Quantitative Precipitation Forecast
Issued by NWS
Issued by NWS
890 FOUS30 KWBC 111553 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1153 AM EDT Sat Oct 11 2025 Day 1 Valid 16Z Sat Oct 11 2025 - 12Z Sun Oct 12 2025 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE FOUR CORNERS STATES AS WELL AS FOR PORTIONS OF COASTAL NORTH CAROLINA AND SOUTHEASTERN VIRGINIA... 16Z Excessive Rainfall Discussion... Overall...few changes needed to either outlook area. Some minor adjustments were made in the southwestern portion of the U.S. based on radar and satellite trends this morning but the changes did not reflect a fundamental shift in forecast reasoning. In the southeastern portion of the U.S....a quick look at the latest CAMs showed good correlation with the outlook area in terms of both placement and amounts. Bann 0830Z Excessive Rainfall Discussion... ...Southwest to the Northern Rockies and High Plains... An amplified upper trough will move east from the West Coast to the Rockies. Deep southwesterly flow ahead of the trough will continue to transport tropical moisture and energy north from the Southwest/Four Corners Region early in the period. The GFS is showing PW anomalies of 4-5 std dev above normal from the Southwest into the central Rockies this morning, with anomalies increasing further to the north into the northern Rockies/High Plains as the trough continues to shift east later today. Moisture and energy associated with the remnants of Tropical Cyclone Priscilla will continue to lift north from the Southwest/Four Corners region, but residual moisture left in its wake will maintain significant anomalies from the Southwest up through Four Corners before a front associated with the upper trough brings in drier air through the Four Corners by tonight. However, PW anomalies are expected to remain notably high across southeastern Arizona and southwestern New Mexico, where moisture moving out ahead of Tropical Cyclone Raymond is expected to spread into the region. Overall, not much change to the previous outlook areas, with a Slight Risk extending from the Southwest through the Four Corners into the central Rockies, where moisture and energy associated with Priscilla are expected to support widespread precipitation, producing locally heavy amounts early in the period. Both the HREF and RRFS show high probabilities for accumulations exceeding an inch covering much of the western Colorado ranges, with high neighborhood probabilities for amounts exceeding 2 inches centered over the San Juans. Further to the south, hi-res guidance show showers and storms firing later today, with repeating development across portions of southern Arizona and New Mexico. Both the HREF and RRFS show high probabilities for amounts over 2 inches centered along the Mogollon Rim into southeastern Arizona and portions of southwestern New Mexico. Lastly, across the northern Rockies and High Plains, strong ascent afforded in part by favorable upper jet forcing, interacting with the previously noted anomalous moisture plume spreading north, may be sufficient to produce some locally heavy amounts, with isolated runoff concerns from eastern Idaho and western Wyoming into parts of southwestern and central Montana today. ...Coastal Carolinas and Southeastern Virginia... An area of low pressure now organizing east of Florida will continue to deepen and track north this morning, before slowing as it reaches the Carolina coast later today. Strong easterly winds north of the center will draw deep moisture inland, with heavy rain likely to impact coastal North Carolina this evening into the overnight before reaching into southeastern Virginia during the overnight as well. Models continue to show the potential for several inches along the North Carolina coast, but with a tight gradient further inland. Maintained a Slight Risk across coastal North Carolina into southeastern Virginia, where in addition to heavy rain, coastal flooding generated by the strong onshore winds is likely to compound runoff concerns. Pereira Day 2 Valid 12Z Sun Oct 12 2025 - 12Z Mon Oct 13 2025 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF SOUTHERN ARIZONA AND NEW MEXICO... ...Southern Arizona to West Texas... Anomalous moisture will remain in place, fortified by moisture associated with the remnants of Tropical Cyclone Raymond pooling along the frontal boundary settling into the area. This moisture interacting with increasing ascent afforded by mid level energy and favorable upper jet forcing will support additional showers and storms, with the potential for heavy rain and flash flooding. Maintained a Slight Risk, but reduced its footprint across the region. Overall, the 00Z models have trended lighter across the U.S., with the heaviest amounts focused south of the U.S.-Mex border. There still remains a decent signal for at least locally heavy amounts to develop, so a Slight Risk was maintained across portions of southeastern Arizona into far southwestern New Mexico, with a Marginal Risk extending farther east into West Texas. ...Mid Atlantic Coast to Southern New England... Models continue to differ on the details on how the low pressure along the East Coast will evolve this period. The general consensus of the models shows an area of low pressure lingering and weakening over the Mid Atlantic, as a second low begins to develop along the Northeast Coast as its associated frontal system interacts with a northern stream low becoming cutoff over the Northeast. The models however differ on the amplitude and track of the system, lowering confidence in the precipitation forecast over the Northeast. Regardless of development, easterly winds will spread at least some moderate to locally heavy amounts from the northern Mid Atlantic coast northward into southern New England, with coastal flooding remaining a compounding concern. Given the uncertainty, with several models keeping heavy amounts offshore, opted to remove the Slight Risk for now. However, should the 00Z ECMWF be the start of a trend toward a more amplified/westerly solution, a Slight Risk may be reintroduced. Pereira Day 3 Valid 12Z Mon Oct 13 2025 - 12Z Tue Oct 14 2025 ...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL ACROSS PORTIONS OF SOUTHEASTERN ARIZONA, SOUTHWESTERN NEW MEXICO, AND SOUTHERN COLORADO... ...Southwest to the Central Rockies... Backing flow ahead of a deep low dropping south into northern California will draw lingering anomalous moisture over the Southwest back to the north into the central Rockies. This moisture interacting with favorable mid to upper level forcing will generate additional showers and storms, with guidance indicating an elevated chance for locally heavy amounts and flash flooding concerns over portions of southeastern Arizona, southwestern New Mexico, and the San Juan Mountains. ...Northern and Central California.... Models are in generally good agreement showing an anonymously deep upper developing and dropping south along the West Coast from the Pacific Northwest to Northern California this period. Moisture with the system will be relatively modest initially, but enough to raise moisture anomalies to over a std dev above normal along its axis of strong onshore flow. This along with strong forcing may be sufficient to produce locally heavy amounts, with isolated runoff concerns, especially in the upslope regions of the coastal ranges and the Sierra foothills. ....Northeast... Plenty of questions remain as to how the low developing along the Northeast coast will continue to evolve, but most agree on at least a localized threat for heavy rain centered along the southeastern New England coast continuing into the period. Pereira 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