Port Mansfield, TX to the Rio Grande River 20 - 60 NM Marine Forecast
|Tonight...Southeast Winds 15 To 20 Knots Diminishing To 10 To 15 Knots After Midnight. Seas 4 To 6 Feet With Occasional Seas Up To 7 Feet. Slight Chance Of Showers After Midnight.|
|Friday...Southeast Winds 10 To 15 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 7 Feet.|
|Friday Night...Southeast Winds 10 To 15 Knots Becoming East 5 To 10 Knots After Midnight. Seas 4 To 6 Feet With Occasional Seas Up To 7 Feet. Chance Of Thunderstorms In The Evening. Chance Of Showers Through The Night. Chance Of Thunderstorms After Midnight.|
|Saturday...Southeast Winds 10 To 15 Knots Diminishing To 5 To 10 Knots In The Afternoon. Seas 4 To 6 Feet With Occasional Seas Up To 7 Feet. Chance Of Showers And Thunderstorms.|
|Saturday Night...East Winds 15 To 20 Knots Diminishing To 10 To 15 Knots After Midnight. Seas 5 To 7 Feet With Occasional Seas Up To 8 Feet. Chance Of Showers And Thunderstorms.|
|Sunday...East Winds 5 To 10 Knots Increasing To 10 To 15 Knots In The Afternoon. Seas 4 To 6 Feet With Occasional Seas Up To 7 Feet.|
|Sunday Night...East Winds 10 To 15 Knots. Seas 3 To 5 Feet.|
|Monday...Southeast Winds 10 To 15 Knots. Seas 3 To 5 Feet.|
|Monday Night...Southeast Winds 10 To 15 Knots. Seas 2 To 4 Feet.|
|Tuesday...Southeast Winds 5 To 10 Knots. Seas 2 To 4 Feet.|
|Tuesday Night...Southeast Winds 5 To 10 Knots. Seas 2 To 4 Feet.|
Synopsis for Baffin Bay to Rio Grande out 60 nm: GMZ100|
405 PM CDT Thu Apr 2 2020
Slightly adverse marine conditions are expected along the Lower Texas Coast from tonight through the weekend due to the slow approach and passage of a weak cold front. Improved winds and seas are anticipated early next week with high pressure in control over the western Gulf of Mexico.
Area Forecast Discussion|
...UPDATED National Weather Service Brownsville TX
630pm CDT Thu April 2 2020
Short Term - Tonight through Friday Night
A relatively zonal 500 mb pattern will prevail tonight into Friday with several weak areas of PV moving over much of TX. Meanwhile, a strong 500 mb trough axis will dig into the NW and NC portion of the lower 48 states throughout Fri and Fri Night. This will push a cold front down into southern TX tomorrow night into early Sat morning increasing the surface convergence steadily. Model MUCAPE values Fri Night/Sat morning will top out into the 1000-2200 J/KG range across much of southern TX which will support isolated stg/svr conv mainly near the frontal boundary. Accordingly, Storm Prediction Center is maintaining Deep South TX and the Rio Grande Valley in a Marginal Risk area mainly for isold damaging wind gusts/isolated large hail late Fri Night/Sat AM.
Otherwise will maintain slght chc/chance probability of precipitation for the northern/western portions of the region for Fri afternoon mainly due to the diurnal heating effects destabilizing the afternoon atms. Otherwise, expect the best probability of precipitation in the short range period to remain confined to 00-12Z Sat period.
Once again warm air advection will prevail ahead of the cold front with temps warming steadily through the period. The ECMWF (European Centre for Medium-Range Weather Forecasts) remains the warmest of the short term models. The latest model blends also lean towards the warmer side of guidance and see no reason to stray from this trend too much.
Overall forecast confidence for the short term forecast wording is above average this afternoon.
Long Term - Saturday through Thursday
With a persistent southeasterly surface flow, low to mid-level moisture will continue to stream into the region heading into the weekend. The cold front sweeping through Texas on Friday is expected to approach Deep South Texas on Saturday morning, and is still expected to stall just north of our area or over the northern ranchlands later that morning. The main concerns continue to be the potential for severe weather for Deep South Texas and heavy rainfall, especially for the northern ranchlands Friday night into Saturday. Storm Prediction Center continues to keep a marginal threat of strong to severe thunderstorms on Friday night for all of Deep South Texas and the Rio Grande Valley, but drops the probability for severe storms slightly on Saturday and blankets the region with a general thunder threat. Forecast soundings show notable instability Friday night into Saturday morning, especially for the northern ranchlands. With expected precipitable water values around 2 inches on Saturday and Sunday, heavy rainfall is possible through the weekend, bringing the threat of flash flooding for primarily poor drainage areas as well as low-lying areas.
Heading into next week, the-mid level ridge parks over the Gulf of Mexico, leaving Texas under a southwesterly flow aloft. Slight rain chances linger each day, primarily out west, with increasing column moisture due to a southeasterly flow bringing moisture from the Gulf and a southwesterly flow aloft with an approaching Baja low from the west. As for temperatures, warm to very warm conditions will continue through the long term, with a slight decrease this weekend with the approach of the cold front and the expected rain and cloud cover, and then very warm temperatures continue into next week.
Marine - Tonight through Friday Night
The surface ridging expected ahead of the approaching cold front will maintain light to moderate onshore winds along the lower TX coastline through Fri Night. Accordingly, low to moderate seas will prevail. The PGF may be strong enough to produce some marginal SCEC conditions throughout the short term period. However, sustained SCA conditions are not expected for either the lower TX Bay or Gulf Waters.
LONG TERM (Friday through Wednesday Night): With an approaching cold front expected to stall over Deep South Texas on Saturday, there is a potential for strong to severe thunderstorms mostly for early Saturday morning. A stronger push of easterly winds is expected on the offshore Gulf waters on Saturday evening, with the potential for Small Craft Advisory conditions. Otherwise, generally favorable marine conditions are expected in the long term with low to moderate wave heigheights and light to moderate east-southeasterly winds.
NOAA Brownsville TX Office: Watches - Warnings - Advisories