textproduct: Corpus Christi

UPDATE

Issued at 828 PM CDT Tue May 26 2026

A Severe Thunderstorm Watch is now in effect for all of South Texas until 6AM. Threats expected will be damaging winds (60+ mph) and large to very large hail (1 to 2+ inches). A line of storms is currently located around La Salle and Webb counties, and will continue to track east. An isolated tornado or two cannot be ruled out. The area is still in a Marginal to Slight risk for excessive rainfall. Given the anteceding conditions an increased risk for flash flooding will exist as these storms move through. Make sure to have multiple ways to receive warnings and plan accordingly.

KEY MESSAGES

Updated at 828 PM CDT Tue May 26 2026

-Line of thunderstorms likely to impact portions of the area tonight into early Wednesday morning.

-Slight risk of flash flooding tonight through Wednesday morning for the northern 2/3rds of the area. Medium chance of minor to locally moderate river flooding primarily for northern rivers/streams.

-Marginal to slight risk of severe thunderstorms capable of strong winds and large hail tonight into early Wednesday morning.

DISCUSSION

Issued at 122 PM CDT Tue May 26 2026

After a brief respite from widespread convection, our focus once again turns to an MCS which will likely impact portions of South Texas tonight into Wednesday morning. As of noon, this MCS was already in its formative stages over West Texas, being fueled by a potent shortwave ejecting through the base of a negatively-tilted trough over the western US. The general consensus among guidance is that this activity will continue to grow upscale through the afternoon with the southern portion of it likely merging with discrete convection developing this afternoon over the Sierra Madre Oriental. This interaction looks to further reinforce the composite cold pool as it progresses south through the Hill country and eventually towards our area tonight.

As has been typical in this active late spring pattern, there is a lot of "noise" in the CAMs regarding the track/timing of the aforementioned MCS. Focusing on the portion of the 12Z guidance suite which at least initialized the ongoing West Texas convection fairly well, the 03Z to 12Z time frame looks to be the main period of concern for our area. A quicker "melding" of the cold pool with the Mexican convection would favor a faster solution like the HRRR which has convection enter northern portions of the area by 03Z and clear the coast by 09-10Z. A slower interaction (as depicted by the NamNest) would keep storms around through 12-13Z. Given this complex interaction with the Mexican convection, I would take the forecast hourly PoPs tonight with a grain of salt. Although the progged trajectory of the MCS would favor the northern tier of counties for the highest rain chances/amounts, the instability gradient will be oriented towards the SE which may result in storms tracking further south than depicted by CAMs (consequently brought likely PoPs due to the southern border) .

Given the robust cold pool, and adequate nocturnal instability (MLCAPE ~2500 J/kg) strong to damaging wind gusts will be the main convective hazard. Mid-lvl lapse rates are steep enough that wouldn't rule out a hail threat, but this would be dependent upon if more embedded discrete elements could maintain themselves within the larger complex. Hydro remains a prominent concern, as some of the max QPF signals in the 12Z guidance suite are in the 4-6 inch range, while 3 hour FFG is generally only around 3-3.5 inches. Elected not to issue a Flood Watch at this time, due to the expectation that the system will be progressive enough to limit most totals to the 1-3 inch range. That being said, trends will need to be monitored as any hint of slower progression or convective redevelopment along the southern flank of the cold pool may warrant a short-fused watch issuance.

Expect the atmosphere will be sufficiently "worked over" behind the AM MCS, to limit convective potential Wednesday afternoon, although will retain 20-30% PoPs as lingering moisture could support isolated showers and storms along the sea breeze. Mid-lvl ridging will begin to build over the area Thursday/Friday supporting generally warmer and drier conditions for the late week period. The ridge will break down heading into the weekend, opening the door for convectively- enhanced shortwaves and associated storms to progress into the area from the west. Right now there is not a strong enough signal for any particular disturbance to justify PoPs over about 30-40%, but this can be refined in future forecast packages.

AVIATION

(00Z TAFS) Issued at 625 PM CDT Tue May 26 2026

Continued concerns for tonight will be showers and thunderstorms through Wednesday morning. The timing for activity has come more into range this cycle for convective related impacts. LRD and COT will begin to see activity with the next few hours and conditions will spread from west to east through Wednesday morning. Conditions will begin to improve late Wednesday morning. Winds will be erratic and gusty in nature at times in the presence of thunderstorms.

MARINE

Issued at 122 PM CDT Tue May 26 2026

Moderate to fresh E-SE winds will prevail today through Wednesday. Light to gentle SE winds will then prevail Thursday through Saturday. There is a high (60-70%) chance of thunderstorms late tonight into Wednesday morning bringing periods of gusty and erratic winds and locally elevated seas.

PRELIMINARY POINT TEMPS/POPS

Corpus Christi 71 85 75 88 / 60 70 20 10 Victoria 69 83 71 88 / 70 70 30 30 Laredo 70 90 73 92 / 60 20 10 10 Alice 70 86 72 88 / 60 60 20 20 Rockport 73 87 77 89 / 70 70 30 10 Cotulla 69 88 72 90 / 70 40 20 10 Kingsville 71 85 73 88 / 60 60 20 20 Navy Corpus 74 85 78 87 / 60 60 30 10

CRP WATCHES/WARNINGS/ADVISORIES

TX...None. GM...None.