Marine Weather and Tide Forecast for Port Arthur, TX

SHORT TERM
(Today through Thursday night)
Issued at 321 AM CDT Tue May 20 2025

A strong upper-level trough continues to move across the CONUS, a surface low is located in the panhandle of Texas. As this system moves east, it will pull a cold front across the region which is the main focus of the severe weather threat today. Ahead of the front, robust warm air advection will lead to another day of hot and muggy conditions.

CAMs are more aggressive with the convection this afternoon than the global models or the NBM. Conditions will be favorable for severe weather with this line with CAPE values between 2000-3000 J/kg and 0-6 km shear at around 35 knots. The best conditions for strong thunderstorms are in central Louisiana, including Rapides, Avoyelles, and Vernon Parishes. Model soundings indicate that damaging straight-line winds will be the main threat with dCAPE values over 1000 J/kg, but large hail (+1 inch) can't be ruled out either. A lack of 0-1 km shear will limit the tornado threat for our are but we can't rule out the possibility of an isolated tornado. Due to these factors, the SPC has extended the Marginal Risk (level 1 of 5) down to the I-10 corridor to include Beaumont and Lake Charles.

The timing of the line will be in the afternoon with CAMs showing the line reaching our Texas counties around noon with the line reaching Acadiana around 5 pm. This will be a fairly fast moving system, so flooding is not expected to be a concern.

After the passage of the front, convection will quickly end as cooler and drier air follows the front. This will be a weak cold front with not much cold air to temper our temperatures. But we will see dew points fall 10 to 25 degrees, dropping into the 50s and 60s with higher values near the coast.

LONG TERM
(Friday through Tuesday)
Issued at 321 AM CDT Tue May 20 2025

Moisture return will start to pickup during the late in the week as the cold front stall offshore. Humidity levels are going to slowly increase but dew points won't reach the 70s until the weekend. The start of next week will see the stalled front move north, bringing more moisture and an unsettled weather pattern.

AVIATION
(06Z TAFS)
Issued at 1130 PM CDT Mon May 19 2025

No changes in the thinking as far as the aviation forecast goes for the remainder of the night. Low level jet feeding into a surface low over the Plains will keep gusty southerly winds through the night. Low level moisture brought in from the southerly winds under a cap in the atmosphere will help produce broken to overcast low level clouds at MVFR levels. Cloud decks will improve to VFR by 20/18z.

Rua

MARINE
Issued at 321 AM CDT Tue May 20 2025

Winds and wave remain elevated but are expected to slowly decrease after sunrise. Exercise Caution headlines will be in effect through tonight. Overnight a cold front will move across the region bringing isolated showers and a few thunderstorms.

The remainder of the week will bring light onshore flow.

PRELIMINARY POINT TEMPS/POPS
AEX 91 63 90 65 / 20 20 0 0 LCH 88 70 89 72 / 10 10 10 0 LFT 89 72 90 73 / 10 10 30 0 BPT 89 70 90 73 / 10 10 10 0

LCH WATCHES/WARNINGS/ADVISORIES
LA...None.
TX...None.
GM...Small Craft Advisory until 5 AM CDT early this morning for GMZ450-452-455-470-472-475.