Issue Date: Thursday, August 20th, 2020
Issue Time: 10:50AM MDT

Summary:

Numerous thunderstorms rolled through the plains of eastern Colorado yesterday, bringing beneficial rainfall to many locations. El Paso County picked up between 0.5 and 1.0 inch of rain from a couple rounds of storms according to CoCoRaHS and Weather Underground stations northeast of Colorado Springs. The highest gauge total was 0.96 inches from a Weather Underground station, with the next highest gauges reporting 0.8 and 0.7 inches. No flooding was reported with these storms.

Up to 0.87 inches of rain fell within 30 minutes in Limon according to a CoCoRaHS observer. Radar indicates a single severe thunderstorm moved through this area between 6:30PM and 7:00PM, which also produced strong outflow winds up to 64 mph according to local storm reports. Higher rain totals near or just over 1 inch are indicated on the QPE as this storm tracked southeast through Lincoln County. The closest rain gauge in Hugo reported 0.41 inches (CoCoRaHS), which is on the northern edge of the storm core, suggesting the higher QPE totals are probable. No flooding was reported with this storm either.

Surprisingly high rain totals were reported in Kit Carson County. A CoCoRaHS observer in Stratton reported 0.65 inches of 24-hour rainfall, and another observer northeast of Burlington reported 0.79 inches. The QPE map does not pick up these higher rain totals over Kit Carson County, likely due to the Denver and Goodland radars being down yesterday. No flooding was reported in Kit Carson County as of this morning.

Storms over the mountains were unable to produce significant rainfall, but wind gusts were reported up to 52 mph from these storms. CoCoRaHS reports across the mountainous regions this morning indicate under 0.1 inches of rain fell from storms yesterday. The strong wind reports were from near Rifle and Aspen. Unfortunately these gusty outflow winds allowed the Williams Fork wildfire to grow rapidly yesterday afternoon. See a summary of current wildfire sizes and containment below.

Wildfire Update:
Pine Gulch – north of Grand Junction: 121,781 acres; 14% contained (still 2nd largest CO wildfire)
Grizzly Creek – Glenwood Canyon: 29,732 acres; 4% contained
Cameron Peak – Medicine Bow Mountains: 16,461 acres; 0% contained
Williams Fork – Arapaho National Forest: 9,457 acres; 3% contained (grew 2,731 acres due to strong winds from thunderstorms)

For rainfall estimates in your area over the last 24, 48, and 72 hours, check out our State Precipitation Map below.

Click Here For Map Overview

Issue Date: Wednesday, August 19th, 2020
Issue Time: 10:25AM MDT (Updated 11AM)

Summary:

Little rain fell across Colorado yesterday due to limited surface moisture, but there were plenty of clouds and smoke in the air, as evident in the visible satellite image last evening (see below). A few weak storms were again able to fire over the Southeast and San Juan Mountains, like the one over Alamosa County visible by the deeper clouds in the satellite image below. These weak storms dropped up to 0.19 inches of rain over Crestone according to rain gauges. Some additional light showers moved through the Northeast Plains overnight, but they produced less than 0.10 inches of rain. The real story was the heat under this anomalously strong ridge. Highs reached the century mark over the Urban Corridor, portions of the eastern plains, Grand Valley, Pueblo County, and the Southwest/Northwest Slopes. It’s been awhile since we’ve seen 100Fs widespread like this, but not surprising with the strength of the high. Aspen and Crested Butte both hit 90F, and then Crested Butte dropped to 46F overnight. That’s quite the swing!

Increased moisture over the northwestern part of the state last night combined with the Pine Gulch wildfire to create some increased instability, which caused a pyrocumulous cloud and lightning over the fire. NWS Grand Junction has even reported ash falling from this unique cloud! No rain appears to have fallen with this fire-induced convection, but outflow unfortunately has caused additional fire growth along the western edge of the fire.

Wildfire Update:
Pine Gulch – north of Grand Junction: 125,100 acres; 7% contained (grew 37,000 acres overnight; now 2nd largest CO wildfire)
Grizzly Creek – Glenwood Canyon: 29,000 acres; 4% contained
Cameron Peak – Medicine Bow Mountains: 15,738 acres; 0% contained
Williams Fork – Arapaho National Forest: 6,726 acres; 3% contained

For rainfall estimates in your area over the last 24 to 72-hours, check out our State Precipitation Map below.

