Drought Information Statement
Issued by NWS Phoenix, AZ

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000
AXUS75 KPSR 291603
DGTPSR

Drought Information Statement
National Weather Service Phoenix AZ
900 AM MST Mon Oct 29 2018

...Substantial Drought Improvements as a Result from Record
Rainfall Across much of the Region in October...

Synopsis...

Abundant moisture from a remnant Pacific hurricane and a persistent,
favorable weather pattern yielded several heavy rainfall events
across much of the Southwest United States during the first half of
October. Record rainfall has been noted across much of central
Arizona with Phoenix experiencing its wettest October on record
(since 1896) and its 3rd wettest month ever. These heavy rains have
helped both short term rangeland and streamflow conditions through
much of the region. Soil moisture profiles and fire weather
conditions have correspondingly improved. However, improvements to
longer term water resources will require additional winter rain and
snow give the prolonged regional drought.

Substantial drought improvements were noted in Arizona over the past
month with modest improvements in SE California. Vast improvements
from Extreme and Severe drought to only Moderate Drought and
Abnormally Dry conditions occurred over much of Arizona. Extreme
drought areas has fallen under 15% as compared to almost 65% prior
to the monsoon season. Severe drought now covers under 50% of
Arizona compared to 97% at the beginning of the monsoon, yet just 4%
at the start of the year.

ENSO has been maintaining a neutral state, however we are
transitioning to an El Nino episode; and confidence is now high that
equatorial Pacific sea surface temperatures will reach El Nino
thresholds later this fall. While many other factors contribute to
the atmospheric pattern, there could be a slight tilting of odds
towards wetter conditions later this year into early next year.


Summary of Impacts...

Heavy October rainfall was beginning to aid in rangeland and pasture
conditions though full recovery may be hindered by the longer term
drought impacts. Reports around the region also indicate stock ponds
are beginning to refill. Rangeland and pasture conditions have
improved slightly, but 58% of the area is still rated as poor or
very poor. This compares to just 13% of the area at this time last
year, but better than the 65% one month ago.

The wet weather over the monsoon season and into the beginning of
October has dampened much of any fire weather threat. 10-hour and
100-hour dead fuel moisture values have improved with recent
rainfall and now are generally around 5-10% in most locations. Areas
with heavier rainfall have experienced even better moisture levels,
and only minimal fire activity should be expected the remainder of
the year.


Climate Summary...

Recent heavy rainfall has brought year-to-date rainfall totals near
or above average in many locations in central and eastern Arizona,
however far Western Arizona and SE California are still lagging
closer to 50% of normal. Totals and rankings are given below (please
note some stations have a limited historical record and rankings may
not be as significant).

                  Since    Since    Dept     Percent     Rank
                  Jan 1    Jan 1    from    of Normal   Driest
                  2018     Normal   Normal

Phoenix AZ        8.75      6.41    +2.34      137       89th
Scottsdale AZ     9.18      8.15    +1.03      113        Msg
Casa Grande AZ    7.55      7.39    +0.16      102       44th
Yuma AZ           1.74      2.80    -1.06       62       33rd
Blythe CA         1.84      3.07    -1.23       60       13th
Tucson AZ        11.87      9.98    +1.89      119       79th
Flagstaff AZ     19.75     17.96    +1.79      110       56th


Precipitation/Temperature Outlook...

The approximate probability values for above, below, or near normal
temperatures and precipitation for November and the 3-month period
November-December-January 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 much better chance of being above normal during
the month of November, as well as the 3-month period of November
through January. Precipitation totals have a slightly better chance
of reaching above average amounts in November, as well as the
November through January period.

                               Temperature        Precipitation
                               Probability         Probability
                             Above/Near/Below    Above/Near/Below
                                  Normal              Normal
November 2018..............   53 / 33 / 14        38 / 33 / 29
Nov-Dec-Jan 2018-19........   42 / 33 / 25        36 / 33 / 31


Hydrologic Summary and Outlook...

Reservoir levels remain well below levels recorded at the same time
last year and are similar to levels in 2016. Spring runoff was near
record low levels and the recent heavy rainfall has only marginally
helped inflow. Better winter rain and snow will be needed to see
better recharge heading into next spring.

                   10/25/2018     10/25/2017      10/25/2016
                    ---------      ---------       ---------
Roosevelt             39              58              35
Horse Mesa            92              91              93
Mormon Flat           95              95              94
Stewart Mtn           93              95              94
Total Salt            49              64              45

Horseshoe             10              10               1
Bartlett              47              82              68
 Total Verde          33              54              43

 Total System         47              63              45


Next Issuance Date...

This Drought Information Statement will be updated on or around
November 22 2018.

&&

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


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