wxgeek's weather-Update Friday Nov 18

Update Friday Nov 18

High Wind Watch currently in effect for JeffCo and South Park and High Wind Warning for southern foothill counties from midnight tonight through 5 pm Saturday. Highest winds in this event will be south of I-70. For our foothill areas, expect sustained winds of 30-50 mph with gusts to 70 mph Friday night into Saturday morning. Strongest winds will be from about midnight til 9 am Saturday. Power outages and downed trees will be likely. Travel will become difficult, especially on north-south oriented roads where crosswinds will be very strong. Winds should diminish by late Saturday afternoon after cold front passage.

Winter Weather Advisory in the central and northern mountains west of the Divide for snow and blowing snow from late Friday night into Saturday afternoon. Expect about 4-8 inches of snow from this system over higher west facing terrain.

Sunday will be cooler and winds will be much lighter, with some lingering snow flurries across the mountains west of the Divide.

Next week still looks dry and breezy with mild temps, especially the middle of the week. Thanksgiving Day looks dry and mild across the entire state. The next system to possibly affect CO will move across the state next Friday/Saturday. Latets models keep the vast majority of moisture with this system west of the Divide, so not looking good for any significant snow through the remainder of November for the foothills at this time.

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Warmer temps back across CO, but increased westerly flow aloft will induce a lee side surface trough, which will cause strong westerly winds to develop this afternoon into tonight across the foothills and adjacent Plains. Wind speeds in the 20-45 mph range will be common, with some gusts up to 60 mph. Combination of winds and low humidities have caused a fire weather watch to be issued for Friday in south central and southeast CO. An upper level trough from the Pacific Northwest will approach CO on Friday which will keep strong southwest winds blowing much of the day with mild temps. This system will bring snow to the northern and central mountains beginning late Friday night into Saturday. Associated cold front will move through the foothills on Saturday evening, but little if any snow will make it east of the Continental Divide on Saturday.

Temps will cool slightly on Sunday, with some lingering snow showers over the northern and centrral mountains west of the Divide. For next week, an upper trough will stay to our south early in the week, so no precip expected from this system in CO. Upper ridge builds in afterwards which will keep mild and breezy conditions across the foothills through Thanksgiving Day. Long range models indicate the next chance for snow will be Friday/Saturday next week.

From a climate standpoint, the ONI has decreased to -0.2 and is expected to continue decreasing through January, so weak La Nina conditions are expected to dominate our weather through January. Climate models then predict the ONI to increase toward Neutral to slightly positive conditions into the Spring. This translates to relatively mild temps and average to below averge snowfall trhough January for the foothills, with better chances for average to above average snow from February through April, which is more the norm anyway. Mountains should continue to receive average to above average snow through January, then more towards average snowfall into the Spring with a shift from snow in the central and northern mountains towards the southwest mountains.
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"Climatology is what you expect, Weather is what you get".

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