The weekly weather forecast for the high country of Rocky Mountain National Park, researched and written by professional meteorologist and mountaineer:  Dan "the weather man" Gottas. 

Warning:  Climbing Life and it's contributors accept no liability for your decisions based on the information contained in this site.  Weather conditions change very quickly and unpredictably, especially in this part of the world, and the actual conditions you find may vary wildly from what we have forecast.   

Issued 10-31-07 10:30am MDT

The Week in Review

Over the last week, the weather in RMNP was characterized by dry, cool, and moderately windy conditions.  Anomalously high pressure in the upper atmosphere over the western US steered most weather disturbances away from the area.  However, a weak cold front was able to move through the region last Friday, bringing clouds and cooler temperatures, particularly to locations below 10 kft and east of the Divide.  As expected, the low-level cloudiness dissipated above 8 kft on Saturday morning, and the northwesterly winds increased above timberline.  Here, sustained winds have been mostly in the 20-30 mph range, with wind gusts as high as 40-50 mph above 12 kft.  Also near 12 kft, temperatures have generally been in the mid 30s during the day and in the upper 20s overnight.  Several daily freeze-thaw cycles have occurred since the frontal passage, which likely bodes well for the alpine ice formations in the Park.

Forecast Discussion

Over the next week, a northwesterly storm track will develop over the northern states of the western US.  This will guide most weather-producing storms onshore through British Columbia and southeastward through the northern high-plane states of the US.  For Colorado, this storm-track configuration allows for low-level cold fronts to move southward along and east of the Divide.  The passage of these fronts is typically accompanied by brief periods of upslope flow east of the Divide, which can vary in depth.  Typically, fronts that extend up to 7-8 kft above sea level (MSL) only produce very light amounts of precipitation east of the Divide, if any.  However, deeper “east-side” fronts (e.g., extending in depth up to 14 kft MSL) are capable of producing light to moderate amounts of precipitation along and east of the Divide.  When the upper-atmospheric storm track is closer in proximity to Colorado, energy associated with the jet stream can phase with these lower-level fronts to produce greater amounts of precipitation for longer periods of time.

At the time of this writing (Oct 31), a weak weather system is affecting the area.  The combination of a weak upper-atmospheric disturbance, moving in from California, and the tail end of an east-side cold front, associated with a disturbance moving through the northern plain states, has produced light precipitation over the region.  Based on observations, RMNP has received about 2-3 inches of snow.  The next system to affect the area will move in on Friday.  No precipitation is expected with this system, as most of its forcing will remain well to the north of RMNP.  However, the northwesterly winds over the highest elevations will increase as the system passes over on Friday night and Saturday morning.  Moderate winds can be expected at higher elevations throughout the weekend.  Another system will move into the area on Monday, bringing cooler temperatures and increasing clouds.  However, each new model run is trending farther north with this system, and it will have only a minor effect on our area, if this trend continues.

Four-Day Mountain Weather Forecast:

Thursday and Friday:  Partly cloudy.

Above 12 kft, highs will be in the 30s F, with lows in the teens.   Winds at 12kft will be west-northwest at 15-20 mph with gusts to 35 mph. 

At 10 kft, expect highs 40 – 45 F and lows in the low 20s.  Winds at 10kft will be from the west at 10-15 mph, gusting to 25 mph. The winds will increase in speed above 10 kft on Saturday morning.

Saturday and Sunday:  Mostly clear sky's. 

Above 12 kft, highs will be in low 40s F, with lows in the upper teens. Winds at 12kft will be northwest at 25-35 mph with gusts to 50 mph. 

At 10 kft, expect highs in the upper 40s F and lows in the low 20s.  Winds at 10kft will be from the northwest at 20-30 mph, gusting to 40 mph.