Saturday, April 13, 2013

Another snowstorm may be headed for Colorado; Cynics Watch, Wait

I'm quoted in a Denver Post article regarding our next shot at accumulating snow for early next week. Take a look!

Details to follow regarding snowfall potential...

Monday, April 8, 2013


A major late-season snow storm coupled with record cold temperatures for this time of year will blast into the Denver metro area late Monday into Tuesday.

The result will be a widespread 6-12" of snow, with slightly higher amounts possible across the northern Denver suburbs (such as Loveland, Greeley, and Fort Collins.)

This will be a very dynamic system, with temperatures near 70 degrees Monday afternoon transitioning to (thunder?)-snow with temperatures crashing from 30s by mid-evening Monday to the teens by early morning Tuesday.

See more details including a freshly-minted "Bust Index" in the latest collaborative forecast from me (@ColoradoWx) and Brendan Heberton (@BrendansWeather) here!

Friday, March 22, 2013

FINAL FORECAST: 6-10"+ Across Denver Metro 3/22-3/23

I've been one of the most bullish outlets over the past few days and I'm sticking to my guns

Many/most outlets are predicting 3-6" for Denver out of this system; the NWS just issued an advisory for 4-8"; my forecast from yesterday for 6-10" with isolated higher amounts still holds. This will be an abnormally cold storm for late March across central Colorado, with temperatures in the low 20s during most of the storm. This will lead to snow:liquid ratios of near 15:1, which I think some other outlets are overlooking.

If my forecast ends up being wrong, I'll own it, especially as it differs fairly considerably from other outlets.

Please also check out my meteorological co-conspirator, Brendan Herberton's weather page here.

Stay warm (wind chills will be in the teens at times Saturday) and if you have to travel -- please be safe!

Thursday, March 21, 2013

6-10" of SNOW for Denver Metro this Weekend!

I remain fairly confident that the necessary ingredients are coming together for 6-10" of snow to fall across the greater Denver metro area from Friday evening into late Saturday/early Sunday. I have have been more bullish than some of my meteorological cohort over the past few days and remain so. I think a combination of good dynamics with the system, much colder temperatures than the bust-like storm 2 weekends ago (hence higher snow:liquid ratios), and plenty of moisture will bring us these amounts, with slightly lower amounts over the northern suburbs.

Click here to see a collaborative forecast, along with some discussion of how my forecast varies from those of my meteorological co-conspirators, Brendan Herberton, Matt Makens and Chris Tomer.

Happy snow!

Friday, March 8, 2013

Biggest Storm of the Season?

Winter storm set to bring beneficial moisture to the Front Range

A good run of the models this morning has boosted confidence in the forecast for our winter storm due in late Friday night. Models are increasingly consistent in bringing a good dose of wet snow to the Denver metro area, and the chance for significant snowfall totals across the region. With that we are upping our snowfall forecast from this morning to 6 - 12 inches for Denver, but resisting the urge to go with the NWS forecast of 8 - 14” --- for now. Areas north of Denver may see more rain and therefore less snow.

Please view my collaborative forecast with @BrendansWeather here.

Saturday, February 23, 2013

Largest Snowfall of The Season Thus Far to Hammer Denver

NWS Issues Winter Storm Watch Ahead of Rapidly Developing Storm

(This is a collaborative forecast by Josh Larson (@coloradowx) & Brendan Herberton (@Brendansweather)

11:30am Saturday: A winter storm headed for Colorado over the next 12 to 36 hours has the potential to bring significant snow to the Front Range urban corridor -- in fact, quite possibly, the heaviest snow so far this season. Model spread over the last 12 hours has been anywhere from about 4 inches in the city to over a foot. With that said, our snowfall forecast has been upped to 5 to 10 inches of snow for Denver, with the potential for higher totals, especially to our south and east.  These numbers are subject to change as the day wears on, and given current trends, they could change up. Double digit snowfall totals certainly not out of the question, but let’s not get ahead of ourselves.

Snow is expected to start around midnight tonight, then become heavy at times through Sunday morning. Best chance for the heaviest snow, where rates could exceed an inch an hour, will be during the very early morning hours Sunday.

The other story we are monitoring with this system is the wind. A Blizzard Watch remains in effect for communities along the Palmer Divide, where sustained winds could cause poor visibility and dangerous driving conditions for a prolonged period of time. In Denver, wind will also cause blowing snow and at times poor visibility, especially during periods of heavier snow.

Snow should gradually diminish late in the day Sunday, before coming to an end Sunday night. In its wake, below normal temperatures will stay with us, and last through at least the middle of next week. With fresh snow cover, single digit lows are likely again by Monday/Tuesday.

This is a rapidly evolving situation that should be monitored closely as the day wears on. Expect updates as necessary over the next 12 to 36 hours, with any adjustments to snow totals and the latest winter weather advisories.

Friday, February 8, 2013

Up to Several Inches of Snow Possible Saturday Night across Denver metro!

CAVEAT: What I'm about to write absolutely pales in comparison to what's happening in the Northeastern United States, but this particular prognosticator is so snow-starved that I'm to the point where even the potential of a few inches of new snow gets me excited.

For the past several days, there's been an ongoing model battle as to whether or not central Colorado would see accumulating snowfall Satuday night into Sunday. There has been a lot of backing and forthing between models, but given the overall pattern, I have struggled to see how we couldn't see at least a couple of inches of snow during the time in question -- even as some models have literally printed out zero precipitation. (But given how many busts we've had so far this "winter," I have been hesitant to pull the trigger, especially in light of conflicting model data.)

However, the newest model data that has just come in suggests that 1-3" of snow is possible tomorrow night over the Denver metro area, with slightly higher amounts possible north and northeast of Denver (areas like my home in Greeley!). Based on what I'm seeing, I think amounts are more likely to bust "high" -- meaning higher than most outlets are currently calling for -- especially in the northeast quarter of the state (approaching the WY/NE border.)

In fact, the newest 0z NAM suggests that 2-3" of snow is possible in Denver and 3-4" is possible in Greeley. These numbers jive with some other, proprietary model data I have access to that suggests these totals are well within the range of possibility.

Rain or a rain/snow mix will develop over the Denver metro area over the mid-to-late afternoon hours and will quickly change to all snow by 6-8pm. This will be a short-duration event, with perhaps as few as 3-6 hours of snow, but some bands, depending on where they set up, can easily produce several inches out of the atmospheric dynamics available.

Further updates likely on Saturday as more model data comes in...