A moisture-rich Pacific system is settling into Colorado, and the biggest concern through the next several days is in the San Juan Mountains and the Upper Rio Grande Valley. A Flood Watch is in effect there through Friday afternoon, including areas around Durango, Pagosa Springs, the eastern San Juans, and the upper Rio Grande Valley. Periods of rain will increase this afternoon and continue at times into Friday, with the heaviest and most persistent rain expected in the southwest mountains.This is a warm, moisture-loaded system at first, which means much of the precipitation will fall as rain rather than snow below the highest elevations. Snow levels are generally around 11,000 to 12,000 feet through tonight and Thursday, so snow will be mainly limited to the extreme high country. Areas near Telluride and the highest peaks of the San Juans could see snow, but the more immediate issue is heavy rain and rapid runoff. The concern is especially high in mountain valleys, near creeks and rivers, and in places with saturated ground or steep terrain. Rain can find the path of least resistance quickly, leading to rising water, localized flooding, rock slides, mudslides, and debris flows. That includes the Gold King Mine burn scar area near Ouray, where heavy rain could lead to rapid debris flow concerns. If you live in the southwest mountains, are traveling through the region, or have family there, make sure everyone has a reliable way to receive Flash Flood Warnings overnight. A Flood Watch means conditions are favorable for flooding. A Flash Flood Warning means flooding is imminent or already happening, and it is time to move to higher ground. Overnight showers and thunderstorms can be especially concerning because water can rise quickly while people are asleep. Keep an eye on low-lying areas, drainage channels, creeks, tributaries, and roadways near steep terrain. Never drive through water covering a road.
This afternoon and evening, showers and a few thunderstorms will become more numerous across the San Juans and nearby mountain areas. Heavy rain is possible around Pagosa Springs, with showers spreading toward the San Luis Valley as well. Alamosa could pick up heavier rain during the evening, roughly in the 7 to 9 p.m. window. These are not expected to be widespread severe storms, but a few rumbles of thunder are possible. By late evening and overnight, showers may remain slow-moving or nearly stationary around parts of the San Juans. That slow movement is one reason the flooding setup bears watching. Some showers may also reach farther east late tonight, including portions of the Wet Mountains and areas closer to Walsenburg and Trinidad. Much of the more organized activity should remain west of I-25, but a few locations along and west of the corridor could wake up to wet ground Thursday morning. Colorado Springs and Pueblo stay mostly dry today, with increasing clouds serving as the main sign of the incoming system. Temperatures in Colorado Springs remain in the upper 60s to low 70s through the evening, while Pueblo County holds in the low 70s. The eastern plains stay relatively warm Thursday, with 70s in El Paso County and near 80 degrees farther east where there will be a little more sunshine. Thursday brings another surge of moisture into the San Juans and western slope. Periods of heavier rain are possible again, with brief breaks between rounds. Pagosa Springs and the surrounding mountains remain in the focus area Thursday afternoon and evening. The combination of rich Pacific moisture, steep terrain, and already wet ground can produce a lot of runoff in a short amount of time, so the flooding concern continues through the end of the workweek. Friday is still warm across southern Colorado, with 70s expected for many lower-elevation communities. It will likely be the last warm day before a much cooler weekend arrives. Scattered rain and high-elevation snow continue to be possible in the mountains Friday, while the plains remain warmer overall. A cold front moves through Saturday, bringing a noticeable drop in temperatures and broader shower chances. Colorado Springs, Pueblo, Walsenburg, Trinidad, and the eastern plains all have a chance for rain as the system shifts east. Saturday afternoon looks like the better opportunity for showers around Colorado Springs, with lingering or additional showers possible Sunday. Temperatures may struggle to get out of the 40s and 50s along and east of I-25 this weekend, making for a much chillier feel than Friday.
Woodland Park, Teller County, and areas closer to Park County and Highway 285 near Conifer will need to watch the forecast closely. A rain-snow mix may develop Saturday afternoon, with snow possible Saturday night into Sunday morning. At this point, a light dusting on grassy surfaces is possible in some of those higher-elevation communities. Our Weather. Together. [P2P:PA]
