Quantitative Precipitation Forecast
Issued by NWS
Issued by NWS
240 FOUS30 KWBC 150055 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 855 PM EDT Tue Oct 14 2025 Day 1 Valid 01Z Wed Oct 15 2025 - 12Z Wed Oct 15 2025 ...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL OVER PORTIONS OF NEW MEXICO... A Marginal risk will continue into the overnight hours across portions of central NM. A general lack of forcing and some low to mid level capping has kept convection fairly isolated to this point across the area. High res guidance suggests we could see an uptick in convective coverage tonight as the nocturnal increase in southeasterly low level flow increases convergence. Still quite a bit of CAPE present over south central NM, generally 1500-2500 j/kg, and so if convection is able to develop heavy rainfall rates are likely. Most cells should be quick enough moving to limit the duration of heavier rain, although localized flash flooding is still possible. Farther northeast where we had a Slight risk the combination of lower instability and quick cell motions should keep the flash flood risk down, although slightly higher convective coverage here still warrants a Marginal risk for possible isolated flash flooding. The risk areas were removed over CA as the heaviest rainfall has ended. Still could see some locally higher rates near the mid level low over central CA, but even these rates are forecast to be on the decline after 03z. Chenard Day 2 Valid 12Z Wed Oct 15 2025 - 12Z Thu Oct 16 2025 ...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL OVER PORTIONS OF THE CENTRAL AND SOUTHERN ROCKIES... ...2030Z Update... No changes were made to the Marginal Risk area which includes portions of southern Colorado and northern New Mexico. The axis of heaviest rainfall associated with the right entrance region of a 120 kt jet and approach of a deep cutoff low remains along the San Juans and Sangre de Cristo mountains. Deep south/southwesterly flow is keeping the expected heaviest precipitation on the south and west facing slopes of those ranges, and has not moved from previous forecasts. Thus, this supports keeping the highlighted area the same with few changes. An expansive precipitation shield will extend from northern Nevada northeast to the northern Plains. Locally heavy rain and snow may impact the higher elevations around Yellowstone/the Tetons, but overall precipitation amounts will be low enough in these areas that a flash flooding risk is not supported. Wegman ...Rockies... The evolution of the longwave pattern across the Western CONUS will lead to the development of a surface low over the Inter-Mountain West with a trailing cold front anticipated to move west to east over the Four Corners into the Continental Divide. The combination of continued ascent within the RER of a vacating jet streak to the north and the frontal approach will lead to one last instance of organized precip within the San Juans down into the Sangre de Cristos. Considering the nature of the pattern bookending quite an active stretch within the aforementioned areas, the threat for flash flooding will lie within the MRGL risk threshold despite the lack of stronger instability that tends to necessitate a greater flash flood potential. Antecedent conditions will trend very wet overall leading to lower FFG`s across the terrain of northern NM into southwestern CO. Totals within guidance are currently running between 0.5-1" with some locally higher amounts based in the individual deterministic. The greatest threat for higher totals lies within the San Juans, an area that has been the benefactor of significant rainfall totals the past 4 days. This will likely be the greatest area of focus for the setup, albeit a threat that will be closer to a 6-8 hr. window as the front approaches. The previous MRGL risk was generally maintained, but trimmed up the southern edge as model trends point to limited potential for heavier rainfall south of the Sangre de Cristos in northern NM. Kleebauer Day 3 Valid 12Z Thu Oct 16 2025 - 12Z Fri Oct 17 2025 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ALONG MUCH OF THE MONTANA/NORTH DAKOTA BORDER... ...2030Z Update... ...Northern Plains... The wraparound/comma-head region of a deepening low that will track north up the Plains will concentrate its longest duration rainfall along the Montana-North Dakota border Thursday through Thursday night. Instability will be minimal, however as with most developing lows, there will still be some on the dry slot-comma-head interface that will locally increase rainfall rates across this otherwise typically dry area. Thus, think there could be some isolated flash flooding impacts, particularly in any poor-drainage areas across portions of eastern Montana and western North Dakota. Nonetheless, expect these instances to be quite isolated, and this a low-end and low-confidence Marginal Risk. Wegman 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