-- Discussion containing changed information from previous version are highlighted. --
738
FXUS64 KBRO 280043 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
743 PM CDT Thu Jun 27 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Friday night)
Issued at 250 PM CDT Thu Jun 27 2024

Mid-level ridge will move further eastward into northern Texas over
the course of the short term period and will be the dominate feature
for Deep South Texas and the Rio Grande Valley. A weak inverted
trough will still be able to move under the ridge and along with the
southeasterly flow carrying tropical moisture to the region could
stir up some isolated showers and thunderstorms. With PWAT values
around 2 inches there will be a considerable amount of moisture that
could foster the growth of any showers and thunderstorms that
develop along a sea breeze.

As for the temperatures, high temperatures are expected to be in the
range of mid to upper 90s with maybe a few places getting into the
triple digits. The heat indices for tomorrow are expected to be in
the range of 107-114. However, the need for a Heat Advisory is still
questionable at this time, as the duration for heat indices greater
than 111 does not meet the required criteria for a Heat Advisory. A
Special Weather Statement could be sufficient enough to cover for
tomorrow. As for the low temperatures, tonight is expected to be in
the range of upper 70s to low 80s. However, tomorrow night expect
more of the lower 80s to spread over the area.

&&

.LONG TERM...
(Saturday through next Thursday)
Issued at 250 PM CDT Thu Jun 27 2024

Conditions will begin dry on Saturday across Deep South Texas with a
broad mid-to-upper level high and a surface high pressure near
Florida, which will keep a southeasterly onshore flow. Meanwhile,
moisture associated with a tropical wave located in the southern Bay
of Campeche, will be advected northwestward within the southeasterly
flow, which will increase cloud coverage and humidity into the
region overnight Saturday with showers and thunderstorms forming by
Sunday morning. The National Hurricane Center (NHC) indicates a low
(30%) chance of development of this tropical disturbance into a
tropical system within the next 7 days. Currently, the forecast
indicates little strengthening and most likely remaining a tropical
wave. Showers and thunderstorms will continue into the evening hours
on Sunday before dying out as the tropical wave moves west into
Mexico and moisture decreases. However, shortwaves riding along the
ridge of the high pressure may bring showers and thunderstorms into
the region Monday afternoon and evening via sea breeze boundaries.
As the high broadens and dominates Deep South Texas, much of the
remainder of the week will feature drier conditions.

Temperature-wise, aside from Sunday, daily highs will range from mid-
to-upper 80s across the barrier islands, lower-to-mid 90s west of
the Laguna Madre and mid-to-upper 90s across the Rio Grande Plains.
Overnight lows will feature lower 80s for the barrier islands and
upper 70s to low 80s further inland. Sunday will be the coolest of
the period, due to the increased cloud coverage and rain, with
temperatures in the mid 80s over the barrier islands and ranging
between 89-92 inland. Factoring in humidity with daytime highs,
Sunday and Monday will be quite a few degrees below Heat Advisory
criteria, due to clouds and cooler easterly onshore flow, but will
otherwise be just beneath advisory standards as daily maximum
apparent temperatures will peak at around 109 to 110, but only for
an hour or two, which may be enough to prompt Special Weather
Statements.

&&

.AVIATION...
-- Changed Discussion --
(00Z TAFS)
Issued at 740 PM CDT Thu Jun 27 2024


VFR conditions prevail the next 24 hours along with light
southeast winds. 10-20% chance of showers Friday afternoon along
the sea breeze with short duration impacts if a shower passes
near or over the airfields.
-- End Changed Discussion --

&&

.MARINE...
Issued at 250 PM CDT Thu Jun 27 2024

Tonight through Friday Night...With high pressure in control over
the Gulf of Mexico, light to moderate winds with low to moderate
seas are expected to persist through Friday night. Winds over the
waters are expected to increase on Friday night, leading to some
adverse conditions that would require Small Craft Exercise
Caution.

Saturday through Thursday...Small Craft Exercise Caution (SCEC)
conditions will likely begin the period as moderate to near fresh
southeasterly winds on Saturday continue into Sunday. Showers and
thunderstorms on Sunday will also be accompanied with elevated seas
of possibly 6-7 feet, generated by a tropical disturbance to the
southeast in the Bay of Campeche. The National Hurricane Center has
a low (30%) chance of development into a tropical system. However,
the latest indications are for a gentle to moderate east-
southeasterly flow on Monday with seas improving and winds becoming
south-southeasterly by Tuesday and more ideal seas for the remainder
of the forecast.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             81  94  82  94 /  10  30  10  10
HARLINGEN               78  96  79  96 /   0  20  10  10
MCALLEN                 80  98  82  97 /   0  10   0  10
RIO GRANDE CITY         79  97  80  97 /  10  10   0   0
SOUTH PADRE ISLAND      83  89  84  89 /  10  20  10  10
BAYVIEW/PORT ISABEL     79  94  81  92 /  10  20  10  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

SHORT TERM...64-Katz
LONG TERM....68-McGinnis/65-Irish
AVIATION...59-GB