Hydrometeorological Discussion
Issued by NWS Tuscaloosa, AL
Issued by NWS Tuscaloosa, AL
691 AGUS74 KWCO 181522 HMDNWC National Hydrologic Discussion - EXPERIMENTAL NWS National Water Center - Tuscaloosa AL 1015 AM CDT WED JUN 18 2025 .Synopsis... Lingering locally considerable flooding possible in Central Plains and Mid-Mississippi Valley... Flash flood potential for the Middle Mississippi Valley into the Great Lakes and New Mexico... Ongoing river flooding in East Texas...Snowmelt runoff concerns across Northern Alaska... .Central Plains and Mid-Mississippi Valley... Widespread rainfall totals of 2 - 5" (locally up to 8") over the last 48 hours has resulted in flash and riverine flooding across southeast KS into far northern OK. Outside of ongoing rainfall in eastern OK, no further significant precipitation is expected, but considerable flooding impacts may linger through this morning as flows route downstream. Minor to moderate river flooding is ongoing or forecast in the Neosho and Middle Arkansas basins, and the Chikaskia River is forecast to reach major flooding flood status by this evening. Rivers are expected to crest before the weekend and should be able to recede relatively unimpeded. The ongoing rainfall in OK has already brought a swath of 1 - 3"+ across the state. The drier soils in the western half of the state likely mitigated flooding impacts, but with the eastern half of the state having a positive departure from normal rainfall of 5 - 8"+ over the last 30 days (NWPS), there is potential for significant flash and small stream flooding. The National Water Model SRF supports this potential, showing widespread exceedance of the 50% annual exceedance probability (AEP) threshold, with pockets of even lower (10 - 2%) AEPs. Signals from the rapid-onset-flooding (ROF) trend service are in the 25 - 50% range and will likely continue to increase as the event progresses. Lower order streams are expected to crest by the afternoon, but in southeast OK where the rainfall is expected to persist the longest, the peaks are not expected until mid-late afternoon. .Middle Mississippi Valley into the Great Lakes... Flash and urban flooding are possible today across parts of MO, IL, northern IN and into MI. Antecedent conditions will likely mitigate any small stream/riverine flooding, with drier topsoils (30 - 50% RSM, 0 - 10 cm, NASA SPoRT) and streamflows generally near mean annual flows. If higher rainfall rates (up to 3"/hr, HRRR) persist over any particular area then some highly localized out-of-bank rises are possible, but the primary threat will be in urban/poorly drained areas. .New Mexico... Isolated flash flooding is possible in and around the Sacramento and southern Sangre De Cristo mountains beginning early next week. .East Texas... Minor and moderate river flooding is ongoing across the area. Recent rainfall has caused renewed rises on some rivers delaying the recession of floodwaters. Most rivers will be in recession by the end of the week. .Northern Alaska... Rapid snowmelt and ice jams have caused flooding in rivers and streams draining the Brooks Range across the North Slope, with conditions expected to continue through at least today. With ice intact on larger rivers, ice jams could result from the snowmelt entering the rivers and lead to sudden rises and flooding. High flows or flooding could lead to bank erosion that could threaten nearby roads and impact access to airstrips and low lying infrastructure. River levels are likely to crest through early to mid week. //Bliss $$