wxgeek's weather-Snow possible wed night, dry and warmer after-Update 10/1

Update thurs Oct 2
Cool and breezy day across the state today in the wake of our system Wednesday that dropped 1-2 inches of snow in higher foothill areas, and 4-7 inches in the higher mountains. Before we start our warm up, another fast moving system will skirt to our north tonight, and mostly bring cooler temps into eastern CO tonight into Friday. Only a slight chance for showers, mostly along the CO/WY border area tonight. Temps tonight expected to drop below freezing in the foothills and near freezing along the Urban Corridor. The other impact will be strong nortwhest winds from the mountains to the plains tonight into Friday. Upper level winds up to 80 mph will move across northeast CO tonight which will create strong winds through the mountains and foothills as well as nto the plains. Surface winds of 30-50 mph will be possible tonight into Friday in the foothills. This will keep temps cooler than normal across most of CO on Friday.

Finally on Saturday, a Fall warmup begins. Upper level ridge will build along the west coast while upper trough moves farther east, so flow aloft decreases and temps warm above seasonal norms over most of CO this weekend under mostly sunny skies. Should be a great weekend to enjoy the Fall colors or other outdoor activities.

Dry and mild pattern is expected to persist through next week into Friday, with temps 5-15 degrees above seasonal norms.

Models now suggest that upper ridge will amplify next weekend along the west coast, which allows an upper trough to move into the Rockies from the northwest. Models indicate precip chances will increase over CO from next Saturday through the following Monday. Snow levels could drop down to around 7000 ft by Sunday and Monday, so currently looks like snow will be possible next weekend for the foothills.

Meanwhile, very warm Pacific waters have generated yet another tropical storm east of Manzanillo, Mexico. Tropical storm Simon is forecast to move to the northwest and become a hurricane this weekend. Current track moves Simon off the Baja coast this weekend, then moves it over Baja just north of Cabo San Lucas early next week, then has it stall over the southern Gulf of California. If this track verifies, could be a lot of additional rainfall for Cabo San Lucas.

---

Update Wed Oct 1

Upper trough and cold front bringing precip to western CO this morning. Cold front currently located along the western slope and is forecast to move east into eastern CO this afternoon. Embedded thunderstorms are present in frontal boundary, and will likely intensify this afternoon as atmosphere destabilizes in afternoon heating. Snow level is currently around 10,000 ft and is expected to lower behind cold front this evening and tonight. Winter Weather Advisory is in effect for most mountain areas of CO above 10,000 ft including the Front Range mountains for 3-7 inches of snow. Strong westerly winds will accompany system., especially at higher elevations which will make travel difficult across higher passes this afternoon and evening.

For our foothills, precip will move into our area this afternoon, with heaviest precip expected for the evening commute, so expect a slower than usual ride home today. Rain, heavy at times, with embedded thunderstorms will move through between noon and 6 pm today before moving east. Snow level with frontal passage will be around 9000 ft, so only higher foothill areas will get snow with primary precip. Snow level will lower to around 7000 ft by midnight, but only light precip is expected from 6 pm to midnight, so snow amounts likely to only be a dusting for most areas. Foothill areas above 8500 ft could see 1-2 inches of snow however, so some slick secondary roads are possible tonight at higher elevations. Most precip should end by midnight, with a few lingering flurries possible through 3 am.

By Thursday morning, skies will be clearing, although some fog and low clouds will be possible in foothill areas through about 9 am. Brisk northwest winds will prevail most of the day Thursday, creating a blustery Fall day as temps will remain well below seasonal norms.

By Friday, upper ridge builds along the West Coast creating a warmer and dry northwest flow regime over CO. Temps will be back above seasonal norms under mostly sunny skies for the weekend. Fair weather pattern will persist into next week with temps remaining above seasonal norms through at least next Friday. Longer range models suggest mild and dry pattern is likely to persist into next weekend and perhaps the following week, although this time of year the forecast can change quickly that far out.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

---

Wild weather across CO Monday, a break day in between systems today. Mostly cloudy across western CO today with mostly sunny eastern CO. Weak system will bring increase in precip mostly west of the Divide from this afternoon into tonight, with a slight chance of an isolated shower east of the Divide. Snow level today and tonight will be around 10,000 ft with 1-3 inches possible along and west of the Divide. Skies expected to clear by Wednesday morning, in advance of a stronger system. Precip will increase by late morning west of Vail Pass and move east during the afternoon into eastern CO with precip persisting into early Thursday morning east of the Divide. Snow level begins around 10,000 to 11,000 ft during the day on Wednesday but will lower as cold front passes Wednesday afternoon/evening. System could include isolated thunderstorms with small hail and gusty winds as well, but storms not expected to reach severe limits as they did on Monday. Snow level could lower to around 6500-7500 ft Wednesday night, so higher elevations of the foothills could see a dusting to an inch or two of snow by Thursday morning. Mountain areas could see 3-6 inches of snow Wednesday into Wednesday night above 8000-9000 ft, especially northern mountains. Heaviest precip amounts will be north of I-70, but precip could extend south to around US 50. With warm temps this week, I would expect most snow in the foothills to melt on major roads, but there could be some slush or snow on secondary roads mostly above 8000 ft. Thus, Thursday morning commute could be a little slower than usual. Wednesday evening commute could also be slower due to rain and/or thunderstorms moving across the Urban Corridor and foothills.

Conditions improve Thursday morning, but temps Thursday will remain well below seasonal averages, and breezy to windy northwest winds will keep things feeling blustry. This week will not be kind to Aspen leaves, with rain, hail, snow and wind removing a lot of leaves, so colors this weekend expected to be much less than last weekend.

By Friday, temps will climb to near seasonal norms under mostly sunny skies as upper ridge builds back over the western U.S. CO will remain under a mostly dry northwest flow aloft through the weekend, with temps climbing above seasonal norms. This dry and warm pattern is expected to persist through all of next week for CO. Beyond that, models vascilating between persisting the upper ridge and bringing a more moist and zonal flow into CO, so will have to wait and see what happens. So it appears after a chilly start to October on Wednesday, October will then turn mostly dry and mild into the middle of the month.

Looks as though September will end with 3.25 inches of precip on Conifer Mountain, so well above the average of just under 2 inches. This marks the third consecutive month with above average precip on Conifer Mountain.

Latest ENSO advisory still has a 65% chance of El Nino conditions forming by October to November. Current ONI is at 0.0 indicating nuetral conditions currently. Looking at past El Nino events, ONI was usually around 0.5 by September. This indicates we may have a slower start to stronger winter type storms this season. Typical El Nino seasons have a strong winter storm in October, but with a slightly delayed start, we may not see stronger storms until November or December.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

Bump for 10/1 update

Bump for oct 2 update