Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Brownsville Texas
331 PM CDT Sat may 30 2015

Short term /now through Sunday night/...the main issue in the short
term will be the ongoing mesoscale convective system/qlcs moving east-southeast along the
Rio Grande moving into Webb County. Latest satellite imagery shows
the ongoing thunderstorm complex across south Texas into northeast
Mexico and a plume of Pacific moisture streaming across central
Mexico into deep south Texas. At the surface...a weak cold front is
located across central Texas this afternoon. Current bro radar shows
isolated showers and thunderstorms associated with the sea breeze
moving across portions of the area.

This mesoscale convective system/qlcs with a strong cold pool is expected to hold together
and reach the western portions of the deep south Texas later this
afternoon. Outflow boundaries from this feature combined with
abundant moisture /precipitable water value of 1.63 inches per bro
12z sounding/...increasing instability...daytime heating and
interaction between the sea breeze and a boundary to the north will
continue to support some additional convection across deep south
Texas for the rest of the afternoon into this evening. The Storm
Prediction Center has the extreme western portions of deep south
Texas /mainly Zapata County/ under a slight risk of severe
thunderstorms with marginal risk across the rest of deep south Texas
for the rest of this afternoon and tonight. Will mention damaging
winds possible across the far west and gusty winds for the rest of
the area through tonight.

Rainfall amounts will be tricky due to movement of the thunderstorm
complex. Rainfall amounts of 1 to 3 inches will be possible this
afternoon and tonight. The weak cold front across central Texas will
drift south tonight combined with some upper level support will
maintain a chance of showers and thunderstorms tonight. The ground
remains nearly saturated across most of deep south Texas from the
rainfall of the past couple of weeks...the potential for flash
flooding exists with heavy rainfall. Average rainfall amounts of 1
to 3 inches...with higher amounts possible...across deep south Texas
late this afternoon through early Sunday morning. A Flash Flood
Watch is in effect for all of deep south Texas now through late

The remnants of the weak cold front will push out into the northwest
Gulf on the east and will continue to support convection upstream
over the Rio Grande plains. Lingering convection is possible across
the area tonight with ample moisture and boundary in the area. Low
temperatures will be in the lower to middle 70s tonight with light
onshore winds.

Will maintain a chance of showers and thunderstorms Sunday due to
the combination of stalled front in the area and abundant moisture
over deep south Texas. Slightly drier air will begin to move south
into the region Sunday night. Will mention a chance of probability of precipitation across
the west Sunday evening due to convection over Mexico moving into
the area. High temperatures will be the middle to upper 80s Sunday with
light northeast winds. Overnight low temperatures Sunday night will
be in the 70s.

&& through Sunday night...broad high pressure across the
northern Gulf will result in a weak pressure gradient along the
Lower Texas coast. A weak cold front will move into the Lower
Texas coastal waters late tonight into Sunday. This will result in
light to moderate northeast winds Sunday...becoming east to
southeast Sunday night. Low to moderate seas will prevail through
the forecast period. Showers and thunderstorms will be possible
tonight and Sunday.


Bro watches/warnings/advisories...
Texas...Flash Flood Watch through Sunday morning for txz248>257.



This product is also available on the web at:


National Weather Service Glossary of Abbreviations