Issue Date: Sunday, July 19th, 2020
Issue Time: 10:15AM MDT

Summary:

The plume of moisture that has been responsible for so much rainfall over western Colorado the last few days shifted slightly east. Not surprisingly, this also shifted the axis of heavier rainfall yesterday. The big rainfall story of the day was the interior of the San Luis Valley. CoCoRaHS in Alamosa ranged from 0.18 to 0.40 inches, and Monte Vista had about 0.25 inches reported. Just west of La Garita, a CoCoRaHS station picked up 1.09 inches. The QPE from MetStorm has a hard time with underestimations in that area, so hoping the new radar data will be added soon.

Looking at MRMS QPE, which does better over the area, QPE over Blanca Peak (Sand Dunes) was 2 inches. A nearby 2 inch CoCoRaHS station and 1.20 inch Whiskey Creek SNOTEL observation indicate there was some very heavy rainfall over the Southeast Mountains yesterday. This definitely confirms my suspicions that MetStorm underestimated rainfall totals over the San Juan Mountains for this last 3-day event. Two Flash Flood Warnings were issued for the Spring Creek burn area. The La Veta Mountain NWS gage recorded 0.18 inches and Weather Underground stations in the area recorded up to 0.25 inches. So far so good over this large, problematic burn area, but it really hasn’t seen a large rainfall event yet. Daily totals in Archuleta County were just over 1 inch, so that puts the 48-hour totals somewhere between 1.5 and 2 inches for the area! To put that in context, that’s a little over half of the typical rainfall totals they see during the month of July. Storms over the San Juan Mountains also produced pea sized hail. Further north, 55 mph gusts were recorded in Glenwood Springs and Silt, which makes since with rain totals dropping off to about 0.15 to 0.25 inches. Flooding was not reported on Saturday.

To see precipitation estimates over your area the last 24 to 72-hours, scroll down to the State Precipitation Map below.

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Issue Date: Saturday, July 18th, 2020
Issue Time: 10:45AM MDT

Summary:

It didn’t take long for storms to fire over the San Juan Mountains yesterday. The monsoonal moisture surge continued to hold high moisture over the area, and with a little heating and mid-level energy, storms kicked off just before 11AM. Storms were more pop-like, but persistent rainfall over the area allowed totals up 1 inch to accumulate over the southern San Juan Mountains. A USGS gage near Telluride recorded 0.22 inches, and CoCoRaHS/SNOTEL in the area were about the same. In the early evening, a storm tracked over Mancos and dropped 0.44 inches in about a 40-minute period. Around this time, a Flood Advisory was issued just north of the area with another storm over Dolores County. MRMS estimated just under 0.75 inches. Rainfall rates were low enough that major flooding was avoid, which was especially good for the 416 burn area. While rainfall activity was a little more scattered over the Northern and Central Mountains, some decent convection was able to form along the peaks and higher terrains. Delta and northern Montrose County had some heavy rainfall with totals estimated between 0.50 inches and 1 inch.

As storms moved east, the highest rainfall totals were again along the southern Continental Divide and Wet Mountains. The Copper Mountain ASOS gage recorded 0.26 inches. While the Southeast Mountains stayed mostly dry, there was some decent rainfall over the San Isabel National Forest and Sangre de Cristos. There was a little higher moisture over the Raton Ridge, and a gage outside Walsenburg recorded 0.33 inches. Not quite as much moisture over lower elevations north of the Raton Ridge, so the storms only produced some light outflow winds as they quickly dissipated when the moved off the mountains. Flooding was not reported on Friday.

To see precipitation estimates over your area the last 24 to 72-hours, scroll down to the State Precipitation Map below.

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Issue Date: Friday, July 17th, 2020
Issue Time: 10:40AM MDT

Summary:

Scattered thunderstorms and showers brought beneficial rain to much of southern Colorado, with many areas receiving up to 0.6 inches of rain over the San Juan Mountains, Southeast Mountains, San Luis Valley, and Raton Ridge. Additionally, a couple storms were able to drop just over an inch of rain over the southeast and northeast plains. Several hail reports up to 2 inch diameter were submitted over far northeastern Colorado as a storm was able to tap into increased moisture along the eastern border. The GOES16 visible + infrared “sandwich” image below shows the clouds and storms over Colorado as of 7PM MDT, including some of stronger storms that formed over eastern Colorado. The highest CoCoRaHS 24-hour rain report of 1.15 inches came in from far western Baca County, where an isolated thunderstorm was able to re-develop over the area for close to 2 hours. This area also had another storm roll over around 6PM MDT, which likely boosted the 24-hour rain total over 1 inch. The QPE map shows this bullseye of rain totals up to 1.5 inches associated with these isolated storms in western Baca County. Another bullseye appears in the QPE map over central Kit Carson County with just over 1 inch estimated, which was due to a couple of thunderstorms tracking over the area after 6PM. The closest CoCoRaHS rain report was up to 0.38 inches just north of this area. No flooding was reported with these storms yesterday.

Back over the western high terrain, a heavy rain report of 0.25 inches was sent in from Pagosa Springs. Being that southern Colorado has been experiencing extreme drought, this 0.25 inches was very welcomed. The Moon Pass SNOTEL station in the northeast San Juan Mountains reported 0.80 inches. QPE in the area was likely underestimated a little. There was also a 0.39 inch report from an ASOS near the 416 burn area. CoCoRaHS observations over the San Juan Mountains were in the 0.15 to 0.30 range. The interior San Luis Valley even got a little rainfall with the widespread storm coverage (under 0.10 inches), and the southern portion of the Valley and edges had reports up to 0.50 inches. Over the Central Mountains, the highest observation was 0.15 inches in Carbondale.

To see how close you got to receiving some rain, check out the 24-72 hour rainfall estimates in your area on our State Precipitation Map below.

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Issue Date: Thursday, July 16th, 2020
Issue Time: 11AM

Summary:

Mother Nature must have heard everyone, including us, worrying about drought in southeast Colorado. Enter another day of widespread heavy rainfall across the region. With plenty of moisture around, storms fired early over the higher terrain of the Central Mountains and Palmer Ridge and moved eastward, growing in scale. The highest measured rainfall in the state was likely the USGS Rod and Gun gauge, which measured 2.39 inches of rain in less than 1 hour. Even more impressively, 1.34 inches fell within a period of only 15 minutes, with 1.67 inches falling in a 20 minute span. This is between a 1 in 50 and 100 year event. Not surprisingly, the normally “flashy” Fountain Creek went from 200 cfs to almost 4,000 cfs in the span of a few hours (see below). Some flooding was reported in the area.

In addition to El Paso County, Fremont, Pueblo, Otero and Las Animas counties also received widespread heavy rainfall, leading to a few additional flooding reports. One was west of Pueblo, and another was in La Junta. Fortunately, no major riverine flooding was reported as flows were generally quite low to begin the day.

In addition to the heavy rainfall, there were numerous reports of large hail under the strongest storm cells. A handful of hail reports were received from the Palmer Ridge area, ranging from 1 to 2 inches in diameter.

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

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