Area Hydrologic Discussion
— Latest
Threat
POTENTIAL IMPACTS: Life-threatening, locally catastrophic flooding WHERE: South-Central Texas WHEN: Through early Wednesday morning
Rainfall & Conditions
QPF: Additional 3 - 6", locally 10" (WPC) Rain Rates: 2 - 4"/hr (WPC) Soil Moisture: Nearing saturation Streamflows: Locally elevated (Observed)
Discussion
The potential for life-threatening and locally catastrophic flash flooding will continue tonight into early Wednesday morning as slow-moving storms develop and expand over this already vulnerable region. Nearly saturated conditions have lowered the threshold for additional flash flooding, with even localized heavy rainfall capable of producing rapid hydrologic responses. Combined with intense rainfall rates, these conditions will support efficient runoff and quick rises on normally dry washes, arroyos, small streams, and low-water crossings. Urban flooding impacts are also expected as intense rainfall rates may quickly overwhelm drainage systems. The overnight timing further increases concerns, as limited visibility may make identifying flooded crossings exceptionally difficult.
The magnitude of hydrologic impacts will depend on where the heaviest rainfall occurs and how much additional runoff is generated across the most sensitive basins. The National Water Model continues to reinforce the significant flash flood threat and has consistently highlighted widespread high magnitude flows on smaller streams and creeks throughout the area of concern. Peak Flow Arrival Time guidance supports continued basin responses, with runoff eventually routing downstream into mainstem channels and producing minor river flooding by Wednesday afternoon.
Addressed To
WFO: MAF, SJT, FWD, EWX, CRP RFC: FWR, WPC
000 AGUS74 KWCO 142157 AHDNWC Area Hydrological Discussion #144 - EXPERIMENTAL NWS National Water Center - Tuscaloosa, AL 453 PM CDT Tue Jul 14 2026 POTENTIAL IMPACTS: Life-threatening, locally catastrophic flooding impacts WHERE: South-Central Texas WHEN: Through early Wednesday morning FORECAST RAINFALL AND ANTECEDENT CONDITIONS... QPF: Additional 3 - 6", locally 10" (WPC) Rain Rates: 2 - 4"/hr (WPC) Soil Moisture: Nearing saturation Streamflows: Locally elevated (Observed) DISCUSSION... The potential for life-threatening and locally catastrophic flash flooding will continue tonight into early Wednesday morning as slow-moving storms develop and expand over this already vulnerable region. Nearly saturated conditions have lowered the threshold for additional flash flooding, with even localized heavy rainfall capable of producing rapid hydrologic responses. Combined with intense rainfall rates, these conditions will support efficient runoff and quick rises on normally dry washes, arroyos, small streams, and low-water crossings. Urban flooding impacts are also expected as intense rainfall rates may quickly overwhelm drainage systems. The overnight timing further increases concerns, as limited visibility may make identifying flooded crossings exceptionally difficult. The magnitude of hydrologic impacts will depend on where the heaviest rainfall occurs and how much additional runoff is generated across the most sensitive basins. The National Water Model continues to reinforce the significant flash flood threat and has consistently highlighted widespread high magnitude flows on smaller streams and creeks throughout the area of concern. Peak Flow Arrival Time guidance supports continued basin responses, with runoff eventually routing downstream into mainstem channels and producing minor river flooding by Wednesday afternoon. GRAPHICAL REPRESENTATION: weather.gov/owp/operations-ahd Additional National Water Center products are available at: weather.gov/owp/operations //Freeman ATTN...WFO...MAF...SJT...FWD...EWX...CRP ATTN...RFC...FWR...WPC