Quantitative Precipitation Forecast
Issued by NWS
Issued by NWS
406 FOUS30 KWBC 250037 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 737 PM EST Mon Nov 24 2025 Day 1 Valid 01Z Tue Nov 25 2025 - 12Z Tue Nov 25 2025 ...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR PORTIONS OF THE LOWER MISSISSIPPI VALLEY INTO NORTHEAST TEXAS... ...01Z Update... The primary changes to the ERO risk areas this evening were to trim the west and northwestern portions of the risk areas in Texas and Arkansas, as the steadiest, heaviest rains have ended in the trimmed areas. Elsewhere, the ERO remains unchanged. A slow moving front is drawing sufficient Gulf moisture northeastward from eastern Texas into portions of the southern Tennessee Valley. Along this corridor of moisture, prodigious lightning producing storms are also peaking in intensity with rainfall rates topping 2 inches per hour. In the areas where this heavy rain is falling, flash flooding has been occurring. Fortunately storms reaching an intensity capable of this intensity of rainfall have been quite isolated among the larger complex of storms. The Slight Risk area continues to highlight the area where enough rainfall has been falling that should a storm move over those areas with heavier rainfall rates, then resultant flash flooding is likely. Slow moving storms associated with the southern end of the line will likely impact the Houston metro later tonight. Much of the CAMs guidance have suggested that by then the storms will be in a progressive line, limiting the amount of time heavy rain is occurring over the flood-sensitive metro. On the other end of the Slight, storms with embedded moderate to briefly heavy rainfall are also moving into northern Mississippi. Guidance suggests moderate rain will continue over this area for much of the night. This too could result in widely scattered instances of flash flooding. Since by late tonight instability will be waning, most of Mississippi other than the northwestern-most counties remain in a Marginal Risk. Thus, it should be noted that both these areas are in the higher end of the Marginal Risk threat. Wegman ...Previous Discussion... The overall forecast philosophy remains on track for this update. Areas of showers and thunderstorms are expected to redevelop from southwest to northeast within an 850mb low-level jet axis extending from near Austin, TX through the ArkLaTex. Some of the convection will interact with left over low-level boundaries from this morning`s convection, further enhancing rainfall potential and resulting in localized 2-4 inch daily totals. The greatest risk of these enhanced rainfall totals will focus around northeast Texas into northwest Louisiana and vicinity. The overall convective scenario should translate eastward toward the Lower Mississippi Valley through the overnight hours and become increasingly displaced from surface-based buoyancy focused across southeast Texas/southwest Louisiana. Flash flooding should remain possible, but gradually decrease in coverage with eastward extent. Risk areas across Oklahoma, northern/central Arkansas, and parts of west-central Texas were trimmed as ongoing convective trends suggest that any remaining flash flood threat has lessened for the remainder of the forecast period. Cook Day 2 Valid 12Z Tue Nov 25 2025 - 12Z Wed Nov 26 2025 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE SOUTHEAST, TENNESSEE VALLEY, AND SOUTHERN APPALACHIANS... 20Z Update... Overall, no large changes were made to the previous area. Both the HREF and RRFS guidance indicate locally heavy amounts, with an isolated threat for flash flooding, are possible in the region. The 12Z HREFmean continues to highlight the southern Appalachians with higher probabilities for amounts of 2-3 inches, whereas the 06Z RRFSmean suggests a broader threat that is centered farther southwest from northwestern Georgia back through central Alabama. Previous Discussion... The low pressure system will continue advancing through the Gulf states and into the Southeast/Carolinas. The latest guidance continues to depict localized totals as high as 2-3" especially near the higher terrain of the region. Should these occur over a short enough period (or exceed 3"+ in areas farther south) than isolated instances of flash flooding are possible. A Marginal Risk remains in effect from eastern Mississippi to extreme southwest Virginia and western North and South Carolina. Pereira/Campbell Day 3 Valid 12Z Wed Nov 26 2025 - 12Z Thu Nov 27 2025 ...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL FOR WESTERN WASHINGTON AND NORTHWEST OREGON... 20Z Update... Made only minor adjustments to the previous outlook. Previous Discussion... An atmospheric river directed toward the Pacific Northwest will advect copious moisture towards the terrain, with some 2 to 3 inch rainfall totals likely. This will increase the threat for runoff and localized flash flooding therefore a Marginal Risk is in effect. Pereira/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