Click Here For Map Overview

Issue Date: Tuesday, August 18th, 2020
Issue Time: 10:30AM MDT

Summary:

Some showers from weak storms over the Central, Southeast, and San Juan Mountains produced generally light rain totals for higher elevation locations, but finally the western San Juan Mountains got some rainfall. An isolated area of high rain totals over the last 24 hours were recorded in La Plata County, where 1.12 and 0.76 inches of rain were reported by CoCoRaHS observers in Hermosa and Trimble, respectively. A USGS rain gauge just north near Electra Lake picked up 0.38 inches and another station just southwest of town picked up 0.41 inches. Composite radar images indicate two rounds of storms moved over this area between 2PM and 5PM. Due to the limited low-level radar observations in the area and the small, isolated storm core, today’s MetStorm Live QPE map does not pick up on this rainfall. No flooding reports were submitted from this rainfall as of this morning. The high rain totals were likely possible due to a pocket of increased dew points (low 40Fs) that banked itself against the southern edge of the San Juan Mountains, as visible from MesoWest observations and mesoscale analysis. This extra low-level moisture likely allowed increased instability and heavier rain rates. Farther east in Archuleta County, up to 0.22 inches of rain fell according to CoCoRaHS rain gauges. Lower accumulations were observed elsewhere.

Temperatures topped out at 98F in Denver yesterday, which beat the previous record of 97F from 2013. Grand Junction hit 97F, which was 3F from their daily record. Temperatures are likely a few degrees cooler than they normally would be with the thick smoke in the area. Near-record heat is expected to continue today with the very strong High pressure system.

Wildfire Update:
Pine Gulch – north of Grand Junction: 87,209 acres; 7% contained
Grizzly Creek – Glenwood Canyon: 25,007 acres; 0% contained (no change)
Cameron Peak – Medicine Bow Mountains: 12,323 acres; 0% contained
Williams Fork – Arapaho National Forest: 6,627 acres; 0% contained

For rainfall estimates in your area over the last 24, 48, and 72 hours, check out our State Precipitation Map below.

Click Here For Map Overview

Issue Date: Monday, August 17th, 2020
Issue Time: 10:20AM MDT

Summary:

Much of the plains of eastern Colorado saw another round of thunderstorms yesterday, which brought heavy downpours, hail up to 2 inches in diameter, and some gusty winds up to 50 mph. QPE indicates some of the heaviest rain fell over northwest Las Animas County. A Weather Underground station near the storm core in Lynn, CO picked up 1.05 inches of rain. The bias-corrected MetStorm Live QPE indicates this storm core rain total was just over 1 inch, which agrees with the rain gauge observation. Storms also rolled through Colorado Springs again, where up to 1.3 inches of rain was reported by a CoCoRaHS observer this morning with no large hail reports. These storms also caused heavy rain reports to be submitted in Colorado Springs, with a report of 1 inch in 40 minutes (~1.5 in/hr rain rates) next to a USGS rain gauge reporting 0.94 inches of rain accumulation. No flooding was reported as of this morning from these heavier rain cores. Take a look at today’s QPE map to see the numerous other plains locations that picked up rain yesterday.

An interesting lone nocturnal storm formed over central Weld County between 1AM and 3AM due to a nocturnal low-level jet transporting moisture westward. This storm dropped around 0.5 inches of rain according to this morning’s rain gauge reports. The storm even prompted a couple of small Flood Advisories to be issued. No flooding was reported as of this morning from this storm.

The four large wildfires burning across Colorado continued to transport smoke south/southeast yesterday, which again made for poor air quality for mountain valley locations and along the Urban Corridor overnight. Below is a summary of the four fires still burning in Colorado (from InciWeb).

Pine Gulch – north of Grand Junction: 85,407 acres; 7% contained
Grizzly Creek – Glenwood Canyon: 25,007 acres; 0% contained
Cameron Peak – Medicine Bow Mountains: 13,305 acres; 0% contained
Williams Fork – Arapaho National Forest: 6,345 acres; 0% contained

Rain totals over the last 24, 48, and 72-hours can be visualized on the State Precipitation Map below.

Click Here For Map Overview