SPM 08-07-2018: Large Hail Causes Devastating Damage

Issue Date: Tuesday, August 7th, 2018
Issue Time: 10:00 AM MDT

Summary:

Yesterday was quite an active day with severe thunderstorm activity over eastern Colorado. By early afternoon, storms began to fire over the high terrains. High low-level moisture helped create very efficient rain totals despite fast storm motion. Outflow boundaries from the storms also helped spark multiple rounds of showers and thunderstorms over one area. Widespread flooding was avoided, but the thunderstorms still produced a lot of damage. High instability, favorable shear parameters and extra lift from a passing shortwave helped produce some very severe thunderstorms over Colorado Springs. Hail up to 3 inches in diameter was reported (baseball), which caused devastating damage and sent several people to the hospital. Reports of car and home windows being blown out were commonplace during the evening. Fountain Creek, known for flash flooding, rose over 4 feet, but thankfully, not out of its banks. It should be able to recover before the next round of thunderstorms this afternoon.

There were several flood warnings and advisories yesterday accompanying the severe thunderstorms. Max 1-hour rain rates were estimated up to 1.5 inches with storm totals over 3 inches due to multiple rounds of rainfall. CoCoRaHS and USGS precipitation gages in Colorado Springs reported storm totals just over 1.5 inches with the highest report being 1.94 inches. At Beulah Valley (Junkins burn scar area), a CoCoRaHS recorded 0.84 inches. Over Las Animas County (Delhi area), a 24-hour, heavy rainfall report of 3.63 inches came in this morning. Severe thunderstorms also moved into Weld and Morgan County that formed over the Cheyenne Ridge. Max 1-hour rain rates were estimated just over 1.5 inches. Despite the heavy rainfall totals recorded yesterday with the fast moving storms, no flooding was not reported as of 10AM on Tuesday morning.

To see how much precipitation in your area, scroll down to the State Precipitation Map below.

Click Here For Map Overview

The map below shows radar-estimated, rainfall gage-adjusted Quantitative Precipitation Estimates (QPE) across Colorado. The map is updated daily during the operational season (May 1 – Sep 30) by 11AM. The following six layers are currently available: 24-hour, 48-hour and 72-hour total precipitation, as well as maximum 1-hour, 2-hour and 6-hour precipitation over the past 24 hour period (to estimate where flash flooding may have occurred). The 24-hour, 48-hour and 72-hour total precipitation contain bias corrections that are not disaggregated into the hourly estimates, so there will likely be some differences. The accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are fire burn areas (post 2012), which are updated throughout the season to include new burn areas. The home button in the top left corner resets the map to the original zoom.

SPM 08-06-2018: Garden Variety Showers and Thunderstorms

Issue Date: Monday, August 6th, 2018
Issue Time: 09:50 AM MDT

Summary:

A couple rounds of garden variety of storms moved through the state on Sunday. The day began with some light and moderate showers over the eastern plains. These storms moved eastward and exited the state by early afternoon. At this time, storms begin to fire under the upslope flow regime over the high terrains with the main activity occurring over the Southeast Mountains/Raton Ridge and Palmer Ridge. To the west over Custer County in the Southeast Mountains, there was a storm report for 0.75 inch hail with rainfall rates estimated just over 0.25/hour. Over the adjacent plains, 24-hour totals were just over 0.5 inches.

The more severe storms formed north of Colorado over the Cheyenne Ridge. As they moved east, the dipped a bit south over the far northeast corner of the state. Daytime clearing allowed the atmosphere to recover from the showers earlier in the morning. Logan County had a severe thunderstorm that produced large hail (2.75 inches) and strong winds (70 mph). Rainfall totals were estimated from radar around 0.75 inches. Further south over Cheyenne County, an evening thunderstorm produced 1.5 inches/hour with a CoCoRaHS in the area reporting 0.9 inches. No flooding was reported on Sunday.

To see how much precipitation over your neighborhood, scroll down to the State Precipitation Map below.

Click Here For Map Overview

The map below shows radar-estimated, rainfall gage-adjusted Quantitative Precipitation Estimates (QPE) across Colorado. The map is updated daily during the operational season (May 1 – Sep 30) by 11AM. The following six layers are currently available: 24-hour, 48-hour and 72-hour total precipitation, as well as maximum 1-hour, 2-hour and 6-hour precipitation over the past 24 hour period (to estimate where flash flooding may have occurred). The 24-hour, 48-hour and 72-hour total precipitation contain bias corrections that are not disaggregated into the hourly estimates, so there will likely be some differences. The accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are fire burn areas (post 2012), which are updated throughout the season to include new burn areas. The home button in the top left corner resets the map to the original zoom.

