FGUS65 KSTR 042016 ESGNM TTAA00 KSLR DDHHMM NATIONAL WEATHER SERVICE COLORADO BASIN RIVER FORECAST CENTER SALT LAKE CITY UT MAR 4, 2011 INTERNAL NWS PRODUCT FOR GUIDANCE PURPOSES ONLY SAN JUAN RIVER BASIN SPRING FLOOD POTENTIAL OUTLOOK The potential for spring 2011 flooding due to snowmelt in the San Juan Basin is not high at this time. Most rivers and streams over the upper portions of the San Juan, Navajo, Piedra, Animas and La Plata are forecast to remain below bankfull. Current snowpack as of March 1st for the entire San Juan Basin is 100 percent of average. February precipitation was 75 percent of average across the entire Basin, with seasonal totals since October 2010 at 100 percent of average. The volume forecast for the April-July runoff period is below average. It is also important to keep in mind that an extended period of high temperatures resulting in rapid snowmelt, or heavy rainfall during the peak flow period, may cause or exacerbate flood problems in any year. Specific spring peak flow forecasts (maximum mean daily flow) as of March 1st. Forecast peaks for this year are 50% exceedance values. For full probabilistic distributions of possible peaks, see: http://www.cbrfc.noaa.gov/product/peakpeak.cgi 2011 Normal Fcst 2010 Flood Bankfull Average Period Peak Peak Flow Flow Peak of River / Site (cfs) (cfs) (cfs) (cfs) (cfs) Peak ------------------ ------- ------- ------- ------- ------ ----------- San Juan - 2350 2450 6750 4987 2485 5/15 - 6/12 Pagosa Springs Animas - 4400 4500 9554 7080 4675 5/28 - 6/14 Durango Animas - 4600** 4000 8810 6580 4900 5/31 - 6/15 Farmington San Juan - 8400* 4300 33838 29324 7340 5/21 - 7/4 Bluff * - Peak flow forecast on the San Juan below Navajo Reservoir include the most probable Spring Release of 14 days at 5,000 cfs. ** - Animas Farmington determined by projected diversion from the Durango Pumping Plant into Lake Nighthorse. CBRFC NNNN $$