Marine Weather and Tide Forecast for Jamaica Beach, TX

DISCUSSION
Issued at 136 AM CDT Wed May 20 2026

First round of storms, one of many to come, is in the process of working its way through the region. Main inpact from these were 30-50mph gusts and some localized heavy downpours. Totals have mainly been under an inch, but there's a few spots that've seen 1-4". Expect rainfall to taper off in the morning hours, and we'll likely be stabilized for a good while afterwards so have trimmed POPs back for the remainder of the day.

We will remain in an unsettled wx pattern for several days ahead...characterized by persistent western troffiness and us being positioned within a very messy southwesterly flow aloft in advance. With deep Gulf moisture in place (PW's 1.7-2.1"), chances of dirnally driven precip will be in place at a minimum. But stronger impulses embedded in the flow aloft will likely trigger more organized storm complexes at times, along with the potential for some stronger storms & heavier rain rates...which can occur during the nighttime hours as well. Unfortunately in this type of pattern, the problem is actually identifying these disturbances when they're beyond 12-24 hours out, then adjusting for periods of stabilization afterwards.

Right now, we're eyeballing the next next stronger impulse and associated widerspread precip making its way in from the west toward Thursday morning. Each round will probably bring somewhere in the order of 0.5-3.0" rainfall to the area. In the short term, we should be able to handle another round or maybe two without too many flood issues, other than the typical localized variety. But as days wear on, the precip totals begin adding up, and the ground becomes increasingly saturated...we'll have be be cognizant of the potential for increasing flood/flash flood impacts in the days ahead. Guidance remains wet thru the holiday weekend into early next week as the western mid-upper trof moves into Texas...and possibly another trof dropping into about the same area later next week.

AVIATION
(06Z TAF Issuance)
Issued at 1126 PM CDT Tue May 19 2026

Two lines of TSRA are the primary concern tonight. One line is about to push offshore in the vicinity of Galveston Bay. The other one is moving east to southeastward from the Brazos Valley. Rain and storms will likely continue impacting many of our terminals tonight, until the storms push offshore by morning. Light to occasionally gusty E to ENE winds expected behind the storms. Near the coast, there may be a period of strong, gust E to SE winds as the storms push offshore. Mostly MVFR conditions expected in the morning, followed by a BKN VFR cloud deck in the afternoon. Next round of SHRA/TSRA may not arrive until late Wednesday night or Thursday morning.

MARINE
Issued at 136 AM CDT Wed May 20 2026

Showers and thunderstorms are in the process of pushing off the coast. Some 30 to 40 knot gusts are anticipated along the leading band of storms as they pass southward. Winds could be chaotic in terms of speed and direction through mid to late morning Wednesday with a localized tight pressure gradient in the vicinity of a MCV. We could see somewhat of a lull in speeds at times in the coming hours, but quickly increase again for 4 to 8 hours Wednesday morning. Have broadbrushed a SCA for all waters to take these factors into account. Otherwise, an unsettled weather pattern will persist into the weekend...with additional rounds of storms likely. Unfortunately, each individual complex will be difficult to time beyond 12 to 24 hours. During breaks in between systems, look for light to moderate onshore winds and 3-5 foot seas. 47

HYDROLOGY
Issued at 305 PM CDT Tue May 19 2026

Multiple rounds of moderate to heavy rainfall are expected this evening through Monday. The first round will start tonight bringing 1-3" with isolated higher amounts of 5-7+". With PW values exceeding the 90th percentile (~1.7-2.1"), rainfall rates of 2-4"/hr are possible in the heaviest downpours. Anywhere we see these intense rainfall rates, localized flash flooding is possible. That being said, we are not anticipating widespread river flooding just yet; however, this will help prime the soils as we continue with a wet pattern.

As the week progresses, multiple rounds of moderate to heavy rainfall on top of primed soils will generate runoff and cause rises on area rivers and watersheds. The greatest threat for heavy rainfall, flash and riverine flooding comes this holiday weekend as intense rainfall rates will bring accumulated values of 4-6+" across most of southeast Texas Saturday into Monday.

Widespread action to minor stage flooding is expected with moderate to isolated major stage flooding possible depending on where the most rainfall accumulates. Remember that you can monitor updated river forecasts via the NWS NWPS webpage (https://water.noaa.gov/).

Landry-Guyton

PRELIMINARY POINT TEMPS/POPS
College Station (CLL) 83 70 79 70 / 30 50 90 60 Houston (IAH) 83 73 82 73 / 30 40 80 50 Galveston (GLS) 84 78 84 79 / 40 30 60 60

HGX WATCHES/WARNINGS/ADVISORIES
TX...High Rip Current Risk through this evening for TXZ436>439.

GM...Small Craft Advisory until 11 AM CDT this morning for GMZ330-350- 355-370-375.

Small Craft Advisory until 6 AM CDT early this morning for GMZ335.