Marine Weather and Tide Forecast for Port Isabel, TX
 | Sunrise 6:43 AM Sunset 8:09 PM Moonrise 8:23 PM Moonset 6:04 AM |
GMZ130 Laguna Madre From The Port Of Brownsville To The Arroyo Colorado- Laguna Madre From The Arroyo Colorado To 5 Nm North Of Port Mansfield Tx- Laguna Madre From 5 Nm North Of Port Mansfield To Baffin Bay Tx- 927 Am Cdt Tue May 13 2025
- Small craft should exercise caution - .
Rest of today - South winds 15 to 20 knots. Choppy on the bay.
Tonight - South winds 15 to 20 knots. Choppy on the bay.
Wednesday - South winds 15 to 20 knots. Gusts to 30 knots in the afternoon. Choppy on the bay.
Wednesday night - South winds 15 to 20 knots. Choppy on the bay.
Thursday - South winds 15 to 20 knots, increasing to 20 to 25 knots with gusts up to 30 knots in the afternoon. Choppy on the bay, increasing to rough in the afternoon.
Thursday night - South winds 15 to 20 knots. Choppy on the bay.
Friday - South winds 10 to 15 knots, becoming southeast 15 to 20 knots in the afternoon. Choppy on the bay.
Friday night - Southeast winds 10 to 15 knots. A moderate chop on the bay.
Saturday - Southeast winds 10 to 15 knots. A moderate chop on the bay.
Saturday night - Southeast winds 10 to 15 knots. A moderate chop on the bay.
GMZ100 927 Am Cdt Tue May 13 2025
Synopsis - An enhanced pressure gradient will result in moderate to occasionally strong southerly winds and moderate to elevated seas, beginning this evening and lasting through at least tomorrow. A small craft advisory has been issued this evening for the gulf waters, and remains in effect through 18z tomorrow (with the potential for extension needed), with small craft on the bay needing to exercise caution. Small craft exercise caution conditions should still persist once the small craft advisory expires. Winds and seas should weaken and conditions should improve to favorable by the weekend.
7 Day Forecast for Marine Location Near Port Isabel, TX
NEW! Add second zone forecast
| Port Isabel Click for Map Tue -- 06:43 AM CDT Sunrise Tue -- 07:03 AM CDT Moonset Tue -- 07:49 AM CDT 1.57 feet High Tide Tue -- 08:07 PM CDT Sunset Tue -- 09:23 PM CDT Moonrise Tue -- 10:29 PM CDT -0.27 feet Low Tide Tide / Current data from XTide NOT FOR NAVIGATION |
Port Isabel, Texas, Tide feet
| 12 am |
| 0 |
| 1 am |
| 0.3 |
| 2 am |
| 0.6 |
| 3 am |
| 0.9 |
| 4 am |
| 1.1 |
| 5 am |
| 1.3 |
| 6 am |
| 1.5 |
| 7 am |
| 1.6 |
| 8 am |
| 1.6 |
| 9 am |
| 1.5 |
| 10 am |
| 1.5 |
| 11 am |
| 1.4 |
| 12 pm |
| 1.3 |
| 1 pm |
| 1.3 |
| 2 pm |
| 1.2 |
| 3 pm |
| 1.1 |
| 4 pm |
| 0.9 |
| 5 pm |
| 0.7 |
| 6 pm |
| 0.5 |
| 7 pm |
| 0.3 |
| 8 pm |
| 0 |
| 9 pm |
| -0.2 |
| 10 pm |
| -0.3 |
| 11 pm |
| -0.3 |
| Matamoros Click for Map Tue -- 05:45 AM CST Sunrise Tue -- 06:05 AM CST Moonset Tue -- 06:21 AM CST 1.34 feet High Tide Tue -- 07:08 PM CST Sunset Tue -- 08:23 PM CST Moonrise Tue -- 09:15 PM CST -0.44 feet Low Tide Tide / Current data from XTide NOT FOR NAVIGATION |
Matamoros, Tamaulipas, Mexico, Tide feet
| 12 am |
| 0.1 |
| 1 am |
| 0.4 |
| 2 am |
| 0.7 |
| 3 am |
| 1 |
| 4 am |
| 1.2 |
| 5 am |
| 1.3 |
| 6 am |
| 1.3 |
| 7 am |
| 1.3 |
| 8 am |
| 1.3 |
| 9 am |
| 1.2 |
| 10 am |
| 1.2 |
| 11 am |
| 1.1 |
| 12 pm |
| 1.1 |
| 1 pm |
| 1 |
| 2 pm |
| 0.9 |
| 3 pm |
| 0.8 |
| 4 pm |
| 0.6 |
| 5 pm |
| 0.3 |
| 6 pm |
| 0.1 |
| 7 pm |
| -0.2 |
| 8 pm |
| -0.3 |
| 9 pm |
| -0.4 |
| 10 pm |
| -0.4 |
| 11 pm |
| -0.3 |
FXUS64 KBRO 131943 AFDBRO
Area Forecast Discussion National Weather Service Brownsville TX 243 PM CDT Tue May 13 2025
New SHORT TERM, LONG TERM, MARINE, CLIMATE
