National Weather Service Text Product Display

Drought Information Statement
Issued by NWS Phoenix, AZ
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Drought Information Statement
National Weather Service Phoenix AZ
145 PM MST Sun May 23 2021

...Extreme and Exceptional Drought Holds into the Dry Spring
Season...

Synopsis...

The 2020-21 Water Year has been much drier than normal for the
entire region with only a series of winter storms in late January
providing some minor drought relief. Most of the area has received
only occasional, spotty light precipitation the past several months
with little to none of the typical spring green up. Overall benefits
from the meager rain and snow this winter and spring have been muted
and hardly sufficient to make a major dent in drought conditions.
The limited higher elevation snowfall has resulted in poor runoff
challenging some of the worst years on record. Now in the midst of
the dry spring months, the region will now have to wait until the
summer monsoon for rainfall and potential drought relief.

Exceptional Drought has maintained its hold on the eastern half of
Pinal County, southern part of Gila County, a small piece of far
southeast Maricopa County, and a small part of northern La Paz
County. Extreme Drought covers the remainder of western Pinal
County, much of Maricopa County, and most of La Paz counties, as a
well as much of eastern Riverside County in southeast California.
Severe Drought covers a small part far southwest Maricopa County,
northern Yuma, southern La Paz, and a small part of central
Riverside counties. Moderate Drought covers much of southern Yuma
and Imperial counties. Only a very small part of far southern Yuma
align in the Abnormally Dry territory. Severe, Extreme, and
Exceptional Drought now covers about 95% of Arizona as compared to
7% of the state at the beginning of June 2020.

La Nina peaked in the tropical Pacific during the winter with sea
surface temperatures now moderating around average. Overall, winter
2020-21 was fairly typical for La Nina in the Southwest with
widespread below average precipitation. The equatorial Pacific and
atmospheric flow has transitioned into a neutral state, and will
remain as such through the summer. There is about a 50% chance of La
Nina returning again in the fall/winter 2021-22 with little chance
of a transition to El Nino.


Summary of Impacts...

Rangeland and pasture conditions remain mostly in a poor to very
poor condition. 90% of the state pasture land rated as poor to very
poor compared to just 13% at this time last May, and the 5-year
average of 35%. While a couple winter precipitation events aided
topsoil moisture, recent dry, breezy weather has started depleting
available moisture. Rainfall needed in the spring for healthy forage
area was mostly absent, and supplemental feed has become necessary.
Reports continue to indicate many stock ponds low or empty requiring
water hauling. Ranchers continue to experience the worst impacts
from this extreme and exceptional drought.

Wildfires were a tremendous problem in Arizona last year with over
959,000 acres burned in the state - almost double the previous 2
years combined. With hot, dry spring weather returned, dry fuels
have also returned as long term drought persists. Acreage burned by
wildfires already this spring is outpacing last year with fuels ripe
for burning. Stage 1 fire restrictions have been put in place across
much of Arizona for state owned lands attempting to limit further
wildfire starts given the very high fire danger.


Climate Summary...

Precipitation during most of the winter season was quite dismal for
much the region with only a couple notable January storms making
larger contributions. Most locations are lagging well behind normal
for this Water Year (since Oct 1st), and likely will not experience
much, if any additional precipitation until the summer monsoon.
Totals and rankings are given below (Please note Normals values have
been updated to the new 1991-2020 benchmark. Some stations have a
limited historical record and rankings may not be as significant).

                  Since    Since    Dept     Percent     Rank
                  Oct 1    Oct 1    from    of Normal   Driest
                  2020     Normal   Normal

Phoenix AZ        1.51      4.75    -3.24       32        8th
Scottsdale AZ     2.07      7.14    -5.07       29        N/A
Globe AZ          4.34      9.48    -5.14       46        N/A
Yuma AZ           1.51      2.13    -0.62       71       63rd
Blythe CA         0.88      2.56    -1.68       34       16th
Tucson AZ         1.44      4.80    -3.36       30        3rd
Flagstaff AZ       9.48     12.50    -3.02       76       42nd


Precipitation/Temperature Outlook...

The approximate probability values for above, below, or near normal
temperatures and precipitation for June and the 3-month period
June-July-August are given below and valid for Southeast California
and Southwest and South-central Arizona. These probabilities are
derived from outlooks issued by the Climate Prediction Center and
are accessible through their website listed below. The temperature
outlook corresponds to the average temperature during the period,
while the precipitation outlook comprises the total precipitation
over the period.

Temperatures have a better chance of being above normal during
the month of June, as well as the 3-month period of June through
August. Precipitation totals have an equal chance of falling
above, below, or near average in June, as well as during the June
through August period.

                               Temperature        Precipitation
                               Probability         Probability
                             Above/Near/Below    Above/Near/Below
                                 Normal              Normal

June 2021...................   59 / 33 /  8        33 / 34 / 33
Jun-Jul-Aug 2021............   54 / 29 / 17        33 / 34 / 33


Hydrologic Summary and Outlook...

Record low inflows were recorded on the Salt/Verde basin early in
the Water Year reflecting a symptom of a poor 2020 monsoon and
lingering dry soil moisture. A brief period of ample rain and snow
in January helped the system, however limited snowfall since has
allowed runoff to lag well behind average. With soil moisture
remaining abnormally dry, total system forecast spring runoff
continues to be adjusted down to the point where this year will be
one of the lowest inflows ever recorded on the Salt/Verde basin.
Fortunately, good precipitation the past 2 years along with
excellent management keeps the system in good shape.


                   05/22/2021     05/22/2020      05/22/2019
                    ---------      ---------       ---------
Roosevelt             74              99              78
Horse Mesa            93              93              94
Mormon Flat           95              95              94
Stewart Mtn           93              96              92
Total Salt            77              98              81

Horseshoe              1              90              46
Bartlett              51              99              98
 Total Verde          32              96              78

 Total System         72              98              81


Next Issuance Date...

The next issuance of this Drought Information Statement will occur
around June 26th.

&&

Related Websites:

Additional information is available at the following locations:

NWS Forecast Office Phoenix: weather.gov/Phoenix
National Integrated Drought Information System: drought.gov
US Drought Monitor: droughtmonitor.unl.edu
Climate Prediction Center: www.cpc.ncep.noaa.gov
Arizona State Climate Office: azclimate.asu.edu
Arizona Dept of Water Resources: new.azwater.gov/drought
Western Regional Climate Center: wrcc.dri.edu
US Geological Survey: water.usgs.gov

Acknowledgement:

Information included in this statement was compiled from various
federal, state, and local agencies.

Questions or Comments:

National Weather Service Phoenix
E-mail: w-psr.webmaster@noaa.gov
National Weather Service Weather Forecast Office
