124 
FXUS64 KBRO 252345
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
545 PM CST Tue Nov 25 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 544 PM CST Tue Nov 25 2025

-Dangerous surf and some tidal run-up at the beach Wednesday 
 afternoon, impacting people here for the long holiday weekend 

-Difficult boating conditions arrive Wednesday for Laguna Madre and 
the Gulf, continuing over the Gulf into Wednesday night

-Some welcome rain late tonight and Wednesday along a front that 
brings a short break through Friday from the record/near record heat 
of the past week

-Stronger front could arrive early Sunday with much cooler 
temperatures and dangerous surf/boating conditions returning

&&

.DISCUSSION...
Issued at 1229 PM CST Tue Nov 25 2025

Tonight through Wednesday: The well-advertised front that will bring 
a change from early October heat to more 'normal' conditions headed 
into Thanksgiving is the main story early in the forecast.  Along 
and especially behind the main boundary showers and perhaps an 
elevated thunderstorm are now expected, favoring the Rio Grande 
Plains/Brush Country/upper Valley between midnight and just after 
daybreak Wednesday, and the populated lower-mid Valley from pre-dawn 
through noon or so Wednesday. QPF forecast is somewhat tricky, as 
surface stability behind the front is countered a bit by decent 
diffluence aloft. High-Res (HREF) model probabilities for >0.5" are 
around 40% across the Rio Grande Plains/upper Valley overnight/early 
Wednesday, with similar values along the coast later on Wednesday. 
Bottom line?  At most, very localized nuisance flooding where high 
rainfall rates fall over poor drainage areas. Otherwise, beneficial 
rain for most, and given the current moderate to extreme drought 
conditions, any little bit helps.  High temperatures Wednesday will 
be dependent on both coverage and duration of rain. Persistent rain 
or rain with short breaks would only allow low to mid 70s for highs, 
but more breaks would be enough for upper 70s to around 80.  The 
current blended forecast leans a bit warmer for the populated RGV 
(near 80) while 70-75 is common elsewhere. The probability for a 
larger error spread is greatest in the populated RGV if daytime rain 
is frequent vs. occasional.  Either way, afternoon temperatures will 
be 10 to nearly 20 degrees lower Wednesday than on Tuesday.

Otherwise, the other issue arrives for those at or planning to head 
to South Padre to enjoy the still very warm (~80 degree) surf.  For 
those there today, take advantage as strong northeast winds up to 25 
mph with higher gusts arrive by or before noon, and dangerous surf 
with intense rip currents follow soon after. By late afternoon 
through early evening, tides may run up the beach given the direct 
swell direction onshore.  Fortunately, predicted tides are in their 
low phase so notable coastal flooding is not anticipated...but 
enough of an energy surge could bring water to the dune line at 
narrow beaches from the north end of the City of SPI through the 
public beach access points.  In short, vehicles should plan to be 
off the beach shortly after sunrise to ensure not getting surprised 
(and stuck) in any water later in the day.

Wednesday Night through Saturday Night:  Any lingering light evening 
rain near the coast should end, with winds becoming light from the 
north. The overnight will be pleasantly cool, which is relative 
since forecast temperatures by daybreak Thanksgiving Day are where 
they should be (50 ranchlands, 55-60 Valley except near the coast). 
That said, temperatures may end up a bit higher than this depending 
on thickness of remaining clouds which would be an insulating 
blanket despite the light northerly flow. Aside from the clouds 
(especially for the Valley), Thanksgiving looks ideal for outdoor 
eating with temperatures at seasonal levels (mid to upper 70s), 
modest humidity, and light east winds as area is under subsidence 
aloft as the surface ridge eases into the Mississippi Valley. 

Low to mid level southeast/south flow quickly returns Thursday night 
and especially Friday, aided by weak shear energy in broad westerly 
flow aloft. Latest GFS hinting at a warm-frontal type setup which 
could bring low chances (10-20%) of light rain/showers, favoring the 
ranchlands. The clouds will put somewhat of a lid on high 
temperatures..but even so, expect readings back to a degree or two 
above average (average for the 28th is mid 70s ranchlands, upper 70s 
Valley).  Southeasterly flow picks up Friday night and Saturday, 
bringing a return to October-like conditions (temperature and 
humidity) with a soupy start and a warm, partly sunny afternoon). 
For the day, temperatures will be around 10 degrees above average 
for both minimum values (63 to 70) and maximum values (83 to 88). 
Another warm and humid night follows Saturday night into the wee 
hours Sunday, with light winds ahead of the next bigger front 
perhaps producing a period of fog.

Residual rip currents on South Padre for Thanksgiving will be a 
concern, before a one-day lull Friday. The stronger southeasterly 
flow arriving Friday night into Saturday will bring a pronounced 
south-north longshore and roughening/buliding surf as well.

Sunday through Tuesday:  Models have come into agreement for a 
faster...and stronger...cold front as some of the coldest air of the 
season surges south through Texas.  Shallow cold air often arrives 
in advance of when the global models think it might, so exact timing 
of the surge remains in question. Confidence has increased based on 
the recent GFS trend which now matches more closely with the 
deterministic ECMWF.  NBM is likely lagging, so will get ahead of 
the situation and lower temperatures several degrees, especially 
across the ranchlands. That said, there is an increasing likelihood 
that afternoon temperatures Sunday could be up to 25 degrees cooler 
than on Saturday - with 10-25% probabilities (reasonable cold case) 
that readings could range from the low to mid 50s across most areas, 
except around 60 near the coast. We'll provide more details and 
perhaps a "sharp change" graphic on this tomorrow (Wednesday).  

