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.
Issued Thursday March 27, 2007
The Week in Review
A mix of winter and spring characterized the weather in the mountains of RMNP over the past week. Two weather systems affected the area on both last Thurs. and this Thurs. (today). In terms of new snow, last Thurs. system only produced a couple of inches, whereas today’s system has productively squeezed out upwards of 6 inches in and around the higher terrain of Indian Peaks and likely RMNP. While the sustained winds have been low with today’s new snow (~15 mph near treeline), southwesterly gusts have occurred in the 20–30 mph range, which may be causing some drifting/slab formation in favored locations.
Sandwiched between the two Thurs. storms, the atmosphere warmed considerably, with temperatures reaching the freezing mark near treeline. However, last week’s forecast guidance underestimated the extent of cloudiness and wind during the warm up. As noted in nearby measurements and by Eli’s observations, strong winds occurred, especially on Sun. and Mon. Much of this activity was associated with the formation of a mountain wave. The complex processes that produce these beastly phenomena often pose a serious forecast challenge for the weather models, particularly during the transition seasons. During these times (like the present), daily monitoring of observations and trends in short-term model forecasts (00 – 48 hour forecasts) can still provide more skill in assessing more favorable mountain-weather windows than would a simple roll of the dice.
With the increased cloud coverage (which prevents solar radiation from directly impacting the snow surface) and higher winds (which through the processes of sublimation and turbulent fluxes acts to cool the snow surface), much of the higher elevation snowpack experienced little wet-snow instability during the warm-up that occurred earlier this week.
| Date |
Time
(PST) |
Snow Water
Equivalent
(inches) |
Snow
Depth
(inches) |
Year-to-Date
Precipitation
(inches) |
Current
Temp
(degrees F) |
Previous Day's Temp
(degrees F) |
| Max |
Min |
Avg |
| 03/22/2008 |
0000 |
15.1 |
51.6 |
14.1 |
21.1 |
31.4 |
21.0 |
25.9 |
| 03/23/2008 |
0000 |
15.0 |
51.1 |
14.2 |
10.9 |
30.3 |
6.9 |
20.7 |
| 03/24/2008 |
0000 |
15.0 |
50.4 |
14.2 |
28.0 |
33.0 |
10.3 |
24.8 |
| 03/25/2008 |
0000 |
14.9 |
49.4 |
14.2 |
35.5 |
43.4 |
26.7 |
35.1 |
| 03/26/2008 |
0000 |
14.9 |
48.7 |
14.3 |
34.1 |
41.8 |
32.2 |
37.6 |
| 03/27/2008 |
0000 |
14.9 |
-99.9 |
14.3 |
31.6 |
45.6 |
31.5 |
38.5 |
| 03/28/2008 |
0000 |
15.3 |
54.2 |
14.5 |
20.2 |
32.7 |
19.6 |
27.2 |
The Upcoming Week
More spring-like (unpredictable) weather is on tap for RMNP over the next week. Enough flow and moisture will be present to allow orographic clouds and snow showers to persist on Fri. and Sat. Another weather system is forecast to move in to the area on Sun. With potentially good jet-stream forcing overhead and a thermodynamically unstable atmosphere, another decent shot of precipitation may occur. The potential for 0.5 – 0.75 inches of snow-water equivalence is currently forecast to fall over the northern mountains from now through early next week. Mountain-top winds are expected to be from the west-southwest over the next several days at speeds sustained in the 20-30 mph range. Some easterly upslope flow is forecast to accompany the Sun./Mon. storm, which will help to enhance the precipitation along the higher terrain below 10 kft east of the Divide.
A large-scale pattern shift is forecast to occur early next week, with energy rolling in off the Pacific through California. With the onset of this pattern, if it indeed occurs, the first weather system to impact our area would occur on Wed.
Detailed 7-Day Forecast
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
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.
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