Area Forecast Discussion
Issued by NWS Brownsville, TX

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS64 KBRO 131939

Area Forecast Discussion
National Weather Service Brownsville TX
239 PM CDT Sun Jun 13 2021

.SHORT TERM (Now through Monday Night): The short term will
personify classic early summer conditions for Deep South Texas and
the Rio Grande Valley. Mid level ridging will dominate through
the short term period, even if it weakens locally as the ridge
axis gradually lifts to the Four Corners region. This pattern will
keep conditions hot and dry with near normal temperatures and no
mentionable PoPs. Winds will generally remain light to moderate in
the absence of a strong pressure gradient. Heat indices will
range from 100 to 105 on Monday, but won`t be high enough to
necessitate a Heat Advisory.

.LONG TERM (Tuesday through Sunday): The main storyline in the
long term continues to be the potential for tropical development
across the Gulf of Mexico. Strong mid/upper level riding over the
Four Corners region will persist through much of the upcoming
week. At the same time, a fairly significant 500mb trough will be
draped and spread over most of the eastern CONUS. The reliable
deterministic forecast models are still persistent that some
tropical development will occur in the southern Gulf of Mexico...with
the latest 12z runs of the GFS and ECMWF in better agreement with
regards to location of development. However, models are still
very much inconsistent with its strength and its track. As
tropical cyclone initiation continues to look more and more likely
in the upcoming week, its track will highly depend on the
strength and position of the aforementioned mid/upper level ridge
and trough in the upcoming days. Since the last forecast package,
the National Hurricane Center has kept the probability of tropical
cyclone development across the Bay of Campeche at 50 percent over
the next 5 days in their 1 PM CDT Tropical Weather Outlook. Will
continue to monitor closely.

Light easterly winds will prevail much of the week, allowing for
the potential of seabreeze activity to get going during the
daytime on Tuesday and Wednesday. Deeper moisture from tropical
activity is forecast to increase by Thursday, depending on what
exactly happens across the Gulf of Mexico. The deeper moisture
will increase PoPs, especially near the coast through Saturday.
But again, the overall confidence of the position/strength of
tropical activity is very low at this time and this forecast will
likely change over the next couple of days. Slightly above average
temperatures are expected to continue on Tuesday and Wednesday.
Temperatures will cool down closer to average for the end of the
upcoming week as cloud cover and precipitation chances increase.
Forecast models have the potential tropical cyclone shifting
northeastward by Saturday evening/Sunday, putting Deep South Texas
on the western or subsident side of it. If this verifies, next
Sunday could potentially be a very hot and dry day across the


.MARINE: Now through Monday Night...Very favorable marine
conditions are expected to continue through early this week with
high pressure in control over the western Gulf of Mexico.
Generally light winds and low seas are anticipated, so Small Craft
Exercise Caution and Small Craft Advisories are not likely to be

Tuesday through Saturday...Very favorable marine conditions will
prevail into mid-week with light easterly winds and low seas.
Confidence lowers by Thursday as potential tropical development
occurs over the Bay of Campeche or southwestern Gulf of Mexico.
NHC still has a 50 percent chance for a tropical depression to
form in the Bay of Campeche by Thursday or Friday. Swells across
the Gulf will help build seas Thursday into the weekend, with SCEC
to SCA conditions likely by Thursday night or Friday morning.
Thunderstorm activity is expected to increase Tuesday and beyond
due to the increase in tropical moisture and instability. Marine
interests should continue to stay tuned.


BAYVIEW/PORT ISABEL  76  90  76  91 /   0   0   0  20
BROWNSVILLE          76  94  76  94 /   0   0   0  20
HARLINGEN            73  95  74  94 /   0   0   0  20
MCALLEN              75  97  75  96 /   0   0   0  20
RIO GRANDE CITY      74 100  74  99 /   0   0   0  20
SOUTH PADRE ISLAND   79  86  78  85 /   0   0   0  20




This product is also available on the web at:

69-Farris/67-Mejia/65-Soria is the U.S. government's official web portal to all federal, state and local government web resources and services.