FGUS65 KSTR 081308 ESGNM TTAA00 KSLR DDHHMM NATIONAL WEATHER SERVICE COLORADO BASIN RIVER FORECAST CENTER SALT LAKE CITY UT June 8, 2009 INTERNAL NWS PRODUCT FOR GUIDANCE PURPOSES ONLY SAN JUAN RIVER BASIN SPRING FLOOD POTENTIAL OUTLOOK The potential for spring 2009 flooding due to snowmelt in the San Juan Basin is very low. Rivers and streams over the upper portions of the San Juan, Navajo, Piedra, Animas and La Plata have reached their snowmelt peaks. Current snowpack as of June 1st for the entire San Juan Basin is 10 percent of average. May precipitation was 110 percent of average across the entire Basin, while seasonal totals since October 2008 were 95 percent of average. The volume forecast for the April-July runoff period is below average. Specific spring peaks (maximum mean daily flow) as of June 8th. Forecast peaks for this year were 50% exceedance values. For full probabilistic distributions of possible peaks, see: http://www.cbrfc.noaa.gov/product/peak/peak.cgi Normal 2009 2008 Flood Bankfull Average Period Peak Peak Flow Flow Peak of River / Site (cfsd) (cfsd) (cfs) (cfs) (cfsd) Peak ------------------ ------- ------- ------- ------- ------ ----------- San Juan - 2690* 2870 6840 5170 2485 5/15 - 6/12 Pagosa Springs Animas - 5160* 5850 9555 5970 4675 5/28 - 6/14 Durango Animas - 5240* 6080 8810 6580 4900 5/31 - 6/15 Farmington San Juan - 5740* 8850 40485 29325 7340 5/21 - 7/4 Bluff * preliminary peaks CBRFC NNNN $$