New 1981-2010 Averages being used this year.
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Lower Colorado Water Supply Outlook, March 1, 2012Lower Colorado Water Supply Outlook, March 1, 2012
Contents
Lower Colorado Summary
*Median of forecasts within each basin.
Salt Basin Conditions
The following conditions influenced this month's forecasts:
Precipitation:
Seasonal October-February
precipitation was
near 80 percent of average in the upper Salt River Basin and 75 percent of average in the Verde River Basin.
February
precipitation was 40 percent of average in the upper Salt Basin and 35 percent of average in the
Verde Basin.
Streamflow:
February streamflow was near 45 percent of median on the Salt River, 10 percent of median on the Tonto, and 40 percent of median
on the Verde River.
Snow:
March 1st snowpack was 40 percent of average in the Verde River Basin. Snowpack in the upper Salt River Basin was
75 percent of average.
Salt River Basin
Snow Plot.
Verde River Basin
Snow Plot.
Soil Moisture:
Modeled soil moisture states are below average at this time.
Climate Forecasts:
La Nina climate conditions suggest decreased chances for precipitation in this area.
The La Nina influence was accounted for in generation of these forecasts.
Forecast Summary:
Dry conditions over the past several months are somewhat consistent with La Nina climate conditions that currently
exist. Below average precipitation and below median runoff are observed more
frequently during La Nina events. March-May
forecast volumes are for 40 percent of median in the
Salt River Basin, near 35 percent of median in the Tonto Basin, and near 40 percent of
median in the Verde Basin.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.
Gila Basin Conditions
The following conditions influenced this month's forecasts:
Precipitation:
Seasonal October-February
precipitation
was 85 percent of average.
February
precipitation was 35 percent of average.
Streamflow:
February streamflow was near 45 percent of median.
Snow:
March 1st snowpack conditions were near 70 percent of average in the upper Gila Basin.
Upper Gila Basin
Snow Plot.
San Francisco Basin
Snow Plot
Soil Moisture:
Below average precipitation resulted in below average modeled soil moisture
states.
Climate Forecasts:
La Nina climate conditions suggest decreased chances for precipitation in this area.
The La Nina influence was accounted for in generation of these forecasts.
Forecast Summary:
Several conditions exist that support much below median March-May streamflow
volumes in the Gila River Basin. These include below average seasonal precipitation and soil
moisture, and below average snowpack. The presence of La Nina climate
conditions suggest drier than average conditions have a better chance of occuring through
the forecast period. March-May
forecast volumes range from 32 to 56
percent of median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.
Little Colorado Basin Conditions
The following conditions influenced this month's forecasts:
Precipitation:
Seasonal October-February
precipitation was
80 percent of average.
February
precipitation was 45 percent of average throughout the Little Colorado Basin.
Streamflow:
February streamflow on the Little Colorado at Lyman was near 15 percent of median.
Snow:
Basin snowpack conditions on February 1st were near 60 percent of average in the southern Headwaters.
Little Colorado
Snow Plot
Central Mogollon Rim
Snow Plot
Soil Moisture:
Below average precipitation resulted in below average modeled soil moisture
states.
Climate Forecasts:
La Nina climate conditions suggest decreased chances for precipitation in this area.
The La Nina influence was accounted for in generation of these forecasts.
Forecast Summary:
The presence of La Nina climate conditions suggest below average precipitation into the
spring. Below average seasonal precipitation exists over the Little Colorado Basin,
with below average soil moisture conditions in the headwaters. Snowpack conditions dropped
from February 1st to March 1st, and remain well below average.
March-May streamflow volumes are
forecast around 45 percent of median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.
Differences between the full period forecasts and the residual forecasts may not exactly equal the actual observed volumes due to rounding conventions (see Definitions section).
Monthly Streamflows
Precipitation Maps
Hydrologist: T.Cox