Download presentation
Presentation is loading. Please wait.
1
An experimental real-time seasonal hydrologic forecast system for the western U.S.
Andy Wood and Dennis Lettenmaier Department of Civil and Environmental Engineering 5th International Scientific Conference on GEWEX Orange County, CA June 20, 2005
2
Topics forecasting system overview selected results for current winter
something to think about
3
Technical Advances related to Hydrologic Forecasting
physical hydrologic models Internet / real-time data snow cats snow survey / graphical forecasts / index methods / i.e., regression satellite imagery computing in water resources SNOTEL network ENSO / seasonal climate forecasts ESP method conceptual hydrologic models aerial snow surveys desktop computing 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s
4
Forecast System Overview
Objective: To create a model-based testbed for evaluating potential sources of improvement in seasonal forecasts since inception of regression/ESP methods operational seasonal climate forecasts (model-based and otherwise) greater real-time availability of station data computing advances new satellite-based products (primarily snow cover) distributed, physical hydrologic modeling for macroscale regions
5
Forecast System Overview
NCDC met. station obs. up to 2-4 months from current local scale (1/8 degree) weather inputs soil moisture snowpack Hydrologic model spin up SNOTEL Update streamflow, soil moisture, snow water equivalent, runoff 25th Day, Month 0 1-2 years back LDAS/other real-time met. forcings for spin-up gap Hydrologic forecast simulation Month INITIAL STATE SNOTEL / MODIS* Update ensemble forecasts ESP traces (40) CPC-based outlook (13) NCEP GSM ensemble (20) NSIPP-1 ensemble (9) * experimental, not yet in real-time product
6
Forecast System Overview
Snowpack Initial Condition Soil Moisture Initial Condition
7
Forecast System Overview
sample validation of historic streamflow simulations
8
Forecast System Overview
monthly hydrographs targeted statistics e.g., runoff volumes
9
Introduction: UW Experimental Hydrologic Forecasting
Precip Temp SWE Runoff Soil Moisture Mar-05 Apr-05 May-05
10
Introduction: UW Experimental Hydrologic Forecasting
Multiple Hydrologic Models CCA NOAA CAS OCN CPC Official Outlooks NWS HL-RMS SMLR CA Seasonal Forecast Model (SFM) VIC Hydrology Model NASA NSIPP-1 dynamical model NOAH LSM ESP weightings calibrated via retrospective analysis ENSO UW ENSO/PDO
11
Topics forecasting system overview selected results for current winter
something to think about
12
WY2005, Dec. 1 hydrologic conditions
13
WY2005, Jan. 1 hydrologic conditions
14
WY2005, Feb. 1 hydrologic conditions
15
WY2005, Mar. 1 hydrologic conditions
16
WY2005, Apr. 1 hydrologic conditions
17
WY2005, May 1 hydrologic conditions
18
WY2005, June 1 hydrologic conditions
19
4/15 ESP forecast: WY2005 Precip, Temp
plots show current + forecast (ESP; min, max and quartiles) against historical min, max and quartiles Yakima R. Basin near Parker, WA
20
4/15 ESP forecast: WY2005 SM, SWE, RO
with SWE assimilation Apr-Sep % of avg 3/15 4/15 chg max 61 57 min
21
Topics forecasting system overview selected results for current winter
something to think about
22
Nowcast/Forecast System Consistency Issue
ESP forecast VIC Retrospective Simulation Daily, 1915 to Near Current VIC “Modern” Simulation (last 5 years) Current Hydrologic State (Nowcast) CPC forecast ASSIMILATION Snow / Soil Moisture / Runoff / ETC Climate Model forecast
23
Nowcast/Forecast System Consistency Issue
ESP forecast VIC Retrospective Simulation Daily, 1915 to Near Current VIC “Modern” Simulation (last 5 years) Current Hydrologic State (Nowcast) CPC forecast ASSIMILATION Snow / Soil Moisture / Runoff / ETC bias correction & downscaling help here… Climate Model forecast
24
New Surface Water Monitor
daily updates 1-2 day lag soil moisture & SWE percentiles ½ degree resolution archive from 1915-current uses ~2130 index stns (poster tomorrow)
25
For more information Westwide streamflow forecasting system
/ Lettenmaier / Projects / fcst / Surface water monitor for the continental US / forecast / monitor /
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.