Quantitative Precipitation Forecast
Issued by NWS
Issued by NWS
947 FOUS30 KWBC 151550 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1150 AM EDT Wed Oct 15 2025 Day 1 Valid 16Z Wed Oct 15 2025 - 12Z Thu Oct 16 2025 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF SOUTHERN COLORADO AND NORTHERN NEW MEXICO... ...16Z Update... No significant changes were needed with this update. Some of the northern valleys in Colorado were excluded from the Marginal, given their positioning on the lee side of the San Juans and Sangre de Cristos. Otherwise, the previous discussion remains valid. Wegman ...Previous Discussion... A large mid/upper wave centered across Nevada at 12Z Wednesday will migrate eastward during the forecast period, spreading height falls across the central and southern Rockies. As this occurs, cooling aloft and surface heating will foster development of a few showers and thunderstorms across southern Colorado and northern New Mexico especially during the afternoon and evening hours. Point forecast soundings across the region depict fast storm motions (30-50 knots) with any developing convection, although steep lapse rates aloft and 0.5-0.75 inch PW both suggest potential for brief heavy rainfall especially where any backbuilding can materialize. Wet antecedent conditions and very high streamflows (per the USGS Water Dashboard) are suggestive of ground conditions that are readily supportive of excessive runoff due to poor drainage. Additionally, a few burn scars across the region could support local excessive runoff at times. Areas of 1-2 inch rainfall totals are possible - especially in upslope and terrain-favored areas. Isolated flash flooding is possible in this regime. Cook Day 2 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... Strengthening mid-latitude cyclone will traverse the Northern High Plains by Thursday afternoon and beyond with a developing closed mid-level vorticity center propagating over eastern MT to the MT/ND border. The subsequent evolution will lead to a period of moderate to heavy rainfall across the above areas with a prominent deformation axis anticipated to setup along the MT/ND border. At this juncture, instability will be lacking from a thermodynamic sense, however the dynamical forcing and prolonged period of enhancement with the axis of deformation will likely spur a widespread area of moderate to heavy rainfall capable of low-end flash flood concerns. These concerns will be suited mainly over those urbanized zones and any low-water crossing. Totals area expected to be a widespread 1-2" of rainfall with some localized totals >2", likely over western and northwestern ND as the heaviest rain will hang on there given the proxy of the surface low progression and positioning of the axis of deformation. A MRGL risk was maintained with a small expansion south to account for the latest QPF trends. Kleebauer Day 3 Valid 12Z Fri Oct 17 2025 - 12Z Sat Oct 18 2025 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Kleebauer 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