-- Discussion containing changed information from previous version are highlighted. --
213
FXUS64 KBRO 281142 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
642 AM CDT Tue May 28 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 248 AM CDT Tue May 28 2024

The main concerns in the short-term will be the continued heat
and the low to medium chance of thunderstorms. The northern edge
of the persistent mid-level will continue to erode and be squashed
southward over Mexico through the period. This will allow the
heat to ease up a bit today into tomorrow.

Most inland temperatures today are expected to reach the upper 90s
or exceed the century mark, supporting heat index readings above
heat advisory criteria (111 to 115 degrees) for a few hours.
Therefore, A Heat Advisory is in effect from Noon until 8 PM this
evening for all of Deep South Texas and the Rio Grande Valley,
except for the barrier islands. Low temperatures tonight should fall
into the mid to upper 70s across much of the area with a few 80s
possible in the Rio Grande Valley and along the coast. Highs on
Wednesday should be a degree or two lower due to the increase cloud
cover and rain chances.

Some convection may develop over the Sierra Madre Oriental Range and
drift towards the Rio Grande Plains this afternoon as another
shortwave traverses around the periphery of the 500 mb ridge.
However, confidence remains somewhat low on convection coverage this
afternoon and evening due to the spread in the current CAMs and the
latest GFS/NAM suggesting that any activity that develops to west
should fade before reaching the Rio Grande Plains or the Upper/Mid
Valley. There is a low to moderate (15 to 40 percent) chance of
convection but any storms could become strong to severe. SPC has
included the western sections of the CWA are in a slight Risk of
severe weather for today and tonight, with a Marginal Risk
elsewhere. SPC has all of Deep South Texas in a general thunderstorm
risk for Wednesday with another possible round of convection.

There is a Moderate rip current risk along area beaches today
through Wednesday.

&&

.LONG TERM...
(Wednesday Night through Monday)
Issued at 248 AM CDT Tue May 28 2024

A 500 mb ridge of high pressure will remain the dominant force
over the BRO CWFA through the period, with the center of this
feature varying from just south of the Baja Peninsula to central
Mexico. Although dry weather will prevail through a majority of
the time for Deep South Texas and the Rio Grande Valley, isolated
showers and thunderstorms are possible Wednesday night and Friday
night, and primarily over the northern ranchlands (Zapata, Jim
Hogg, Brooks, and Kenedy counties). This will be due to convection
initiating over neighboring Mexico courtesy of a pair of mid-
level shortwaves and then migrating into ranchland area.

Additionally, well above normal daytime high and overnight low
temperatures will also occur. Anticipated heat indices for the
long term forecast period suggest that a HEAT ADVISORY is most
likely for inland portions of the BRO CWFA Thursday and again
Saturday through Monday, with a SPECIAL WEATHER STATEMENT Friday
in lieu of the HEAT ADVISORY. Ultimately, will see if this regime
holds as the new work week continues to progress.

Finally, the intensity of the pressure gradient, with thermal low
pressure over Mexico interacting with building high pressure over
northeast Mexico, may result in a WIND ADVISORY for the three
immediate coastal counties (Cameron, Willacy, and Kenedy) from
Saturday through Monday.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 628 AM CDT Tue May 28 2024

Mainly mid to high clouds and light south winds prevail across
Deep South Texas early this morning. Drier conditions, in the
wake of last evenings convection, should maintain VFR conditions
this morning into the afternoon. Light southeast to southerly
winds this morning will increase and become gusty later this
morning into the afternoon. Short-term models including, the
latest HRRR, indicate some convection may develop over the higher
terrain of Mexico this afternoon and move eastward towards the
region this evening. Will not mention any convection for the
terminals at this time due to low confidence.
-- End Changed Discussion --

&&

.MARINE...
(Today through Wednesday)
Issued at 248 AM CDT Tue May 28 2024

Generally moderate southeast winds and moderate wave heights will
prevail in the short term. High pressure across the Gulf will
provide the driving force for the seasonal winds.

(Wednesday Night through Monday)
Steadily increasing winds and building seas will occur along the
Lower Texas Coast through the period. This will be due to thermal
low pressure over inland Mexico gradually interacting more
intensely with high pressure building over the northeast Gulf of
Mexico. Small Craft Should Exercise Caution be will a certainty,
with Small Craft Advisory becoming more likely beginning Friday
and continuing through the end of the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             95  80  94  81 /  10  10  20  10
HARLINGEN               98  78  97  79 /  10  10  20  10
MCALLEN                100  80  99  81 /  10  20  10  10
RIO GRANDE CITY        101  78 100  79 /  10  30  10  20
SOUTH PADRE ISLAND      86  81  86  82 /  10  10  20  10
BAYVIEW/PORT ISABEL     92  80  92  80 /  10  10  20  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory from noon today to 8 PM CDT this evening for
     TXZ248>255-351-353>355.

GM...None.
&&

$$

SHORT TERM...63-KC
LONG TERM....66-Tomaselli
AVIATION...63-KC