Marine Weather and Tide Forecast for Port Lavaca, TX

DISCUSSION
Issued at 1242 AM CST Sun Nov 8 2026

The 500 hPa closed low is slowing down as it places all of South Texas under abundant diffluence aloft through Monday night as the low itself begins to fill. At the surface, a surface boundary has set up west of Alice, spanning north to south. This is helping push in Gulf moisture into South Texas and setting up an area of moisture convergence. At the same time, a low LLJ will start advecting additional moisture at the low to mid-levels. We're already seeing 1.7"+ PWATs advecting into South Texas. Given all these factors, in addition to elevated instability and some slantwise/CSI instability, we're in for a soggy 24-36 hr period across South Texas. Comparing what is being forecast (at least from the ECMWF, the Extreme Forecast Index (EFI) for Laredo has been between 0.85 to near 1.0 with a Shift of Tails (SOT) closer to the 2-4 range for QPF. In otherwords, what the model is forecasting is extreme outlook for QPF relative to the model climatology while the high SOT is indicating that the event will substantially outperform the mean. This is further supports the overall trend of a high spread amount global and CAM solutions. While these statistical evaluations show the potential for the higher end of solutions remaining a possibility, this does not lead to the confidence as to 1) where the highest rainfall amounts will fall and 2) the magnitude of these amounts.
While the overall soils will be able to absorb a good portion of the forecast rainfall, any moderate to heavy rainfall rates in addition to slow-moving storm motion/training will increase the risk for flash flooding, especially as these storms move into the more urbanized areas across South Texas (such as Laredo, Alice, Kingsville, Corpus Christi, etc). There will be several bouts of moderate to heavy rainfall (some localized convective storms)
through the morning and again tonight into Monday morning. In between these heavier rounds overall scattered showers will continue. The latest forecast is calling for widespread areas of 2-4 inches along the coastal areas generally from Rockport and locations southwest, with the Brush Country seeing greater confidence of 3-6 inches (accumulations through Monday night). Where convective storms move over slowly or train across several bouts will be where higher end rainfall amounts of 7-9 inches will be greatest. NBM shows much of Webb County under a 20-40% chance of surpassing 6 inches for this period. Interestingly, HRRR guidance has been a bit more aggressive with an MCS-like structure developing over the Rio Grande Plains around 3am and then moving eastward toward the Coastal Bend through mid-morning, bringing a localized area of 5-7 inches through this afternoon. We will watch this trend carefully especially given the urbanized setting in the region.

Isentropically supported showers and storms will start winding down Monday night, but rain chances continue Tuesday (20-30% chances across South Texas) and Wednesday (20-40% chances along the coastal areas and into the Victoria Crossroads). After the front clears the area on Thursday, drier air filters into the region through Saturday leading to slightly-below to near-normal high temperatures. By Sunday, onshore flow returns bringing back Gulf moisture into South Texas.

Across our waters, beaches and coastlines, the return of coastal flooding concerns begin with the upcoming high tide cycle with P- ETSS guidance showing water levels reaching 2-2.5 ft above MSL and again with Monday's high tide cycle. As such, a Coastal Flood Advisory has been issued for Gulf-facing beaches and along the bays/estuaries (so if you're an angler hoping to park on the sand back along Nueces Bay, you've been warned about the possibility of vehicles being cutoff from dry land). Additionally, the easterly component of the wind at 20-25 kts will lead to a high rip current risk, but will decrease by Monday morning.

AVIATION
(12Z TAFS)
Issued at 515 AM CST Sun Nov 8 2026

IFR ceilings across the Brush Country will spread east today with showers and thunderstorms. We can expect periods of LIFR today, especially where heavy rainfall occurs. These conditions are expected to continue through the TAF period.

MARINE
Issued at 1242 AM CST Sun Nov 8 2026

Easterly winds at 20-25 kts can be expected today with seas increasing to 6-8 ft leading to Small Craft Advisory conditions.
Additionally, strong showers and thunderstorms will increase across the western Gulf waters through the day and continue through at least Monday night, when precipitation and rougher conditions start subsiding. From Tuesday, winds drop down to light and gentle breezes (BF 2-3) with seas decreasing to near 2 ft. Rain chances return Tuesday with 20-40% chances, increasing 40-60% on Wednesday before another frontal system brings fresh northerlies.

FIRE WEATHER
Issued at 1242 AM CST Sun Nov 8 2026

Due to the high chance for widespread wetting rains this weekend and above 40% across South Texas through the upcoming weekend, the fire risk will remain low.

PRELIMINARY POINT TEMPS/POPS
Corpus Christi 75 64 71 61 / 90 100 90 20 Victoria 68 56 66 54 / 70 50 90 10 Laredo 72 62 66 60 / 100 100 90 50 Alice 72 58 68 56 / 100 100 90 30 Rockport 78 63 73 61 / 70 80 90 20 Cotulla 66 57 65 56 / 100 100 100 60 Kingsville 75 63 71 59 / 100 100 100 20 Navy Corpus 77 69 73 67 / 90 100 90 20

CRP WATCHES/WARNINGS/ADVISORIES
TX...Flood Watch through Monday morning for TXZ229>233-239>246- 342>346-442-443.

Coastal Flood Advisory from noon today to 3 AM CST Monday for TXZ245-342>347-442-443-447.

High Rip Current Risk through late tonight for TXZ345-442-443- 447.

GM...Small Craft Advisory until midnight CST tonight for GMZ231-232- 236-237.

Small Craft Advisory until midnight CST tonight for GMZ250-255- 270-275.