Laguna Madre from the Port of Brownsville to the Arroyo Colorado Marine Forecast
|Today...East Winds 5 To 10 Knots Increasing To 10 To 15 Knots In The Afternoon. A Light Chop On The Bay Building To A Moderate Chop In The Afternoon. Widespread Showers And Isolated Thunderstorms.|
|Tonight...East Winds 10 To 15 Knots Diminishing To 5 To 10 Knots After Midnight. A Moderate Chop On The Bay Subsiding To A Light Chop After Midnight. Numerous Showers And Isolated Thunderstorms.|
|Monday...Northeast Winds 5 To 10 Knots Becoming East 10 To 15 Knots In The Afternoon. A Light Chop On The Bay Building To A Moderate Chop In The Afternoon. Numerous Showers And Isolated Thunderstorms.|
|Monday Night...East Winds 10 To 15 Knots Becoming Southeast 5 To 10 Knots After Midnight. A Moderate Chop On The Bay Subsiding To A Light Chop After Midnight. Chance Of Showers And Thunderstorms.|
|Tuesday...East Winds 10 To 15 Knots. A Moderate Chop On The Bay. Chance Of Showers And Thunderstorms.|
|Tuesday Night...East Winds 10 To 15 Knots Becoming Southeast 5 To 10 Knots After Midnight. A Moderate Chop On The Bay Subsiding To A Light Chop After Midnight. Chance Of Showers And Thunderstorms In The Evening, Then Slight Chance Of Showers And Thunderstorms After Midnight.|
|Wednesday...East Winds 5 To 10 Knots Increasing To 10 To 15 Knots In The Afternoon. A Light Chop On The Bay Building To A Moderate Chop In The Afternoon. Chance Of Showers And Thunderstorms.|
|Wednesday Night...East Winds 10 To 15 Knots Becoming Southeast 5 To 10 Knots After Midnight. A Moderate Chop On The Bay Subsiding To A Light Chop After Midnight. Slight Chance Of Showers And Thunderstorms.|
|Thursday...East Winds 5 To 10 Knots Increasing To 10 To 15 Knots In The Afternoon. A Light Chop On The Bay Building To A Moderate Chop In The Afternoon. Slight Chance Of Showers And Thunderstorms.|
|Thursday Night...East Winds 10 To 15 Knots Diminishing To 5 To 10 Knots After Midnight. A Moderate Chop On The Bay Subsiding To A Light Chop After Midnight.|
| Area Forecast Discussion|
National Weather Service Brownsville TX
409am CDT Sunday May 31 2020
Short Term - Now through Monday
IT satl imagery and short range model guidance continue to indicate a 500 mb closed low centered over NE Mex. This closed low will continue advect in deep layer moisture over the Rio Grande Valley throughout today and Mon. The 00Z BRO sounding shows and MUCAPE of 2044 J/KG with a pretty elevated PWAT (Precipitable Water) of 1.82 inches over the region. At the surface, a stationary front is also draped from west to east over the northern portion of the Gulf of Mex with the western end of the boundary ending close to the lower TX coastline. The 500 mb low over NE Mex will start to lift northwards later today and Monday reaching the Big Bend region early next week. This will likely lift the stationary front along the lower TX coastline farther north as a weak warm front on Mon. The combination of the upper low, the surface convergence near the old frontal boundary and the persistent deep layer moisture over the region will maintain pretty substantial conv chances throughout the short range period. The NAM/ECMWF (European Centre for Medium-Range Weather Forecasts) and GFS all maintain pretty high probability of precipitation throughout the period and will stick close to a blend of these three models through Mon.
WPC has expanded the Marginal Risk for excessive rainfall farther southwards from the Coastal Bend area to include Kenedy, Willacy and Cameron counties for today. The high PWAT (Precipitable Water) values do support the potential for locally heavier tropical rains later today. However, the latest KBRO reflectivity indicate that the overall cellular movement of the encroaching conv off of the Gulf of Mex is relatively quick. So this may help hold down the overall rainfall rates somewhat. However, will maintain the mention of locally heavy rainfall, especially along the lower TX coastline today and Mon. Since the overall conv overnight has been limited to the immediate coastline and the offshore areas, will hold off on issuing any Flash Flood Watch for today. However, as like yesterday morning, if the conv shifts into a more of a training event with sustained conv lines moving in over the same locations, or slows down, then localized flash flooding could become more of an issue.
Temps may be a bit tricky today as highs yesterday overshot model guidance as diurnal heating appeared to have more influence Sat afternoon. Will opt for high temps a bit above model blends for today and tomorrow.
Will mention only isolated thunderstorms today embedded in overall moderate to heavy tropical showers as the lightning activity this morning has been pretty minimal. This is more typical of a tropical airmass moving into the region.
Long Term - Monday Night through Saturday
A somewhat weak and broad 500 mb low will continue to move northeastward across the western and central portions of the state of Texas through midweek before merging into the mid level ridge building over the central CONUS during the latter part of the week. At the surface, broad high pressure slowly pushing off the East Coast will supply light to moderate east-southeast winds to Deep South Texas and the Rio Grande Valley through most of the period. With the 500 mb low moving out of the area at the start of the long term, rain chances will primarily be diurnally driven and enhanced by any sea breeze that may develop each day, with the best chances near the coast. Precipitable water values will remain around 1.8 to 2.1 inches through at least mid week, so any showers or thunderstorms that do develop may become efficient rain producers. Temperatures will start off slightly below normal through midweek with Probability of Precipitation and cloud cover in place, and increase to near normal for the second half of the week.
Forecast confidence begins to decrease on Thursday through the rest of the forecast period as model solutions diverge. With that said, both the GFS and the ECMWF have a low form in the southwestern Gulf of Mexico and then track north through the western Gulf and slowly approach the coast heading into the weekend. While a great deal of uncertainty remains regarding the track and potential intensity of this system, it could increase Probability of Precipitation along the coastal areas next weekend.
Now through Monday...Broad surface ridging over the SE U.S. will combine with broad trough.ing over the SW Gulf to maintain a persistent low surface onshore wind flow throughout Mon. The Bay and Gulf swells will likely remain pretty low throughout the period. So no SCA (Small Craft Advisory) conditions expected throughout the short term for either the Bay or Gulf waters.
Monday Night through Saturday...With broad high pressure in place over the eastern Gulf, generally light to moderate east- southeast winds are expected through much of the period. Seas will also start off generally favorable and gradually build through the period with persistent easterly winds and the potential approach of a low pressure system from the southwestern Gulf. Models are showing this low pressure system form in the southwestern Gulf of Mexico towards the end of the week and then move northward and potentially impact the lower Texas coastal waters next weekend. Showers and thunderstorms will be possible each day through the period.
NOAA Brownsville TX Office: Watches - Warnings - Advisories