Marine Weather and Tide Forecast for Portland, TX

DISCUSSION
Issued at 222 AM CDT Sat Jun 13 2026

A pattern change will begin today as deeper tropical moisture spreads northwest into South Texas ahead of a broad disturbance over the Bay of Campeche that currently has a low 20% chance of tropical formation over the next seven days. While mid- level ridging will remain in place early Saturday, increasing PWATs near 2.0-2.50 inches will support scattered showers and thunderstorms, especially along the coast and across the eastern half of the CWA GEFS PWAT Mean is progged to be around 2.10" at the time of today's 18Z balloon launch, so we'll see how well this verifies and that should give us a better idea how much moisture will be available next week. Regardless, any convection will be capable of producing brief heavy rainfall due to efficient warm rain processes.

Rain chances increase further Sunday into Tuesday (moderate to high)
as tropical moisture continues to pool across the region while a weak boundary settles south into Texas. The interaction between this boundary, increasing lift aloft as weakening in high pressure aloft due a strong trough north of the region, and deep moisture will support periods of showers and thunderstorms. Confidence is increasing in widespread rainfall during this period, though the exact placement of the heaviest rain remains uncertain. Current forecast rainfall totals generally range from 3-5 inches with locally higher amounts possible where storms train or repeatedly move over the same areas. WPC continues to highlight South Texas in a Marginal Risk (level 1 of 4) for excessive rainfall, and localized flooding will be possible, especially in urban, low-lying, and poor drainage areas.

By Wednesday into Thursday, rain chances should gradually decrease as the best moisture and forcing shifts east and the mid-level pattern begins to recover. However, sufficient moisture will remain in place to support continued scattered diurnal convection, mainly during the afternoon and early evening hours.
By Friday, a more typical summertime pattern may return with isolated to scattered seabreeze convection and warmer temperatures.

Temperatures will remain hot Saturday with highs in the 90s inland and heat indices near 100 to 105 degrees. Increased cloud cover and rainfall should lower temperatures slightly Sunday through Tuesday, with highs mainly in the 80s to lower 90s. Heat indices may still approach moderate heat risk levels at times, especially during breaks in cloud cover.

Long-period swells around 7-8 seconds combined with seas building to 5-7 feet and astronomically higher tides near the new moon will maintain an elevated rip current risk this weekend into early next week. A High Risk of rip currents is expected, with minor coastal flooding possible during times of high tide, especially along Gulf- facing beaches with water reaching the dunes. This also includes any vulnerable low-lying coastal locations.

AVIATION
(06Z TAFS)
Issued at 1221 AM CDT Sat Jun 13 2026

MVFR conditions generally expected overnight tonight. Tomorrow, southeast winds with gusts up to 20-25KT will accompany low-end shower chances across South Texas. Have opted to maintain VCSH and PROB30s. Saturday night expecting mainly dry conditions with predominately VFR conditions. Looking ahead to Sunday and early next week, rain and thunderstorm chances across a wide area of TX will increase to moderate to high as a disorganized system approaches South and Deep South Texas from the Bay of Campeche.
Chances for tropical development of this system remain low (20%)
and has low end chances for heavy rainfall.

MARINE
Issued at 222 AM CDT Sat Jun 13 2026

Overall, a Moderate to Fresh onshore flow (BF 4-5) will persist through the forecast period as pressure gradients tighten between high pressure over the western Gulf and lower pressure to the south. Scattered to numerous showers and thunderstorms will develop Saturday through Tuesday, with locally heavy rainfall, frequent lightning, and brief gusty winds will be possible in and around any storm, Seas will build through the weekend as long- period swells increase, leading to hazardous conditions for small craft at times. Small Craft should Exercise Caution conditions will be possible early in the week, with Small Craft Advisory conditions likely the during the second half of the week over the Gulf waters.

FIRE WEATHER
Issued at 222 AM CDT Sat Jun 13 2026

Fire weather concerns will remain low through the period due to increasing moisture, elevated relative humidity values, and increasing rain chances (moderate to high). Wet fuels and widespread cloud cover leading to cooler temps early next week should further limit fire weather potential.

PRELIMINARY POINT TEMPS/POPS
Corpus Christi 89 80 90 79 / 40 20 40 60 Victoria 92 78 91 76 / 20 10 60 60 Laredo 94 77 94 77 / 30 10 40 40 Alice 90 77 91 77 / 40 10 70 40 Rockport 91 82 91 81 / 20 20 40 60 Cotulla 94 77 94 76 / 30 10 30 50 Kingsville 89 78 90 77 / 40 20 60 40 Navy Corpus 88 82 89 81 / 30 30 40 70

CRP WATCHES/WARNINGS/ADVISORIES
TX...Coastal Flood Advisory until 1 PM CDT this afternoon for TXZ345- 442-443-447.

Coastal Flood Advisory from 1 AM to 1 PM CDT Sunday for TXZ345- 442-443-447.

High Rip Current Risk through Monday morning for TXZ345-442-443- 447.

GM...None.