


Hydrometeorological Discussion
Issued by NWS Tuscaloosa, AL
Issued by NWS Tuscaloosa, AL
942 AGUS74 KWCO 131524 HMDNWC National Hydrologic Discussion - EXPERIMENTAL NWS National Water Center - Tuscaloosa AL 1015 AM CDT SUN JUL 13 2025 .Synopsis... Considerable flooding is ongoing in portions of central TX, and isolated flash and urban flooding possible elsewhere in New Mexico and the Southern Plains...Flash and areal flooding possible in Florida...Isolated flooding potential in the Middle Mississippi Valley into the Ohio Valley, Northern Plains into the Upper Midwest, and Mid-Atlantic into the Northeast... .New Mexico and the Southern Plains... Locally heavy rainfall continues this morning in central TX where considerable flooding is expected to continue through this afternoon. Widespread 3 - 5", isolated 9" (MRMS) has fallen over the past 12hrs with an additional 2 - 4" (HRRR) possible this afternoon. Additionally, model guidance is suggesting a resurgence of heavy rainfall late this evening into tonight which will keep the threat of at least locally considerable impacts elevated. Streams have yet to recover from the historic rainfall experienced earlier this week and soils remain primed for enhanced runoff. The National Water Model (NWM) Short Range Forecast continues to suggest that rivers and streams in the Texas Hill Country are susceptible to rapid onset flooding with probabilities generally near 26 - 50%. High Flow Magnitude Forecast is signaling many of the streams and creeks are running high with annual exceedance probabilities roughly 20 - 4% with some tributaries at 2%. Many of these reaches are forecast to peak over the next 8 hours with some of the larger mainstems remaining peaking late this evening. Furthermore, minor to isolated moderate river flooding is ongoing or forecast to begin shortly and continue through the week. Dry conditions begin to prevail by day 3 (Tue) which will allow streams to recede unimpeded. Elsewhere across the Southern Plains, scattered showers and thunderstorms persist through day 3 (Tue), particularly in portions of the OK Ozarks. Ongoing training rainfall has kept this area at risk for isolated flash flooding impacts. Due to the very active summer season, soils in this area remain wet with streams running above normal. Fortunately, dry conditions are forecast which will bring a much needed reprieve from the heavy rainfall and flooding threat. In New Mexico, locally heavy rainfall rates of 2 - 3" are possible this afternoon through this evening which may elicit some flooding impacts on small streams, arroyos,and low water crossings. This area remains sensitive as numerous rounds of monsoonal rainfall have fallen over the past several days. Recently burned areas will also remain susceptible to flash flooding and debris flows. .Florida... Multiple rounds of moderate to heavy rainfall are forecast over the next week (7-day totals of 3 - 5", locally higher) across much of FL with the heaviest rainfall concentrated over the Florida Peninsula through day 4 (Wed). The antecedent soil conditions and streamflows are variable across many of the basins in the state. The southern Peninsula in particular is currently experiencing D1 - D3 drought conditions (NIDIS) so initially some of this rainfall may serve to be beneficial. However, as the ground conditions begin to saturate, and canals and creeks begin to run high, the threat for isolated urban and areal flooding increases. While confidence in the exact placement and magnitude of any such responses are low due to the timing, this area will still need to be monitored through the next week for any changes to the forecast. .Mid-Atlantic into the Northeast... Summer showers and thunderstorms continue (1 - 3", 48hr QPF) across the region which could elicit some isolated instances of flash and urban flooding through day 2 (Mon). Streamflows are above normal to much above normal (USGS) and soils remain variable across the area which would suggest that while widespread flooding impacts are not anticipated, though the possibility of impacts in the flashier basins should not be underestimated, particularly in the basins with steep or complex terrain. While the highest chances for impacts are over the next 48hrs, rainfall is forecast to continue through the week which will keep conditions primed for potential flooding. As the extended range draws closer this area may need to be reevaluated in the coming days. .Northern Plains into the Upper Midwest... Locally heavy rainfall (1 - 2", locally 5") is possible on day 3 (Tue) which may cause isolated flash, urban, and small stream flooding. The primary threat for this system will be the flash flooding from training rainfall or in areas with high rainfall rates. The NWM Medium Range Forecast is signaling some reaches with AEPs of 50 - 20% which may add some confidence to a lack of widespread flooding responses. Furthermore, peak flows are generally over the next 3 - 5 days with mostly clear conditions allowing for recessions to begin on these streams and creeks. .Middle Mississippi Valley into the Ohio Valley... Scattered showers and thunderstorms are forecast over the next 7 days (1 - 2", locally higher possible) which may cause some isolated flooding impacts. Due to the highly uncertain nature of convection it will be difficult to nail down exactly where impacts may materialize. The primary concern in this region is basins that experience high rainfall rates or training rainfall that can quickly overcome these ground conditions to enhance flows. //Capp $$