Marine Weather Net

Laguna Madre from the Arroyo Colorado to Port Mansfield, TX Marine Forecast


TONIGHT

SE
WINDS
10 - 15
KNOTS

FRIDAY

NE
WINDS
10 - 15
KNOTS

FRIDAY NIGHT

E
WINDS
10 - 15
KNOTS

SATURDAY

SE
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
GMZ132 Forecast Issued: 337 PM CDT Thu Apr 09 2020

Tonight...Southeast Winds 10 To 15 Knots Becoming Northeast 5 To 10 Knots After Midnight. A Moderate Chop On The Bay Subsiding To A Light Chop After Midnight. Chance Of Showers And Thunderstorms.
Friday...Northeast Winds 10 To 15 Knots. A Moderate Chop On The Bay. Slight Chance Of Showers And Thunderstorms.
Friday Night...East Winds 10 To 15 Knots. A Moderate Chop On The Bay. Chance Of Showers And Thunderstorms In The Evening, Then Slight Chance Of Showers And Thunderstorms After Midnight.
Saturday...Southeast Winds 10 To 15 Knots. A Moderate Chop On The Bay. Slight Chance Of Showers And Thunderstorms In The Morning.
Saturday Night...South Winds 10 To 15 Knots. A Moderate Chop On The Bay.
Sunday...Southwest Winds 10 To 15 Knots Shifting Northwest In The Afternoon. A Moderate Chop On The Bay.
Sunday Night...North Winds 5 To 10 Knots Becoming Northeast 10 To 15 Knots After Midnight. A Light Chop On The Bay Building To A Moderate Chop After Midnight.
Monday...Northeast Winds 15 To 20 Knots. Choppy On The Bay.
Monday Night...Northeast Winds 10 To 15 Knots Becoming East 5 To 10 Knots After Midnight. A Moderate Chop On The Bay Subsiding To A Light Chop After Midnight.
Tuesday...Northeast Winds 5 To 10 Knots Increasing To 10 To 15 Knots In The Afternoon. A Light Chop On The Bay Building To A Moderate Chop In The Afternoon.
Tuesday Night...Northeast Winds 10 To 15 Knots. A Moderate Chop On The Bay.
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Synopsis for Baffin Bay to Rio Grande out 60 nm: GMZ100
337 PM CDT Thu Apr 9 2020

The cold front continues to push south into Friday with northerly winds and building seas, especially offshore into Friday night. Thunderstorms are expected through tonight, with frequent lightning and damaging winds possible. The front lifts north as a warm front on Saturday before another weak cold front returns Saturday night into Sunday. Marine conditions, especially offshore may remain adverse through most of the period. Small Craft Caution conditions are likely and Small Craft Advisories may be needed at times.
Area Forecast Discussion
...UPDATED National Weather Service Brownsville TX
623pm CDT Thu April 9 2020

Daytime heating and the orographic impact from the higher terrain in Mexico has fired up some severe conv west of Zapata County. This activity is tracking generally ESE and could move into the Zapata/Starr County areas around 00-02Z time frame. Accordingly, Severe Thunderstorm WW98 is in effect for the western 2/3rds of Deep South TX until 11pm CDT.

.Severe Weather Expected Late This Afternoon through the Overnight... Short Term - Tonight through Friday Night
Busy short term period expected as low pressure develops across northeastern Texas and a cold front approaches Deep South Texas. The 500mb ridge continues to weaken into this evening and a shortwave arrives across the western counties late this afternoon into this evening and dives southeast toward the lower valley into Friday morning. Temperatures have already reached the low 90s across the Rio Grande Valley with dewpoints ranging from 71-73. Model soundings show CAPE values above 3500-4000 j/kg across the western counties and upper RGV, with bulk shear eventually reaching between 40-50 kts. Lapse rates steepen into this evening as well to near or above 7 degrees C/km. This would help support supercell thunderstorms with damaging winds and large hail, potentially above 2 inches.

Overall the most severe convective parameters continue to fall in line with the current Storm Prediction Center enhanced risk, with slight risk edging through most of the mid and lower Rio Grande Valley and marginal risk mainly along the coast. To help with afternoon CAM initialization and get a newer peek at the strength of the coastal cap, an 18Z balloon was released at BRO. Low level shear remains light, but the cap is diminishing. There may be little to stop storms from progressing further southeast across the valley into tonight.

The cold front is expected to gradually head south into Friday before stalling and expected to return north as a warm front into Saturday. The 500mb low across southern California continues to deepen, strengthening the southwesterly flow aloft into Friday night, and sending another shortwave across South Texas. Thunderstorm chances through Friday and into Friday night, with near normal temperatures. The best chance for any severe weather into Friday night remains mainly north of the ranchlands.

Long Term - Saturday through Thursday
A warm front will continue to advance north into central Texas on Saturday. This allows for humid southerly flow and very warm temperatures to return across Deep South Texas. A slight chance for a few lingering showers may commence near the coast and across the northern ranchlands for Saturday morning.

Our attention then turns to a sharp upper level trough moving into Texas Saturday night into Sunday. This helps to propel a pacific cold front across the region from late Saturday night into early Sunday. We will keep an eye on the convective potential in regards to this front. Latest model guidance concentrates the activity to the north of the CWA as model soundings show a fairly strong capping inversion over our region. However, environmental conditions would support possible severe weather, if the capping inversion, were able to erode. The Storm Prediction Center does highlight a slight risk of severe weather just north of the CWA on Day 3. Behind the frontal passage, much drier air advances across the region under moderate northwesterly flow, which could produce potential elevated to critical fire weather concerns Sunday afternoon across portions of the region.

Northern stream shortwave energy phasing with the potent trough in the southern plains will then propel a polar cold front or at least stronger surface high pressure southward across the state and into the region from Sunday night into Monday morning. Much cooler and pleasant temperatures are expected behind this front through early next week. Models indicate little, if any, signal for rainfall with this frontal passage. Models then show a possible reinforcing cold front or another surge of surface high pressure from mid-to-late week. This keeps the cooler temperatures and comfortable conditions in place across the region. A few showers could develop within the cooler airmass towards mid-to-late week.

Marine - Now through Friday night
Favorable marine conditions continue into Friday as a cold front works southward across Deep South Texas. Thunderstorms with frequent lightning and damaging winds are possible by tonight into early Friday. The frontal boundary slows and stalls across the coastal waters, elevating winds and building seas, especially across offshore Gulf of Mexico waters Friday afternoon into Friday night. Small Craft Caution to borderline Small Craft Advisory conditions are possible Friday night.

Saturday through Tuesday night: Southerly winds return Saturday with the warm front advancing northward. A series of cold fronts from early Sunday into next week will lead to moderate to elevated winds and seas throughout the long term period. For much of the period, mariners can expect small craft exercise caution to small craft advisory conditions.

FIRE WEATHER (Sunday)...Elevated to critical erratic fire behavior will be possible on Sunday afternoon following a cold front thanks to a dry northwesterly flow. The relative humidities will fall into the 10 to 20 percent range with 20 foot winds of 15 to 20 knots. A Red flag warning could be warranted given these conditions.

NOAA Brownsville TX Office: Watches - Warnings - Advisories
TX...None. GM...None.