Hydrometeorological Discussion
Issued by NWS West Gulf RFC

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AGUS74 KFWR 291603
1102 AM CDT THU SEP 29 2016



                  ...METEOROLOGICAL DISCUSSION...

A trough of low pressure has been located along the lower Texas
Gulf coast into northeast Mexico the past 48 hours, and this trough
had produced heavy rain along and just offshore from South Padre
Island. Some of this rain did fall over Deep South Texas the past 24
hours, with maximum amounts of 0.75 of an inch observed at Port
Mansfield TX.  This rain has now worked its way southwest out of
Texas as the upper low has moved into central Mexico.

Meanwhile, a strong low pressure system is located just north of
Louisville Kentucky this morning.  This low is bringing in a
secondary push of cooler, drier air into much of the WGRFC region.
This much drier and cooler weather is expected for the rest of the
week into the weekend. The low pressure system will remain nearly
stationary over Kentucky and Indiana through Saturday night.  This
will cause a ridge of high pressure to remain over west Texas.
The showers and thunderstorms that develop today or beyond will be
confined to far west Texas, northern Mexico, western New Mexico and
southwest Colorado to the west of this ridge. Dry weather is forecast
over the remainder of Texas and Louisiana through Sunday.

By Sunday morning the Great Lakes low pressure system will begin
to move northeast, and by Monday morning the low will move to near
Lake Ontario.  This will bring a more zonal flow of air early next
week.  Even with this change, the next major storm system will not
approach the WGRFC area until later Monday and Tuesday of next week,
so mostly dry weather conditions will persist until then.  This next
storm system will begin to bring precipitation to the Texas
panhandle by Tuesday morning and across the remainder of Texas late
Tuesday into Wednesday morning.

                    ...PRECIPITATION FORECAST...
For Today into Friday morning, Mean Areal Precipitation (MAP)
amounts of 0.25 to 0.50 inch are forecast for portions of extreme
western New Mexico and southwest Colorado.  MAP amounts of less than
0.25 of an inch are forecast for the Mexican Gulf coast, northern
Mexico, the western third of New Mexico and western Colorado.

For Friday into Saturday morning, MAP amounts of 0.25 inch are
forecast for portions of central New Mexico and southwest into
central Colorado.  MAP amounts of less than 0.25 of an inch are
forecast for northern Mexico into far west Texas, the western
half of New Mexico and the western two thirds of Colorado.

For Saturday into Sunday morning, no significant MAP amounts are
forecast for the WGRFC area.  MAP amounts of less than 0.25 of an
inch are forecast for far west Texas and much of Colorado.

For Sunday into Tuesday morning, no significant MAP amounts are
forecast for the WGRFC area.  MAP amounts of less than 0.25 of an
inch are forecast for parts of New Mexico, the Texas panhandle,
and southwest Colorado.

Because of the widespread rain over the past few weeks over parts
of New Mexico and Texas, drought conditions are minimal. The U.S.
Drought Monitor categorizes Texas as 5% abnormally dry, with less
than 1% of the state in moderate drought. New Mexico remains
unchanged with 47% of the state abnormally dry and 4% in the
moderate drought category. Due to the lack of heavy rainfall
forecast, no significant runoff is expected the next 5 days.

                     ...HYDROLOGIC DISCUSSION...
...Nueces Basin...
...Major Flooding...
The water that fell up near Uvalde still working its way through
Asherton which is forecast to crest later today into tonight in
major flood.  This water will take 4 days to crest downstream at
Cotulla early next week near major flood stage as well.  After which
it will take another 4 days for water to arrive at Tilden, and
another 2 until Three Rivers.  So this water will take a long time to
make its way downstream into Lake Corpus Christi.  Lake Corpus
Christi has begun making releases to handle the water on its way.

...San Antonio Basin...
...Minor Flooding...
The crest is past Falls City slightly lower than forecast due to
some modeling issues routing the water between Floresville and Falls
City.  The wave is approaching Runge and should crest later today in
minor flood before moving down to Goliad in a couple of days.

...Remainder of WGRFC Basins...
All other rivers, while wetter than normal for most of the area, are
mostly inside their banks.  Rainfall forecast has diminished for the
next few days allowing some of these flood waters to work their way
into the Gulf.  No additional significant flooding expected at this

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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