Marine Weather Net

Port Mansfield, TX to the Rio Grande River 20 - 60 NM Marine Forecast


5 - 10




10 - 15


10 - 15

The Marine Weather Forecast In Detail:
GMZ170 Forecast Issued: 945 PM CST Sun Jan 26 2020

Rest Of Tonight...Northeast Winds 5 To 10 Knots Diminishing To Around 5 Knots After Midnight. Seas 2 To 4 Feet.
Monday...East Winds Around 5 Knots Increasing To 5 To 10 Knots In The Afternoon. Seas 2 To 4 Feet.
Monday Night...Southeast Winds 10 To 15 Knots. Seas 2 To 4 Feet.
Tuesday...South Winds 10 To 15 Knots Becoming West 5 To 10 Knots In The Afternoon. Seas 3 To 5 Feet. Chance Of Showers And Slight Chance Of Thunderstorms.
Tuesday Night...Northwest Winds 15 To 20 Knots Becoming North 20 To 25 Knots After Midnight. Seas 5 To 7 Feet With Occasional Seas Up To 8 Feet. Slight Chance Of Rain Showers In The Evening.
Wednesday...North Winds 15 To 20 Knots Diminishing To 10 To 15 Knots In The Afternoon. Seas 5 To 8 Feet With Occasional Seas Up To 9 Feet.
Wednesday Night...Northeast Winds 5 To 10 Knots Shifting East After Midnight. Seas 2 To 4 Feet. Slight Chance Of Showers.
Thursday...East Winds 5 To 10 Knots. Seas 2 To 3 Feet. Chance Of Showers.
Thursday Night...East Winds 5 To 10 Knots Becoming Northeast 15 To 20 Knots After Midnight. Seas 2 To 3 Feet. Showers Likely And Slight Chance Of Thunderstorms.
Friday...North Winds 15 To 20 Knots. Seas 5 To 8 Feet With Occasional Seas Up To 9 Feet. Chance Of Showers.
Friday Night...North Winds 10 To 15 Knots. Seas 5 To 7 Feet With Occasional Seas Up To 8 Feet.
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Synopsis for Baffin Bay to Rio Grande out 60 nm: GMZ100
945 PM CST Sun Jan 26 2020

Light northerly winds continue this evening as high pressure builds. Patchy fog will be possible overnight, mainly across the bay waters and further inland. Winds shift onshore on Monday as high pressure slides east. Low pressure develops across North Texas and works toward the northern Gulf of Mexico through the rest of the week, bringing a stronger cold front on Tuesday night, and hazardous seas possible, especially offshore Tuesday night into Wednesday morning. Winds and seas are expected to become more favorable Thursday with high pressure across the western Gulf of Mexico.
Area Forecast Discussion
...UPDATED National Weather Service Brownsville TX
1123pm CST Sunday Jan 26 2020

AVIATION...High pressure continues to build southward across the region with skies remaining mostly clear through the evening. A strong signal for fog continues overnight as winds lighten and dry air moves over a relatively moist surface. So, have maintained the mention of IFR to LIFR conditions with visibility dropping after midnight and worsening towards sunrise. The better chances for fog will be at BRO and HRL. By mid-morning, southeast flow will return and sufficient mixing will allow categories to improve to VFR thereafter.

Short Term - Now through Monday night
The weak cold front made it through the Rio Grande Valley this morning with light northwesterly winds doing little to stop temperatures from reaching the 80s this afternoon. MFE has led the way, hitting 86F by 2 PM. Clearing skies, with light and variable winds overnight, will allow temperatures to crash rapidly this evening into tonight. As a result, patchy fog should develop early, with areas of fog and possibly dense fog after midnight across most of central to eastern Deep South Texas. A Dense Fog Advisory may be needed across portions of the lower RGV.

As high pressure heads offshore on Monday, with low pressure developing across North Texas, allowing southeasterly flow to return, with a stronger cold front approaching the northern ranchlands late Monday night. Have kept POPs mostly out of the CWA to this point. Bumped highs on Monday up a few degrees, maybe not high enough. Low temperatures Monday night may not dip too far either with increasing cloud cover and the approaching front. Patchy fog may once again develop, especially across the northern ranchlands.

Long Term - Tuesday through Sunday
500mb shortwave trough across the state Tuesday will provide low to mid level moisture across east Texas into south Texas before it moves eastward Tues afternoon and subsidence increases across southwest Texas in the wake of the upper level trough. This will provide a chance of elevated convection...mainly along the coastal sections of the CWA...Tues morning before the drier air moves across the area Tues afternoon. Northwest flow aloft Wednesday will continue to provide subsidence across south Texas before the 500mb flow backs to the southwest Wednesday night as the global models continue to prog a 500mb low/trough moving into northwest Mexico Thursday. Low to mid level moisture will return across southwest Texas Wednesday night but unsure how much moisture and when the moisture will increase the rest of the state Thursday as the GFS and ECMWF (European Centre for Medium-Range Weather Forecasts) diverge with the timing/movement of the upper trough/low as the GFS is faster and wetter than the ECMWF and the ECMWF slowly brings the upper level feature across northwest Mexico eastward. The GFS progs a coastal trough developing across the western Gulf of Mexico Thurs night into Friday. Will go with a blend of the model guidance for the rest of the forecast period for now but it appears rain chances will return...mainly across the coastal sections...Thursday afternoon into Thursday night and possibly continue into early Friday.

Marine - Now through Monday night
A weak cold front with northerly winds worked across the coastal waters this morning allowing seas to subside. As high pressure heads offshore on Monday and low pressure develops across North Texas, expect onshore flow to return, building seas slightly Monday night ahead of the next frontal passage.

Tuesday through Friday...Moderate south winds will prevail across the coastal waters Tues morning before a cold front moves offshore the lower Texas coast Tues afternoon. Winds will diminish and become light Tues afternoon and shift to the northwest and increase Tues night. Small craft advisories will be needed for the coastal waters Tues night as strong north to northwest winds develop in the wake of the front. The pressure gradient will begin to relax across the lower Texas coast Wednesday with high pressure settling across south Texas. Moderate north winds will prevail across the western Gulf of Mexico Wednesday before veering to the east and diminishing Wednesday night as the surface ridge begins to shift eastward. Winds will continue to veer to the east and southeast Thursday and continue to diminish. Light to moderate east to southeast winds Thursday will become light and variable Thurs night as a coastal trough develops offshore the lower Texas coast. The pressure gradient will increase across the coastal waters Friday as low pressure across the western Gulf deepens and moves eastward. Strong to very strong north winds will develop across the western Gulf Friday and a gale watch may be needed for the offshore waters Fri morning. Otherwise...small craft advisories will be needed for all of the coastal waters Fri morning through Fri afternoon.

NOAA Brownsville TX Office: Watches - Warnings - Advisories
TX...None. GM...None.