Hydrometeorological Discussion
Issued by NWS West Gulf RFC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7
000
AGUS74 KFWR 151649
HMDFWR
HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE...WEST GULF RFC...FORT WORTH TX
1049 AM CST FRI DEC 15 2017

                VALID DECEMBER 15 THROUGH DECEMBER 20

...PRECIPITATION OVER DEEP SOUTH TEXAS WILL SPREAD INTO EAST
TEXAS AND LOUISIANA THIS WEEKEND...

                   ...METEOROLOGICAL DISCUSSION...
A deep low pressure system in the upper atmosphere is located over
western Mexico near the Gulf of California this morning.  Moisture is
abundant ahead of this low which has resulted in widespread light
precipitation from northern Mexico into south Texas the past 24
hours.  The heaviest rainfall amount has been around 0.30 of an inch
near Rio Grande City. This upper low will move little the next 24
hours, thus showers and possibly a thunderstorm can be expected to
continue over Mexico, Deep South Texas, along the Texas Gulf coast
into southern Louisiana through tonight.

By Saturday, the focus for showers and thunderstorms is forecast to
shift towards portions of east Texas and western Louisiana.  The
upper level low pressure is forecast to move northeastward into west
Texas, then into northern Oklahoma Saturday night.  As this occurs
a surface trough will move quickly eastward which will enhance the
rainfall.  At this time maximum rainfall amounts of around one inch
are expected.  As the upper low moves further east the rainfall will
end over Texas Sunday.  Meanwhile, a new upper air low is forecast to
drop south into Utah and Arizona.  As a result a new area of rain and
snow is expected Sunday over especially southern New Mexico.

By Monday the upper low will move over New Mexico. Well out ahead of
this low some showers may redevelop over east Texas and western
Louisiana.  Otherwise the precipitation areas will be confined to
New Mexico and west Texas.  By Tuesday this upper low will slide
quickly eastward across north Texas into Arkansas.  Due to the speed
of this storm heavy rainfall amounts are not expected, but amounts of
0.50 to 1.00 inch may occur across southeast Texas and southern
Louisiana.  Although this precipitation will bring some relief to
the dry conditions over portions of the state, unfortunately the
drought is expected to continue. No flooding is expected the next 5
days.

Dry weather is forecast from Tuesday night into Wednesday as a
surface high pressure system dominates the weather over our region.

                    ...PRECIPITATION FORECAST...
For Today into Saturday morning, Mean Areal Precipitation (MAP)
amounts of 0.25 to 0.50 inch are forecast for portions of Deep South
Texas and northern Mexico.  MAP amounts of less than 0.25 of an inch
are forecast over the southern third of Texas into southern
Louisiana.

For Saturday into Sunday morning, MAP amounts of 0.25 of an inch
or more are forecast over the southeast half of Texas and western
Louisiana.  The heaviest rain, with MAP amounts of 1.00 inch, are
forecast for portions of southeast and east central Texas into
northwest Louisiana.  MAP amounts of less than 0.25 of an inch
are forecast over the eastern two thirds of Texas into Louisiana, as
well as over southwest New Mexico and far southwest Texas.

For Sunday into Monday morning, MAP amounts of 0.25 to 0.50 inch
are forecast for portions of extreme southeast Texas and southwest
Louisiana, as well as over the southern half of New Mexico into far
west Texas.   MAP amounts of less than 0.25 of an inch are forecast
over the southeast quarter of Texas into most of Louisiana, as well
as over west Texas and most of New Mexico.

For Monday into Wednesday morning, MAP amounts of 0.25 of an inch
or more are forecast over the southeast third of Texas and most of
Louisiana.  The heaviest rain, with MAP amounts of 1.00 inch, are
forecast for portions of extreme southeast Texas into southwest
Louisiana.  MAP amounts of less than 0.25 of an inch are forecast
over most of the WGRFC area except for northern New Mexico and
southern Colorado.

The latest U.S. Drought Monitor for Texas shows the area considered
to be abnormally dry is around 71%, with around 26% of the state
experiencing moderate drought and 12% in severe drought.  In New
Mexico, 89% of the state is having abnormally dry conditions, with
16% in moderate drought conditions (over the western portions).
With the dry weather this fall, a large portion of the WGRFC forecast
area is experiencing some type of abnormally dry or drought
condition.  The heaviest rainfall the next five days will fall in
locations where soils are at least abnormally dry, thus no
significant runoff is expected.

                     ...HYDROLOGIC DISCUSSION...
...Sabine Basin...
Toledo Bend is running 7000 cfs for 2-3 hours each day for low flow
considerations until further notice.

...Remainder of WGRFC Basins...
All rivers across the WGRFC area are at or below normal flows and are
expected to remain below criteria levels over the next 5 days.

              ...SUPPLEMENTARY GRAPHICAL INFORMATION...
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:
http://water.weather.gov/ahps/

The Flood Potential Outlook can be viewed on our webpage at:
http://www.weather.gov/wgrfc/wgrfcfop

The West Gulf River Forecast Center is now on Facebook:
http://www.facebook.com/NWSWestGulf

National Precipitation Analysis:
http://water.weather.gov/precip/

The forecast rainfall amounts (QPF) can be viewed on our webpage at:
http://www.weather.gov/wgrfc/wgrfcqpfpage

The US Drought Assessment:
http://www.cpc.ncep.noaa.gov/products/Drought

The latest on Reservoir Information for Texas:
http://www.waterdatafortexas.org/reservoirs/statewide

STORY

$$




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.