Marine Weather and Tide Forecast for Bayou Vista, TX

SHORT TERM
(Today through Thursday Night)
Issued at 433 AM CST Wed Jan 15 2025

The radar is pretty active early this morning, perhaps surprisingly so if you go outside and haven't experienced more anything more than a bit of a sprinkle. This is a pretty strong example of the column moistening from the top down. We had high clouds 24 hours ago, plus mid-level clouds tonight, and apparently enough moisture and lift for elevated showers to sprout across the area. However, the low levels are still quite dry, as parts of the area still have dewpoints below 40 and RH below 60 percent, which is pretty low for this area at this time of night.

Of course, this moisture is filling in at lower levels. IAH has begun reporting a few clouds below 3,000 feet, down from the 6,000 or so feet that most locations are reporting their lowest clouds at. And as we continue to build that moisture at lower levels, the showers will gradually become a bit more substantial today. They still won't be anything more than some light to occasionally moderate showers, but certainly more than sprinkles.

Now, why is that? Well, as we often see this time of year, the surface feature driving unsettled weather is a coastal trough developing off the Texas coast, developing underneath a weak upper trough passing overhead. When these situations create stormier conditions, it's often because these two features at the surface and aloft are in a phase where they build/support each other, and track up the Texas coastline
We are
getting neither of those today.

Today, the upper trough looks to scoot its way more west-to-east over the open Gulf, with a weaker trough chasing behind it, well offshore and not tracking towards our upper coast. This limits onshore flow and the return of significant moisture and warmer air. It also turns winds around to be offshore more quickly, ushering drier continental air sooner. And finally, it keeps the best lift well away from our area. And thus, we get only lighter showers!

Temperature-wise, expect the lows this morning to be among the warmest of the week, thanks mainly to the overcast sky. The only night with higher minimum temps should be Friday night (more on that in the long term section). We get the flip side of that coin during the day today, with temperatures only rising 10ish degrees (or fewer, in spots!) for afternoon highs in the lower to middle 50s. Once winds turn offshore and scour out what modest moisture we've been able to build, that should allow for a chillier night tonight, with lows in the upper 30s and lower 40s. But despite that, I'd expect highs tomorrow to actually be a bit warmer thanks to some more sun, with highs around or a little above 60 degrees.

Congratulations, you have read (or skipped over) six paragraphs about the part of the forecast almost none of us care about! Please proceed to the long term section of the forecast, aka "Showtime!"

LONG TERM
(Friday through Tuesday)
Issued at 433 AM CST Wed Jan 15 2025

High pressure continues eastward on Friday, with southeasterly flow bringing WAA and moisture advection. This warms up highs into the 60s/lower 70s on Friday with temperatures for Friday night in the 40s/50s. Rising moisture will introduce rain chances Friday evening/overnight, but by in large Friday will be a benign and pleasant day, at least compared to what's coming...

A shortwave over the Southern Plains will push a strong cold front through SE Texas on Saturday. Timing with this front remains the same, entering the Brazos Valley early Saturday morning then pushing off the coast by the afternoon. Showers/thunderstorms will be possible along/ahead of the front, with gusty north/northeast winds developing in it's wake. Cold air filters in behind this system, with lows temperatures for Sunday morning currently forecasted to be in the upper 20s/30s inland and lower 40s along the coast. Wind Chill will put apparent temperatures in the upper teens/upper 20s inland and lower 30s near the coast early that morning.

While we'll warm above freezing during the day (highs in the 40s area-wide), a deep upper level low over the Hudson Bay (Canada) will push a strong 1050mb surface high into the Northern PLains/Great Basin on Sunday. This frigid arctic airmass will fill in across the much of the CONUS overnight into next week, bringing even colder conditions to SE Texas. Low temperatures for Monday & Tuesday morning are currently forecasted to be in the 20s inland to lower 30s along the coast. Hard Freeze conditions (Temps 24 or lower) will be possible in areas north of I-10, and especially so across the Brazos Valley/Piney Woods area, where NBM probabilities show high confidence (70-90% chance) for reaching Hard Freeze temperatures.
Wind Chill temperatures are forecasted to be in the 20s to lower teens. LREF ensemble probabilities still suggest that there is a low to medium (35%) chance of Wind chills hitting single digits over the far northern reaches of our CWA early Tuesday morning. Uncertainty grows beyond the 7 day forecast, though at present we may have to wait till the second half of the week to see temperatures warm up again.

