Updated Thu Jun 9, 2022 3:30pm MST | Published Thu Jun 9, 2022
Summary
- Heat wave. Hot into Monday (which will likely be the hottest day), isolated storm chances.
- Disturbance from Tuesday to Wednesday will bring cooler temperatures, but moisture may just miss us to the north.
Forecast Discussion
As ridging builds over the western United States, we’ll see increasing heat into the start of next week.
There’s a chance for record high temperatures to be tied or broken from Saturday to Monday, with highs in the 90s to low 100s on the plains and 60s to 80s in the mountains.
Many areas still holding snow may not see a proper freeze-thaw cycle, which makes wet avalanches a considerable risk this weekend. Even at 14,000ft., it’s unlikely for temperatures to get at or below freezing. That said, clear skies at night may allow for just enough outgoing longwave radiation to keep wet slides at bay in the early hours of the morning. Be very aware of how much liquid water is percolating through the snowpack!
We’ll see at least some subtropical moisture advecting into Colorado through the weekend which will keep isolated thunderstorms in play.
A very weak disturbance on Sunday breaks down the ridge a bit and may cool things off a few degrees. This disturbance could enhance thunderstorm potential over northern Colorado but not by a particularly significant amount.
On Monday, the ridge really starts to break down as a mid-level trough starts to drop into the region. However, this will initially advect hot and dry desert air into Colorado. Combined with downsloping westerly winds, this could be the hottest day so far this year for areas along and east of the Divide.
Right now this trough doesn’t look to drop far enough south to bring decent precipitation chances much south of the Wyoming border, but there’s disagreement in the models about this. The key factor will likely be the tropical storm off the coast of Mexico which you can see at the bottom of the image above. This will influence the southerly track of the aforementioned trough.
At the very least we’ll see a weak cold front knock temperatures down from Tuesday to Wednesday and it’s a safe bet that thunderstorm chances will be substantially higher than on Monday.
After that, ridging returns but it looks to be positioned a little further east over the Great Plains. This would allow for moisture to advect into the desert southwest, which may lead to enhanced precipitation and cooler temperatures in western Colorado.
Thunderstorm Risk Grids
Note, “Lightning Risk” means the chance of a cloud to ground lightning strike occurring in the forecast area between 12pm and 12am.
Snowpack Maps
Seasonal temperatures and isolated storms over the past week have allowed for rapid melting of Colorado’s remaining snowpack. Still, there are many lines that are still in especially in northern Colorado.
Right now SNOTEL charts are showing basically no snow left as almost all of these are at elevations below 11,000-12,000ft. This is a bit of a misnomer as there is still decent coverage in some mountain ranges above treeline.
While northern Colorado’s snowpack remains at about average for early June, southern Colorado saw one of the fastest melt-outs on record.
With such little snow to work with, there are some pretty disparate results across subbasins when looking at just SNOTEL sites:
However, the reality is likely less drastic:
According to the SNODAS model, here’s where you’re likely to find snow in Colorado:
Monsoon / Long Range Discussion
It’s almost time for the North American Monsoon to start influencing our weather. Though the North American Monsoon has the largest impacts in the desert southwest, parts of Colorado (particularly the San Juans and Sangres) are affected as well, with lesser impacts in northern Colorado. This pattern is most prevalent from July to September.
La Niña conditions are currently present, and La Niña summers are typically correlated with average to above average monsoonal moisture, though this isn’t a sure bet. On top of this, there are drier soil moisture anomalies in the southern plains. This makes it more likely that the high pressure associated with the monsoon may shift east out of the desert southwest / Mexican Plateau.
If that ends up happening, then the initial summertime pattern should be favorable for tropical monsoonal moisture to pulse into the desert southwest and into southwestern Colorado.
However, front-loading the precipitation into the start of the monsoon, plus the fact that La Niña is expected to weaken by the end of summer, could make for a drier setup later this summer.
There is some evidence for this in long term modeling: seasonal products from the Euro model show high pressure shifting west back over the desert southwest by August. This would make for drier conditions in New Mexico, though it doesn’t necessarily close the door for southwestern Colorado.