Issue Date: Wednesday, August 10th, 2022
Issue Time: 9:30 AM MDT

Summary:

Yesterday was quite calm across the state. The only rainfall across Colorado was in the south, from the Southeast Mountains over to the western border on the Southwest Slope. Most observations in this region were trace – 0.1”, but some higher totals include 0.28” in Alamosa, 0.14” near Chromo, 0.24” near Mancos, and 0. 42” northwest of Durango. The precipitation was reported as a result of afternoon and evening storms, via CoCoRaHS observations.

No flooding or severe weather was reported yesterday.

If you observe flooding in your area, remember to use the “Report a Flood” page to make any flood reports when you can safely do so. For precipitation estimates in our area, check out the map below.

Click Here For Map Overview

Issue Date: Tuesday, August 9th, 2022
Issue Time: 9:00 AM MDT

Summary:

Monday saw relatively quieter weather compared to Sunday’s widespread heavy rainfall and flooding. Isolated to widely scattered showers and storms developed with daytime heating by mid-afternoon across mainly the southern half of the state, with storms remaining confined to the high terrain.

The heaviest rain was observed across the far southern Front Range, and southwestward and southeastward from there across the southern mountains and foothills. QPE data indicates amounts were generally in the 0.5”-1.5” range, with notable observations of 0.95” west of La Veta and 0.58” north of Pagosa Springs from automated gauges. Several Flash Flood Warnings were issued along the southern I-25 corridor, although no flooding was reported. One of the warnings was for portions of northeast Fremont/southwest Teller Counties west of Colorado Springs, with a CoCoRaHS observer reporting 0.72” of rain and hail up to 0.5” near Cripple Creek. The other two warnings were issued for north central Custer County and for the Spring Creek burn scar.

For the northern half of the state, the only noteworthy precipitation was from isolated cells that tracked into eastern Weld County, prompting a Severe Thunderstorm Warning; no reports of severe weather were received. Rain gauge coverage is sparse, but QPE data suggests a narrow swath of up to 1.5” of rain from eastern Weld into northwestern Morgan Counties.

If you observe flooding in your area, remember to use the “Report a Flood” page to make any flood reports when you can safely do so. For precipitation estimates in our area, check out the map below.

Click Here For Map Overview

Issue Date: Monday, August 8th, 2022
Issue Time: 11:45 AM MDT

Summary:

As anticipated, yesterday was a very active day across Colorado. By late morning scattered showers developed over the Northeast Plains and Palmer Ridge along a weak frontal boundary dipping into the state from the northeast to southwest. In the afternoon, isolated to widely scattered storms began firing up in the high elevations of the Front Range, Central and San Juan Mountains, Raton Ridge, and Southeast Plains; scattered storms also developed in the Southwest Slope. These storms quickly increased in coverage and intensity, spilling onto the Southeast Plains and tapping into moisture funneling in from southwest along the stalled frontal boundary draped across the southeast quadrant of state. In the evening, strong thunderstorms developed along the Front Range, Urban Corridor, Southeast Mountains, Raton Ridge, and Southeast Plains. General drying occurred from north to south as storms began to taper off overnight for the Urban Corridor. Showers and thunderstorms remained overnight for the Palmer Ridge and Southeast Plains. Lingering moisture overnight and this morning resulted in many waking up to dense fog across the Eastern Plains.

A total of 27 flood warnings or advisories were issued across the state yesterday and wide swaths of heavy rain was reported from Fort Collins to Walsenburg and Pueblo to Kit Carson! In addition to the many flood warnings, several severe thunderstorm and tornado warnings were issued for the Eastern Plains. Torrential rainfall also occurred with the severe thunderstorms, making them particularly dangerous with a combination of high winds, large hail, heavy rain, and several reported funnel clouds.

The Cameron Peak and Spring Creek burn scars were the two scars most threatened by heavy rain yesterday and both were issued flash flood warnings for all or portions of each scar. A CoCoRaHS gauge near Livermore in Larimer County reported 1.00 inches of rain yesterday, accompanied by up to 0.75 inch hail. Thankfully no flooding was reported on either of these scars, though there were still plenty of flood reports across Central and Southern Colorado.

In La Plata county, a “mudslide occurred north of the Vallecito Marina and Yacht Club as a result of heavy rain from thunderstorms”. The Vallecito Reservoir and Vallecito Creek MesoWest gauges only reported 0.01 and 0.06 inches of rain, respectively, but CoCoRaHS observers in Bayfield (south of the reservoir) reported between 0.32-0.48 inches of precipitation yesterday, and the Durango area received up to 0.70 inches of rain. A bit further west in Cortez, up to 0.87 inches was reported along with “minor flooding on local fields and ditches”.

In Alamosa, a CoCoRaHS observer reported 0.70 inches of rain from a “heavy thunderstorm” that caused street and parking lots to flood. 

On Poncha Pass in the Central Mountains, a “boulder the size of an engine” was reported to have fallen on Highway 285. Nearby rainfall reports are modest, ranging from only 0.09-0.13 inches. However, 72-hour QPE for this area suggests up to 0.50-1.00 inches of rain have fallen in this area in the last few days.

In Walsenburg, Huerfano County Road 340 was reported flooded by law enforcement. Impressive rainfall totals of 1.75 inches and 2.20 inches were reported in or near Walsenburg and Lathrop State Park.

