The State of the Atmosphere: Monday, February 28th, 2022
There's a lot to get to in this week's SOTA, from wrapping up an active February, to a warm start to March, and finally a look at, yes, our next chance of snow.
Denver International Airport picked up 15.8" of snow this month, bringing the official season-to-date snowfall for Denver to 34.9" to end February which is 0.9" above the longterm average for this point of the season.
The fact we're now above average for the season is remarkable. This, after Denver saw its latest first snow on record and came into the new year with just 4.8" of snow in the books (average is 20.6" to end December).
At 15.8" of snow this month, this makes February 2022 the 14th snowiest on record for Denver. The snowiest February on record came back in 2015, when the city picked up 22.4" of snow.
The month was also quite cold. Through yesterday the average temperature this month is 28.3°F which is -4.2°F below average. This won't land us in the list of coldest on record (the coldest was 17.7°F, 1889 and 20th coldest is 27.6°F, 1985) but is still quite chilly for a time where below-average months are hard to come by. As you can see in the image below, Northeast Colorado saw some of the greatest cold extremes this month with the cold centered over the central CONUS and warmer along the western and eastern coasts.
The week ahead
The remainder of the workweek will be anything but cold. Ridging has taken over the pattern and will continue to drive temperatures well above average through at least Thursday and likely Friday as well across Northeast Colorado.
Two-meter temperature anomalies show temperatures (map below in degrees C) will be well above average for the next five days across the High Plains, and really most of the United States. For the Front Range this will equate to a couple of days where highs could be more than 20 degrees above average for this time of year!
Highs in Denver will climb into the upper 60s, to perhaps 70°F. In fact, GFS MOS guidance has a high of 73°F in Denver on Thursday! We'll hedge a a couple degrees cooler than this for now, but it's definitely within reach. The record high for March 3rd is 76°F set back in 1921, and doesn't appear to be in jeopardy even as we kick off the month with some very mild air across the region.
The European model shows our warmest day coming Wednesday vs Thursday, but the details here aren't all that important – it'll be feeling quite warm and spring like over the next several days. You'll note in the outlook below, the warmth isn't expected to last into the weekend, so get out and enjoy!
Weekend snow?
The warmth doesn't look to last all that long, even if welcome by many after a cold and snowy February. If we compare the 5-day 500mb mean for the second week of March vs the one for this one above, we see the ridge is replaced by a trough across the intermountain west, with ridging off the east coast.
And... corresponding temperature anomalies showing COLD once again taking over the pattern, with the greatest cold anomalies focused along the northern High Plains, including Northeast Colorado next week:
While models are in good agreement on the pattern turning chilly and unsettled after Friday, there's little agreement on the details. We see troughing move into the Great Basin and eventually impact our weather, but in many respects the energy is disorganized and with that we see a great amount of uncertainty of how cold or how much snow we may see this weekend and to that end into next week.
A look at the latest GFS illustrates this, with ridging in place over the next several days then troughing (blues) working its way in from the west.
At the surface this equates to an increased chance of rain and snow as we head toward Friday and the weekend:
Models differ with one another, and themselves, on how organized this weekends pattern will be. The GFS has been flip-flopping, the Euro a bit more consistent in being a bit more organized with the initial wave that moves through, and therefore shows better snow potential.
This morning's GFS was further north with the initial piece of energy, and thus had more rain, less snow, and overall less precipitation for the Denver area than it's run overnight. Really, the last 4 runs have been all over the place. One showing widespread 6"+ snow across the region, one with near-0" of snow, and the others some combination of them both.
It's a messy, messy pattern, which certainly promotes chilly and wet, but is very low confidence in how chilly and how wet. Another way to illustrate this is looking at the 10 day forecast from the GEFS. Great confidence in warm and dry through Thursday... then good confidence it gets colder and wetter... but hard to decipher any agreement between the various ensemble members in just how wet or cold it may get and when.
For now it's best to focus on the warmth ahead, but know a pattern change is coming. We're kicking off March this week after all, and it's Denver's snowiest month on average. Near record warmth followed by cold and snow is a hallmark of this time of year.
We'll get focused on the details as we head toward the weekend, but an early idea on who see the best odds of accumulating snow this weekend is shown below – good snow headed for the high country, the Front Range foothills and western Palmer Divide should remain focused on the forecast, and greater uncertainty (but potential) for the urban corridor and Northeast Plains.
