Marine Weather and Tide Forecast for Oyster Creek, TX

DISCUSSION
Issued at 1111 PM CDT Mon Apr 20 2026

The radar depicted widespread moderate rain, but only light rain reached the surface. What's the deal?! Was it magic?! Nope...even better...SCIENCE! PW values gradually increased throughout the day up to near the 75th percentile (~1.38") due to the development of a coastal trough/low down near the South TX coast. Moisture gradually increased from west to east and there was even a few rumbles of thunder west of the Brazos River as elevated convection drifted in from our west earlier in the afternoon. Rainfall rates around the San Antonio metro were near 2"/hr leading to instances of flooding, but why did we only see light rain? Drier air above the surface is the answer! Forecast soundings depicted a pocket of drier air around 3km above the surface for most areas in Southeast TX. As the moisture gradually increased, the air above the surface became more and more saturated leading to some raindrops reaching the ground.
This is why most of you saw light rain at most today.

Now how can we tell that the majority of the rain evaporated? The answer is...our radar! Our radar (the lovely KHGX WSR-88D) is located to the southeast of Houston in northern Galveston County.
The radar beam height increases the further you get from the radar...so you may have noticed high reflectivity returns out west, but those returns became lighter as they got closer to the radar.
The radar was sampling moderate rain aloft, but through observations at the surface (special thanks to those that used mPING today) we were able to confirm that evaporation aloft was occuring. At times, there were enough raindrops reaching the ground to wet surfaces/roadways, but certainly not enough to cause any rainouts.
You might be thinking "why did he write two paragraphs about something from the past?!" I do it for the love of the science! :)
Since Tuesday is Big Word Day, I can officially say that science is supercalifragilisticexpialidocious! I can't use more than one big word though because of my hippopotomonstrosesquippedaliophobia.
Before y'all ask, yes spell check did just give up on that one.

Going into Tuesday though, the drier air aloft goes bye-bye as the atmospheric column becomes fully saturated with an embedded shortwave trough pushing into the region. PW values will be near or above the 90th percentile (~1.58"), so there is potential for locally heavy rainfall. Latest CAM guidance depicts the rain moving in early Tuesday morning, so plan accordingly for your morning commute. Instability on Monday was slim to none, but there will be a bit more in place on Tuesday. Not enough for any worries about strong or severe storms, but enough for some rumbles of thunder.
This instability should also be enough for efficient rainfall processes. If heavy rainfall falls over an area for an extended period of time, then this could lead to localized instances of flooding. This is especially the case for urban areas or areas with poor drainage/low-lying areas. As a result, WPC has kept most of Southeast TX in a marginal risk (level 1 of 4) of excessive rainfall on Tuesday. Keep in mind that this is taking into account the somewhat more saturated soils from Saturday's heavy rainfall, which could lead to quicker transitions to runoff. Current QPF totals show a general widespread 1-2", but locally higher amounts will be possible. HRRR LPMM shows the potential for isolated spots of 3+".

We get a small break from the heavier downpours going into Tuesday night, but another round of rain is expected on Wednesday with another shortwave passing through. Wednesday looks to start out with sporadic showers in the morning. Daytime heating aids in the development of scattered thunderstorms in the afternoon hours. For Wednesday, the marginal risk of excessive rainfall is currently mainly for areas east of the Brazos River and south of Conroe.
Convective coverage is not anticipated be as expansive as what we see on Tuesday, but it still warrants keeping an umbrella with you.
As a matter of fact, go ahead and keep that with you for...*checks forecast*...ever. Even though moisture availability decreases going into the end of the work week, there will still be enough in place to pair with additional embedded shortwaves for daily chances of showers and storms. Going into the weekend, we'll be monitoring an upper level low and a frontal boundary pushing into TX. The front itself is not expected to push through our area, but it will help increase chances for showers/storms over the weekend. I know it seems like it's rained every weekend this month...and that's because it has. It's for the greater good though! ~79% of Southeast TX remains in at least a severe drought (not counting this past weekend's rainfall). This rain certainly won't be a drought buster, but every little bit helps!

As far as temperatures go, widespread light rainfall led to high temperatures in the mid 60s to low 70s on Monday...so you shouldn't be surprised that the same is expected for Tuesday. Ridging aloft will be in place throughout the work week though leading to a gradual warming trend after Tuesday. High temperatures are expected to be back in the upper 80s by Friday and potentially continuing into the weekend. Just keep in mind that rain chances are present each day, so some tweaks to the temperature forecast could still occur as the week goes on. Low temperatures will be in the 50s/60s for another couple of nights, then only bottoming out in the 60s/70s midweek and beyond.

Batiste

AVIATION
(00Z TAF Issuance)
Issued at 639 PM CDT Mon Apr 20 2026

An upper level disturbance is pushing west to east across southern TX this evening, producing light shower activity roughly from I-45 westward. Predominantly VFR conditions this evening and overnight will go below VFR Tuesday morning as a secondary disturbance moves into the region from the west. All terminals are expected to experience scattered shower activity beginning in the morning and persisting through much of the day on Tuesday. Winds will gradually increase out of the east area-wide to 10-15 kts with gusts up to 20-25 kts.

McNeel

MARINE
Issued at 1111 PM CDT Mon Apr 20 2026

Small craft will need to exercise caution through Tuesday afternoon in the Gulf waters. Moderate southeasterly winds persist throughout the day on Tuesday, but will subside going into Tuesday night. The elevated southeasterly winds will lead to an increased risk of rip currents early this week. An extended fetch of moderate southeasterly winds around midweek will likely lead to another round of increased seas, especially in the offshore Gulf waters. This may lead to another period of caution flags on Wednesday into Thursday for the Gulf waters. Increased chances for storms return Tuesday into Wednesday as an upper level disturbance pushes through. Water levels are expected to remain near 3.0 feet above Mean Lower Low Water during high tide cycles through at least the end of the work week.

Batiste

PRELIMINARY POINT TEMPS/POPS
College Station (CLL) 58 66 61 80 / 80 90 40 60 Houston (IAH) 62 69 64 80 / 50 80 50 80 Galveston (GLS) 70 76 72 79 / 50 70 50 80

HGX WATCHES/WARNINGS/ADVISORIES
TX...High Rip Current Risk through late Tuesday night for TXZ436>439.

GM...Small Craft Should Exercise Caution until 1 AM CDT Tuesday for GMZ330-335.

Small Craft Should Exercise Caution through Tuesday evening for GMZ350-355-370-375.