Area Forecast Discussion
Issued by NWS Corpus Christi, TX
Issued by NWS Corpus Christi, TX
139 FXUS64 KCRP 281117 AFDCRP Area Forecast Discussion National Weather Service Corpus Christi TX 617 AM CDT Mon Sep 28 2026 ...New AVIATION... .KEY MESSAGES... Issued at 613 AM CDT Mon Sep 28 2026 - Temperatures will remain above normal through the first half of the week. - Heavy rainfall and flash flooding become increasingly possible Wednesday/Thursday. - Minor coastal flooding remains possible this week. && .DISCUSSION... Issued at 1230 AM CDT Mon Sep 28 2026 Hot and mainly dry conditions will continue the first half of the work week as mid-level ridging remains in control. The ridge begins to shift east Tuesday as a western CONUS trough approaches, allowing moisture and rain chances to increase from west to east. Temperatures should consequently begin trending downward by midweek due to increased convection and cloud cover. Attention then turns to an increasing heavy rainfall and flash flooding threat Wednesday and Thursday. Deep Gulf moisture and Pacific moisture from remnants of Polo will surge into South Texas ahead of the approaching upper trough, with PWATs climbing above 2 inches and potentially approaching 2.5 inches Thursday. These values would be more than 2 standard deviations above normal and support efficient rainfall production. Increasing large-scale ascent combined with a developing pre-frontal trough, an embedded shortwave, and potentially a surface low should provide sufficient forcing for numerous showers and thunderstorms. The heavy rainfall threat initially increases across the Rio Grande Plains Wednesday, where WPC has portions of Webb county in a Slight Risk (level 2 of 4) for excessive rainfall. The threat becomes more widespread Thursday as deeper moisture and stronger forcing overlap across the region. WPC has placed all of South Texas in a Slight Risk for excessive rainfall Thursday. Locally heavy rainfall rates and repeated rounds of thunderstorms could result in flash flooding, particularly where storms train or repeatedly move across the same locations. Current QPF for Wednesday through Sunday generally ranges from 2.5 to 5 inches across South Texas. However, these amounts will likely be refined over the coming days as confidence increases in the placement and timing of the heaviest rainfall, especially as higher-resolution guidance becomes available. Uncertainty remains regarding the evolution of the mid-level low and how far south the associated front ultimately progresses. However, a complete frontal passage does not appear necessary for heavy rainfall given the expected pre-frontal forcing and anomalously high moisture. Rain chances remain high Thursday into Friday before gradually decreasing this weekend as the upper system shifts east. Minor coastal flooding also remains possible around times of high tide this week. P-ETSS guidance continues to indicate elevated water levels following an upward trend, although relatively short swell periods and modest onshore flow may limit the overall threat. && .AVIATION... (12Z TAFS) Issued at 613 AM CDT Mon Sep 28 2026 VFR conditions are expected for most of this TAF cycle. Localized fog could still develop at ALI for the next two hours but confidence in that is lowering. Eastern sites will see gusty winds in the afternoon and the western sites during the evening. MVFR ceilings could develop at COT and LRD towards the end of the forecast period. Until we closer to that time period I decided to just go with a SCT cloud group. && .MARINE... Issued at 1230 AM CDT Mon Sep 28 2026 Gentle to moderate (BF 3-4) onshore flow will persist through Tuesday before strengthening to fresh (BF-5) Wednesday and Thursday. Increasing winds and building seas may result in Small Craft Advisory conditions during the middle of the week. Winds will weaken back to gentle to moderate Friday while shifting to the northeast in response to an approaching front. Rain and thunderstorm chances increase to moderate Tuesday and continue to rise through midweek, peaking Thursday as deep moisture and an approaching disturbance support widespread showers and thunderstorms. Rain chances will gradually diminish thereafter, though moderate chances will persist through the weekend. && .FIRE WEATHER... Issued at 1230 AM CDT Mon Sep 28 2026 No significant fire weather concerns are anticipated through the period. Increasing moisture will bring moderate rain chances Tuesday for eastern portions of South Texas, followed by widespread showers and thunderstorms starting around mid-week through the weekend. Heavy rainfall and flash flooding will be possible across all of South Texas, with widespread wetting rainfall expected to limit fire weather concerns through the latter half of the week. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 93 78 92 80 / 10 20 30 10 Victoria 98 73 96 76 / 20 10 40 20 Laredo 101 77 100 79 / 0 0 0 0 Alice 97 75 96 76 / 0 10 20 10 Rockport 92 79 91 80 / 10 30 40 20 Cotulla 99 76 99 77 / 0 0 0 0 Kingsville 95 76 94 78 / 0 10 20 10 Navy Corpus 90 81 89 82 / 10 30 30 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...BF/80 AVIATION...JCP/84