The National Weather Service has issued a Winter Storm Warning for Denver which goes into effect 2am Saturday through 5pm Saturday. Their forecast calls for 8 - 14 inches in Denver during this period. I am not sure I buy it.

Models certainly moved in a positive direction last night. And, there is enough precipitation produced by many of the models to believe 8 - 14 inches might fall, but there are serious doubts as to whether that much snow will accumulate, here is why. . . temperatures! At this time, the majority of the snowfall is expected to fall during daylight hours Saturday. With our higher sun angle, near freezing temperatures, and warm surfaces - snow will have a difficult time sticking. If we see trends towards a more prolonged event, or even a delayed onset pushing some of the heavier snowfall into the evening hours, then we will get on board with higher snow totals. It does look like there will be several hours of heavy snow on Saturday.

We will up our forecast to 4 - 8 inches for Denver, acknowledge that more than that might actually "fall", and see where we are at the end of the day and adjust those numbers accordingly. Definitely a lot to watch over the next 24 hours, stay tuned!

For those of you who jumped on the site this morning, you would have seen a Winter Storm Watch issued by the National Weather Service for the potential of 7 - 12" for Denver. Since then, they have reduced that number to 4 - 10", which reflects the uncertainties we have been discussing here for days. The Winter Storm Watch remains, and goes into effect late Friday night.

Not much new to report since last night. Models continue to be at odds on how this system eventually tracks across Colorado, and with that it would still be a disservice to issue an official snow totals forecast. In general, even the more bullish models have come down a bit today, so even if we managed a more favorable track, and mostly (or all) snow, 10" certainly seems to be the high side at this time. We will continue with our 3 - 6" range until further notice.

The NAM and GEM 12z models pulled most of our moisture well to the north and east. The NAM so much so, in fact, that I was willing to ignore it completely if it were not for other models hinting at similar solutions. The EURO and GFS remain more favorable for us, though the GFS remains warmer, limiting snowfall especially north of the city.

Here is a good graphic from Matt showing the breakdown for 4, 8, and 12 inches in Denver as of this afternoon.

In short, it is still very much a wait and see. With any luck at all tonight's model runs will help shed some light, and with more luck still they won't completely erase our hopes for snow. With 36 hours to go, it is anyone's ballgame!

Confidence remains low with regard to our weekend storm. Quite frankly, the models continued to be a mess today, with little agreement between each other, and even with themselves on a run to run basis. There are two primary concerns tonight regarding snowfall potential in Denver.

Storm Track
Storm track matters a great deal, and this remains up in the air. Some 12 hours ago it seemed like we had great agreement between the GFS and NAM models, and things looked very promising in that respect. This afternoon's run of the GFS pushed the heaviest precip north and east of the city, brings mostly rain to Denver, and the NAM dropped precip totals through Saturday by several tenths.

The European model has been relatively consistent over the last day, but brings in noticeably less QPF than the other models, and looks like a completely different storm than it did a few days ago.

The Canadian model, which actually did decently well with our last storm, brings our next storm in way too far north for any substantial snowfall in the Denver metro area whatsoever.

Temperatures
This one, as I mentioned last night, I still have a hard time believing. That said, it is pause for concern, as the models continue to suggest much of the precip that falls would be in the form of rain. In the example of the 18z GFS, it produced an inch of precip for Denver, but only about an inch of snow - that means about 90% of it would fall as rain. Again, I think this system, should it execute according to plan, would cool us much faster than models are picking up, and we would see mostly snow. But, something to note.

To summarize. . .
Not feeling too much better about this system than I was last night. I was hoping for a bit more consistency today, and I am just not seeing it. If anything, the trend is for the worse. The two big things to watch over the next days will be temperatures and storm track. Still a lot of time for this thing to go one way or another.

As far as timing and totals go, we should expect one more day of very mild weather before cooling off slightly Friday. Moisture will begin moving into northeast Colorado late Friday, with our heavy snow potential setting up for Saturday and Saturday night. By Sunday the system should push east of Denver, with things drying out latest Sunday evening. I have been getting a lot of folks asking about totals, of which I am hesitant to answer. Without seeing the all important models runs tonight, I would say Denver could be looking at 3 - 6" at this time. The NWS and others are hedging on the higher side with 6 - 12" for Denver, but I think there are too many concerns at this time for me to go there. Plenty of time to sort out the details, and things will almost certainly look very different in another six hours!

Here is a quick look the snowfall totals produced by the GFS, EURO and GEM:

Stay tuned!

Our weekend snowstorm continues to look probable, but the last 12 hours have been a bit turbulent in the model world if you are looking for the "big one". Here is a quick update one how things are looking. . .

Over the last 24 hours the EURO has come more in line with the GFS and a faster moving storm. While models continue you produce 5 - 10" (more or less. . .) of snow for Denver, this is nowhere near where we were a few days ago. If the models continue to flatten out our system and speed it up, this thing might belly flop after all.

The other issue as mentioned last night will be the the temperatures. We have been having some discussion internally surrounding this, and it is worth pointing out that some of the models have several hours of rain before changing to snow - which would greatly hurt totals. Point and case is the 12z GFS that just came in. On the left is 60 hour precip through Sunday, and snowfall totals are on the right. Notice the limited accumulation north of town despite the good precip totals. Plenty to debate regarding the reality of this, but certainly something of concern.



Several more models to come in tonight, and then another round tomorrow. We will continue to update as things continue to develop!