The weekly weather forecast for the high country of Rocky Mountain National Park, Colorado; researched and written by professional meteorologist and avid mountaineer: Dan "the weather man" Gottas.
Thursday September 18, 2008
The Week in Review
The big weather news over the past week was the respectable alpine snow event that occurred last Thursday evening / Friday morning. Snow fell as low as ~10 kft at times, and accumulated up to 10 inches above the freezing level (~12 kft) near Longs Peak. The storm squeezed out around 1.00 – 1.25 inches of water / water-equivalence across the higher terrain along the Front Range. With the warm up since the storm, most of the snow has compacted down to a few inches, and remains mostly on north-facing aspects.
Summer-like weather conditions returned to the region, with temperatures steadily climbing and winds relaxing over the past five days. These conditions, combined with nearly flawless skies on Sunday through Tuesday, produced full days of pleasant weather conditions for climbing.
By mid week, an increase in atmospheric water vapor induced deep convection in the afternoon. Isolated thunderstorms formed on Wednesday, and became more widespread on Thursday with help from a weak upper-atmospheric pressure disturbance. Thursday’s storms produced lightening and locally heavy showers across much of the higher terrain, with snow falling down to 12 kft in some of the more intense showers.
The Upcoming Weekend
We will be dealing with convective-weather conditions on Friday through Sunday, as the atmosphere will remain moist and thermodynamically unstable. On Friday, afternoon convective activity should be less than what it was on Thursday. However, by Saturday afternoon, an upper-atmospheric pressure wave will drag its heels across northern Colorado as it moves into the northern Rockies. With this, the convection will receive an added boost. Convective precipitation, with the potential for 0.25 inches locally, and lightening are probable over the higher terrain on Saturday afternoon and evening, and in the late morning / early afternoon on Sunday. Storm motion will generally be from the west.
While this weekends disturbance is not forecast to usher in cooler temperatures, daytime cloudiness and scattered precipitation will act to lower daytime temperatures 5 – 10 F from what we experience earlier this week. In locally heavy showers, snow levels will likely be down to 11 – 12 kft. The numerical forecast of alpine temperatures and winds for the weekend is as follows:
The next upper-atmospheric weather disturbance is forecast to affect the area near midweek. At the current time, this system is not expected to be much of a precipitation producer. However, temperatures may cool down, which would produce better conditions for water-ice growth in the alpine areas.
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.
|