SPM 08-05-2018: Mid-Level Moisture Fueled Scattered Showers/Storms

Issue Date: Sunday, August 5th, 2018
Issue Time: 9:30 AM MDT

Summary:

A plume of moisture transported by the building upper-level ridge fueled scattered showers/thunderstorms across Colorado yesterday, mainly during the afternoon and evening hours. Most of the activity was garden variety, producing light rainfall and gusty winds, while a couple of stronger storms produced periods of moderate rainfall and strong winds. Due to the decent wind speeds aloft, showers/storms moved at a good clip towards the east, and it was a good day of wetting rains with no flash flooding concerns. Overnight, a secondary disturbance aloft moved across the region, kicking off another round of scattered showers/weak thunderstorms, mainly along and north of I-70. As far as storm reports are concerned, the following are the thunderstorm observations of note submitted to the National Weather Service:

60 mph (estimated) thunderstorm wind gust: 1 mile W of Firestone (Weld County)
59 mph thunderstorm wind gust: 1 mile N of Buckley AFB (Arapahoe County)
58 mph thunderstorm wind gust: 2 miles E of Loveland (Larimer County)
54 mph thunderstorm wind gust: 5 miles NW of Mack (Mesa County)
0.7 inches of heavy rainfall: 6 miles ESE of Oak Creek (Routt County)
For a look at precipitation estimates in your area, please see our State Precipitation Map below.

Click Here For Map Overview

The map below shows radar-estimated, rainfall gage-adjusted Quantitative Precipitation Estimates (QPE) across Colorado. The map is updated daily during the operational season (May 1 – Sep 30) by 11AM. The following six layers are currently available: 24-hour, 48-hour and 72-hour total precipitation, as well as maximum 1-hour, 2-hour and 6-hour precipitation over the past 24 hour period (to estimate where flash flooding may have occurred). The 24-hour, 48-hour and 72-hour total precipitation contain bias corrections that are not disaggregated into the hourly estimates, so there will likely be some differences. The accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are fire burn areas (post 2012), which are updated throughout the season to include new burn areas. The home button in the top left corner resets the map to the original zoom.

SPM 08-04-2018: Passage of Upper-Level Trough Led to Wetting Rainfall

Issue Date: Saturday, August 4th, 2018
Issue Time: 9:30 AM MDT

Summary:

An upper-level trough shifted through the region yesterday, pulling in monsoonal moisture from the southwest across Colorado. The plume of moisture provided the fuel for plenty of showers/thunderstorms yesterday; scattered for areas west of the Continental Divide, more widespread for areas east of the Divide. Activity was generally of the garden-variety, producing gusty winds and light-to-moderate rainfall. A couple of thunderstorms were stronger than the rest, resulting in the following storm reports to the National Weather Service:

1.50 inch hail: 2 miles NNE of Idalia (Yuma County)
0.75 inch hail: 6 miles NE of Idalia (Yuma County)
0.25 inch hail: Craig (Moffat County)
67 mph thunderstorm wind gust: 4 miles WSW of Lamar (Prowers County), 2 miles SSE of Gold Hill (Boulder County)
64 mph thunderstorm wind gust: 3 miles SSW of Boulder (Boulder County)
62 mph thunderstorm wind gust: 1 mile NW of Rocky Flats (Jefferson County)

Additionally, power outages were reported over portions of Northwest Denver due to thunderstorm wind damage last night. No flash flooding was observed yesterday. For a look at precipitation estimates in your area, please see our State Precipitation Map below.

Click Here For Map Overview

The map below shows radar-estimated, rainfall gage-adjusted Quantitative Precipitation Estimates (QPE) across Colorado. The map is updated daily during the operational season (May 1 – Sep 30) by 11AM. The following six layers are currently available: 24-hour, 48-hour and 72-hour total precipitation, as well as maximum 1-hour, 2-hour and 6-hour precipitation over the past 24 hour period (to estimate where flash flooding may have occurred). The 24-hour, 48-hour and 72-hour total precipitation contain bias corrections that are not disaggregated into the hourly estimates, so there will likely be some differences. The accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are fire burn areas (post 2012), which are updated throughout the season to include new burn areas. The home button in the top left corner resets the map to the original zoom.