Should this occur, coastal conditions will also deteriorate with 
roughening/dangerous surf and perhaps some minor run-up by afternoon.

Monday and Tuesday will maintain the relative chill, along with 
clouds and pockets of light rain in southerly overrunning. Will 
lower temperatures a bit on these days as well (compared with the 
blends) to get on top of the situation. Bottom line?  Potential is 
growing for the first multi-day window of much below average 
(daytime) temperatures that will make the start of December feel 
like...December.

&&

.AVIATION...
(00Z TAFS)
Issued at 544 PM CST Tue Nov 25 2025

Through 00z Thursday....VFR conditions are expected to prevail 
through this evening. However, over the next 6-9 hours, 
deteriorating weather conditions are expected to occur. Clouds will 
lower in elevation and increase in coverage with showers and 
thunderstorms developing after midnight tonight in response to an 
approaching frontal boundary. 

Overnight tonight through the remainder of the flying conditions 
will primarily range between VFR and MVFR. Showers and storms are 
expected to develop and move into the TAF sites during the overnight 
hours sometime between 07z-12z. Any showers or storms that move over 
a TAF site will have the capabilities of reducing cigs/vsbys to IFR 
levels. The threat for widespread showers and storms will come to an 
end by noon on Wednesday. There could be some lingering showers 
during the afternoon hours with cloud coverage gradually improving 
through the rest of the day. 

Winds will continue out of the southeast through this evening with 
speeds between 5-10 kts. Following the passage of a frontal 
boundary, winds will shift out of the northeast later tonight and 
persist through the remainder of the 00z period with speeds between 
10-20 kts. 

&&

.MARINE...
Issued at 1229 PM CST Tue Nov 25 2025

Tonight through Wednesday Night: Light winds and generally slight 
seas will prevail through midnight before the surge of northeast 
flow arrives post-front/rapidly building pressure gradient soon 
after. Timing makes the issuance of the initial Small Craft Advisory 
difficult, as the strongest winds may arrive just before daybreak 
across the waters north of Port Mansfield and elsewhere at or just 
after daybreak. Model trends continue to increase winds into the 20-
25 knot range, and seas should easily reach 7, if not 8 feet, for a 
time between 9 AM and 6 PM Wednesday. Will add a "Small Craft 
Advisory Will Be Needed" headline to get ahead of the situation.

Laguna Madre winds should drop back below 15 knots soon after sunset 
Wednesday, but remain 15-20 knots and gusty across the Gulf well 
into the evening as seas may hold at or above 7 feet as well. Winds 
and seas should subside later at night to moderate levels by 
daybreak Thanksgiving.

Thursday through Saturday Night: Relatively benign conditions 
Thursday and Thursday night will begin deteriorating Friday, as east-
southeast flow picks up in synoptic gradient that will be enough to 
overcome the weak marine layer to edge speeds toward Advisory levels 
by late afternoon. Seas will rise back toward 7 feet but probably 
hold up just short.  That will not be the case Friday night into 
Saturday morning (at least) as gradient sharpens with low level 
southeast flow over 30 knots. Seas/wind waves will build over 7 feet 
making for very difficult conditions for small craft. Winds will be 
slow to subside Saturday as gradient slackens ahead of the next 
front, but seas may hold at or above 7 feet for much of the day. 
Conditions settle down to moderate levels...briefly...Saturday night 
before things get going again toward daybreak near Baffin Bay, post 
front.

Sunday and Sunday Night: Ranges of potential include winds of 
moderate Small Craft (20 to 25 knots) up to minimal Gale (frequent 
gusts of 35 knots) Sunday, dependent on the strength and intensity 
of the next front. More to follow as the event gets closer, but at 
minimum, Sunday will not be fit for small craft with gusts at or 
above 30 knots and seas building and churning back to at least 8 
feet. 

&&

.CLIMATE...
Issued at 1229 PM CST Tue Nov 25 2025

The record/near record heat of the past week has pushed nearly all
RGV locations into the top five warmest Novembers on record
through the 24th. Those rankings may rise a bit higher after today
(25th). With day/night averages only expected to drop close to the
long-term normals, if not a touch above, Wednesday through Friday
- and another 10 degree above average number for Saturday - we're
  locking in on another top-ten warmest finish for everyone when
  we count the numbers at the end of November. Sunday's now
  expected cool-down won't be enough to flip the script.

Here are the rankings, and departure from the top, for available
locations (with minimal missing data) through the 24th:

Brownsville (since 1878): 76.3 degrees, #2, -0.8 degrees from #1
McAllen (since 1941):  76.9 degrees, #2, -1.1 degrees from #1
Harlingen (since 1912): 73.2 degrees, #6, -1.2 degrees from #1
Weslaco (since 1914):  74.6 degrees, #3, -1.3 degrees from #1
RGC (since 1897)*: 73.9 degrees, #4, -2.9 degrees from #1

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             70  79  65  80 /  60  50  10   0 
HARLINGEN               66  79  58  79 /  60  30   0   0 
MCALLEN                 69  79  60  80 /  60  40   0   0 
RIO GRANDE CITY         65  76  54  78 /  70  40   0   0 
SOUTH PADRE ISLAND      73  79  71  76 /  60  40  10   0 
BAYVIEW/PORT ISABEL     68  79  65  78 /  60  40   0   0 

&&

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

$$

SHORT TERM...52-Goldsmith
LONG TERM....52-Goldsmith
AVIATION...23-Evbuoma