Surprisingly Complex/Low Confidence Forecast Is Accumulating Snow Still Possible Wednesday??

Despite my confidence earlier today, tomorrow's forecast has, since this morning, actually gotten a lot more complicated and less certain rather than the other way around -- a definite departure from the norm.

The computer models that I, and the meteorological community at large, rely on are in significant disagreement about a number of different, important factors over the next 36 hours: the speed of the approaching area of low pressure; the amount of upslope flow (northwest winds as opposed to northeast winds can make a WORLD of difference when you're talking mountain topography); and the timing of events.

What I do think is that (accumulating) snow is looking quite a bit less likely (at least for the daylight hours) tomorrow than I believed this morning. And, at this time of year, the sun angle is comparatively high meaning that snow falling during the daylight hours, especially when air temperatures are above freezing, is unlikely to stick to most paved surfaces -- therefore likely to be low impact.

The big question now is whether (as temperatures cool during the second half of the day tomorrow following the passage of a cold front) there's enough moisture remaining that we see accumulating snow Wednesday night into Thursday morning. One model says no way; another says yes and 4+ inches possible. I haven't decided yet which way I think things will progress but gut feeling is now (sorry, snow-lovers) saying the former -- accumulating snow chances significantly diminishing.

I'll try for another update during the first half of the day tomorrow, when some wet snow flakes may very well be falling, but are unlikely to stick to anything other than elevated and/or grassy surfaces.

A Snowy Start to April Now All But Assured 2-4"+ Snow Wed; Major Snowstorm this Weekend?

Folks, as I alluded to in Sunday's post, winter isn't ready to give up just yet. In fact, it's looking like the next 10 days to two weeks will feature significantly above normal snowfall courtesy an energized Pacific storm track and plenty of cold air in place -- especially for this time of year.

I'm increasingly confident about accumulating snow on Wednesday (probably in the 2-4" range, but this subject to change), and it still looks like a potentially major winter storm is possible this coming weekend. Looking further afield, I see even more potential snow threats next week.

Hold onto your hats!

More later...

Winter Telling Us It's Not Quite Over Several Chances for Snow Over Next Week

The next week looks to feature (well?) below normal temperatures for our region as well as a continued active Pacific storm track. I believe that there are at least 3 separate chances for snow in the Denver metro area over the next week.

The first (minor event):

• 50/50 chance for light snow tonight; up to an inch of accumulation

The second (possible event):

• Wednesday into Thursday when up to several inches may be possible

The third (possible event):

• This coming weekend the potential for a MAJOR snowstorm
• Confidence very low given how far away we are from this potential storm

So while Boulder is still recovering from nearly 18" of snow -- the same amount in a 24 hour period as had fallen the entire winter season up until then -- I believe there will be more accumulating snow for the area before Spring really takes hold.

(For those who are interested, Denver less than half (!) the amount of snow Boulder did because the upslope flow was not as strong there as it was right up against the foothills. DIA officially recorded 8.3" for the event versus Boulder's ~18".)

Late-Season Storm To Realize Its Full Potential 8-14"+ of Wind-Whipped Snow to Plaster Region

Make no mistake, folks: this one is the real deal. "Winter" so far over much of Colorado (east of the Rockies) has more or less been -- with the exception of a couple short blasts of Arctic cold -- missing in action. Temperatures have been at above normal levels for more than two-thirds of the winter and most (non-mountain) locations have only seen between 30-40% the normal amount of snowfall -- the lowest this late in the season in decades.

Thursday's wind-whipped snow will change that in a heartbeat. It's clear to me that this storm system -- a vigorous, deep area of low pressure approaching from the north and west and tracking south of us (the ideal location for prolonged upslope flow) -- means business and is likely to produce...

8-14+" of snow over the greater Denver metro area

It is possible that some locations will see as much snow in the next 24 hours as they've seen all season thus far! I do believe some isolated spots, primarily northwest of Denver, and/or along the foothills, have a shot at up 20" of snow!

And this storm is not exactly going to keep a low profile:

• Blizzard-like conditions are possible, especially from 8am to 4pm Thursday
• We'll see sustained east to northeasterly winds of 20-30mph with occasional gusts, especially near the foothills, to near 50mph
  
• Whiteout conditions may develop at times because of the aforementioned heavy snow coupled with high winds
  
• With temperatures dropping throughout the course of the day Thursday (from the mid to upper 20s during the morning hours to the mid teens by nightfall) and high winds, wind chill temperatures may drop to near ZERO at times.
• There will be significant ground and air transportation disruptions and I believe it's possible that Denver International Airport (now replete with a scary, larger-than-life blue horse) might shut down at some point
• This storm system will also funnel in bitterly cold Arctic air from western Canada, and we may see temperatures in the single digits by Friday morning.
  

Finally, a word about snow/storm duration: I expect that snow will fall (with occasional breaks) from around 4am Thursday through 10pm in the evening (+/- a few hours).

Snow lovers: get out and ENJOY! (Those ready for spring....sorry, not quite yet. In fact, I think the weather from here on out until the end of the first week of April is likely to be active, stormy, and potentially quite snowy.) And to everyone on the roads Thursday: please slow down and allow lots of space between you and the car ahead of you as roads -- especially non-treated, secondary ones -- may be treacherous with low visibilities.

[Note: image above courtesy Accuweather.com]

6-12" of Wind-Whipped Snow Thursday Winds to 50mph, Windchills to Zero Possible

After digesting the most recent model guidance, I'm comfortable with my earlier first call of 6-12" in the general Denver metro area. It's still a little unclear where the highest amounts are likely to be, but if I'd have to guess it would probably be right up along the foothills as well as areas south and east of Denver around the Palmer Divide; (this is subject to change however).

