Marine Weather Net

Bays and Waterways from Baffin Bay to Port Aransas Marine Forecast


TONIGHT

E
WINDS
10
KNOTS

THURSDAY

E
WINDS
5 - 10
KNOTS

THURSDAY NIGHT

SE
WINDS
10 - 15
KNOTS

FRIDAY

SE
WINDS
10
KNOTS

The Marine Weather Forecast In Detail:
GMZ230 Forecast Issued: 340 PM CDT Wed Apr 14 2021

Tonight...East Wind Around 10 Knots. Bays Smooth To Slightly Choppy. A Slight Chance Of Showers And Thunderstorms. Patchy Fog After Midnight.
Thursday...East Wind 5 To 10 Knots Increasing To 10 To 15 Knots In The Afternoon. Bays Slightly Choppy To Occasionally Choppy. Patchy Fog In The Morning. A Slight Chance Of Showers And Thunderstorms.
Thursday Night...Southeast Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy. A Slight Chance Of Showers And Thunderstorms After Midnight.
Friday...Southeast Wind Around 10 Knots. Bays Slightly Choppy. A Slight Chance Of Showers And Thunderstorms.
Friday Night...Southeast Wind 5 To 10 Knots Becoming Northeast 15 To 20 Knots After Midnight. Bays Choppy To Occasionally Rough. A Chance Of Showers And A Slight Chance Of Thunderstorms After Midnight.
Saturday...North Wind 15 To 20 Knots. Bays Choppy To Occasionally Rough. A Chance Of Showers.
Saturday Night...North Wind 15 To 20 Knots. Bays Choppy To Occasionally Rough. A Slight Chance Of Showers In The Evening, Then A Chance Of Showers After Midnight.
Sunday...North Wind 15 To 20 Knots. Bays Choppy To Occasionally Rough. A Chance Of Showers In The Morning, Then A Slight Chance Of Showers In The Afternoon.
Sunday Night...North Wind 10 To 15 Knots Decreasing To 5 To 10 Knots After Midnight. Bays Slightly Choppy To Occasionally Choppy.
Monday...Northeast Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy. A Slight Chance Of Showers.
Monday Night...Northeast Wind 10 To 15 Knots Decreasing To 5 To 10 Knots After Midnight. Bays Slightly Choppy To Occasionally Choppy.
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Synopsis for Middle Texas coastal waters from Baffin Bay to Matagorda ship channel - GMZ200
340 PM CDT Wed Apr 14 2021

A weak to occasionally moderate onshore flow can be expected this evening. Isolated to scattered thunderstorms will move into the bays and near shore waters mainly north of Rockport late this afternoon and early this evening. Some of these storms could become severe with large hail and strong wind gusts. Fog is expected to redevelop later this evening over the bays and near shore waters and continue through Thursday morning. A frontal boundary will move into the coastal waters early Thursday morning resulting in a weak to moderate northeast flow. Winds will be weak to moderate easterly Thursday afternoon Thursday night. Weak to moderate onshore flow will persist through Friday before a strong cold front pushes through late Friday night into Saturday morning. This will result in chances for showers and thunderstorms over the coastal waters Friday through Friday night, with only chances of showers Saturday through Sunday. Strong north to northeasterly winds will follow in wake of the front Saturday morning through Sunday afternoon, causing Small Craft Advisory conditions.
Area Forecast Discussion
...UPDATED National Weather Service Corpus Christi TX
631pm CDT Wednesday April 14 2021

Showers and a few thunderstorms have formed north of the sea breeze boundary and south of the slowly advancing frontal boundary south through DeWitt County. Still narrow window for some stronger storms to form in very unstable air mass as the short wave trough moves into the region. Severe Thunderstorm Watch

Short Term - Tonight Through Thursday Night
Focus in the short term will be severe threat for the northern Coastal Bend and Victoria Crossroads into early this evening. SPC mesoanalysis page shows MLCAPE values from 3000-4000 J/kg over the coastal plains with marginally adequate effective shear of 30-40 knots. Water vapor imagery shows the mid level short wave trough about to move into the western Brush Country. Convection has slowly been increasing along a weak low level convergence axis from a weak sea breeze/surface trough from Mathis to Port Lavaca. Latest HRRR (High-Resolution Rapid Refresh) model continues to forecast convection increasing in coverage and intensity as the short wave trough approaches. Severe Thunderstorm Watch is in effect until 8 PM. Expect activity will diminish by mid evening as CINH increases.

Fog will likely develop over the near shore waters and move inland into the coastal plains late this evening and overnight ahead of the weak frontal boundary that will slowly sag to the southern part of the forecast area by early Thursday morning. The boundary is expected to stall there and gradually move northward by the evening hours. Warm air advection will be better over the western Brush Country Thursday morning to provide a slightly better chance of convection there. But models show the better lift associated with an upper level short wave trough moving into northwest Texas Thursday will be well north of the region. Will only hold on to slight chance Probability of Precipitation for the area Thursday. Can not rule out isolated convection affecting the region Thursday night, but the same reasoning applies for this period as well as another short wave trough will be passing well north of the forecast area. Will keep slight chance Probability of Precipitation for Thursday night for possible stray convective development.

Tide levels are running around 1.25 feet above expected along the Middle Texas coast. Although tides are falling toward low tide, the swell periods have increased to 9 to 10 seconds. Looking at Port Aransas web cam, the higher periods produced tide running up closer to the dunes. If the tidal anomalies continue along with these higher periods, tides will likely reach the dunes at the next high tide around 12Z Thursday. A Coastal Flood Advisory will probably need to be issued later this evening or on the mid shift.

Long Term - Friday through Wednesday
Zonal flow aloft at 250mb with the jet over the Texas Panhandle will shift eastward through the weekend. Meanwhile, the broad trough will become a positively tilted trough as a strong mid-level trough develops over the western CONUS. A mid-level low over the central Great Plains will push a strong cold front through South Texas overnight Friday night. Ahead of the front, isolated to scattered showers and thunderstorms will be possible as isentropic lift and PWATs (Precipitable Waters) over 1.75" (greater than 75th percentile) are in place. CAPE values 1000-2000 J/kg with very weak to non-existent cap over the Coastal Bend and Victoria Crossroads may develop a few strong thunderstorms Friday. Expect greatest coverage in the afternoon, focused over the northeastern counties. The greatest concern is whether there will be enough lift support ahead of the front for convection to spread further southwest into South Texas.

In wake of the front Saturday morning, there are significant model differences in regards to Quantitative Precipitation Forecast. The GFS and NAM have much of the activity south of the area by Saturday morning, keeping the area dry. Whereas the ECMWF (European Centre for Medium-Range Weather Forecasts) contains noticeable accumulations over South Texas through the day Saturday, especially over the southern half. Due to the inconsistencies and lower confidence, have reduced Probability of Precipitation Saturday to isolated to scattered showers, with greatest coverage expected over the waters and southern half. Removed thunderstorm potential beginning Saturday as there is decreasing PWAT (Precipitable Water) and minimal CAPE, both surface and elevated based. Precip chances will decrease north to south through Saturday night.

Kept only isolated showers inland during the day Sunday and Monday as PWATs (Precipitable Waters) decrease to near an inch over the Coastal Bend and Victoria Crossroads. Greatest confidence and coverage will be over the waters. High pressure will continue to increase heading into early next week, allowing for drier conditions to take over with cloud coverage decreasing. There is uncertainty regarding the progression of a mid- level shortwave trough Tuesday; the GFS plunges it southward over South Texas while the ECMWF/CMC keeps it north. Therefore, the GFS brings rain chances back Tuesday whereas the ECMWF/CMC remains dry. Only included isolated showers over the waters and Coastal Bend on Tuesday.

Temperatures on Friday will remain warm ahead of the front with highs ranging from 80 to 95, before decreasing significantly behind the front. Highs are expected to range from the mid 60s to mid 70s Saturday through Monday, with Sunday struggling to reach the 70s. Lows will generally be in the low to mid 50s Saturday night through Monday night. Temperatures are hinted to warm up Tuesday with the possible return of onshore flow and break of clouds. Lastly, minor coastal flooding remains possible in wake of the front as moderate to strong north to northeast winds persist.

Marine Discussion

A weak to occasionally moderate onshore flow can be expected this evening. Isolated to scattered thunderstorms will move into the bays and near shore waters mainly north of Rockport late this afternoon and early this evening. Some of these storms could become severe with large hail and strong wind gusts. Fog is expected to redevelop later this evening over the bays and near shore waters and continue through Thursday morning. A frontal boundary will move into the coastal waters early Thursday morning resulting in a weak to moderate northeast flow. Winds will be weak to moderate easterly Thursday afternoon Thursday night.

Weak to moderate onshore flow will persist through Friday before a strong cold front pushes through late Friday night into Saturday morning. This will result in chances for showers and thunderstorms over the coastal waters Friday through Friday night, with only chances of showers Saturday through Sunday. Strong north to northeasterly winds will follow in wake of the front Saturday morning through Sunday afternoon, causing Small Craft Advisory conditions. Winds are expected to decrease to moderate Sunday night and persist through Tuesday. Slight chances of rain return Monday and Tuesday.

NOAA Corpus Christi TX Office: Watches - Warnings - Advisories
TX...None. GM...None.