FGUS65 KSTR 051531
ESGNM 
TTAA00 KSLR DDHHMM
NATIONAL WEATHER SERVICE
COLORADO BASIN RIVER FORECAST CENTER
SALT LAKE CITY, UT
   

                      SPRING FLOOD POTENTIAL 
             FOR THE COLORADO RIVER BASIN WITHIN COLORADO

                         MARCH 5, 2021

The 2021 spring runoff flood potential due to snowmelt is not high
at this time for the San Juan River basin. Dry conditions continue 
to dominate in the San Juan River basin. In addition to the dry winter, a dry summer and fall resulted in much below average soil moisture conditions. It is possible the dry soils could result in a decrease in overall runoff. However, it should be emphasized that snow typically accumulates into April; therefore conditions may change before the runoff begins.  

PRECIPITATION (% OF AVERAGE) AND SNOWPACK (% OF MEDIAN):

SUBBASIN                 FEB PRECIP     OCT-FEB PREC    MAR 1 SNOWPACK
----------------------   ----------     ------------    ---------------
ABOVE NAVAJO RES              60             80               99
ANIMAS                        65             65               80     

Current model peak flow guidance indicates spring peak flows will be below
average at this time. However, specific forecast procedures and flood flow levels do not exist for all streams.

The current volume forecasts for the April through July runoff period are
below average, ranging between 35 and 75% of average. 

It is important to keep in mind that an extended period of much above normal 
temperatures or heavy rainfall during the melt period can cause or exacerbate flooding problems in any year.

A list of specific spring peak flow forecasts are available at:
http://www.cbrfc.noaa.gov/rmap/peak/peaklist.php

A map of the current spring peak flow forecasts is available at:
http://www.cbrfc.noaa.gov/lmap/lmap.php?interface=peak


The spring runoff potential will be evaluated in mid-March and an updated
product will be issued at that time.

CBRFC/Nielson