FGUS65 KSTR 052038
ESGNM 
TTAA00 KSLR DDHHMM
NATIONAL WEATHER SERVICE
COLORADO BASIN RIVER FORECAST CENTER
SALT LAKE CITY UT
APR 5, 2006 

           INTERNAL NWS PRODUCT FOR GUIDANCE PURPOSES ONLY

 SAN JUAN RIVER BASIN SPRING FLOOD POTENTIAL OUTLOOK

The 2006 spring runoff flood potential remains below average for streams 
throughout the San Juan River Basin. The Upper San Juan and Animas River basins 
both showed improvement in snow water equivelants during March but remain below, 
to much below average for April 1, 2006. The observed water year precipitation to
improved from 50% to 63% of average. Snow water equivalents as of April 1 were 65%
in the Upper San Juan and 73% in the Animas. Observed March streamflow decreased 
from 56% to 45% of average.  The spring runoff forecasts range from 16%-68% of 
average with a median forecast of 55% of average.

Although we are currently still in the throws of a weak La Nina episode numerous
full lattitude troughs have been providing much needed precipitation and snow to the 
region. The forecast through mid month with reasonably high confidence suggest this pattern 
will continue. Following mid month the uncertainty rises considerably. Given the basin
wide conditions on as of April 1st any additional rainfall and snow will only improve 
water supply and raise the threat of spring flooding due to snowmelt. Currently however
the spring snowmelt flood potential remains below average.  

It is important to note that the spring flood threat due to snow melt runoff is 
determined by hydrometeorologic events that occur during the next two months. 

Peak flow information for the 2005 water year and forecast for the 2006 spring snomelt
runoff are as follows:


SAN JUAN - PAGOSA SPRINGS
2005 Peak 4420cfsd 5/23
2006 50% Exceedance Peak Forecast 1950cfsd
Average time of peak 5 15 - 6 12

ANIMAS - DURANGO
2005 Peak 8070cfsd 5/25
2006 50% Exceedance Peak Forecast 3650cfsd
average time of peak 5 28 - 6 14


SAN JUAN - BLUFF, NR 
2005 Peak 12100cfsd 5 28
2006 50% Exceedance Peak Forecast 8700cfsd
average time of peak 5 21 - 7 4


CBRFC/BMB
NNNN
$$