Issue Date: Friday, July 1st, 2022
Issue Time: 11:00 AM MDT

Summary:

Yesterday was the last day of June and it officially feels like North American Monsoon season is here! The morning began with widely scattered storms and showers over the Northwest Slope, Grand Valley, and Northern Mountains associated with a plume of monsoonal moisture. Eastward storm motion moved showers onto the Front Range, Urban Corridor, and Northeast Plains as the morning progressed. By early afternoon, daytime heating combined with that available moisture sparked rounds of storms, which began building in the Grand Valley, Northwest and Southwest Slopes, Central and San Juan Mountains, as well as the lingering storms on the Urban Corridor, Palmer Ridge, and Northeast Plains. As afternoon turned to early evening, there were numerous showers over much of the state of Colorado with the exception of the Southwest Slope.

Rounds of rainfall prompted several flood advisories to be issued for Western Colorado including San Miguel, Eagle, Ouray, Montrose, Rio Blanco, Moffat, Garfield, and Mesa Counties, with the largest threat of arroyo and small stream flooding from excessive rainfall. QPE and gauge observations across the region support widespread 0.25-0.50 inch rainfall with pockets of higher accumulations under localized convection. In addition to the advisories, a flash flood warning was issued for Chaffee County including Cottonwood Pass near Buena Vista. A MesoWest gauge north of Cottonwood Pass picked up 0.73 inches of rain yesterday in about 4 hours between 1:00 and 5:00 pm. Thankfully, no flooding has been reported so far.

This was another day of substantial rainfall on the Grizzly Creek scar in Glenwood Canyon. A USGS gauge on the scar, East Fork of Dead Horse Creek, received over 1.30 inches of rain in 24-hours yesterday as seen in the hyetograph below. Rainfall was spread out over the course of the day into two fairly low-intensity pulses from 6 am until after noon and then again during the overnight hours from 10 pm to before 2 am, which minimized flood and debris flow risk in the canyon. At the same gauge, the 2-day total of 2.43 inches is just below the 25-year ARI value of 2.51 inches – impressive rainfall to not cause any flooding in this particularly sensitive area.

Yesterday’s storms were generally benign for most of the state, with the exception of a severe thunderstorm on the Southeast Plains extending along the US-50 corridor from La Junta to Holly on the Kansas border. The main threat from the severe thunderstorm was high winds, and there were a couple 62-mph thunderstorm wind gusts observed. Rainfall was also impressive with a total of 1.00 inch from a CoCoRaHS observer north of La Junta, who also reported hail. 0.81 inches was reported in Las Animas and 0.54 inches in Lamar, also from CoCoRaHS observers.

Storms across Colorado began drying out and lifting overnight. There was no flooding reported yesterday. For precipitation estimates in our area, check out the map below.

Click Here For Map Overview

Issue Date: Thursday, June 30th, 2022
Issue Time: 10:15 AM MDT

Yesterday was an exciting day all across Northern Colorado. In the early afternoon scattered storms began to fire up in the Northern and Central Mountains before spilling onto the Front Range, Urban Corridor, Palmer Ridge, and Northeast Plains and increasing in coverage and intensity as the day progressed.

Afternoon and evening thunderstorms with heavy rain prompted several flood advisories to be issued yesterday in the Northern Mountains, particularly for the sensitive Mullen, East Troublesome, and Cameron Peak burn areas. The North Inlet of Grand Lake near the East Troublesome burn scar saw 0.71 inches yesterday at a MesoWest Station, and a CoCoRaHS observer near the Cameron Peak scar reported 0.32 inches as well. Despite the rainfall, thankfully no flooding or debris flows were reported on these scars; though Troublesome Creek saw a sharp rise in discharge from near 50 cfs to over 100 cfs from the rain yesterday, as seen in the hydrograph below.

A bit further west, the Grizzly Creek burn scar also saw very heavy rain yesterday. Several USGS gauges east of Glenwood Springs on the scar itself reported near an inch of rain between 6:00 and 10:00 pm, with some rainfall rates as high as 0.10 inches in just 5 minutes. 24-hour totals include:

• 1.24 at East Fork of Dead Horse Creek (hyetograph below)
• 1.19 at No Name
• 0.99 at Cinnamon Creek Complex

A total of 0.57 inches was also reported in Glenwood Springs. However, QPE for this area only shows 0.25-0.50 inches through Glenwood Canyon.  The heavy rainfall here also prompted a flash flood warning issued by GJT at 5:36 pm for Grizzly Creek burn area, which then prompted a closure of I-70.  Again, there were thankfully no reports of flooding or debris flows on this burn scar from heavy rain yesterday either.

