP ESP - El Nino
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Snake: 96 / 83
El Nino flow deficits come in April through July
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Forecasts of April-September Flow
Upper Snake: 95 / 83
ESP ESP - El Nino
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Forecasts of April-September Flow
Waneta: 99 / 84
ESP ESP - El Nino
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Forecasts of April-September Flow
Arrow: 101 / 92
ESP ESP - El Nino
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Forecasts of April-September Flow
Mica Dam: 101 / 93
ESP ESP - El Nino
Sep 1 ESP / ESP-El Nino fcst: Summer Volumes
Arrow: 101 / 92
El Nino flow deficits come in June and July
Presentation Outline
1. Introduction: UW Experimental Hydrologic Forecasting
System
2. Water Year 2007 Outlook
3. Water Year 2006 Assessment
Recap WY2006, Dec. 1 hydrologic conditions
Soil Moisture SWE
Recap WY2006, Jan. 1 hydrologic conditions
Recap WY2006, Feb. 1 hydrologic conditions
Recap WY2006, Mar. 1 hydrologic conditions
Recap WY2006, Apr. 1 hydrologic conditions
Recap WY2006, May. 1 hydrologic conditions
Recap WY2006, Jul. 1 hydrologic conditions
Oct. 1 Soil Moisture Comparison
THIS YEARLAST YEARTHIS YEAR
Other views of changing hydrologic conditions
www.hydro.washington.edu/forecast/monitor/
Soil moisture change in last month
Soil Moisture for last 2 weeks
The daily update of surface conditions enables animationed views of recent changes
Recap WY2006, Related Snow Plots
Observed SWE Change inlast month
Winter 2005-06: seasonal volume forecast for APR-SEP flow
OBS
Forecasts made on 1st of Month
Winter 2005-06: seasonal volume forecast for APR-SEP flow
OBS
Forecasts made on 1st of Month
Winter 2005-06: seasonal volume forecast for APR-SEP flow
OBS
Forecasts made on 1st of Month
Understanding Uncertainty
All those whose duty it is to issue regular daily forecasts know that there are times when they feel very confident and other times when they are doubtful as to the coming weather.
It seems to me that the condition of confidence or otherwise forms a very important part of the prediction, and ought to find expression.
-W.E. Cooke (1906)
Calibrating Model Forecast Uncertainty
J F M A M
J F M A M
Models are overconfident
Statistical calibration of outputs can add needed uncertainty to forecasts
Understanding Uncertainty