Matagorda Bay Marine Forecast
|Rest Of Tonight...East Winds 5 To 10 Knots Becoming Northeast After Midnight. Bay Waters Smooth. Patchy Fog Early In The Evening. Areas Of Fog In The Late Evening And Overnight. A Chance Of Thunderstorms In The Evening. A Chance Of Showers. Isolated Thunderstorms After Midnight.|
|Thursday...Northeast Winds 10 To 15 Knots Becoming East 15 To 20 Knots In The Afternoon. Bay Waters Slightly Choppy Becoming Choppy In The Afternoon. Areas Of Fog Early In The Morning. Patchy Fog Late In The Morning. A Chance Of Showers Early In The Morning. Isolated Thunderstorms. A Slight Chance Of Showers In The Late Morning And Afternoon.|
|Thursday Night...East Winds 10 To 15 Knots. Bay Waters Slightly Choppy. A Slight Chance Of Showers And Thunderstorms.|
|Friday...Southeast Winds Around 10 Knots Becoming South In The Afternoon. Bay Waters Smooth To Slightly Choppy. A Slight Chance Of Showers And Thunderstorms In The Morning, Then A Chance Of Showers And Thunderstorms In The Afternoon.|
|Friday Night...Southeast Winds 5 To 10 Knots Becoming North 15 To 20 Knots After Midnight. Bay Waters Smooth Becoming Choppy After Midnight. A Chance Of Showers And Thunderstorms.|
|Saturday...North Winds Around 20 Knots. Bay Waters Choppy. A Chance Of Showers.|
|Saturday Night...North Winds 15 To 20 Knots. Bay Waters Choppy. A Slight Chance Of Showers In The Evening.|
|Sunday...North Winds 15 To 20 Knots. Bay Waters Choppy.|
|Sunday Night...North Winds 10 To 15 Knots. Bay Waters Slightly Choppy.|
|Monday...Northeast Winds 10 To 15 Knots. Bay Waters Slightly Choppy.|
|Monday Night...Northeast 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|
728 PM CDT Wed Apr 14 2021
Isolated strong to severe thunderstorms are possible through the evening hours today in the Bays and nearshore Gulf waters as a weak frontal boundary sits just north of the coast. Outflow from storms over the coastal counties will push offshore this evening. The front will slowly move off the coast early Thursday with winds becoming briefly northeasterly followed by a quick shift to easterly by Friday morning. Onshore flow returns by Friday night ahead of another stronger cold front that will push through the coastal waters on early Saturday morning. Moderate to strong northeasterly winds will develop in the wake of this front throughout the weekend with caution to advisory level winds anticipated.
| Area Forecast Discussion|
National Weather Service Houston/Galveston TX
634pm CDT Wednesday April 14 2021
Short Term - Today through Thursday
Weak frontal boundary/wind shift has pushed to to around the I-10 corridor. Seabreeze to the south has moved a few miles inland. Resulting llevel convergent zone situated in between both. Further aloft a weak shortwave was noted on w/v imagery across south Tx. Shra and a few tstms have initiated across southern parts of the area. Assuming cloudiness remains about the same, or thins, we'll have a few hours of daytime heating left. This and some enhanced lift from the shortwave may allow a couple strong to severe cells to develop between now and sunset. Forcing isn't overly impressive, but with somewhat steep lapse rates aloft there could be a hail threat and strong winds in cells where stronger updrafts become established. Localized heavy downpours can never be ruled out with 2" PW's in place and a slow moving boundary/focusing mechanism. Precip will weaken and coverage begin diminishing with the loss of heating.
The boundary should push toward the coast, perhaps 10-30 miles offshore later tonight. Llevels of the atmos saturate however, so chances of -ra and/or drizzle will remain in the forecast overnight. Sea fog closer to the coast and offshore will be an issue until ne winds increase late tonight.
Cloudiness will remain in place Thurs. Combination of that and cooler temps should minimize overall instability for most of the day. That said, guidance pointing toward another shortwave embedded in the zonal flow heading toward the region during the late afternoon hours and generating some precip. Better chances/coverage should be situated across the nw/n parts of the area...and some of the 12Z hires guidance pointing toward the possibility of some elevated stronger cells near the Brazos Valley late in the afternoon and evening. So, future shifts will need to keep an eye on hail threats up that way. 47
LONG TERM [Thursday Night Through Wednesday]... Going into Thursday night with lingering cloud cover, overnight low temperatures will be rather mild in the low-to-mid 60s. As the previous cold front becomes washed out off the coast, winds will start out as easterly on Thursday night/Friday morning then transition to a southeasterly wind. Resultingly, there will not be a decrease in the moisture in the area as PW values (Precipitable Water values) hold steady around 1.5"-1.8" through Friday afternoon. Another stronger cold front will approach the region going into Friday night. Instability in the area will range from 1000-1500 J/kg. This should be enough to develop scattered thunderstorms along the frontal boundary, especially in the southern half of the CWA. Jet dynamics aren't exactly favorable for upper-level support, so the showers and thunderstorms that do develop will be the result of low-level convergence along the front. Favorable jet dynamics do come into the equation on Saturday as a departing jet streak places the region in the right entrance region, so Probability of Precipitation linger throughout the day. With instability quickly dropping post-FROPA, expecting only scattered coverage of rain showers on Saturday.
How about those post-FROPA temperatures? Well if you missed below normal temperatures, then you're in luck! Overnight lows on Friday will feature low-to-mid 50s with lows in the 40s expected for both Saturday and Sunday. In the daytime over the weekend, afternoon high temperatures will struggle to reach the 70s thanks to Cold Air Advection prevailing through Monday morning. Surface high pressure moves overhead on Monday and then slides off to the east by Tuesday, so temperatures will be on an upward swing going into early next week. Fortunately, only looking at highs in the mid-to-upper 70s for Tuesday and Wednesday. Backtracking a little bit to Tuesday...GFS and ECMWF (European Centre for Medium-Range Weather Forecasts) are in agreement on a weak coastal low developing in the western GoM , but there is disagreement on how far north this low moves and also how much moisture is associated with it. Leaned more towards the ECMWF which keeps the low further south and our area dry, so Probability of Precipitation are minimal throughout the first half of next week. It is worth noting that although the ECMWF indicates some spotty rain showers in the afternoon/evening hours next week, forecast soundings indicate that there will be too much dry air both aloft and near-surface to get any significant precipitation to reach the ground.
Isolated strong to severe thunderstorms are possible through the evening hours today in the Bays and nearshore Gulf waters as a weak cold front sits just north of the coast. Lingering coastal flooding around Galveston Bay will continue to gradually decrease throughout the day. The front will slowly move off the coast on Thursday with winds becoming briefly northeasterly followed by a quick shift to easterly by Friday morning. Onshore flow returns by Friday night ahead of another stronger cold front that will push through the coastal waters on early Saturday morning. Moderate to strong northeasterly winds will develop in the wake of this front throughout the weekend with caution to advisory level winds anticipated.
NOAA Houston/Galveston TX Office: Watches - Warnings - Advisories
TX...High Rip Current Risk until 8pm CDT this evening for the following zones: Bolivar Peninsula...Brazoria Islands... Galveston Island...Matagorda Islands.
Coastal Flood Advisory until 7pm CDT this evening for the following zones: Bolivar Peninsula...Chambers...Coastal Galveston...Coastal Harris...Galveston Island.