Thursday, June 24th, 2009

Rocky Mountain National Park Weather Forecast

With the passing of the summer solstice, a more summer-like weather pattern finally arrived in the mountains of RMNP.

The Week in Review

Since June 21^st, atmospheric high pressure built over the region and brought a rising trend in diurnal temperature cycles and minimal winds. 

With rising 2-m temperatures cycles above the freezing mark, early mornings following overnight clear skies became the target for the most favorable snow and ice conditions in the alpine region.

Deep convective activity occasionally occurred during some of the daytime hours, but was the most widespread and strongest over the lower elevations of the eastern slope and eastern plains, where very moist air resided.

During the showers that did occur, snow levels rose above the 12-13 kft level.  The Estes Valley received about 0.15 inches of rainfall during the past week, with locally greater amounts received in surrounding mountainous locations where convective activity was more active.

The Upcoming Week

Weak remnants of a low-pressure circulation off the California coast will eject northeastward on Thursday and Friday.  The large scale flow to the east of this system will transport subtropical moisture northward into Colorado.

With this, widespread cloudiness and periods of precipitation are expected to dramatically increase (read not great for snow conditions).  With the destabilizing effects of daytime heating and the condensation process, thunderstorms activity will be on the increase and will be greatest during the afternoon.

The atmosphere will begin to dry out over the weekend, as the low-pressure wave moves east of the divide on Friday night.  Enough moisture will remain for the formation of afternoon cumulus clouds, with perhaps an isolated afternoon thunderstorm.  However, the skies during the overnight hours should clear, allowing for strong enough radiation cooling to produce firm snow conditions in the early morning.

Continued drying is forecast through Monday, but moisture may increase again on next Tuesday and Wednesday, which would be enough to increase the daytime convective activity.

Happy summer to all!

The NWS numerical forecast for the mountains of RMNP over the upcoming weekend is as follows:

Detailed 7-Day Forecast

NWS Forecast for the 12,000 foot level near Longs Peak 

The link above will take you to the National Weather Service forecast for the 12,000 foot level near Longs Peak.  These forecasts are derived from computer-generated numerical forecasts, and are updated shortly after 3:30 am, 9:30 am, 3:30 pm, and 9:30 pm local time.  In the lower right-hand corner of the page, one can view forecasts for other locations in the Park by clicking on the desired location in the terrain map.

Do-It-Yourself Weather Forecast Links

Weather Observations and Forecasts

The link above provides a list of web links to various sites containing a variety of meteorological data and information.  Collectively, these resources can be used to monitor and study current weather conditions, as well short-term, medium-range, and climate forecasts