Issue Date: Monday, September 21st, 2020
Issue Time: 10AM MDT

Summary:

It was another beautiful September day across the state, minus the haze, with afternoon cloud cover over the mountains. There was a nice cloud deck over the southern Front Range/Urban Corridor in the morning associated with a weak boundary. This kept temperatures a bit cooler than they normally would have been. With the speed max overhead, there were windy conditions over the Front Range and Northern Mountains during the afternoon. Gusts reached between 30 and just under 40 mph, which helped expand the ongoing fires in the area.  As far as rain, scattered light showers developed over the Front Range during the early evening hours and spilled into the adjacent plains. Most storms began to evaporate as they moved into the lower elevations, but some light showers were observed in Weld County on the southern side of the Cheyenne Ridge. Not many observations in the area, and QPE was under 0.25 inches (between 0.10 and just under 0.20 inches). Light showers also formed this morning along a convergence boundary produced by the lee trough. As anticipated, flooding was not forecast.

Large ongoing Colorado wildfires update (as of 9:55AM from InciWeb):
Cameron Peak in the Medicine Bow Mountains: 104,157 acres; 15% contained
Middle Fork Fire in Routt County: 6,187 acres; 0% containment
Williams Fork in the Arapaho National Forest: 12,320 acres; 16% contained

To see precipitation estimates over your area the last 24-hours, scroll down to the State Precipitation Map below. Due to only light rainfall the last couple of days, the map continues to look blank.

Click Here For Map Overview

Issue Date: Sunday, September 20th, 2020
Issue Time: 10:00AM MDT

Summary:

Showers moved through northwestern Colorado yesterday and last night with an advancing trough, but precipitation stayed weak. This morning, rain gauges are reporting up to 0.08 inches of rainfall over the Northwest Slope, Northern Mountains, and Central Mountains regions. We will take what we can get, but this is not much of a beneficial rainfall.

Along with showers, winds gusted up to 56 mph, which did not help the fire situation. Fortunately, the increased humidity kept fire activity low for the current Colorado wildfires (see update below). The Mullen Fire in southern Wyoming was not so lucky as a significant smoke plume could be seen streaming northeast of its location in the Medicine Bow Mountains, indicating rapid fire growth. In fact, fire fighting resources were pulled back due to the strong and erratic winds for the Mullen Fire. Although the advancing trough was able to push the thickest smoke east out of the state, smoke from the Mullen Fire is still impacting air quality for select locations in the northern Urban Corridor (see image below). Air quality monitors in Greeley and Longmont are both showing Unhealthy levels, whereas Boulder air quality is actually in the Good levels. We just can’t seem to escape wildfire smoke this year.

Ongoing Colorado wildfires update (as of 9:55AM from InciWeb):
Middle Fork in the Park Range: 5,837 acres; 0% contained
Cameron Peak in the Medicine Bow Mountains: 102,596 acres; 15% contained
Williams Fork in the Arapaho National Forest: 12,320 acres; 16% contained

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

Click Here For Map Overview

Issue Date: Saturday, September 19th, 2020
Issue Time: 10:15AM MDT

Summary:

Once again no precipitation fell across Colorado yesterday. However, we finally got some upper-level clouds to move in over the northwestern part of the state yesterday afternoon ahead of a strong trough moving into the Pacific Northwest. Although these high clouds did not bring any surface moisture or precipitation, they are a sign of more interesting weather this weekend.

Temperatures were 5-10F above normal yesterday, with highs in the mid 80Fs for Grand Junction and Denver. Some locations in the Southeast Plains even reached the 90F mark, with Lamar recording the highest temperature of 91F. Although this warmth is above normal, it has stayed below record values. However, it is not helping our current drought and fire situation.

Air quality remains to be an issue due to the wildfire smoke over the state. The image below shows the air quality index (AQI) for a permanent monitoring site in Longmont (northern Urban Corridor). You can see that air quality has been in the moderate (yellow) to unhealthy (red) range since Tuesday afternoon (15 September). Much of eastern Colorado is again under an Air Quality Alert today, so you may want to limit your outdoor exercises if you are sensitive to the smoke. Pay attention to your local NWS office for more information. Luckily, the passing trough and southwesterly winds today should start pushing some of this smoke out of the state, but it will likely be some time before we see crystal clear skies.

Ongoing Colorado wildfires update (as of 10:10AM from InciWeb):
Middle Fork in the Park Range: 5,837 acres; 0% contained
Cameron Peak in the Medicine Bow Mountains: 102,596 acres; 15% contained
Williams Fork in the Arapaho National Forest: 12,280 acres; 16% contained

Check out our State Precipitation Map below to see 24, 48, and 72 hour precipitation totals, although you will have trouble finding any accumulations due to the dry conditions.

Click Here For Map Overview

Issue Date: Friday, September 18th, 2020
Issue Time: 9:30AM MDT

Summary:

Groundhog Day, broken record, same old story – pick any of these idioms to describe the last few days of weather. Thursday was another day with above average temperatures, dry weather, and smoky conditions under the ridging pattern. With increasing winds and little to no precipitation anticipated for the event over the weekend, there is a chance that ongoing fires may expand. Even though the statewide open fire ban is coming to an end, doesn’t mean there won’t be fire restrictions. You can follow the latest on fire bans and danger for Colorado here: http://www.coemergency.com/p/fire-bans-danger.html

Large ongoing Colorado wildfires update (as of 9:30AM from InciWeb):
Cameron Peak in the Medicine Bow Mountains: 102,596 acres; 15% contained
Middle Fork Fire in Routt County: 5,445 acres; 0% containment
Williams Fork in the Arapaho National Forest: 12,280 acres; 16% contained

With the continuing 2020 drought (bottom image), I wanted to take a look at precipitation across the state since May (top image). Below is a map that shows the number of days with measurable precipitation for various sites across Colorado since May 1 (source: ACIS). Measurable precipitation is defined as greater than or equal to 0.05 inches, and stations had to have no more than 5 missing days of data to be included in the map. One area that sticks out is the always active Palmer Ridge (Colorado Springs area), which had just over 30 days of measurable precipitation. For reference, on average they have 34 days of measurable rainfall (May to September), so this is not too far off from normal. Another area that sticks out on the map are the low numbers of precipitation days over the Grand Valley. However, this is only about 8 days below normal for the analyzed time frame. After looking through climatology of precipitation days (listed below), there is generally a decrease in the number of precipitation days this year, but they aren’t too far off from normal. The worsening drought indicates that perhaps it is more the amount of rainfall, rather than the rainfall days contributing to the dry conditions.

Station/Days of Precip Climo (May – Sept)

To see precipitation estimates over your area the last 24-hours, scroll down to the State Precipitation Map below. Due to the continued dry conditions, the map looks blank.

Click Here For Map Overview