SHORT TERM
(Tonight through Wednesday night)
Issued at 243 PM CDT Tue May 13 2025
Due to high pressure and southerly winds advecting warming air into the region, there will be a major heat risk tomorrow. Temperatures and heat indices are expected to climb into the mid-to-upper 90s closer to the coast, and into the triple digits in the Western portion of the CWA The Western Ranchland counties could see temperatures and/or heat indices as high as 110 degrees. If temperatures trend any higher on future guidance, a heat advisory could potentially be needed tomorrow.
Overnight lows tonight and tomorrow are expected to be in the low-to- mid 70s. Skies are expected to be mostly sunny to partly cloudy.
Winds will be light to moderate and southerly, shifting to a more southeasterly direction by tomorrow night. Due to a pressure gradient, winds could also be gusty at times.
LONG TERM
(Thursday through next Tuesday)
Issued at 243 PM CDT Tue May 13 2025
Key Messages:
- Major to extreme heat risk across all of Deep South Texas through at least early next week.
- This heat will be dangerous to anyone who does not take the proper heat safety precautions and is spending a prolonged period outdoors.
It will feel more like summer across all of Deep South Texas through at least early next week as the region remains under the influence of strong ridging aloft. While the ridge will shift sightly toward the east toward the weekend and may drop temperatures by a degree or two, persistent low level southerly to southeasterly flow will allow for an uptick in humidity as Gulf moisture is transported toward the region. In combination with afternoon temperatures in the mid to upper 90s along the immediate coast and triple-digits further inland, heat index values will each afternoon will range from 100 to 112 degrees across the entire region. A Heat Advisory may be needed for portions of the region late this week and into early next week.
In addition to the oppressive daytime heat, we'll also have to keep a close eye on overnight low temperatures heading into early next week as low clouds develop each night along the immediate coast. NBM deterministic low temperatures range from the mid to upper 70s, but the NBM 50th percentile guidance indicates some areas, especially along the immediate coast, realize slightly warmer low temperatures in the low 80s. This could potentially tie or break record highest low temperatures late this week and into the weekend.
All in all, the combination unseasonably hot afternoons and warm nights will limit any relief from the heat across Deep South Texas, which will result in a major to extreme heat risk for all who spend a prolonged period outdoors without adequate hydration or effective cooling.
Outside of heat concerns, an enhanced pressure gradient will result in breezy southerly to southeasterly winds each day. The combination of hot temperatures, breezy winds, and lower humidity will result in elevated fire weather concerns, mainly along and west of US-281.
AVIATION
(18Z TAFS)
Issued at 1214 PM CDT Tue May 13 2025
VFR conditions are expected at all airports. Winds are expected to be southeasterly and gusty up to 30 knots.
MARINE
Issued at 243 PM CDT Tue May 13 2025
Tonight through Tomorrow Night...Due to a tighter pressure gradient, adverse marine conditions are expected tonight into tomorrow due to higher winds and wave heights. A Small Craft Advisory is in effect for the Gulf from this evening into tomorrow, and may need to be extended as windy conditions will continue through tomorrow night.
