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Colorado Basin River Forecast Center Spring 2009 Peak Flow Outlook Webinar. April 9 th , 2009 Ed Clark Senior Hydrologist. Available for download at: http://www.cbrfc.noaa.gov/present/2009/2009apr_peaks.ppt. Outline. What is in peak flow forecast? Forecast method Current Basin Conditions
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Colorado Basin River Forecast CenterSpring 2009 Peak Flow Outlook Webinar April 9th, 2009 Ed Clark Senior Hydrologist Available for download at: http://www.cbrfc.noaa.gov/present/2009/2009apr_peaks.ppt
Outline What is in peak flow forecast? Forecast method Current Basin Conditions Regional Forecast Summaries Flooding Concerns Recreational Points of Interest Web Reference: www.cbrfc.noaa.gov/gmap/gmap.php
Normal Time of Peak: 5/22-6/16 Yearly Instantaneous Peaks Time of Peak
10% 10% Exceedence Probability 25% Exceedence Probability 50% Exceedence Probability 50% 75% Exceedence Probability 90% 90% Exceedence Probability Default on hydrograph plots show daily exceedence based on historical obs Previous years flow showing variability
Expected Peak Flow • Derived from the operational model and depend upon current snowpack and soil states. • More uncertainty than volumetric forecast as peak flow values are heavily dependent upon specific weather conditions during melt. • Mean Daily Peak. Average flow over a 24 hour period. • Regulated flow. This is the flow observed in the stream.
Pure Snowmelt Peak Vs Rain Enhanced Peaks • Even small precipitation events during peak melt can greatly increase stream levels. • The daily updated forecasts provide the current 10 day forecast based on precipitation and temperature projections from weather models. Web Reference: www.cbrfc.noaa.gov
Web Reference: http://www.cbrfc.noaa.gov/precip/qpe/mapsum/mapsum.cgi??cbrfc?M?2009?02
April 7, Snow Pack Conditions Web Reference: http://www.cbrfc.noaa.gov/gmap/gmap.php
Upper Green Near average to below average peak flows. Flooding due to snowmelt not anticipated. Peak Flow Forecasts by Region
Peak Flow Forecasts by Region Yampa and Upper Colorado Main-stem • Near average to above average peak flows. • High snowpack in the Roaring Fork increase the potential for above average peaks. • Flooding due to snowmelt not anticipated with the exception of Colorado at Cameo and Yampa at Deerlodge
Peak Flow Forecasts by Region Gunnison, Dolores and San Juan • Average to below average peak flows expected • Flooding due to snowmelt not anticipated.
Peak Flow Forecasts by Region Duchesne and Lower Green • Average to below average peak flows expected • Flooding due to snowmelt not anticipated.
Peak Flow Forecasts by Region Eastern Great Basin and Virgin • Near Average peak flows • Flooding due to snowmelt not anticipated.
Spring 2009 Flooding Concerns • Colorado nr Cameo (Mesa County, CO) 25% chance of exceeding flood flow. • Yampa at Deerlodge (Moffat County, CO) 40% chance of exceeding Flood Flow. Green at Jensen, UT (Dagget County, UT) has a 15% chance of exceeding flood flow.
Points of Flooding Concern Colorado at Cameo 10% 50% 90%
Points of Flooding Concern Yampa at Deerlodge 10% 50% 90%
CBRFC Recreation Boating Products Also available by phone 801-539-1311 Web Reference: http://www.cbrfc.noaa.gov/rec/rec.html
Recreational Boating Points Colorado at UT/CO State Line (Westwater Canyon) 10% 50% 90%
Recreational Boating Points Yampa at Maybell (Cross Mountain) 10% 50% 90%
Recreational Boating Points Green at Green River, UT (Desolation/Grey Canyons) 10% 50% 90%
Recreational Boating Points Animas nr Durango 10% 50% 90%
Recreational Boating Points San Juan at Bluff 10% 50% 90%
Recreational Boating Points Provo nr Woodland 10% 50% 90%
Recreational Boating Points Muddy Creek nr Emery (The Chute) 10% 50% 90%
Recreational Boating Points North Fork of the Virgin 10% 50% 90%
Where to find this information www.cbrfc.noaa.gov www.cbrfc.noaa.gov/product/peak/peak.cgi
Web Reference: www.cbrfc.noaa.gov/wsup/pub2/peak/peak.php?year=2009&month=4
Aspinall Unit Operations and Colorado Water Supply Meeting USBR Grand Junction Office Thursday, April 23rd , 2009 9:30 AM – 5:00 PM Hosted by: United States Bureau of Reclamation National Weather Service Forecast Office Colorado Basin River Forecast Center
Questions Next Call: May 12th, 10:00 AM MDT Contacts Edward.Clark@noaa.gov tel: 801-524-5130 ext 325 CBRFC URL: www.cbrfc.noaa.gov
Reservoirs Effecting San Rafael Tributaries http://www.ewcd.org/reservoirs/teacup.php/ Note: Flows in many popular paddling sections that are below reservoirs are hard to predict. However, one may gleam some information of the potential for in channel flow my looking at the current storage capacity in the upstream reservoirs. High storage indicates that more water will be available for release downstream http://www.usbr.gov/uc/water/basin/tc_wf.html