Wednesday, February 24th, 2010

Rocky Mountain National Park Weather Forecast
 

A change in the storm-track position over the past two weeks allowed winter weather to return the mountains of RMNP

The Week in Review

Through the beginning of February, this winter’s split-flow storm track pattern has left RMNP drier than normal, with most storms either guided south of the region or blocked from the north by a persistent region of high pressure over the northern Rockies.

Over the past two weeks, this El-Nino induced pattern was modified by other faster-acting processes, which led to a westward shift of the high pressure ridge from the northern Rockies to the Pacific Northwest.  This westward shift opened the door for weather disturbances to track across RMNP.

The much needed new snow fell mostly over the last two weekends.  A total of about two feet of new snow was measured at Bear Lake, with an additional 1-3 feet  observed by Eli over the higher surrounding terrain above the lake.

As an added bonus, wind speeds near and below treeline remained low during the snowy periods, which maintained an extended stretch of unconsolidated powder conditions. 

With the return of stable northwesterly flow near mountain top on Wednesday Feb 24, the wind once again accelerated to moderate levels and transported and transformed the new snow into drifts and slabs on lee and cross-loaded aspects near and above treeline.

Last week's weather events in the Pacific Ocean and the resulting moisture in Colorado.

click  on chart above to enlarge

The Upcoming Week

The mean ridge position will once again migrate over the northern Rockies over the next week. However, two more weather systems propagating along the southern storm track will affect RMNP over the next week; one on Thu (2/25) and another on Sun (2/28).

While most of the weather action will remain south of RMNP, there will be enough moisture and forcing to produce a few inches of new snow with each system.

Moderate northwest winds are forecast to accompany the system on Thursday and the formation of new drifts and slab is expected.  These winds are expected to subside on Friday (2/26), as a short wave ridge moves across the region. Winds are currently expected to also be light with any new snow that falls on Sunday.

The next weather system to affect the area will arrive next Thursday, March 4th.

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