Flood Potential Outlook
Issued by NWS

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Hydrologic Outlook
National Weather Service El Paso TX/Santa Teresa NM
743 PM MST Wed Mar 8 2017

...Spring Flood Outlook...

...Spring snowmelt flooding risk is very low across southwest and
south-central New Mexico and Far West Texas...

PRECIPITATION, SNOWPACK, AND STREAMFLOW
Precipitation over the past 90 days has been above normal over
most of the region, but there has been a considerable downward
trend in precipitation amounts and coverage over the past month.

Snowpack data from the USDA/National Resource Conservation Service
indicate that significant snow pack which had developed over the
headwaters of the Gila River has largely melted, particularly over
elevations below 9,000 feet. This has allowed most gauges along
the Gila River to flow around 200 percent of median, though
streamflow has gradually been dropping as snow pack diminishes.

It should be noted that the most significant historical flood
events on the Upper Gila River, outside of Monsoon Season, have
occurred in December and January, and involved heavy rainfall
falling over above-normal snowpack. The latest known Gila River
flood to cause impacts was in mid-February 2005. So, the risk of
Spring Flooding on the Gila is historically low.

For the Rio Grande headwaters in Colorado and northern New Mexico,
snowpack remains well above normal. However, with Elephant Butte
Reservoir storage (volume) running at 15 percent of capacity (and
33% of normal), there is essentially no risk of flooding from
snowmelt below the dam.

RESERVOIR SUMMARY
Most reservoirs in New Mexico have ample storage capacity at this
time. Below is the current reservoir storage in acre-feet (a-f)
and percent of capacity for selected reservoirs in New Mexico as
of March 8th, 2017. Data provided by the Bureau of Reclamation.

Reservoir                Current            Current %
                        Storage A-F         Capacity

Caballo Reservoir         31,338               9%
Elephant Butte Reservoir 302,402              13%


STREAMFLOW FORECASTS
NWS River Forecast Centers, in conjunction with our partners in
the NRCS, USACE, and the USBR, produce seasonal streamflow
forecasts for selected river locations and basins in New Mexico.
These forecasts are based on hydrologic conditions as of the 1st
of the month and may not reflect current trends and forecasts.

As of March 1, inflow (March-July) into Elephant Butte Reservoir
as measured at San Marcial, NM is mostly likely to be above the
30-year average.

Streamflow in the Upper Gila basin as measured at the Gila and
Virden gauges is mostly likely to be around 1.5 times average.

Forecasts issued by NWS/West Gulf River Forecast Center:

                                FORECAST RUNOFF                      AVERAGE
                                                                      RUNOFF
                                  MOST     REASONABLE   REASONABLE     30YR
                                PROBABLE    MAXIMUM      MINIMUM    1981-2010
    FORECAST           FORECAST        %            %            %
      POINT             PERIOD 1000  30YR   1000  30YR   1000  30YR    1000
                          (*)   AF   AVG.    AF   AVG.    AF   AVG.     AF
                    *(1)APR-SEP
                    *(2)MAR-JUL

Rio Grande River
 San Marcial, NM          (2)   695   136   1020   200    372    73     510
 (Immediately above Elephant Butte Reservoir)

-----------------------

Forecasts issued by NWS/Colorado Basin RFC:

                           Period     50%  %AVG    10%    30%    70%    90%    AVG
                           ------    ----  ----   ----   ----   ----   ----    ---
Gila River
  Near Gila                Mar-May     55   162     84     67     48     40     34
  Near Virden              Mar-May     65   151    101     78     56     47     43

50% Most probable volume in 1000 acre-feet.
%AVG  Most probable volume in percent of the 1981-2010 average.
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.
AVG   Average volume for the 1981-2010 period.


DROUGHT
No short-term drought conditions currently exist across the Rio
Grande or Upper Gila valleys.

SHORT-TERM OUTLOOK
The 8-14 day temperature and precipitation outlooks issued by the
NWS/Climate Prediction Center continue an increased probability
of normal to above normal temperatures and drier than conditions
for most of New Mexico and Far West Texas. Please refer to the
latest forecasts for more current weather information.

LONG-TERM OUTLOOK
The NWS/Climate Prediction Center has ended the La Nina Advisory
and ENSO neutral conditions exist over the Pacific Ocean. Models
guidance is expecting the neutral ENSO conditions to continue for
the spring and into Summer 2017. The current CPC forecast for
March through May 2017 continues the increased likelihood of
warmer and drier conditions for New Mexico. These outlooks are
issued monthly with the next outlook to be issued on March 16th.
Outlooks can be found at the NWS/CPC website at
http://www.cpc.ncep.noaa.gov

SPRING FLOOD OUTLOOK
Based on the above factors, there is a very low flood risk for
the Rio Grande Basin below Elephant Butte reservoir, as well as
the Upper Gila River basin.

FOR MORE INFORMATION
The NWS El Paso Hydrologic Service Area (HSA) is serviced by two
river forecast centers: West Gulf RFC (Ft Worth, TX), and the
Colorado River Basin RFC (Salt Lake City, UT). These RFCs issue a
variety of hydrologic forecast products during the year. Further
products and current information can be found at the following
locations:

http://www.srh.noaa.gov/wgrfc
https://www.cbrfc.noaa.gov

You can also find additional weather and water products and
forecasts at the NWS El Paso website at:

http://www.weather.gov/ElPaso

$$

Hardiman



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