Marine Weather Net

Galveston Bay Marine Forecast




5 - 10


5 - 10


5 - 10

The Marine Weather Forecast In Detail:
GMZ335 Forecast Issued: 335 AM CDT Sun Sep 22 2019

Today...Southeast Winds Around 10 Knots. Bay Waters Smooth To Slightly Choppy. A Chance Of Showers Until Late Afternoon. A Chance Of Thunderstorms In The Late Morning And Early Afternoon. A Slight Chance Of Showers And Thunderstorms Late.
Tonight...Southeast Winds 5 To 10 Knots. Bay Waters Smooth.
Monday...Southeast Winds 5 To 10 Knots. Bay Waters Smooth. A Slight Chance Of Showers. A Slight Chance Of Thunderstorms In The Afternoon.
Monday Night...Southeast Winds 5 To 10 Knots. Bay Waters Smooth.
Tuesday...Southeast Winds 5 To 10 Knots. Bay Waters Smooth.
Tuesday Night...Southeast Winds 5 To 10 Knots. Bay Waters Smooth.
Wednesday...Southeast Winds 5 To 10 Knots. Bay Waters Smooth.
Wednesday Night...South Winds 5 To 10 Knots. Bay Waters Smooth. A Slight Chance Of Showers After Midnight.
Thursday...Southeast Winds 5 To 10 Knots. Bay Waters Smooth. A Chance Of Showers. A Slight Chance Of Thunderstorms In The Afternoon.
Thursday Night...Southeast Winds 10 To 15 Knots. Bay Waters Slightly Choppy. A Slight Chance Of Showers And Thunderstorms In The Evening, Then A Chance Of Showers After Midnight.
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Synopsis for High Island to the Matagorda Ship Channel out 60 nautical miles including Galveston and Matagorda Bays - GMZ300
335 AM CDT Sun Sep 22 2019

Light to moderate onshore winds will continue through Thursday. Periods of scattered showers and thunderstorms expected. Moderate onshore flow should prevail by next weekend.
Area Forecast Discussion
National Weather Service Houston/Galveston TX
637am CDT Sunday September 22 2019

Short Term - Tonight Through Tuesday
Radar imagery this morning shows decent coverage of showers over the Gulf waters stretching north across the coastal counties through Hardin and Orange counties to our east. Taking a look at the GOES-16 total precipitable water imagery, 1.8 to 2.0 inches prevail across the Gulf waters with a plume of higher precipitable water values (PWs) closer to 2.0 inches stretching across the eastern Gulf waters and into Hardin County where the best coverage of showers is ongoing. This axis of better moisture should continue to shift inland through afternoon hours and act as a boundary for more widespread development of showers and thunderstorms. Convective temperatures should reach into the low to mid 80s, and with high temperatures expected to top out in the upper 80s to low 90s, isolated thunder will be possible with the help of daytime heating. NAM12 shows decent mid-level frontogenesis values across Chambers to Polk counties by the afternoon hours, which should also aid in convective development. Short term guidance such as the HRRR (High-Resolution Rapid Refresh) and RAP13 appear to have initialized best this morning, and show more scattered coverage this afternoon east of I-45 with more isolated development to the west. Along the axis of best moisture, a few brief heavy downpours look possible, with the HRRR (High-Resolution Rapid Refresh) showing hourly rain rates between a quarter of an inch to an inch and a half per hour. That said, any additional rainfall over Liberty and Chamber counties specifically, is only going to delay the recession of any lingering flooding. An areal flood warning remains in effect through 11am this morning, to account for those river and local tributary levels that remain high with very saturated soils. This areal flood warning may need to be extended. Most of the convection should wane with the loss of daytime heating by the early evening hours. Tonight low temperatures should lower into the mid 70s to low 80s.

.LONG TERM [Monday through Sunday evening]... Overall, the early portion of next week will be characterized by quiet and dry conditions, with the chances of convective precipitation gradually increasing by next weekend. By Monday the upper-level ridge and surface high pressure continue to build in over the south-central CONUS, and the characteristic moderate onshore flow pattern across Southeast Texas continues. Generally weaker moisture transport throughout the beginning portion of the week will result in a reduced chance of diurnal showers and thunderstorms initiating over the coastal waters and progressing inland as we typically see in such a flow pattern. By Thursday, however, the ridge shifts eastward and an upper-level weakness within the prevailing zonal flow develops over the northwest Gulf of Mexico. Global model guidance shows a plume of enhanced moisture transport developing along with this feature, returning precipitable water values (PWs) across the CWA to the 1.75 to 2 inch range. This will increase convective activity associated with daytime surface heating to a more climatologically normal rate. Moisture transport further amplifies as we move into next weekend and PWs climb above 2 inches, bringing the potential for more widespread coverage of showers and thunderstorms. Despite this, precipitation amounts are not expected to be substantial enough to produce further flooding impacts to areas recently impacted by TS Imelda.

Small craft should continue to exercise caution at least through the early afternoon hours when the pressure gradient begins to slacken over the region. A Beach Hazard Statement remains in effect through early Monday morning to account for the risk for strong rip currents along Gulf facing beaches and elevated tide levels. At Galveston Bay Entrance, tide levels should peak between 3.0 and 3.5 feet above MLLW during times of high tide. Tide levels should fall around or even beneath 3.0 feet above MLLW late Monday evening.

Onshore flow around 15 knots should lower to 10 to 15 knots, later this afternoon. Seas should also lower to 3 to 4 feet by Monday morning. Light to moderate onshore flow should prevail through a majority of next week, with seas remaining around 2 to 4 feet. Moderate onshore picks back up by the weekend, increasing to 15 to 20 knots.

We continue to see a gradual fall in river levels following the recent flooding rains: - The West Fork of the San Jacinto near Sheldon has fallen out of minor flood stage and is expected to continue to lower below action stage by Tuesday morning. - The Trinity River at Moss Bluff has fallen below minor flood stage this morning and is forecast to continue to fall below action stage by Monday evening. - Cedar Bayou near Crosby continues to hold steady in minor flood stage.

A daily record high minimum temperature was observed at Galveston yesterday. The minimum temperature of 83 degrees ties a record for the highest observed for September 21, which last occurred in 1992..

NOAA Houston/Galveston TX Office: Watches - Warnings - Advisories
TX...None. GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 10am CDT this morning for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM...Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM.