Marine Weather Net

Bay and Waterways from Port Aransas to Port O'Connor Marine Forecast


TONIGHT

SE
WINDS
5 - 10
KNOTS

WEDNESDAY

SE
WINDS
5 - 10
KNOTS

WEDNESDAY NIGHT

SE
WINDS
10 - 15
KNOTS

THURSDAY

SE
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
GMZ235 Forecast Issued: 323 PM CDT Tue Jun 22 2021

Tonight...Southeast Wind 5 To 10 Knots. Bays Smooth. A Slight Chance Of Showers And Thunderstorms.
Wednesday...Southeast Wind 5 To 10 Knots. Bays Smooth. A Chance Of Showers And Thunderstorms In The Morning, Then A Slight Chance Of Showers And Thunderstorms In The Afternoon.
Wednesday Night...Southeast Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy.
Thursday...Southeast Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy.
Thursday Night...Southeast Wind Around 15 Knots. Bays Slightly Choppy To Choppy.
Friday...South Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy.
Friday Night...Southeast Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy.
Saturday...Southeast Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy. A Slight Chance Of Showers And Thunderstorms In The Afternoon.
Saturday Night...Southeast Wind 10 To 15 Knots. Bays Slightly Choppy To Occasionally Choppy.
Sunday...Southeast Wind 5 To 10 Knots. Bays Smooth. A Chance Of Showers And Thunderstorms.
Sunday Night...Southeast Wind 5 To 10 Knots. Bays Smooth. A Slight Chance Of Showers And Thunderstorms In The Evening, Then A Chance Of Showers And Thunderstorms After Midnight.
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Synopsis for Middle Texas coastal waters from Baffin Bay to Matagorda ship channel - GMZ200
323 PM CDT Tue Jun 22 2021

Winds will be variable along the coast this evening due to outflow from showers and thunderstorms. Outflow boundary over the Gulf waters will move back toward the coast overnight as southeast winds develop. Scattered thunderstorms will be possible over the coastal waters through the night into Wednesday morning with activity diminishing in the afternoon. A weak onshore flow Wednesday morning will become weak to moderate in the afternoon and moderate Wednesday night. Onshore flow will strengthen as we close out the work week as low pressure deepens across the Plains. Onshore flow will weaken as we go through the weekend with weak to moderate levels expected. Chances for showers and thunderstorms will begin to increase late this weekend and into early next week as an inverted trough begins to take shape across the Gulf.
Area Forecast Discussion
National Weather Service Corpus Christi TX
343pm CDT Tuesday Jun 22 2021

Short Term - Tonight Through Wednesday Night
Outflow boundary from morning convection arched from along the coast to near Kingsville then northwest across Duval County to near Cotulla early this afternoon. Deep moisture in place with dewpoints around 80 and modest heating led to instability increasing to around 3000 J/kg this afternoon according to Storm Prediction Center mesoanalysis page. Storms formed along this boundary around 18Z and now interactions along a plethora of outflow boundaries continue to initiate convection over the Coastal Bend. Expect convection will be decreasing by early this evening with loss of heating and decreased instability from outflow. Kept mention of slight chance Probability of Precipitation for early evening over the southern portion of the forecast area.

Outflow boundary will be over the near shore waters this evening and drift back toward the coast overnight. The weak mid level shear axis will remain over the Gulf waters tonight. A low level convergence zone will set up along the coast later tonight. With high moisture still in place with models showing precipitable water values near or slightly above 2 inches, the low level convergence will provide a focus for convective development overnight. Expect this activity will move into the coastal counties before daybreak and slowly move inland over the coastal plains during Wednesday afternoon. Activity will be scattered in the morning but decrease to isolated by the afternoon as drier air from developing upper ridge to the northwest has negative influence on rain chances. Temperatures will be back to near normal with sufficient humidity to bring heat index values to the 105-109 range with a few locales reaching 110 degrees. Dry conditions are expected for Wednesday night as the upper ridge sags south into the region.

.LONG TERM (Thursday through Tuesday)... Upper level ridging will shift into the area as we start off the long term. Drier air will filter in with PWATs (Precipitable Waters) dropping to near 1.5" by Friday morning. At the surface, onshore flow will continue as we head into the weekend. Winds will pick up a bit on Friday as the pressure gradient tightens in response to a deepening low pressure across the Plains. Deeper moisture will begin to return late this weekend and into early next week aided by a 25-30 knot LLJ. Meanwhile, our upper level ridging will begin to breakdown as a upper level low closes off and slowly slides across the Northern Plains. This will allow for an inverted trough/tropical wave to take shape across the Gulf and push to the west. The GFS and CMC are the most aggressive with the feature while the ECMWF (European Centre for Medium-Range Weather Forecasts) shows more of a general weakness aloft. With PWATs (Precipitable Waters) soaring to near 2.5", we can expected an increase in showers and thunderstorms early next week. Locally heavy rainfall appears possible as model soundings show an almost fully saturated profile. Without any significant upper level forcing, most of the activity will be diurnally driven and focused along the sea breeze.

Taking a look at our temperatures, Thursday and Friday look to be our warmest days with highs ranging from 100-104 out west and near 90 along the coast. A Heat Advisory may be needed Thursday as heat indices reach 100-114 degrees across the Brush Country and Northern Coastal Plains. Increasing cloud cover and rain chances will keep temperatures at bay with highs only in the upper 90s across the Brush Country.

Marine
Winds will be variable along the coast this evening due to outflow from showers and thunderstorms. Outflow boundary over the Gulf waters will move back toward the coast overnight as southeast winds develop. Scattered thunderstorms will be possible over the coastal waters through the night into Wednesday morning with activity diminishing in the afternoon. A weak onshore flow Wednesday morning will become weak to moderate in the afternoon and moderate Wednesday night.

Onshore flow will strengthen as we close out the work week as low pressure deepens across the Plains. Onshore flow will weaken as we go through the weekend with weak to moderate levels expected. Chances for showers and thunderstorms will begin to increase late this weekend and into early next week as an inverted trough begins to take shape across the Gulf.

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