Hydrometeorological Discussion
Issued by NWS West Gulf RFC

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AGUS74 KFWR 301738
1138 AM CST MON NOV 30 2015



                  ...METEOROLOGICAL DISCUSSION...
The major storm system which brought widespread rainfall to the WGRFC
area has now shifted eastward to western Nebraska. As upper
disturbances in the southwest flow moved across the region the past
72 to 96 hours, widespread rain and embedded thunderstorms occurred
over most of Texas, as well as over the southeast half of New Mexico.
Higher elevation snows also fell over the mountains of southern
Colorado, with some additional snow noted the past 24 hours over the
mountains of northern New Mexico and Colorado. The heaviest rain the
past 24 hours was around 2.00 inches, and it was most widespread
around Marshall TX.  Some parts of north Texas between Dallas and
Sherman exceeded 10 inches of rain for this event.

The rainfall that had been so persistent over most of Texas decreased
last night. The strong upper level low pressure system which was over
Wyoming began moving east.  As this transformation occurred drier air
began to move eastward over west Texas. This caused the more
significant rainfall over Texas to get shoved eastward into
Louisiana.  Some residual showers continue this morning south
southwest of the DFW metroplex as an upper air disturbance passes
through, but this rain will gradually diminish and move east by

By Tuesday morning the upper low will be over northern Iowa. Drier
air should cover a good part of the WGRFC area, but some additional
light rainfall development can be expected from deep south Texas into
southeast Texas and Louisiana from Tuesday through Wednesday as the
dry air undercuts the lingering moisture.  Also, an upper air
disturbance will develop and approach Texas from the northwest.  As
this upper disturbance crosses Texas the rainfall will linger along
and near the Texas Gulf coast. After this disturbance moves east of
the WGRFC area on Thursday all the precipitation should push east of
our region.

A ridge of high pressure is forecast to approach our region from
the west on Thursday, and this ridge will move across Texas on
Friday into Saturday morning.  As a result, dry weather is forecast
Thursday through Saturday morning.

                    ...PRECIPITATION FORECAST...
For Today into Tuesday morning, no significant Mean Areal
Precipitation (MAP) amounts are forecast for the WGRFC area.  MAP
amounts of less than 0.25 inch are forecast for southeast Texas
and Louisiana, as well as a small part of northern New Mexico into
southern Colorado.

For Tuesday into Wednesday morning, MAP amounts of 0.25 to 0.50 inch
are forecast over the middle and upper Texas Gulf coast into
southeast Texas and western Louisiana.  MAP amounts of less than 0.25
inch are forecast for the southeast third of Texas and Louisiana.

For Wednesday into Thursday morning, no significant MAP amounts are
forecast for the WGRFC area.  MAP amounts of less than 0.25 inch are
forecast for the southeastern quarter of Texas and the southern two
thirds of Louisiana.

For Thursday into Saturday morning, no significant MAP amounts are
forecast for the WGRFC area.

Topsoil moisture is very high due to recent rainfall events, which
means it will require less rainfall for runoff to occur. That, along
with the vegetation being dormant now that the growing season has
ended, means runoff will be quicker. Over Texas only 7% of the state
is abnormally dry, while over New Mexico, 26% of the state is
abnormally dry. The rainfall forecast through the next five days will
not lead to any additional runoff in spite of the wet soil moisture
conditions and the cold season vegetation patterns.

                     ...HYDROLOGIC DISCUSSION...
...Trinity Basin...
...Major Flooding...
Heavy rainfall during the holiday weekend across the upper Trinity
basin has generated moderate to major flooding along several mainstem
locations from Dallas (DALT2) to Long Lake (LOLT2) with widespread
minor to moderate flooding within smaller streams and tributaries.
It has been reported that a levee has been breached about a half mile
downstream of Rosser and is affecting the area around Highway 34 and
other local roads and low lands.

...Brazos Basin...
...Moderate Flooding...
Significant rainfall has generated rises on the Brazos River basin.
At this time, moderate river flooding is occurring on the Leon River at
De Leon.  Minor river  flooding is also forecast to occur on the
Navasota River near Easterly.  Continued higher flows are occurring
along parts of the mainstem Brazos River and tributaries.

...Sabine Basin...
...Moderate Flooding...
Heavy rainfall during the holiday weekend across the upper Sabine
basins has generated minor to moderate flooding along the mainstem from
Mineola (MLAT2) to Gladewater (GDWT2), as well as within the smaller
headwater streams and tributaries.

...Neches Basin...
...Minor Flooding...
Widespread rainfall during the holiday weekend across the upper
Neches basins has generated minor flooding along the mainstem from
Lake Palestine and Neches (NCST2) to Diboll (DIBT2).

...Remainder of WGRFC Basins...
Elsewhere, river flows are normal to above normal for this time of
year.  No additional rainfall is expected during the next 5 days.

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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