Multiple flood reports were made across the Denver Metro Area and Urban Corridor last night, including:

• Street flooding at Colfax Ave and Monaco Parkway from hail covering street drainage. There were reports of up to 6 inches of water running across the road and 0.75 inch hail stones
• Multiple roads flooded in City Park area east of Denver
• A newly constructed portion of I-70 was closed between York St. and Brighton Blvd. due to floodwaters, stranding several vehicles and prompting rescue from Denver Fire (tweet below)
• Reports of nuisance flooding and water ponding on roads in Thornton, Westminster, Aurora, and Commerce City

Floodwater blocking I-70 between York and Brighton! Traffic at a complete standstill #Denver #cowx pic.twitter.com/IINXxdn0nb

— Chris Riske (@RiskeChris) August 8, 2022

Most of the Metro Area flooding was a result of very quick, very intense storms over impervious surfaces where most of the rainfall was translated to runoff. A MHFD gauge at Niver Detention Pond in Thornton (below) picked up 2.05 inches yesterday, with over 1.75 of that falling in a single hour. The 25-year, 1-hour ARI precipitation in Thornton is 1.77 inches – so this storm was just below a 25-year ARI. In other words, there was just a 4% chance of a storm of this magnitude occurring in any given year!

Across the Urban Corridor rainfall totals vary wildly, with some locations picking up impressive totals and others completely missed. Some highlights for the Urban Area/Front Range include:

• 1.71 in Berthoud
• 1.71 in Westminster
• 1.63 in Lyons
• 1.60 in Kittredge
• 1.27 in Niwot
• 1.18 in Broomfield
• 1.05 in Conifer
• 1.01 in Hygiene
• 0.95 in Sedalia
• 0.85 in Windsor

West of Colorado Springs, a debris flow was reported in Divide with rocks on Highway 24 between Lower Twin Rocks Road and Jade Road. A CoCoRaHS observer in Divide reported up to 0.71 inches of rain, but a nearby observer in Florissant reported 2.29 inches yesterday! In Colorado Springs itself, there were several reports made on social media of water flowing across residential roads, and rocks/mud washed onto Hay Creek Road.

A bit further south in the Florence-Canon City-Penrose area, flooding was reported along Highway 115 near Pathfinder Park, along County Road 13A, and debris flows were reported on Highway 67 north of Highway 50, and on Highway 50 itself around Mile Marker 228 (west of Canon City). A CoCoRaHS observer in Penrose reported 1.95 inches of rain yesterday, and the Freemont County Airport reported 1.42 inches.

Lastly, heavy rain caused multiple flooded roadways across the northern and western portions of Pueblo West, stranding at least one vehicle. There was also a “100-foot wide channel of flowing water through properties – at least several inches deep” reported. Between 1.32-1.82 inches of rain were reported by CoCoRaHS observers in Pueblo West Yesterday.

Other notable totals across Southern Colorado:

• 2.72 in Haswell
• 2.50 in Model
• 2.18 in La Junta
• 2.15 in Karval
• 1.95 in Penrose
• 1.75 in Westcliffe
• 1.74 in Colorado Springs
• 1.50 in McClave
• 0.68 in Chromo
• 0.65 in Pagosa Springs

Remember, if you observe flooding in your area please use the “Report a Flood” page to make any flood reports when you can safely do so. For precipitation estimates in our area, check out the map below.

Click Here For Map Overview

Issue Date: Sunday, August 7th, 2022
Issue Time: 11:50 AM MDT

Summary:

Saturday featured continued showers and storms, although increasingly drier mid-level air limited precipitation coverage to mainly the southeast half of the state. Convection initiated over the Palmer Ridge and foothills of the southern mountains/central Front Range by late afternoon, with storms subsequently tracking northeastward into the Plains.

The heaviest rain was observed over the Palmer Ridge and Southeast Plains; for the Palmer Ridge, QPE indicates amounts of up to 3” across northeast El Paso/southeast Elbert Counties, while for the Southeast Plains, QPE indicates amounts of up to 2” for portions of Crowley, Otero, and Bent Counties. One Flash Flood Warning and three Severe Thunderstorm Warnings were issued south of Limon, with an 80-mph gust and shingles torn off houses reported near Kutch. Notable rainfall totals in this area include 3.14” and 2.50” south of Simla and 1.75” near Ramah. Near La Junta and Las Animas, a Flash Flood Warning and several Severe Thunderstorm Warnings were issued; Highway 50 was reported as flooded between Reynolds Avenue and County Road 24 and at mile marker 394. An underpass was reported flooded in La Junta, with an 87-mph gust measured at an automated station near Cheraw; multiple power poles were also reported down. Near the Kansas border, a Severe Thunderstorm Warning was issued south of Burlington, with a 52-mph gust and nickel-sized hail reported.

Across the central Front Range and Urban Corridor, QPE indicates rainfall amounts of up to 1.75”. Penny-sized hail was reported in Denver, along with 0.95” of rain falling in just 20 minutes, which has an estimated ARI of about 14 years! Other notable rainfall totals include:

• 1.66” and 1.28” near Nederland
• 1.14” in Denver
• 1.14” near Brighton
• 0.84” near Broomfield

Heavy rain was also observed over the southern mountains and foothills, with localized totals of up to 1.50” per QPE data. Rain gauge observations include 1.31” west of Antonito, 1.01” north of Del Norte, and 0.74” in Trinidad.

If you observe flooding in your area, remember to use the “Report a Flood” page to make any flood reports when you can safely do so. For precipitation estimates in our area, check out the map below.

Click Here For Map Overview