Chinook

CoCoRAHS snow plots

Fort Collins -CSU station has got 7.3" of snow since Saturday. The monthly average temperature is 46.2, which is 3.7F below normal for the month. We will finish the month with temperature departure colder than -3.7F. By the way, I had to go to the Midwest Regional Climate Center web site to look up these values for our co-op station (non-airport.) The NOWDATA on the NWS web site has not been working since earlier in October. Perhaps they should call it "THENDATA," because it worked *then*, but it doesn't work now.

8-12" forecast was a bust for much of the Denver area. 6-8" was a bust for Fort Collins/ Loveland. Certainly, things were slippery though, so it had an impact. It's not like it just melted off the road or anything. I think my storm total is about 4".

A storm report from DIA said 5.9" of snow. There was a heavy snow band east of DIA. For my area, we have got storm reports of 3" or more west of I-25. I can't really tell how much has fallen, but it's probably 2-3". Since we had some snow on Sunday, it's kind of hard to tell. It is 14 degrees here, so that is like a mid-January arctic temperatures. It's certainly not very helpful for the roads.

NWS lowered the snow forecast values in the north and in Wyoming

By the way, Weatherbell.com still allows the general public to view NDFD (National Digital Forecast Database) products, including snowfall and freezing rain. https://maps.weatherbell.com/view/model/ndfd-conus?d=conus&p=t2m_f

Graphics from NDFD graphics from NWS Boulder Denver

I had about 3" on elevated surfaces and 2.5" on the ground. I reported 2.5" to the NWS last night and that seems the most reasonable. It continued to snow after 10:00PM last night, but obviously not much accumulated. On to round two!

Snow is continuing here. It's not falling fast. We have over 2" and it has been accumulating on the grass since early afternoon. The radar right now shows there are higher dBz values in south Denver than here. That could sort of mean anything though. With colder temps, radar is not always super good at estimating QPF rates, so that's why you need people to measure and report on road conditions.

Several inches of snow have fallen in central Wyoming. Areas around here are in the 20s. My place has had light snow. I think Cheyenne may be getting a little closer to 1"

Here is the ECMWF snow-equivalent QPF up to Friday, 7:00AM

Our area has a winter storm watch. I am wondering about this will play out time-wise. The models have a 2nd wave of snow on Tuesday (GFS has this at about 12z-18z Tuesday). Nevertheless, there is a lot to be concerned about.

By the way, I just checked the forecast PW value during the rainstorm, for Detroit. That is a value 1.45." This would be at about the general maximum for this time of year for the DTX sounding location (see SPC sounding climatology.) The average for this time of year would be 0.57."

There are some respectable tropical-storm force wind gusts to 43 kt at the place that has the temperature of 81 in this image.

The cold front and snow storm system for Sunday to possibly Tuesday looks like it could be more significant than previous runs showed. Previous runs of the Canadian showed a lot of snow, at slightly later time frames. Now the Canadian is bonkers with 1.2" of QPF for Denver. The Euro has 1.2" of QPF for the city of Denver and northwards.

Today my area was 42 degrees and breezy by late afternoon. I saw a few rain drops out of the first band of precipitation at about 1:00PM. Such things remind me of late November and December in the Midwest. Right now, Denver has 34 degrees and snow with 1/2 mile visibility, with moderate dBz values on the radar.

Last night, we had another period of wind gusts of 30-60mph. I was in Fort Collins at 10:00PM and there were some 30mph wind gusts blowing leaves all over the place. There were brief 60mph winds recorded at the west side of Fort Collins. There is a winter weather advisory for Denver for tonight and tomorrow, with a winter storm warning from the Palmer Divide down to New Mexico border. NWS forecast for Colorado Springs: The GFS and other models show another cold front and snow for WY and CO on Sunday-Monday. Our area already has a temperature departure of -2.9F for the month (Denver.)

The TDFW short-range radar showed some rotation at State Highway 121 (Sam Rayburn) , and continued to about 1.5 miles south of Fairview. The KFWS radar had this, but it was a little hard to interpret. map of area: this must be some sort of traffic monstrosity. How many roads are there??

Possible tornado near Asher, Oklahoma.

this is the official warning text

There is a new tornado watch and some storms near Fort Worth. It looks like the severe-warned storms are a result of a supercell split with left- and right-moving supercells.

This is new. I didn't see this on the NWS web page yesterday.

Some normal weather last evening changed to windy weather of 30-50mph wind gusts in the Front Range cities. For my area, the greatest gusts were in the middle of the night at about 4:00AM. Currently, DIA has the strongest gusts of the day.

18z GFS has 8" of snow and 0.91" of QPF for downtown Denver on Wednesday to Thursday. This is likely a case of the GFS being precipitation-happy in the 120hr-168hr period, but it's worth watching. 12z Euro prediction:

GFS/ECMWF have snow for Denver area on Wed night to Thu morning.