864
FXUS64 KBRO 170531
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
Issued by National Weather Service San Juan PR
1231 AM CDT Tue Jun 17 2025

...New AVIATION...

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 1226 PM CDT Mon Jun 16 2025

Visible satellite imagery and this mornings` RAOB shows opposing
flow at the surface and aloft. Moist southerly flow is allowing
for pop-up showers and along both outflow and seabreeze boundaries
east of I-69C, sheared off from the northerly flow aloft. This is
keeping storms sub-severe, however, it does little to encourage
storm motion. Slow moving, training showers and storms bringing
heavy rainfall (thanks to an anomalously moist atmosphere... 12Z
Sounding PWATs of 2.02") leave concern for flooding. Flood
Advisories are in place this afternoon for portions of Kenedy,
Willacy, and Hidalgo counties, and continue to be monitored.

Showers and thunderstorms should diminish late this afternoon.
Through mid-week, low chances of precipitation will continue bar
the chance of seabreeze activity in the afternoons. Ridging aloft
transiting into central CONUS will support dry air advection into
the mid-layers, limiting moisture depth. Near-normal temperatures
exist, but low-level moisture will maintain heat indices in the
triple digits just shy of Heat Advisory criteria.

&&

.LONG TERM...
(Thursday through next Monday)
Issued at 1226 PM CDT Mon Jun 16 2025

As the aforementioned ridge progresses over ECONUS, southerly
flow in the midlevels will return deeper tropical moisture and
bring anomalously high PWATs (greater than 90th percentile of
climatology) to the region. This predominately southerly flow will
bring moderate to high (50-80%) chances for showers and
thunderstorms Thursday afternoon/evening through Friday. Highest
PoPs exist along the coast. Chances of rain decrease to moderate
CWA-wide over the weekend. WPC has placed Cameron, eastern
Hidalgo, and southern/eastern Willacy counties in a Marginal Risk
(level 1 of 3) for excessive rainfall on Thursday and Friday.
Deep moisture content will likely support continued chances of
excessive rainfall through the weekend.

Increased rain chances and cloud cover will leave high and low
temperatures below average.

&&

.AVIATION...
(06Z TAFS)
Issued at 1223 AM CDT Tue Jun 17 2025

Mostly clear to partly cloudy skies with light to moderate
southerly winds prevail across all TAF sites. Generally VFR
conditions are expected through the next 24 hours. Moderate winds
overnight will increase and become breezy later this morning, some
gusts near 25 knots will be possible. Limited cloud cover are
anticipated with little to no chance of rain.

&&

.MARINE...
Issued at 1226 PM CDT Mon Jun 16 2025

Moderate southerly flow through midweek will increase seas to around
4 feet, leading to possible necessity of Small Craft Exercise
Caution headlines. Winds subside and remain south-southeasterly,
maintaining slight seas for the remainder of the period. There is
a moderate to high chance (50-80%) of showers and thunderstorms
late this week starting Thursday continuing through the weekend.
Conditions will be degraded within showers and thunderstorms.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             94  80  94  80 /  10   0  10  30
HARLINGEN               97  78  96  78 /  10   0  10  10
MCALLEN                101  79 100  79 /   0   0   0  10
RIO GRANDE CITY        100  77 100  78 /   0   0   0   0
SOUTH PADRE ISLAND      88  81  88  80 /  10   0  10  30
BAYVIEW/PORT ISABEL     93  79  92  78 /  10   0  10  20

&&

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

$$


AVIATION...CVB-SJU