Marine Weather and Tide Forecast for Portland, TX

FXUS64 KCRP 142334 AFDCRP

Area Forecast Discussion National Weather Service Corpus Christi TX 634 PM CDT Sat Jun 14 2025

New AVIATION

DISCUSSION
Issued at 1217 PM CDT Sat Jun 14 2025

Synoptic Overview: South Texas will remain sandwiched between two H5 ridges, one positioned over the Atlantic and the other over the SW US through most of the forecast period. At the surface, warm southeasterly flow will largely prevail through the period along the western periphery of the eastern High, and eastern periphery of the western US thermal low. Overall this period will see reduced mid- latitude (i.e. westerly influences) as we begin to transition to more of a tropical/easterly dominated climatic regime (which will likely largely persist for the next few months).

Details: PWATs generally in the 1.7 to 1.9 inch range, MUCAPEs in the 3500-4000 J/kg (both roughly corresponding to the 75th to 85th climo percentiles) will prevail through the weekend. These thermodynamic parameters combined with weak surface convergence focused along the coast and sea-breezes will support scattered showers and thunderstorms. Given the S-SE component of the low-lvl winds would expect that low-lvl convergence will be maximized over northern portions of the coastal bend so consequently. Light flow aloft and unimpressive shear profiles should preclude the development of organized storms, although wet microbursts always remain a possibility with CAPE values this high. Locally heavy rainfall and flooding is a threat with HRRR LPMM maxima of over 2 inches focused near the Victoria Crossroads Sunday afternoon.
However, the scattered storm coverage and a moderate southerly component of the low-lvl flow should keep any hydro threat localized. Outside of any storms the main concern will be heat, with peak heat indices in the 105-112 range and the only real relief coming in the form of thunderstorm outflows and convective debris cloud cover.

Heading into early next week, slightly drier air (pwats decreasing down to 1.5 to 1.6 inches) will begin to filter in by Tuesday- Wednesday, which should reduce storm coverage into the isolated range, focused largely near the coast and Gulf waters. Seasonably high MaxT and Max ApparentT values can be expected to persist keeping low-end heat concerns going through the period. Forecast uncertainty increases heading into the Thursday-Friday timeframe as deeper tropical moisture, characterized by PWATs near 2 inches, begins to lift northward. There remains uncertainty in both the northward extent of the moisture surge as well as with the northward extent of any forcing associated with an inverted trough/tropical wave feature. However, the signal is strong enough to at least support an increase in PoPs/Sky and a slight decrease in temperatures for Thu/Fri relative to mid-week.
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