Quantitative Precipitation Forecast
Issued by NWS
Issued by NWS
439 FOUS30 KWBC 310056 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 856 PM EDT Sat Aug 30 2025 Day 1 Valid 01Z Sun Aug 31 2025 - 12Z Sun Aug 31 2025 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE CENTRAL PLAINS... ...Plains... 0100 UTC Update -- Thermodynamic trends, particularly with respect to deep-layer instability and thus short-term rainfall rate potential, support more of an isolated/localized excessive rainfall risk across the Southern Plains overnight, especially considering the relatively weak/diffuse deep-layer QG support. The latest HREF QPF exceedance probabilities support this as well, thus have dropped the Slight Risk that was across a good chunk of TX into eastern NM in favor for a Marginal. Hurley Day 2 Valid 12Z Sun Aug 31 2025 - 12Z Mon Sep 01 2025 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM SOUTHERN NEW MEXICO INTO WEST/CENTRAL TEXAS AND FOR EASTERN NEBRASKA... ...1930Z Update... No major changes were needed for the ERO risk areas on Day 2/Sunday. A Slight Risk across eastern Nebraska and Kansas remains largely the same. A slow-moving upper level disturbance will continue to support additional shower and thunderstorm development throughout Sunday and Sunday night. With barely moving forcing and plentiful moisture still moving in from the south, any convection will still have the potential to produce locally heavy rain. With that said, most of the rainfall in the area will be light, but adding constantly to previous days` rainfall, which in many areas will already be fully saturated. Thus, any new rain will mostly convert to runoff right away, enhancing the flooding threat. Further south, the Slight across New Mexico and Texas is largely the same, with a small expansion to include the Houston area and much of the upper Texas Gulf Coast. Easterly flow will allow storms that develop over the Gulf to move into the coast. Meanwhile a stalled out front over the area will provide the forcing into the rest of Texas and New Mexico. For many areas, dry clay soils will allow for most of the rainfall in the typically dry desert areas to convert to runoff quickly. The Marginal Risk between the 2 Slights was added to much of eastern Oklahoma. This area is likely to be in a minimum of rainfall for coverage, but given the soils are sensitive to heavy rainfall from prior days` rains, it seems isolated flash flooding is quite possible. Wegman ...Previous Discussion... Convection over eastern Nebraska and Kansas will likely see enough instability and moisture to support high rain rates. Soils in this region should also be saturated from heavy rain/storms expected on Saturday, resulting in a heightened flash flood risk. The inherited Slight Risk was expanded south and east to cover more of eastern Kansas. The Slight Risk area in Texas was also expanded to include more of eastern Texas and far southeast Arizona. This was to account for an increasing trend in QPF and the potential for repeat thunderstorm activity over areas that will be saturated by storms. The better focus for higher QPF will be for locations near or east of the Hill Country across eastern Texas. The broader Marginal Risk areas for the southern tier and portions of the Central/Northern Plains continue to highlight the level threat for excessive rainfall and flooding potential across the region. Campbell Day 3 Valid 12Z Mon Sep 01 2025 - 12Z Tue Sep 02 2025 ...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL FOR THE SOUTHERN TIER, PLAINS AND TENNESSEE VALLEY... ...1930Z Update... No major changes were made. Heavy rain threats will continue along the Missouri River near Iowa, Nebraska, Kansas, and Missouri from the same nearly stationary upper level disturbance bringing rain to the area the past few days. Elsewhere, the flooding threat will be highly dependent on how well Monday`s rains overlap with the footprint of previous days rains. The front stalled along the Gulf Coast and into Texas will push a bit further south as compared with previous days, which for most areas should mean the offset will limit the flooding potential. Nonetheless, the focus for heavy rain along the I-10 corridor from Houston to San Antonio may still cause impacts, and will continue to be monitored closely. Wegman ...Previous Discussion... A surface front will continue to be draped across the southern tier of the country providing a focus for the monsoonal moisture and Gulf moisture. There will be some upper level support for isolated convection therefore the Marginal Risk was maintained from New Mexico and southeast Arizona across southern/central parts of Texas and the Gulf Coast through the Florida Peninsula. To the north, a frontal system and a shortwave or two aloft will support storms with higher rain rates across the Mid-Mississippi Valley and the Tennessee Valley to Southern Appalachians. Maintained the Marginal Risk areas for the Tennessee Valley and for the Plains. Campbell Day 1 threat area: https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt Day 2 threat area: https://www.wpc.ncep.noaa.gov/qpf/98epoints.txt Day 3 threat area: https://www.wpc.ncep.noaa.gov/qpf/99epoints.txt