Hopefully, you’ve heard of the potentially memorable fire danger day that’s coming Friday. If you haven’t, please assume others haven’t either and spread the word. Fire danger hasn’t been this high since 2011 in and around Denver.
It’s an important enough weather event that the National Weather Service is warning almost everyone from the Foothills to the eastern Plains to prepare an emergency kit should the area you live in have to evacuate due to a wildfire. Over 2 million residents of Colorado are under Red Flag Warnings Friday. Let’s talk about what is making this day so dangerous.
First off, forecasting fire danger involves looking at temperatures, humidity levels, wind speeds and moisture in the ground and vegetation. A nearly perfect storm of weather factors will come into play to create such a dangerous day as is expected.
Drought and lack of moisture
We’ve had very minimal moisture in the last 30 days. Most areas around Denver have only seen a fraction of what typically falls in that time. Denver has been placed back in drought conditions recently after a short stint without them.
The lack of moisture isn’t just affecting soil conditions, vegetation is drying out as well. Vegetation as dry as it is now acts as the fuel for fires. After the wet Spring we had in 2021, grasses grew big and many of those long grasses are still around now. There have been many fires already this year that have used these grasses as fuel.
It has been a very windy month already and although the winds Friday may not be the strongest our area has ever seen, the winds will be the most widespread, especially in recent memory. That means that a lot more people will see just how windy it can get here.
A storm developing and strengthening while moving over Colorado is the culprit for these winds. Sustained winds should reach 25-35 mph while gusts will be commonly blowing up to 55-60 mph. Some areas further to the south and east of Denver could gust to 70 mph.
A difference in Friday’s winds is that they’ll be blowing from the south and southwest. This will allow any fires that start to move north and northeast. It is important to know your directions! This southerly wind will also be bringing in some big-time heat.
Winds will shift Friday evening and the main focus of intense winds will as well. The Foothills should prepare for an extremely windy Friday night with gusts to 70+ mph expected in Boulder, Estes Park, Conifer and the adjacent Plains.
Near Record High Temperatures
Temperatures across Denver are expected to rise into the mid-80s. A good 20-degrees higher than normal for this time of the year. the higher the heat, the happier the fire.
Warmth helps to feed warmth and these near-record temperatures will be plenty high enough to allow vegetation to dry out even further. It will also help to evaporate even more moisture from the ground. Friday should be our hottest day of 2022.
Desert Dry Air
If you’ve been using extra chapstick and lotion lately, you’ll really need it Friday. For a Red Flag Warning to be issued, humidity values have to reach 15% or below.
Friday’s humidity values are expected to dip down to between 5-10%. Although our humidity values have been frequently dipping below 20% lately, values below 10% are not seen very often.
This fire danger event is a once in every 10 or 15-year event. Russ Schumacher, the Colorado State Climatologist, compared Friday’s event to April 17 of 2018. During the event, two 40,000+ acre fires ignited that sparked and spread rapidly under similar conditions.
Thanks to the dry ground, dust and dirt will be easily blown around Friday. Dust storms are expected Friday across all of the eastern Plains. These can greatly and suddenly reduce visibility while driving. Keep this in mind if you have plans to travel east of the mountains or in the San Luis Valley.
Please prepare and plan for an impactful weather event. Again, any fires that spark will move from south to north. Talk to your friends and neighbors about this weather as well.
Winds will shift Friday night after a cold front moves through. This will bring bettering fire conditions Saturday and Sunday but there won’t be enough moisture to extinguish any existing fires but in fact, they could continue to spread through Saturday under continuing windy conditions.
Unfortunately, the cooler and more damp air won’t last long. We will be returning to warmer and more dry conditions by next week. Fire danger could once again rise so we will have to prepare for the possibility of more fire danger and windy conditions.
Stay safe and stay vigilant. Please take extra precautions to mitigate any risks for sparks or flames.