6-day Forecast Discussion Updated for Friday, July 3, 2009
PLEASE NOTE: Please have a look at one of our sponsor resorts' forecasts for full detail, including base and top temperature forecasting; (Aspen / Beaver Creek / Breckenridge / Keystone / Vail / Winter Park ).
AVERAGE TEMPERATURES FOR THIS TIME OF YEAR; -At 8,000 feet (Aspen); Low 46, High 78 -At 9,000 to 9,500 feet (Breckenridge, Winter Park); Low 36, High 70 -At 12,500 to 13,000 feet (The top elevation of some resorts); Low 32, High 58
SUMMARY FOR THE NEXT 6 DAYS-//>UPDATED FOR FRIDAY, JULY 3rd at 11:00am...Today -> There is a plume of deep subtropical moisture extending up from Mexico and the desert southwest, crossing the area but being pushed eastward this morning. We had dewpoints in the mid 50's at Aspen, upper 40's at Breckenridge, and 40 at 12,000 feet in the last 12 hours, which is pretty impressive for such high elevations. It means the air was about as tropical moisture laden as it gets. Moisture is being scoured out as evidenced on water vapor satellite imagery, but there is plenty of moisture left to fire off scattered to numerous thunderstorms and showers this afternoon and evening. Wind gusts to 50mph, frequent or continuous lightning, small hail, and some heavy showers are possible in any storm. With drier air working in, and not much else going on overhead tonight, we expect activity to mostly end by/ after midnight under partly cloudy skies.
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Independence Day and Sunday -> Drier northwest breezes are the expected wind pattern under a ridge of high pressure aloft, and the only real moisture is expected to be in the lower levels of the atmosphere. Therefore, we expect partly cloudy skies and a chance for afternoon and early evening thunderstorms and showers. These will be the diurnal type, triggered mostly by daytime heating, and mostly isolated in nature, so very hit and miss on the showers. The dominant weather feature is expected to be sunshine.
Monday-> A strong Gulf of Alaska low pressure system (that can bee seen ginning up in the Gulf now) moves into the northwest US, mostly Washington and Oregon, and spins off some upper air weather disturbances to help enhance the usual daily thunderstorm threat, and increase thunderstorm coverage. The winds out ahead of this low help to draw some increased moisture in also. So, we could see a more busy day as far as showers and thunderstorms are concerned, and they may be stronger storms. Thunderstorm activity may continue Monday night also, before drying winds push available moisture eastward on Tuesday.
Tuesday and Wednesday -> A strong (558-dM) low pressure system is now across the northwest US, and stronger/ drier southwest winds are expected across the Rocky Mountains. Mostly sunny skies are expected. We cannot rule out an isolated thunderstorm, especially on Tuesday, but for the most part we should be warm, windy, and mostly sunny.
Thursday and Friday -> A high pressure ridge building from the southeast displaces weakening and departing low pressure. As it does we are looking at warmer temperatures, and monsoonal moisture slowly returning. It looks like mostly a low to medium grade monsoon, with isolated afternoon thunderstorms (and not much rain) by next Friday, becoming more scattered (increased coverage) by next weekend.
Please submit any ideas or comments to chris@snowforecast.com. We appreciate your use of the site! CM
Friday
Jul 03, 2009
Hi 66°f / 54°f (base/top) Lo 45°f / 39°f (base/top)
Sky Condition:
Becoming mostly cloudy with scattered to numerous thunderstorms and showers this afternoon. Heavy showers are possible. Skies clear to partly cloudy as thunderstorms end in the late evening/ overnight.
Snow Potential
None expected, and snow levels near 14,000+ feet.
Wind:
Becoming W/ NW at 10 to 20mph. Wind gusts to 50mph are possible in any thunderstorm.
Saturday
Jul 04, 2009
Hi 69°f / 54°f (base/top) Lo 36°f / 38°f (base/top)
Sky Condition:
Partly cloudy and milder, with drier west/ northwest breezes. Mostly isolated thunderstorms and showers develop in the afternoon. Shower activity ends in the evening.
Precipitation:
30% chance for rain showers in the afternoon (.01 to .10 inches).
Snow Potential
None expected.
Wind:
Becoming W/ NW at 10 to 20mph by afternoon. Wind gusts to 40mph are possible in any thunderstorm.
Sunday
Jul 05, 2009
Hi 70°f / 56°f (base/top) Lo 35°f / 42°f (base/top)
Sky Condition:
Partly cloudy and mild, with west/ northwest breezes. Mostly isolated thunderstorms and showers develop again in the afternoon. Shower activity mostly ends in the evening, but a few stray isolated thunderstorms may linger into Monday morning.
Precipitation:
30% chance for rain showers in the afternoon (.01 to .10 inches), then a 10% chance in the evening and overnight.
Snow Potential
None expected.
Wind:
W/ NW at 5 to 15mph. Wind gusts to 40mph are possible in any thunderstorm.
Monday
Jul 06, 2009
Hi 68°f / 56°f (base/top) Lo 43°f / 42°f (base/top)
Sky Condition:
Partly cloudy with an isolated shower possible in the morning, becoming mostly cloudy with scattered thunderstorms and showers by afternoon/ evening. Isolated heavy showers are possible. Isolated thunderstorms are possible overnight.
Precipitation:
40% chance for rain showers by afternoon (.05 to .15 inches, isolated 1/4" possible).
Snow Potential
None expected, with snow levels near 14,000 feet.
Wind:
Becoming W at 10 to 20mph by afternoon. Wind gusts to 50mph are possible in any thunderstorm.
Tuesday
Jul 07, 2009
Hi 71°f / 57°f (base/top) Lo 38°f / 43°f (base/top)
Sky Condition:
Partly cloudy and becoming a bit windy. Drier air works in, with maybe an isolated thunderstorm mainly over the upper ridges or peaks by afternoon.
Precipitation:
10% chance for rain showers mainly on the higher ridges/ peaks.
Snow Potential
None expected.
Wind:
Becoming SW at 10 to 20 gusts to 30mph. Wind gusts to 45mph are possible above timberline, and in any thunderstorm.
Wednesday
Jul 08, 2009
Hi 70°f / 56°f (base/top) Lo 44°f / 40°f (base/top)
Sky Condition:
Mostly clear and dry, with a few clouds developing in the afternoon, but no thunderstorms are expected. We continue a bit windy, especially above the tree line.
Precipitation:
None expected.
Snow Potential
None expected.
Wind:
Increasing to SW at 15 to 25 gusts to 35mph by afternoon. Wind gusts to 45mph are possible above timberline.
Long range forecast / discussion...July 09 to 12
--High pressure ridging returns, and becomes centered close by, and to the east somewhat, for limited subtropical moisture seeping in. T-Storm and shower activity continues isolated to scattered (10% to 40% coverage each afternoon/ evening) through mid and into late July.
--For those who want to know, it looks like an El Nino SST pattern is developing and strengthening. We would expect more moisture for thunderstorms and showers this summer, and Pacific Hurricane activity with this development. We do not think this will be a dry summer compared to average, in fact it may be a bit wet. This fall/ winter the El Nino should still be with us. This usually means a near to below average snowfaall year for northern Colorado, and near to above average snowfall for southern Colorado. That is very general, but we will try to work up some snowfall and temperature comparisions as we get closer.CM
