Galveston Bay Marine Forecast
|Tonight...South Winds 5 To 10 Knots. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms Early In The Evening. A Slight Chance Of Showers And Thunderstorms Late.|
|Wednesday...West Winds Around 5 Knots Becoming Southeast In The Afternoon. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms In The Morning, Then A Chance Of Showers And Thunderstorms Early In The Afternoon. A Slight Chance Of Showers And Thunderstorms Late In The Afternoon.|
|Wednesday Night...Southeast Winds 5 To 10 Knots Becoming South After Midnight. Bay Waters Smooth.|
|Thursday...Northeast Winds 5 To 10 Knots Becoming Southeast In The Afternoon. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms.|
|Thursday Night...South Winds 5 To 10 Knots Becoming Southwest After Midnight. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms Early In The Evening.|
|Friday...West Winds Around 5 Knots Becoming South In The Afternoon. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms In The Morning, Then A Chance Of Showers And Thunderstorms In The Afternoon.|
|Friday Night...Southwest Winds 5 To 10 Knots. Bay Waters Smooth. A Chance Of Showers And Thunderstorms Early In The Evening.|
|Saturday...Southwest Winds Around 5 Knots Becoming South In The Afternoon. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms In The Afternoon.|
|Saturday Night...Southwest Winds 5 To 10 Knots. Bay Waters Smooth.|
|Sunday...Southwest Winds 5 To 10 Knots Becoming South In The Afternoon. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms In The Afternoon.|
|Sunday Night...Southwest Winds 5 To 10 Knots. Bay Waters Smooth.|
| Synopsis for High Island to the Matagorda Ship Channel out 60 nautical miles including Galveston and Matagorda Bays - GMZ300|
328 PM CDT Tue Jul 27 2021
Weak high pressure over the Gulf of Mexico will produce a light onshore flow through the end of the week.
| Area Forecast Discussion|
National Weather Service Houston/Galveston TX
310pm CDT Tuesday July 27 2021
.SHORT TERM [Through Wednesday Night]... Cloud cover last night kept temperatures on the mild side, but that same cloud cover provided the area with a little protection from the sun this morning keeping the morning temperatures a bit cooler than yesterday. However, conditions have quickly returned to the mid to upper 90s across the area due to clearing skies. PWATs (Precipitable Waters) have climbed steadily over the last 24 hours with satellite derived values of around 2.2" along and south of I-10 and east of I-45. Dew point temperatures are around three to four degrees hotter this afternoon compared to yesterday, so if you think it feels hotter out there - you are correct. A shortwave embedded in the bottom side of the upper level ridge is moving across the region this afternoon/evening. This will help support some Probability of Precipitation up showers and thunderstorms mainly where the highest PWATs (Precipitable Waters) are located. Model soundings show a long-skinny CAPE profile for this afternoon, so the showers that do form will be capable of producing quick bouts of heavy rainfall. The heavy rainfall should not last long as the storms will dissipate shortly after formation. All activity will end shortly after sunset with the loss of daytime heating, but partly cloudy skies will continue through the night. The higher PWATs (Precipitable Waters) will stick around through the day on Wednesday keeping the chance of isolated to scattered thunderstorms in the afternoon.
Overnight low temperatures will continue to be in the mid/upper 70s to low 80s through Wednesday night. Daytime high temperatures on Wednesday will be back into the upper 90s with heat indices in the 103-106 degree range.
.LONG TERM [Thursday through Wednesday]... A sprawling upper level ridge of high pressure will be centered over Kansas on Thursday. The ridge will extend east to west from eastern NV into western GA. SE TX will lie on the periphery of the upper high and weak upper level disturbances are expected to continue to undercut the ridge and move westward into SE TX from the Gulf. Will carry chance Probability of Precipitation both Thursday and Friday for mainly diurnally driven showers and thunderstorms. The upper level ridge will retreat slightly westward but the orientation of the ridge will transition from E-W to NW-SE and extend into SE TX so in essence, the ridge will still dominate the weather locally with warm and dry conditions for next weekend. Will go above climo for MaxT values Thu-Sunday and go with persistence for MinT values.
As we approach next week, deterministic global models suggest a pattern change with a developing long wave trough deepening and retrograding west as the upper level ridge over the inter-mountain west retrogrades and weakens. The upper level flow will become northerly and this type of pattern is favorable to drive a backdoor cold front into the area late Monday or Tuesday. The upper flow will also allow a series of upper level disturbances to drop south into eastern TX and this should produce scattered showers and thunderstorms through next week. FWIW, ensemble guidance supports the pattern change with the upper ridge shifting west and a deep long wave trough over the eastern U.S. Temperatures for early next week should trend cooler with lower heights, cloud cover and precipitation. 43
Weak high pressure over the eastern gulf of Mexico will produce a light to occasionally moderate onshore flow. Winds are expected to increase slightly toward the weekend as pressures fall over West Texas and the pressure gradient tightens. No flags or advisories are expected through next weekend. 43
NOAA Houston/Galveston TX Office: Watches - Warnings - Advisories