Chinook

Interesting fact: a volcano erupted in Tonga (southwest Pacific Ocean) at 04z (Jan 15.) and sent an atmospheric pressure wave and a tsunami halfway across the world. There was a small (?) tsunami detected in Alaska. Barometers picked up a pressure fluctuation across the USA.

It's almost like somebody photshopped this map such that Joplin has rain. Weird one, huh?

looks like there is some snow on the southwest half of the Denver metro

Seems like there's a decent snow rate at Des Moines right now.

Kinda funny how the NWS watches/warnings are a little sporadic at the moment

GFS Analogs #6, #7 and #12 kind of look like the GFS/Canadian this evening, but, hey, winter of 2002-2003 shows up three times, and ... Snowmageddon, and 12/5/03, the last storm that is in the Kocin-Uccellini (2004)

I'm pretty sure this will get lost if I post it in Mid-Atlantic, New York or other subforums, so here it is. Analogs #6, #7 and #12 kind of look like the GFS/Canadian this evening, but, hey, winter of 2002-2003 shows up three times, and ... Snowmageddon, and 12/5/03, the last storm that is in the Kocin-Uccellini (2004)

My thinking is that the East Coast has had more high-NESIS storms from 2002-03 up to the "Great Snow" of 2015, but possibly including the January 23, 2016 storm. Then, I think things have been somewhat more quiet, particularly for Boston starting 2018-2019. "Great Snow" is somewhat in reference to the colonists' "Great Snow of 1717." My area has stayed cooler than Denver since the weekend, with diminishing snow depth, but not zero.

a little off topic here: Models continue to tease the East Coast with the possibility of a major snowstorm for the big cities. Most recent ECMWF has this offshore, but still nobody knows what will happen!

Montana is 50 degrees warmer than yesterday

I measured 4.5" last night, and this morning it didn't seem like a lot more. This morning I had to resort to measuring snow on top of snow, or snow on top of objects. So that's kind of bad. CoCoRAHS has some 4.5" values in Loveland, and also one measurement of 7.1" Most of Fort Collins had 5". snow basins: the South Platte basin has gone from 59% of snow water equivalent on December 8th to 122% today. 129% in the Upper Colorado River basin today. Everything in the West is above 100% except for up near Great Falls, MT, and Pueblo (upper Arkansas River basin).

Once again, my super color scheme that shows relatively small changes in reflectivity. Narrow bands of snow make you think the mountains are blasting out lake-effect snow.

Pine Bluffs, WY, east of Cheyenne, already got more than 10". For my place, maybe 1/2" per hour for 4 hours, or something like that. I'll check later. It gets harder for me to measure snow without the base layer as the grass.

It's getting into Denver now, with 1/2 mile visibility at Erie and BJC

Now upper and lower Larimer County have winter storm warnings, possibly for different reasons. I think the reason for the W.S.W. for lower Larimer County is higher winds, which is kind of surprising since it isn't windy yet. It isn't snowy yet, either.

Each global model has somewhat more than the NAM QPF of 0.2" for Fort Collins-Loveland-Greeley.

It looks like there is a chance of snow for northern Colorado on Wednesday. It will be with a WNW flow aloft. It could perhaps favor Cheyenne and western Nebraska. It's kind of one of those wait-and-see situations. edit: 00z GFS is kind of nuts for Cheyenne to Fort Collins, hmm, 0.52" of preciptation and 11.7" of snow... 22.5:1 snow ratio. sounds high.

For those interested, it's my first time making a cross-section plot of the frontogenesis, which is highly aligned with upward vertical velocity. The cross-section here goes through the cold air damming zone and snowstorm. You can see the chunk of cold air sitting just east of the Appalachians, with a small zone of temeperature inversion.

I measured 8" in a couple of places. So that's a good one, in my book. I could post pictures, but they are much like other pictures I've posted in the past. As for the observed snowfall graphics on Pivotalweather, it comes from the NOHRSC. I would imagine they will have to do a correction for 24-hr snowfall amounts in Colorado, as probably some more correct values will show up on tomorrow's analysis.

This is a vertical cross section directly through the storm from north (left) to south (right) showing a huge difference in temperatures in the whole atmosphere, and the upward vertical velocity areas (pink) above the slanting frontal surface. You can see the temp inversions with the shape of the 0C isotherm, -12C isotherm, -18C isotherm.

current radar, with alternate color table making 25-30dbz look like red and magenta

Happy snowy New Year to everybody! Finally, the snow drought is over. Fort Collins, got, officially 0.7" in November, which was the only snow up until yesterday, I believe.

I changed the GRLevel3 color palette to make the colors look really wild

snow is starting in the Denver metro area.

We got a snow band develop east of the mountains here at 8:00AM. It is officially starting for my area! Some accumulation on the grass.