Thursday through next Tuesday...Light to moderate winds and low to moderate seas will prevail through early next week, with Small Craft Exercise Caution to borderline Small Craft Advisory conditions expected every afternoon along the Laguna Madre and Gulf waters.
CLIMATE
Issued at 243 PM CDT Tue May 13 2025
High temperatures through the end of the week may tie or break daily record high temperatures at Brownsville, Harlingen, and McAllen. Daily record highest low temperatures may also be tied at all three climate sites.
May 14th Record High Temperature / Highest Low Temperature Brownsville: 96 in 2024 / 80 in 1896 Harlingen: 95 in 2020 / 79 in 2008 McAllen: 98 in 1995 / 80 in 1995
May 15th Record High Temperature / Highest Low Temperature Brownsville: 95 in 1893 / 80 in 2020 Harlingen: 96 in 2003 / 78 in 2020 McAllen: 100 in 1945 / 80 in 1995
May 16th Record High Temperature / Highest Low Temperature Brownsville: 95 in 2024 / 81 in 2024 Harlingen: 97 in 2003 / 78 in 1999 McAllen: 100 in 2003 / 81 in 2024
May 17th Record High Temperature / Highest Low Temperature Brownsville: 96 in 1946 / 80 in 2017 Harlingen: 97 in 2018 / 79 in 1961 McAllen: 102 in 1946 / 81 in 2017
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 75 92 77 95 / 0 0 0 0 HARLINGEN 73 96 75 97 / 0 0 0 0 MCALLEN 75 100 77 101 / 0 0 0 0 RIO GRANDE CITY 72 105 76 106 / 0 0 0 0 SOUTH PADRE ISLAND 77 85 77 85 / 0 0 0 0 BAYVIEW/PORT ISABEL 74 91 76 92 / 0 0 0 0
BRO WATCHES/WARNINGS/ADVISORIES
TX...High Rip Current Risk from 7 PM CDT this evening through Wednesday evening for TXZ451-454-455.
GM...Small Craft Advisory from 7 PM this evening to 1 PM CDT Wednesday for GMZ150-155-170-175.
Area Forecast Discussion National Weather Service Brownsville TX 243 PM CDT Tue May 13 2025
New SHORT TERM, LONG TERM, MARINE, CLIMATE
SHORT TERM
(Tonight through Wednesday night)
Issued at 243 PM CDT Tue May 13 2025
Due to high pressure and southerly winds advecting warming air into the region, there will be a major heat risk tomorrow. Temperatures and heat indices are expected to climb into the mid-to-upper 90s closer to the coast, and into the triple digits in the Western portion of the CWA The Western Ranchland counties could see temperatures and/or heat indices as high as 110 degrees. If temperatures trend any higher on future guidance, a heat advisory could potentially be needed tomorrow.
Overnight lows tonight and tomorrow are expected to be in the low-to- mid 70s. Skies are expected to be mostly sunny to partly cloudy.
Winds will be light to moderate and southerly, shifting to a more southeasterly direction by tomorrow night. Due to a pressure gradient, winds could also be gusty at times.
LONG TERM
(Thursday through next Tuesday)
Issued at 243 PM CDT Tue May 13 2025
Key Messages:
- Major to extreme heat risk across all of Deep South Texas through at least early next week.
- This heat will be dangerous to anyone who does not take the proper heat safety precautions and is spending a prolonged period outdoors.
It will feel more like summer across all of Deep South Texas through at least early next week as the region remains under the influence of strong ridging aloft. While the ridge will shift sightly toward the east toward the weekend and may drop temperatures by a degree or two, persistent low level southerly to southeasterly flow will allow for an uptick in humidity as Gulf moisture is transported toward the region. In combination with afternoon temperatures in the mid to upper 90s along the immediate coast and triple-digits further inland, heat index values will each afternoon will range from 100 to 112 degrees across the entire region. A Heat Advisory may be needed for portions of the region late this week and into early next week.
In addition to the oppressive daytime heat, we'll also have to keep a close eye on overnight low temperatures heading into early next week as low clouds develop each night along the immediate coast. NBM deterministic low temperatures range from the mid to upper 70s, but the NBM 50th percentile guidance indicates some areas, especially along the immediate coast, realize slightly warmer low temperatures in the low 80s. This could potentially tie or break record highest low temperatures late this week and into the weekend.
