by Jessica Moore, guest writer
Colorado weather is well known for its variability, and that standard holds true through the winter season. Colorado winters can be mild and dry, but they can also be frigid and wet, and produce periods of heavy snow, high winds, and even blizzard conditions.
Why all this variability? Much of the unpredictability lies in the strength and position of the jet stream relative to Colorado. When we have a more westerly component to the jet stream – meaning our upper-level atmospheric winds are primarily out of the west, moving east – we’re going to pick up more Pacific Ocean moisture.
This means that two things will happen: the subtropical jet stream will help prevent the polar jet stream from bringing as much frigid, arctic air down into Colorado, leaving us with warmer surface temperatures; it also means that we’ll see more moisture with the storm systems that do move through the region. This is especially the case if we have Gulf Moisture being transported northward into the Eastern Plains of Colorado by proxy of a low-pressure system situated in New Mexico or southwestern Texas.
During winter and early spring in Colorado, it is critical to see moisture (generally in the form of snow, but occasionally rain if the surface temperatures are warm enough) from March through June. A good depth of moisture in the ground and on the surface goes a long way toward staving off the return (or worsening) of drought conditions across the state.
The 2024 winter season has been unique in that Colorado has seen several all-time daily precipitation records met or broken over the last several weeks. For example, the winter storm that moved through Colorado from Friday, February 2nd through Saturday evening, February 3rd brought significant snow for portions of southern and central Colorado. The Denver Metro received more than 2 inches of liquid equivalent (meaning the combined total of rain and melted snow). Boulder received 1.74 inches of precipitation (from the 9.1 inches of snow officially observed), breaking its all-time daily precipitation record for February 3rd. Some portions of the Front Range Mountains’ lower foothills received 15 to 20 inches of snow with that storm.
Below is a display of observed precipitation totals from precipitation gauges near Boulder and surrounding areas where the highest rain and snowfall totals occurred during the February 2nd through the 3rd storm.
Map image provided courtesy of the CoCoRaHS Mapping System.
Further south in Colorado Springs, total snow accumulations ranged from 5 to 9 inches. That accumulation seemed to occur over a relatively short period, thereby catching a lot of people off guard and leading to many stranded vehicles, car accidents, and unexpected delays on the roadways around town. Thankfully, the brunt of the storm hit over the weekend, so the work commute was not affected.
Below is an image of a neighborhood in Cimarron Hills in northeast Colorado Springs during the period of heaviest snowfall on Saturday afternoon, February 3rd. The roadways were quite snow-packed and difficult to navigate by this time.
This week, we’ve seen a return to mild and pleasant temperatures hovering around the low to mid-50s Fahrenheit. A weak system is anticipated to move through the region beginning late afternoon Friday, dropping temperatures into the low 30s. We’ll likely see a dusting to a few inches of snow with this system, but it should be a low-impact storm compared to the storm on February 3rd. The temperatures will begin warming by Sunday and should return to pleasant 50s and low 60s next week.
According to Brian Bledsoe, the Chief Meteorologist of KKTV in Colorado Springs, the city experienced its “wettest year on record” in 2023. This is due, in part, to the strong El Niño pattern that we’re now transitioning out of. He goes on to explain that during an El Niño, Colorado will typically experience “a warmer than average winter”. He continues to explain that this is due to the position of the subtropical jet during an El Niño winter and the way it tends to block the intrusion of colder air from the Arctic. Regarding this current winter, Brian notes that “we are 1 and ½ feet above where we should be in terms of snowfall this season”. That’s a great thing for the moisture we all know Colorado needs.
Below is a graphic display of the Drought Monitor to give an idea of the present drought conditions across the state of Colorado as of February 13th, 2024. Eastern Colorado is completely drought-free, while the Sangre de Cristo, San Juan, and northern Front Range Mountains are experiencing Moderate to Severe Drought, and portions of western Colorado are Abnormally Dry. These conditions may change and perhaps even improve as we expect to continue with an active weather pattern similar to what we’ve seen over the last several weeks or so.
The graph below gives a look at the SWE – or the Snow Water Equivalent – for the state of Colorado through today, represented by the black line trace for 2024. Currently, our SWE for the season is nearing the median percentage for this time of year in Colorado at about 10.6 inches. As you can see, we’ve not yet reached our climatological peak for precipitation for the year, which typically occurs between late April to mid-May, after which point the SWE drops off rapidly with the warming of temperatures and the resulting snowmelt.
With El Niño transitioning into La Niña this spring into summer, it is anticipated that our active weather pattern will continue well into March and, hopefully for our drought conditions, beyond into April, May, and June. The longer we can stave off the drying impacts of an impending La Niña in Colorado, the better for mitigating our drought and resulting fire weather during the summer and early fall months.
