Hydrometeorological Discussion
Issued by NWS West Gulf RFC

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AGUS74 KFWR 211751
HMDFWR
HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE...WEST GULF RFC...FORT WORTH TX
1150 AM CST FRI NOV 21 2014

                VALID NOVEMBER 21 THROUGH NOVEMBER 26

...SIGNIFICANT RAINFALL IS EXPECTED FOR THE NORTHEASTERN HALF OF TEXAS
THIS WEEKEND FOLLOWED BY MOSTLY DRY WEATHER NEXT WEEK...

                   ...METEOROLOGICAL DISCUSSION...
A deep low pressure system over southern California is going to
produce a widespread (beneficial) precipitation event this weekend.
Low level southerly winds have transported Gulf moisture northward,
and already a weak upper air disturbance produced light rain over
roughly the southeast third of Texas and western Louisiana the past 24
hours.  The California low pressure system is moving east within an
active southern branch of the jet stream, and will dive southeast into
Mexico south of the Desert Southwest tonight.  The upper level flow
will become more favorable for the transport of deeper mid level
moisture, which will set the stage for showers and thunderstorms.
With abundant moisture and significant large scale lift (courtesy of
the previously mentioned storm system), widespread showers and
thunderstorms should form late tonight, which will become more
organized Saturday.  Some severe thunderstorms are expected
Saturday.

The low pressure system is forecast to cross Texas Saturday
afternoon and night.  As a result, rainfall amounts could exceed 1
to 3 inches, with isolated 4 inch amounts in some areas of northern,
central and southeast Texas. Locally heavy rainfall could produce
areas of runoff. Due to the localized nature, widespread river
flooding is not expected.

On Sunday morning the strong Pacific storm system will exit the area,
leaving drier weather in its wake.  The dry weather is expected to
persist through Monday.

On Monday night and Tuesday another upper air disturbance and cold
front are forecast to move through Texas. Atmospheric moisture will
be limited, thus only isolated showers are expected with its passage.
Cool, dry weather is expected from Tuesday night into Thanksgiving
Day as high pressure approaches the region.


                    ...PRECIPITATION FORECAST...
For Today into Saturday morning, Mean Areal Precipitation (MAP)
amounts of 0.25 to 0.50 inch are forecast for northern, central and
southeast Texas, with the heaviest rain forecast west of the DFW
metroplex.  MAP amounts of less than 0.25 inch are forecast for
most of the remainder of Texas and northwest Louisiana.

For Saturday into Sunday morning, MAP amounts of 0.25 to 0.50 inch
or more are forecast for the area east of a line from Childress to
Midland to Corpus Christi.  The heaviest rain, with MAP amounts of
2.00 inches, are forecast for parts of northeast, central and
southeast Texas.  Lighter MAP amounts are expected across most of
Texas, extreme northern New Mexico and southern Colorado.

For Sunday into Monday morning, MAP amounts of 0.25 inch are forecast
for southern Colorado and north central New Mexico.  Lighter MAP
amounts are forecast for the northeastern third of New Mexico, much
of Colorado and the Texas panhandle.

For Monday into Wednesday morning, no significant MAP amounts are
forecast for the WGRFC area.  MAP amounts of 0.25 inch or less are
forecast for extreme southeast Texas and most of Louisiana.

Moderate or worse drought conditions continue to be observed over
parts of New Mexico and Texas.  In Texas, about half the state is
experiencing moderate or worse drought (44%) and 10% has extreme to
exceptional drought. In New Mexico, nearly two thirds of the state is
experiencing moderate or worse drought (63%) and 2% has extreme to
exceptional drought. Significant rainfall is expected the first
half of this weekend and should be heavy enough to produce runoff in
some areas, mainly over the northeastern 1/2 of Texas.  However, the
runoff will not be enough for significant mainstem river flooding to
occur.

                     ...HYDROLOGIC DISCUSSION...
...WGRFC Basins...
Rivers will remain below flood criteria the next couple of days.
However, significant precipitation is forecast across portions
of Texas this weekend. As a result, some higher than normal flows
and minor flooding is possible in southeast Texas as well as the
headwater areas in the middle portions of the Brazos and Colorado
river basins.

              ...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.srh.noaa.gov/wgrfc/?n=wgrfcfop

The West Gulf River Forecast Center is now on Facebook:
http://www.facebook.com/US.NationalWeatherService.WGRFC.gov

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

The forecast rainfall amounts (QPF) can be viewed on our webpage at:
http://www.srh.noaa.gov/wgrfc/?n=wgrfcqpfpage

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

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

STORY

$$




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