All in all, the combination unseasonably hot afternoons and warm nights will limit any relief from the heat across Deep South Texas, which will result in a major to extreme heat risk for all who spend a prolonged period outdoors without adequate hydration or effective cooling.
Outside of heat concerns, an enhanced pressure gradient will result in breezy southerly to southeasterly winds each day. The combination of hot temperatures, breezy winds, and lower humidity will result in elevated fire weather concerns, mainly along and west of US-281.
AVIATION
(18Z TAFS)
Issued at 1214 PM CDT Tue May 13 2025
VFR conditions are expected at all airports. Winds are expected to be southeasterly and gusty up to 30 knots.
MARINE
Issued at 243 PM CDT Tue May 13 2025
Tonight through Tomorrow Night...Due to a tighter pressure gradient, adverse marine conditions are expected tonight into tomorrow due to higher winds and wave heights. A Small Craft Advisory is in effect for the Gulf from this evening into tomorrow, and may need to be extended as windy conditions will continue through tomorrow night.
Thursday through next Tuesday...Light to moderate winds and low to moderate seas will prevail through early next week, with Small Craft Exercise Caution to borderline Small Craft Advisory conditions expected every afternoon along the Laguna Madre and Gulf waters.
CLIMATE
Issued at 243 PM CDT Tue May 13 2025
High temperatures through the end of the week may tie or break daily record high temperatures at Brownsville, Harlingen, and McAllen. Daily record highest low temperatures may also be tied at all three climate sites.
May 14th Record High Temperature / Highest Low Temperature Brownsville: 96 in 2024 / 80 in 1896 Harlingen: 95 in 2020 / 79 in 2008 McAllen: 98 in 1995 / 80 in 1995
May 15th Record High Temperature / Highest Low Temperature Brownsville: 95 in 1893 / 80 in 2020 Harlingen: 96 in 2003 / 78 in 2020 McAllen: 100 in 1945 / 80 in 1995
May 16th Record High Temperature / Highest Low Temperature Brownsville: 95 in 2024 / 81 in 2024 Harlingen: 97 in 2003 / 78 in 1999 McAllen: 100 in 2003 / 81 in 2024
May 17th Record High Temperature / Highest Low Temperature Brownsville: 96 in 1946 / 80 in 2017 Harlingen: 97 in 2018 / 79 in 1961 McAllen: 102 in 1946 / 81 in 2017
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 75 92 77 95 / 0 0 0 0 HARLINGEN 73 96 75 97 / 0 0 0 0 MCALLEN 75 100 77 101 / 0 0 0 0 RIO GRANDE CITY 72 105 76 106 / 0 0 0 0 SOUTH PADRE ISLAND 77 85 77 85 / 0 0 0 0 BAYVIEW/PORT ISABEL 74 91 76 92 / 0 0 0 0
BRO WATCHES/WARNINGS/ADVISORIES
TX...High Rip Current Risk from 7 PM CDT this evening through Wednesday evening for TXZ451-454-455.
GM...Small Craft Advisory from 7 PM this evening to 1 PM CDT Wednesday for GMZ150-155-170-175.
| Stations | Dist | Age | Wind | Air | Water | Waves | inHg | DewPt |
| PTIT2 - 8779770 - Port Isabel, TX | 0 mi | 54 min | S 20G | 87°F | 82°F | 29.78 | ||
| BZST2 | 3 mi | 54 min | SSE 23G | 81°F | 81°F | 29.74 | ||
| PCGT2 - 8779748 - South Padre Island CGS, TX | 3 mi | 54 min | S 25G | 83°F | 83°F | 29.75 | ||
| RLIT2 | 14 mi | 54 min | S 17G | 86°F | 83°F | 29.76 | ||
| PMNT2 | 36 mi | 54 min | 89°F | 84°F | 29.75 |
Wind History for Port Isabel, TX
toggle option: (graph/table)
Link to 1 hour of 5 minute data for KSPL
Terminal Aerodrome Forecast (TAF) for KSPL
Wind History Graph: SPL
(wind in knots)
GEOS Local Image of SouthCentralPlains
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Brownsville, TX,
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