Light Snow Late Today into Friday

A weak storm system will bring 1-3" (perhaps a few isolated locations up to 4") of snow to the Denver metro area from late afternoon Thursday into early Friday. Note: as is often the case for Denver snows, I believe that the heavier amounts will focused over Denver's western/foothill suburbs, like Broomfield, Boulder, etc.

At this time the National Weather Service is only calling for a "40% chance of scattered snow showers," and with no snowfall amounts mentioned, seems to suggest little or no accumulation. I don't agree with their dismissive forecast at the moment.

One of us will be right. Hopefully it's me.

Snowfall Forecast for February 20-22 3-7" Denver; 5-9" Northwest Suburbs

I apologize for being too tired to write a full post tonight. So, I'll get down to the details.

I believe that on-and-off snow over the next 48-60 hours will produce moderate to significant snowfall accumulations for the Denver metro area; the snowfall we see this weekend may well produce the highest snowfall amounts from a single storm system since early January.

My predictions:

• Areas within an ~15 mi radius of downtown Denver (and areas southeast of this zone) are likely to see THREE TO SEVEN INCHES of snow from the overnight hours Friday night into the early morning hours Monday
• Areas further north and west of ~15 mi way from downtown Denver (say, Broomfield to Boulder) are likely to see FIVE TO NINE INCHES of snow during the same period

I should note that I believe the heaviest snow will fall from approximately (give or take a few hours) mid-afternoon Saturday through Sunday morning.

Futhermore, ski areas in the southwestern quadrant of the state (think Telluride, Silverton) may well pick up 18-40" of snow during, approximately, this same time period!

On-and-off Snow, and Cold, Through Tuesday Significant Accumulations Possible...

I think that the NWS may be under-estimating the potential for moderate to significant accumulations of snow over the coming several days.

At this point, I believe that between 5 and 10 INCHES of snow is a real possibility for the entire Denver metro area from tonight through early Tuesday, as two separate storm systems crashing into the Pacific coast trek east.

I'll have a full update tonight...

Slap-In-The-Face Cold Over the Next Week...

...The next 7-10 days may feature among the coldest temperatures of the entire winter. It is possible that from tonight (Tuesday) on, we may not get above freezing again until next Monday.

A series of Arctic cold fronts will bring extremely cold temperatures to the region, with overnight low temperatures in the low single digits (some below zero readings possible) Wednesday & Thursday night...and it won't likely get above the mid-to-upper teens for highs on Thursday.

2-5" of snow seems likely starting Tuesday night through early Thursday, with more snow probable over the weekend...

....MORE TO LATER TODAY

Final Forecast: Major Snowstorm of 5-10"

**Note: Updated at 4pm, Saturday November 14**

After, admittedly, a little bit of hemming-and-hawing (or, I prefer to say, tweaking) of my forecast over the past 36 hours, it looks like all the ingredients are in place for a major early winter storm for the entire Denver metro area. While it won't deliver record-breaking accumulations that the last storm brought us two weeks ago, it will still produce heavy accumulations, with most places seeing accumulations in the mid-to-high single digits and some isolated places seeing accumulations over a foot. Unlike our storm two weeks ago, too, weather is colder now, and the sun angle is lower, and snow will accumulate more effectively on paved surfaces. That means that by mid-evening Saturday roads most roads are likely to already be snow-covered.

TOTAL EXPECTED ACCUMULATION

(for Denver Metro Area)

FIVE TO TEN INCHES

So let's get on with the detailed forecast:

Saturday night:

• Overcast skies with periods of moderate-to-heavy snow
• Roads snow-covered by mid-evening
• Temperatures drop into the mid-20s
• 3-6" of snowfall accumulation likely by dawn

Sunday:

• Overcast with periods of moderate-to-heavy snow, especially during the morning
• Snowfall is likely to taper in intensity and coverage by the middle of the day
• Another 2-4" of snowfall accumulation likely by late afternoon
• Afternoon highs near 30

Sunday night:

• Slight chance of scattered snow showers during the evening
• Little or no additional accumulation expected
• Cold overnight lows drop to the low 20s
• Monday morning's commute could be ugly!

Extended outlook:

• From this juncture, Monday through Wednesday look dry with temperatures moderating well into the mid-40s for highs with overnight lows primarily in the 20s

Note: Image above courtesy Accuweather.com; my forecast deviates slightly from theirs as you can tell.

Near-Record Heavy Snow to Plaster Colorado Accumulation: 7-14"; Isolated Areas See 2 Feet!

If you follow me on Twitter (@joshlarson) you know that I've been hinting at a major winter storm for our region since last Thursday...

All of the right ingredients appear to be coming together to produce a near-record fall snowstorm for the Front Range. We've got a deep trough (dip in the jet stream) of low pressure and abundant moisture to work with to produce HEAVY SNOW starting late Tuesday/early morning Wednesday and likely lasting well into the day Thursday.

I anticipate significant disruptions to transportation/travel with the likelihood of many cancelled/delayed flights in & out of DIA and the slight possibility that the airport may even shutdown entirely at some point -- though know I'm a better predictor of weather than airport closings. :)

My forecast:

**7-14 INCHES OF HEAVY SNOW**

*Isolated amounts of up to 2 FEET possible, especially north and west of Denver (i.e. Boulder, Fort Collins, Estes Park)

When all is said and done, this storm has the potential to become one of the most impressive October snowstorms in recent memory...

* Note: image above courtesy Accuweather.com

Record Cold Over the Next 48 HoursQuestion is: How Much Snow Falls?

The second Arctic front in as many days will push across the area early this evening, dropping temperatures from their afternoon highs in the 50s quickly to below freezing. With this front comes another opportunity for snow (yesterday's was a bust), and I have reason to believe that most places to the north of downtown Denver will indeed see accumulating snow.

Basically, the further north in Colorado (and closer to Wyoming) you go, the better chance for accumulating snow. So, Boulder has a better shot at seeing accumulating snow than Denver, and Fort Collins has a better shot than Boulder. Honestly, I have a gut feeling that this system will "over-perform" in that snow totals over the northern quarter of the state (including Boulder) will be higher than the National Weather Service's (NWS) current forecasts.

We'll see record lows in the teens (!!!) tonight (record low for this date at DEN is 25 degrees) along with a 70% of light snow -- possibly mixed with freezing drizzle at times.

"GUT FEELING" SNOWFALL ACCUMULATIONS:

• Denver: little or no accumulation (NWS predicting under 1")
• Boulder: 2-3" (NWS predicting under 1")
• Fort Collins: 3-5" (NWS predicting under 2-4")

**Note: Confidence on scale of 1-10 is only about a 4**

It's possible that a few left over snow showers or even pockets of freezing drizzle may linger into the day tomorrow, but the vast majority of any precipitation that falls will be Friday night. (And, note, I would not be shocked if downtown Denver ends up seeing no flakes at all; they may be just a little too far south this time around.)

We'll see record low temperatures again on Saturday; (the record low high temperature for the date in Denver is 34). I'm thinking it's quite possible temperatures won't make it out of the 20s for highs -- and at best may hit freezing (32). Also, we're highly likely to break records Saturday night, with bitterly cold overnight lows from 15-20 degrees (the record low temperature in Denver is 22).

From Sunday on out, however, we'll see moderating temperatures each day, with highs well into the 60s possible by mid next week. In fact, I think the entire rest of the month of October is likely to feature normal to above-normal temperatures. This cold bout is just a tease!

*Note: graphic above courtesy Accuweather.com