Marine Weather and Tide Forecast for Portland, TX

DISCUSSION
Issued at 1224 AM CST Sat Nov 7 2026

An upper-level trough is digging into the Four Corners region with a subtropical jet streak forecast to move over South Texas. This, combined with a 500 hPa closed low cutting off from the main flow and residing over northern Mexico by Sunday. Closer to the surface, easterly flow will result in upslope flow against the Sierra Madre Oriental ranges in northeastern Mexico. Latest REFS and Canadian guidance shows that this orographically induced vertical ascent will start off this rain event for locations along the Rio Grande and into the Edwards Plateau Saturday afternoon and evening. Early Sunday morning, the LLJ and approaching frontal system further enhances the shower/storm activity across the Brush Country.
Forecast soundings across the Brush Country shows skinny CAPE profiles with the warm cloud layer pushing 10k ft and PWATS climbing to near 2.0" (approaching the +2SD), effective warm rain processes and convectively enhanced rainfall rates are looking to be in store across South Texas throughout Sunday and spreading towards the coastline. The limiting factors that may keep rainfall totals will be the positioning of the surface front (does it make it down into Deep South Texas, or stay closer to the region between Corpus Christi and Baffin Bays. The convergence along this line will be the secondary area of the highest rainfall totals. Should this front make it into Deep South Texas, the convectively induced higher rainfall rates may remain south of the Benavides area. Either way, given the increased confidence in multiple areas of higher rainfall rates/totals and overall guidance painting 2-4 inches through Monday morning with localized 5+" totals (and yes, some guidance has gone as high as 9 inches, though this is on the extreme end), a Flood Watch has been issued for most of South Texas from this afternoon through Monday morning. While flash flood guidance is on the higher end (generally 3 to 5 inches for a 6 hr period), should any of these storms start training or slow-moving over the same areas (and especially over the urban areas of Laredo and along the Coastal Bend), flash flooding may become a concern. For this reason, the WPC has included most areas under a Marginal Risk for Excessive Rainfall (level 1 of 4), and a Slight Risk (level 2 of 4) on Sunday across South Texas.

Temperatures today will be near seasonal for most locations (upper 70s/low 80s) with lows in the 60s/70s for Sunday morning. Temps on Sunday will struggle to climb much more from the morning low and temperatures dropping into the 50s across the northern Brush Country by Monday morning. This isentropically induced rainfall event will start winding down throughout the day on Monday. Low-end rainfall chances (10-30%) will continue through Wednesday (better chances closer to the coast). Then higher pressure builds in as an additional mid-level trough moves through the South Central Plains.
This northerly flow will usher in drier air (PWATs dropping from 1.5" values on Wednesday down to 0.75" PWATs by Friday). This will keep highs slightly below normal and the return of widespread 50s for low temperatures by the start of the upcoming weekend.

Outside of the threat of heavy rainfall this weekend, there are also concerns for coastal flooding as the new moon phase approaches this weekend, combined with 20-25 kt E/NE'ly winds. While the wave energy is currently forecast to not exceed 7-8 seconds, P-ETSS guidance along the Middle Texas Coast is forecasting water levels reaching 2- 2.5 ft for the high tide cycles from Sunday through at least mid- week. This will make for tricky driving conditions on local beaches (combined with the downpours) and for those parking along our local bays and estuaries could see periods where water levels will make certain areas impassable. Small Craft Advisory conditions will also be needed for the open Gulf waters from mid-morning Sunday through Monday morning. Lastly, these strong easterlies will lead to a High Rip Current Risk Sunday into Sunday night.

AVIATION
(06Z TAFS)
Issued at 1224 AM CST Sat Nov 7 2026

Generally VFR conditions will prevail through the morning. There will then be a medium chance (40 percent) of showers and MVFR cigs over KLRD and KCOT this afternoon with a low (20 percent)chance of MVFR cigs at KCRP and KALI. Conditions will deteriorate over KLRD and KCOT after sunset with high chances (70 percent) of sub-VFR conditions in showers and isolated thunderstorms. Winds will generally favor a NErly direction around 5-10kts, although wind direction at KCOT and KLRD may trend more northerly while the Coastal Plains terminals trend more easterly by this afternoon/evening.

MARINE
Issued at 1224 AM CST Sat Nov 7 2026

Moderate easterly winds (BF 4) today will increase to more fresh breezes (BF 5) tonight. 2-3 ft seas today will increase to 4-6 ft tonight. Sunday, easterly winds increase to fresh to strong strength with seas increasing to 5-7 ft. Rain chances increase from tonight through Sunday and into early next week. By Monday night, winds decrease to more gentle to moderate breezes with seas decreasing to 3-4 ft, and then near 2 ft by mid-week.

FIRE WEATHER
Issued at 1224 AM CST Sat Nov 7 2026

The fire risk will remain low through the forecast period due to minimum relative humidity values well above 30%. In addition, a medium to high chance for wetting rains can be expected across South Texas over the weekend and into early next week.

PRELIMINARY POINT TEMPS/POPS
Corpus Christi 81 70 77 64 / 20 30 70 50 Victoria 82 59 71 55 / 10 10 80 40 Laredo 76 66 73 61 / 60 100 90 90 Alice 79 65 74 58 / 30 50 80 60 Rockport 82 68 78 62 / 10 20 70 50 Cotulla 75 59 68 56 / 60 90 100 90 Kingsville 81 68 77 63 / 30 40 70 60 Navy Corpus 80 73 79 69 / 20 20 60 50

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

High Rip Current Risk from Sunday morning through late Sunday night for TXZ345-442-443-447.

GM...None.