Laguna Madre from Port Mansfield to Baffin Bay Marine Forecast
|Today...Southeast 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 In The Morning.|
|Tonight...Southeast Winds 10 To 15 Knots Becoming South 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 Through The Night.|
|Friday...Southeast 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.|
|Friday Night...Southeast Winds 10 To 15 Knots Becoming South 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.|
|Saturday...Southeast Winds 10 To 15 Knots. A Moderate Chop On The Bay. Slight Chance Of Showers And Thunderstorms.|
|Saturday Night...Southeast Winds 10 To 15 Knots Becoming South 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.|
|Sunday...South Winds 5 To 10 Knots Becoming Southeast 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.|
|Sunday Night...South Winds 10 To 15 Knots. A Moderate Chop On The Bay. Chance Of Showers And Thunderstorms.|
|Monday...South Winds 10 To 15 Knots Becoming Southeast 15 To 20 Knots In The Afternoon. A Moderate Chop On The Bay Building To Choppy In The Afternoon. Slight Chance Of Showers And Thunderstorms.|
|Monday Night...Southeast Winds 10 To 15 Knots. A Moderate Chop On The Bay. Slight Chance Of Showers And Thunderstorms.|
Synopsis for Baffin Bay to Rio Grande out 60 nm: GMZ100|
332 AM CDT Thu Aug 22 2019
Weak trough of low pressure continues to head north from the Bay of Campeche into the western Gulf of Mexico into this weekend. The chance of showers and thunderstorms across the offshore and coastal waters continues into next week. Southeasterly winds gradually increase through the weekend with a strengthening pressure gradient, building seas from light to moderate. Small craft may need to exercise caution across the Laguna Madre and nearshore Gulf of Mexico waters during the afternoon hours Friday through Monday due to elevated winds.
Area Forecast Discussion|
...UPDATED National Weather Service Brownsville TX
556am CDT Thu August 22 2019
Short Term - Today Through Friday
igh pressure across the western Gulf of Mexico continues to weaken as weak mid level low pressure edges further north into the Gulf through the short term. The best moisture remains offshore through the period, however, showers and thunderstorms were able to develop across the seabreeze over the past couple of days and, while isolated, should continue to develop today and tomorrow.
Seabreeze development and possible outflow boundary convection was able to work into Zapata County late yesterday afternoon, as suggested late by some CAMs. Have nudged POPs slightly further west today and tomorrow and will continue to remain optimistic for more rainfall where it is desperately needed. Unfortunately, most of any chance for rainfall will remain across the more typical seabreeze locations through Friday.
Have only slightly adjusted temperatures today, with McAllen likely staying above 100 again, but potentially being the furthest east any triple digit heat extends. For Friday afternoon, models bring in slightly drier air aloft. With only isolated rainfall expected, have bumped up temperatures a degree or two. Humidity values across the mid and lower valley range 35 to 50 percent on Friday, leading heat indices once again toward 105 to 109 degrees.
Long Term - SFriday Night through Wednesday
The long term period begins with mid level ridging aloft and a tropical wave/trough over the western Gulf. Therefore, have continued to go with above average temperatures and a slight chance of showers and thunderstorms this weekend.
On Sunday, a shortwave trough will push through our area, bringing our best chance for showers and thunderstorms for the long term period. However, due to differences in model solutions, will only go with 30 percent Probability of Precipitation on Sunday, and that may even be a bit generous. Heading into next week, model solutions continue to diverge, decreasing forecast confidence Monday onward. On Monday, a 500 mb high centered over the Desert Southwest begins to slide in behind the shortwave trough. The GFS has an inverted trough over Mexico begin to nudge into our CWA Tuesday night which hinders the eastward propagation of the ridge. The ECMWF brings this ridge further eastward with a weaker inverted trough over Mexico, allowing the ridge to dominate over our area. With this being said, have leaned towards the cooler and wetter solution of the GFS for now.
Overall, the long term period will begin with above average temperatures this weekend and then become slightly less hot with diurnally/sea breeze driven rain chances each day due to a weakness in the midlevel ridge aloft and sufficient low to mid level moisture.
MARINE (Today through Friday): High pressure continues to weaken across the western Gulf, with a weak mid level trough of low pressure sliding north into Friday, bringing an increased chance of showers and thunderstorms across offshore and coastal waters. Seas continue to subside through today but are expected to build on Friday through a combination of increasing southeasterly or southerly winds and southeasterly swell. At this time, marine conditions remain below any headline criteria, however, small craft may need to exercise caution across the bay and nearshore waters Friday afternoon.
Friday Night through Wednesday...As the pressure gradient increases southeast winds through mid week next week, cautionary wording may be needed each afternoon/evening over the Laguna Madre. Seas of generally 2 to 4 feet with the occasional 3 to 5 feet can be expected through Monday on the coastal Gulf waters. Beyond that, seas drop to 1 to 3 feet. Showers and thunderstorms will be possible at times across the coastal waters through the period.
Essentially very little has changed over the past week across Deep South Texas, with critically dry fuels and extremely limited rainfall. Temperatures dip a degree or two today with slightly increased cloud cover and low to mid level moisture. Humidity values still drop across west and central locations into the upper 20s to mid 30 percent range. Winds are expected to be a little lighter today, especially across the mid and upper valley locations, with stronger gusts expected west during the late afternoon hours. Having a tough time meeting criteria for a fire danger statement this afternoon, however, it remains an elevated concern. Burning of any kind should be postponed. Conditions may need to be monitored again Friday.
NOAA Brownsville TX Office: Watches - Warnings - Advisories