Note that whiteout conditions are possible at times on Thursday with occasional wind gusts to near 50mph and wind chills to ZERO at times!

Here's how I see things unfolding...

• Showers of rain and wet snow Wednesday evening change to all snow after midnight
• Periods of moderate snow overnight with dropping temperatures
• Several inches of snow possible by dawn Thursday
  
• Moderate/heavy snow Thursday + falling temps to near 20 by late afternoon
  
• Winds gusting to 50mph at times may create whiteout conditions
• Significant accumulations during the daylight hours Thursday
• Major ground and air travel disruptions are possible
  
• Snow continues moderate to heavy into Thursday evening
• Snow tapers off (generally) from NW to SE by around midnight
• Bitterly cold temperatures in the single digits by dawn Friday

Once again, at this time I'm generally expecting 6-12" of snow across the greater Denver metro area. It's possible that some places may see a bit less than this and that others may see more , but 6-12" is my best hunch at the moment.

[[ Current forecast confidence on a scale of ONE (huh?!) to TEN (supremely confident) is a 6.75 ]]

I'll make sure to update the forecast/conditions Wednesday and especially during the day Thursday.

Major Thu/Fri Snowfall Increasingly Likely

I'm becoming increasingly confident of the potential for a significant, accumulating snowfall for the Denver metro area from mid-day Thursday through mid-day Friday.

Indications are that near-blizzard conditions may develop late Thursday into early Friday with the possibility of heavy, wind-whipped snow.

My first guess forecast accumulation potential is 6-12"

I'll continue to refine these numbers as we get closer to the event.

More later...

Monday/Tuesday "Blizzard" is a NO GO But it **Will** Snow Later in the Week!

I'm more than ready to give a no-go/abort/cancel for significant (any?!) accumulating snow during the Monday/Tuesday time frame that I was revved up about only 48 hours ago. Such is the -- bipolar -- nature of dynamic, developing western storm systems during spring time. Fickle is the word that immediately comes to mind.

That being said, and I understand peoples' (warranted) skepticism due to the fact that this Mon/Tue snow threat has all but vanished, it is becoming more and more apparent that another storm system will develop over central Rockies region by the end of the work week, bringing the likelihood of accumulating snow back into the picture.

Regardless of the exact details of how the weather unfolds this week, I promise you (risky, no?) that the Monday-Friday time period this week will, overall, feature well below normal temperatures along with near-certain accumulating snowfall...just not the way I initially envisioned it.

I'll keep you posted...

Monday Snow: Many Questions Still Remain

While I would like nothing more than to be able to issue a confident, clear-cut forecast for this upcoming Monday's snow event, it would be irresponsible of me to, simply because way too many questions still remain. This is, at present, a tough, low confidence forecast.

Why?

I believe that the computer modeling (there are numerous regional, national and global forecast models run multiple times per day) is having a tough time resolving how things will (atmospherically) unfold mainly because the atmospheric energy associated with the strong area of low pressure poised to push through the region Monday into Tuesday is still thousands of miles away -- out over the Pacific.

The most recent runs of the models (over the past 24 hours) have generally tended to point to a much less impactful storm situation than one that I envisioned as a possibility on Thursday. The problem is that a jog of 50 miles in the track of the area of low pressure could make the difference between Denver seeing 2" of snow or 14" of snow. At the moment, it appears that the forecast storm track will not be ideal for heavy snow in the Denver metro area, and that places that really get socked will be further north and west -- we're talking north of Fort Collins into Wyoming.

We're still 48+ hours away until we see any meaningful precipitation in the Denver metro area, so models may waffle back and forth (still) until they get a better handle on things, though. I'm confident that we'll see some snow on Monday (especially the latter part of the day) into Tuesday, but I'm quite a bit less enthused about the potential for heavy snow (i.e., double digit amounts) than I was a day or so back.

I'll keep you posted....

URGENT: Potential Blizzard Next Monday, Tuesday

You heard it here first: the chances for a serious dumping of snow next Monday and Tuesday are very real. A deep, and slow moving, area of low pressure will push from the West coast to the Intermountain region by early next week.

Rain changing to heavy wet snow, accompanied by fierce winds (>50mph) are possible Monday into Tuesday. Note that heavy wet snow combined with strong winds has the potential to be very damaging this time of year -- power outages, roof collapses, etc. So this has the potential to be a disruptive and/or destructive event.

The Denver metro area has the potential to see more snow with this one storm than we've had ALL SEASON thus far (~18").

**The most recent computer modeling suggests the possibility of 1-3 FEET of snow!!**

More to follow...

Is There Still (Any?!) Hope for Snow?!

Right now this "winter" -- the quotes are there for a very real (and depressingly so) reason -- is among the top ten warmest winters for Colorado (east of the Rockies/Foothills) in the past century! Significantly more disturbing, (at least for this particularly ardent snow fanatic), if the weather doesn't change DRASTICALLY over the next 2 weeks, this could go down as *the* least snowy winter season in over a century! OUCH :(

I won't hold my breath, since I've already done that (and been disappointed) about 1,100 different times already this "winter "-- to ZERO avail -- but there are some early indications that the period March 22-31 *may* finally (?!?!) bring colder than normal and potentially snowy weather to our region.

If we don't get at least another 6"+ of snow during the remainder of March in the Denver metro area, this will easily go down as one of, if not **the**, least snowy March's since records have been kept! *Sigh*

Keep hope alive. And I'll keep you posted....