Bora!

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After a relatively mild Friday here along the Colorado Front Range Foothills much colder weather is on its way for the rest of the weekend. An area of low pressure currently forming over the Eastern Plains of Colorado will track northeastward to South Dakota by Saturday morning. Strong northwesterly winds behind this departing storm system will usher in much colder air Saturday morning. Winds will be strong and gusty, particularly along the Continental Divide above 10000 feet. If you are visiting Brainard Lake Saturday morning, be prepared for winds in excess of 40 mph with gusts over 50 mph. This combined with temperatures only in the 30s F will make it feel much, much colder.

Along the Colorado Front Range, you will hear of two different types of barrier (or Foehn) winds: chinooks and boras. Simply stated, chinooks are warm and dry winds while boras are much colder. These types of wind often develop when there is low pressure on the east side of the Continental Divide and high pressure on the west side, and they can be enhanced by other factors. For example, deep lows in the mid levels of the atmosphere tracking across Wyoming often result in damaging chinook and bora winds in the Front Range Foothills, particularly in the cold season. The winds we experience on Saturday will be chilly boras.  They should be short lived – as the storm system pulls away from Colorado, the winds should quickly diminish during the afternoon. After morning lows around 32 F, highs will only reach into the upper 40s F during the day here in Nederland – nearly 20 degrees colder than Friday’s high temperatures.

A reinforcing shot of cold air will sweep across the Central Rockies Saturday night, and high temperatures on Sunday will only be in the low 40s F (yep, it will be a cool day in the Rockies). Normally for this time of year we see highs in the low 50s F with lows in the mid 30s F. The good news is that it looks to be dry.

It could get very cold around here on Wednesday and Thursday, and some snow is even possible. More on this system later.

Enjoy the weekend!

 

 

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