SPM 09-26-2021: Getting Warmer Under Building High-Pressure

Issue Date: Sunday, September 26th, 2021
Issue Time: 9:00 AM MDT

Summary:

Saturday saw another day with the weather pattern across Colorado dominated by the building high-pressure ridge in the west. This, combined with very dry air, acted to prevent any rainfall and allowed for temperatures to continue to creep up well above seasonal normal. The map below shows yesterday’s high temperatures from all NWS reporting stations across Colorado. Highs were in the 80s (even reaching 90 degrees in a few spots) along the Western Slopes, Grand Valley, Urban Corridor, Raton Ridge, and Eastern Plains. The high elevations of the Northern, Central, San Juan, and Southeast Mountains were in the 70s, along with portions of the Palmer Ridge. As expected, no flooding was reported on Saturday.

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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 accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are vulnerable fire burn areas (post 2012), which are updated throughout the season to include new, vulnerable burn areas. The home button in the top left corner resets the map to the original zoom.

SPM 09-25-2021: Warm, Dry September Day

Issue Date: Saturday, September 25th, 2021
Issue Time: 9:05 AM MDT

Summary:

Building high pressure over the west has kept air dry and stable, preventing any precipitation across Colorado on Friday. Instead, skies remained mostly clear and temperatures hovered at or above seasonal normals. The Northern, Central, Front Range, and San Juan mountains saw highs in the upper 60s and low 70s, while the Western Slopes, Urban Corridor, Palmer Ridge, and Northeast Plains were in the Upper 70s. Highs were in the 80s for the Grand Valley, Raton Ridge, and Southeast Plains. As expected, no flooding was reported on Friday. For rainfall estimates, check out the State Precipitation Map at the bottom of today’s post.

Air quality across the state has also improved since the summer, when smoke and ozone pollution combined to produce terrible haze over much of the state. Currently, a low-pressure system off the coast of Southern California is helping to keep skies clear of smoke for Colorado – pulling the smoke west and offshore rather than east over the continental US. The Boulder NWS shared the following total smoke forecast, showing the large plume of heavy smoke over California and Nevada.

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 accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are vulnerable fire burn areas (post 2012), which are updated throughout the season to include new, vulnerable burn areas. The home button in the top left corner resets the map to the original zoom.

SPM 09-24-2021: Weak Cold-Frontal Passage Brings Light, High-Elevation Snowfall

Issue Date: Friday, September 24th, 2021
Issue Time: 10:15 AM MDT

Summary:

Thursday started out overall uneventfully, with temperatures creeping back up just above seasonal normal across the state. By afternoon however, a weak but fast-moving cold-frontal passage made its away from north to south across the state. This helped to kick off isolated evening showers, including snow, in the high elevations of the Northern, Central, San Juan, and Front Range Mountains. Several SNOTEL stations scattered across the high elevations picked up 0.1 inches of liquid equivalent precipitation. For the rest of Colorado, dry weather prevailed. As expected, no flooding was reported on Thursday. For rainfall estimates (or lack thereof) in your area, check out the State Precipitation Map at the bottom of today’s post. Note: a small area of precipitation appears to be over the Lincoln-Kit Carson-Cheyenne county area. This is actually a radar artifact from a large wind farm, rather than precipitation.

Every year, SmokyMountains.com produces a fall foliage map highlighting which week peak fall colors will occur across the county. The wet spring and warm summer delayed peak fall foliage a bit across Colorado, but it has arrived for the northwest portion of the state. The slider map found here can help decide when to head out and where for the best leaf peeping!

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 accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are vulnerable fire burn areas (post 2012), which are updated throughout the season to include new, vulnerable burn areas. The home button in the top left corner resets the map to the original zoom.

SPM 09-23-2021: Another Dry Day – Expanding Drought Conditions

Issue Date: Thursday, September 23rd, 2021
Issue Time: 9:50 AM MDT

Summary:

Thanks to the high-pressure ridge dominating the weather across Colorado, no precipitation was reported yesterday. Temperatures also continued to rise to above seasonal normal, with highs in the upper 70s and low 80s for much of the state. As expected, no flooding was reported on Wednesday. For rainfall estimates in your area, including antecedent rainfall, check out the State Precipitation Map at the bottom of today’s post.

Today’s Drought Monitor update for conditions as of Tuesday, September 21 show drought expanding across much of Colorado. Last week, 34.6% of the state was not experiencing any type of drought, compared to only 16.92% as of this week. West of the divide, conditions remained largely the same, though with much of the region experiencing “D1 Moderate” to “D4 Exceptional” drought. The main expansion has been in “D0 Abnormally Dry” conditions across a large swatch of Central and Southern Colorado, covering portions of the San Juan Mountains, San Luis Valley, Front Range Mountains, Urban Corridor, Palmer Ridge, and Southeast Plains. Additionally, in the Southeast Plains areas of “D1 Moderate” drought have expanded from last week and a small area on the Oklahoma border in Baca County has been increased to “D2 Severe” drought. Only small pockets of Eastern Colorado remain with no drought conditions.

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 accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are vulnerable fire burn areas (post 2012), which are updated throughout the season to include new, vulnerable burn areas. The home button in the top left corner resets the map to the original zoom.