The Urban Corridor, Northeast Plains, and Palmer Ridge were also treated to an exciting evening of widespread storms before dissipating during the overnight hours.  These thunderstorms largely produced gusty winds, including a 74-mph gust in Foxfield! Plenty of lightning was also observed with these storms and the #cowx hashtag is full of great shots of storm structure and lightning from yesterday. Rainfall remained modest, largely 0.10-0.20 inches of precipitation has reported by CoCoRaHS observers up and down the Urban Corridor.

While there was precipitation on the Northwest Slope yesterday, there are little observations to confirm the swath of 0.50 inch precipitation across Moffat, Routt, and Jackson counties, seen in the QPE map below. Some observations in the area include:

• 0.52 in Cowdrey
• 0.36 in Clark
• 0.18 in Craig

Most of Southern and Eastern Colorado remained hot and dry yesterday. Daily high temperatures exceeded 100 degrees near the Nebraska and Kansas borders on the Northeast Plains, and upper 90s for the Southeast Plains.  There was no flooding reported yesterday. For precipitation estimates in your area, check out the map below.

Summary:

Note: The Grand Junction radar was down for maintenance until yesterday. This will impact the accuracy of QPE, especially in the southwestern portion of the state.

Click Here For Map Overview

Issue Date: Tuesday, June 28th, 2022
Issue Time: 9:45 AM MDT

Summary:

Building high-pressure to the west of Colorado allowed for mostly clear skies and limited rainfall potential yesterday. Still, some isolated high-based showers and storms were able to develop in the early afternoon in the Southwest Slope, San Juan Mountains, and Central Mountains. As the afternoon progressed, discrete but widely scattered cells extended into the Northern Mountains, Front Range, and Southeast Mountains as well.

In Western Colorado, daily maximum dewpoint temperatures increased the further south in the state. Dewpoints in the 40s were seen in the Grand Valley and Central Mountains, compared to mid-to-upper 50s for the Southwest Slope and San Juan Mountains, which corresponded with the highest precipitation totals in the state yesterday.

One CoCoRaHS observer in Pagosa Springs reported 0.84 inches yesterday, though other observations around town are between 0.04-0.28 inches. A quick storm west of Durango dropped 0.64 after noon, as seen in the hyetograph below from La Plata-Cherry Creek Ditch near Hesperus. The isolated nature of yesterday’s storms is also seen in the QPE below, with pockets of higher accumulations limited to higher elevations of the San Juan, Central, and Southeast Mountains.

The eastern half of the state remained hot and dry, with temperatures across the Urban Corridor, Northeast Plains and Southeast Plains reaching into the 90s. There was no flooding reported yesterday. For precipitation estimates in your area, check out the map below.

Note: The Grand Junction radar is down for maintenance. This will impact the accuracy of QPE, especially in the southwestern portion of the state.

Click Here For Map Overview

Issue Date: Tuesday, June 28th, 2022
Issue Time: 9:45 AM MDT

Summary:

Similar to yesterday, most precipitation was confined to the mountains and southern portion of the state- the Northwest Slope, Northern Mountains, and Grand Valley on the western side of Colorado all saw very little or no rainfall. In the southwest, totals were lower than those from yesterday’s activity- up to almost 1.0” in Pagosa Springs with reports of hail, while high observations from other areas were generally between 0.2”-0.45”. The San Luis Valley and Southern Mountains also received up to 0.45”. A flash flood warning was issued southwest of Colorado Springs in the Sangre de Cristo Mountains, and a severe thunderstorm warning was issued directly southwest of Colorado Springs earlier that afternoon. Despite this, Pueblo and Colorado Springs received little to no rainfall. In the Southern Plains, areas received 0.1″-0.5” from steady rain yesterday morning.

In the Central Mountains, most areas were dry or saw less than 0.1”, but brief storms produced up to 0.62” in some locations. There was a flash flood warning issued east of Glenwood Springs yesterday afternoon over the Grizzly Creek burn scar that caused I-70 to be shut down overnight. However, no flooding was reported and the highway is now back open. There was also a Flood Advisory issued over a western part of the Cameron Peak burn scar, but no flooding was reported there as well.

The Front Range received up to 0.32” of precipitation near Idaho Springs in the mountains, and up to 0.35” of rainfall north of Estes Park. Additionally, north of Fort Collins, there was a short evening storm that created up to 0.28” of rainfall. Reports from the mountains and foothills outside of these higher observations, however, generally reported under 0.1″ of rainfall.

There was no flooding reported yesterday. For precipitation estimates in your area, check out the map below.

Note: The Grand Junction radar is down for maintenance. This will impact the accuracy of QPE, especially in the southwestern portion of the state.

Click Here For Map Overview