Hydrometeorological Discussion
Issued by NWS West Gulf RFC

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AGUS74 KFWR 051627
1126 AM CDT MON OCT 5 2015



                  ...METEOROLOGICAL DISCUSSION...
An upper level ridge of high pressure continues to dominate the
weather over eastern Texas this morning, while a series of storms
systems affect the western parts of the WGRFC area.  The upper level
ridge will persist for another day or two and will continue to
produce dry conditions over a good part of Texas.  Meanwhile a low
pressure system has moved southward into southern California.  This
low will be moving little through Tuesday morning.  As this low
sits and spins additional moisture from the eastern Pacific Ocean
will continue to stream northward over New Mexico.  This moisture,
combined with upper air disturbances ahead of the main low pressure
system, will continue to result in showers and a few thunderstorms
over a good part of New Mexico and far west Texas today through
Tuesday. Portions of far west Texas received in excess of 1.00 inch
of rain the past 24 hours.

The closed low over the west will be slow moving.  It will cross
into Arizona by Wednesday morning and move to a position near El Paso
by Thursday morning.  So while east Texas and western Louisiana
remain dry, precipitation will continue over New Mexico, southern
Colorado, and west Texas into the middle of the week.  Rainfall
amounts in excess of 1.00 inch are possible over parts of southern
New Mexico as a result.

By Thursday the upper air low will progress slowly southeastward,
and will move into Mexico west of the Texas Big Bend by Friday
morning. As this low moves southeastward the area of rain will spread
or develop eastward into more of Texas.  Fairly widespread rainfall
can be expected over west Texas late Wednesday, and over the rest of
the state Thursday and Friday.  Initially the heaviest rain will
be over the Rio Grande and Pecos River drainages in southwest Texas.
But as the upper low shifts to the southwest of the Big Bend the
heaviest rain will shift to the area southeast of Del Rio by Saturday
morning.  The upper low should weaken and begin shifting westward
over the weekend and the rain should begin to decrease.

                    ...PRECIPITATION FORECAST...
For Today into Tuesday morning, Mean Areal Precipitation (MAP)
amounts of 0.25 to 0.50 inch are forecast over northwestern and
southwestern New Mexico into southwestern Colorado, and over far west
Texas near El Paso.  MAP amounts of less than 0.25 of an inch are
forecast over western Texas, the western two thirds of Colorado and
most of New Mexico.

For Tuesday into Wednesday morning, MAP amounts of 0.25 to 0.50 inch
are forecast over the southern half of New Mexico into far western
Texas, as well as over northwest New Mexico into extreme southwest
Colorado.  MAP amounts of less than 0.25 of an inch are forecast over
western Texas and most of Colorado and New Mexico.

For Wednesday into Thursday morning, MAP amounts of 0.25 to 0.50 inch
or more are forecast over the southeast half of New Mexico, and for
the western third of Texas. The heaviest rain, with MAP amounts of
1.50 inches, are forecast over west Texas and extreme southeast
New Mexico west of Midland/Odessa.  MAP amounts of less than 0.25 of
an inch are forecast over the western half of Texas, all of New
Mexico and most of Colorado.

For Thursday into Saturday morning, MAP amounts of 0.25 to 0.50 inch
or more are forecast over the southeast two thirds of New Mexico into
extreme southern Colorado, almost all of Texas and northwest
Louisiana.  The heaviest rain, with MAP amounts of 3.00 inches, are
forecast over southwest Texas near and just south of Del Rio.  MAP
amounts of less than 0.25 of an inch are forecast over the remainder
of the WGRFC area of responsibility.

Drought conditions have returned to a good part of Texas.  Only the
Gulf coast, far west Texas and the panhandle are free from abnormally
dry conditions. Topsoil moisture has decreased over the past month,
which means it will require more rainfall to fall for runoff to
occur. In Texas 65% of the state is abnormally dry, with 18% in
severe drought.  In New Mexico, 43% of the state is also abnormally
dry.  Some beneficial rainfall will occur from central and southeast
New Mexico into the southwest third of Texas the next several days,
and some runoff will likely occur.  Elsewhere, the rainfall forecast
over the next five days will not be heavy enough to cause significant

                     ...HYDROLOGIC DISCUSSION...
...WGRFC Basins...
WGRFC rivers are below bankfull. The forecast for the rest of this
week shows rain increasing over southern and western Texas as
well as over New Mexico. This rainfall for the next few days may
cause some minor flooding over eastern and southern New Mexico and
southwest Texas.  Elsewhere, only light rainfall is expected over
northern and eastern Texas, keeping the rivers in these areas near
normal if not below normal levels.

The following URLs (all lower case) provide additional graphical
information on current and forecast hydrologic conditions, past and
future precipitation, and drought and climate forecasts.  This
information is provided by a variety of National Weather Service,
NOAA, and private sector entities.

For specific information on river conditions, refer to the AHPS
pages from the local NWS offices at:

The Flood Potential Outlook can be viewed on our webpage at:

The West Gulf River Forecast Center is now on Facebook:

National Precipitation Analysis:

The forecast rainfall amounts (QPF) can be viewed on our webpage at:

The US Drought Assessment:

The latest on Reservoir Information for Texas:



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