With these cold conditions comes the question of winter precipitation, and it appears as though the conditions are looking favorable for it's development. A coastal trough is still progged to form near the Deep S Texas/Mexico coastline on Monday, providing influx of moisture across the Texas coastal bend. Pacific moisture filling in aloft, 700-850mb frontogenesis and a shortwave trough passing over Texas will provide the necessary components for precipitation. LREF, GFS and ECMWF ensembles all show a more distinct clustering of QPF beginning on Monday, providing higher confidence in precipitation. Compared to yesterday, guidance does appear a tad warmer aloft, with ensemble means showing 500mb temperatures in the range of -14 to -19. Dynamic Ensemble Soundings still keep most of the temperature profile below zero, though the upper end of the IQR has shifted above the freezing mark.
Deterministic soundings still shows signs of seeder-feeder processes occuring, but also feature a stronger warm nose aloft.

The main takeaway is that we now have medium to high confidence (40- 50% chance) that wintry precipitation will occur over southeast Texas during the first half of next week. All winter precipitation types are still on the table right now, but broadly speaking guidance and the NBM seem to still favor snow as the dominant precip type. Areas north of the I-10 are more likely to see snow/mix of sleet. Areas to the south may see a mix of snow/sleet/freezing rain and potentially liquid rain right along the barrier islands/nearshore waters. As for how much snow/sleet/ice, uncertainty is too high to put a specific amount on it just yet.
Broadly speaking, it's more snow to the north and more ice to the south. We'll have a better idea of "how much" over the next few days, but for now we should prepare for some accumulating winter precipitation.

AVIATION
(06Z TAF Issuance)
Issued at 1112 PM CST Tue Jan 14 2025

Some scattered rain showers have formed through isentropic lifting across the northern three sites (CXO and northward) and are likely to persist through ~15Z. By the late morning hours, rain will be more likely near the coast. Closer to the coast, coverage of rain showers will gradually increase later this morning and persist into the late afternoon hours. This increasing moisture will come paired with MVFR/IFR ceilings south of I-10 in the afternoon hours...mainly impacting HOU/SGR and southward. Winds will be mainly northeasterly throughout the day on Wednesday with some potential for gusts near 20-25 kt along the coast. Conditions will begin to improve towards the end of the TAF period with ceilings beginning to trend towards the MVFR/VFR range near the coast. Rain shower coverage will also be on a downward trend towards the end of the TAF period.

Batiste

MARINE
Issued at 433 AM CST Wed Jan 15 2025

A coastal trough will bring scattered showers/storms, east/northeast winds of 15 to 25 knots and seas of 3 to 6 feet through late tonight. This will warrant caution flags and occasionally Small Craft Advisories through early Thursday. During this time frame, low tide levels are expected across the bays, which may make navigation difficult in some spots. Southerly winds return Friday morning and strengthen overnight ahead of the next cold front. This strong cold front should push offshore sometime Saturday afternoon, bringing showers/storms as it passes then gusty northerly winds and high seas in it's wake. Cold arctic air will works its way to the coast on Sunday into next week. Chances of a hard freeze occuring around Galveston Bay next week are low (20-35%). Even higher winds and seas are looking more likely for next week as a coastal trough develops offshore.

PRELIMINARY POINT TEMPS/POPS
College Station (CLL) 57 35 63 40 / 20 0 0 0 Houston (IAH) 54 39 62 42 / 40 10 0 0 Galveston (GLS) 55 45 58 50 / 70 30 0 0

HGX WATCHES/WARNINGS/ADVISORIES
TX...None.
GM...Small Craft Should Exercise Caution through this evening for GMZ330.

Small Craft Advisory until 9 PM CST this evening for GMZ350-355.

Small Craft Advisory until midnight CST tonight for GMZ370-375.