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890
FGUS65 KSTR 041519
ESPAZ

NATIONAL WEATHER SERVICE
COLORADO BASIN RIVER FORECAST CENTER
SALT LAKE CITY, UTAH

APRIL 4, 2018

ARIZONA WATER SUPPLY OUTLOOK - AS OF APRIL 1 2018:


Precipitation:

Seasonal October-March precipitation was 35 percent of average in
the Salt-Verde River Basin, 40 percent of average for the Gila Basin and
30 percent for the Little Colorado Basin. March precipitation was
35 percent of average in the Salt-Verde River Basin, 40 percent in the
Gila River Basin, and 35 percent of average in the Little Colorado Basin.

Streamflow:

March Streamflow was around 10 percent of median in the Salt-Verde,
30 percent in the Gila, and generally 5 percent in the Little Colorado.

April 1st Snow:

Basin snowpack conditions were near 0 percent of median in the
Salt-Verde River Basin, the Little Colorado River Basin and the upper
Gila basin.

Soil Moisture:

Modeled soil moisture states were much below average at the
beginning of the water year. March through May runoff volumes
are primarily influenced by the frequency and magnitude of winter
rain events.

Climate Conditions:

La Nina climate conditions suggest chances for below average precipitation
in Arizona.

Forecast Summary:

The April-May forecast volumes were between 0 to 17 percent of median in the
Little Colorado Basin, 3 to 41 percent of median in the Salt-Verde
Basin. In the Gila Basin, volumes were between 4 and 39 percent.


SPECIFIC SITE FORECASTS ARE AS FOLLOWS:

Afos message output for EGDD: /nvm1/users/tracy.cox/wsup/wy18/lc/lcapr.drv
Developed:                    Apr 1 2018

LOWER Colorado
                           Period     50%  %MED    10%    30%    70%    90%    MED
                           ------    ----  ----   ----   ----   ----   ----    ---
Little Colorado River
  Lyman Lk, abv, St. John  Apr-Jun   0.61    17   0.86   0.62   0.61   0.60    3.5
Zuni River
  Black Rock Res, abv      Apr-May   0.00     0   0.03   0.01   0.00   0.00   0.10
Chevelon Ck
  Winslow, nr, Wildcat Cy  Apr-May   0.00     0   0.23   0.00   0.00   0.00   1.70
Gila River
  Gila, nr                 Apr-May    6.8    41   10.2    6.9    6.8    6.7   16.5
  Virden, nr, Blue Ck, bl  Apr-May    8.5    40   12.1    8.7    8.4    8.4     21
San Francisco River
  Glenwood, nr             Apr-May   1.42    19    2.0    1.5   1.42   1.40    7.3
  Clifton                  Apr-May    2.4    14    7.2    2.5    2.3    2.3   17.3
Gila River
  Solomon, nr, Head Of Sa  Apr-May   12.1    31   17.8   13.0   12.1   12.0     39
  San Carlos Res, Coolidg  Apr-May   0.64     3    3.9    0.7   0.62   0.61   18.4
Salt River
  Roosevelt, nr            Apr-May   16.8    13     21     18   16.4   15.7    127
Tonto Ck
  Roosevelt, nr, Gun Ck,   Apr-May   0.24     4   0.92   0.27   0.22   0.19    5.9
Verde River
  Tangle Ck, blo, Horsesh  Apr-May   14.1    39   18.6   14.3   13.8   13.7     36

50% Most probable volume in 1000 acre-feet.
%MED  Most probable volume in percent of the 1981-2010 median.
10% Volume that has a 10 percent chance of being exceeded.
30% Volume that has a 30 percent chance of being exceeded.
90% Volume that has a 90 percent chance of being exceeded.
70% Volume that has a 70 percent chance of being exceeded.
MED   median volume for the 1981-2010 period.

All forecast volumes reflect natural flow.  Actual observed flow may
be affected by upstream water management.


****************************************************************************

PRECIPITATION SUMMARY:

                       MARCH`18        SEASONAL
BASIN                 % Average       % Average

  Upper Gila             40              40
  Salt-Verde             35              35
  Little Colorado        35              30

***************************************************************************

SNOWPACK SUMMARY:

                      APRIL 1 2018
BASIN                  % Average

  Upper Gila               0
  San Francisco            0
  Salt-Verde               0
  Little Colorado          0


***************************************************************************

OBSERVED STREAM FLOW SUMMARY:

                       MARCH`18
BASIN                  % Median

  Gila                    30
  Salt-Verde              10
  Little Colorado          5

**************************************************************************

For additional forecast information refer to the Water Supply section of
the CBRFC web page at: www.cbrfc.noaa.gov/wsup/pub2/map/html/cpub.php

CBRFC

NNNN

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