A couple of trends I've noticed so far today...

- The models are way too warm in the short term.

At 17z (11am) the temperature in Norman, OK was 26.1F at the mesonet. That is much colder than the models thought it would be at that time. The 12z NAM was predicting an 11am temperature in Norman of 34.2F and the 06z GFS thought the temperature would be up to 34.3F at noon (which is looking highly unlikely since it is still 27.5F at 11:45am). update: actual noon temp was 27.9F

- Precipitation to our south and west is slightly greater in extent and intensity than some of the models were predicting for this time frame.

11:08am actual southern plains radar image: http://imageshack.us/photo/my-images/29 ... lains.gif/

14z HRRR composite reflectivity forecast for 11am: http://rapidrefresh.noaa.gov/hrrrconus/ ... fc_f03.png

12z RUC composite reflectivity forecast for 11am: http://www.twisterdata.com/data/models/ ... URFACE.png


Whether or not these trends will continue or have any impact on the forecast for tonight is yet to be seen. I just wanted to bring attention to them so that we can start to get a handle on how well the models might/might now be handling this developing event.

The Weather guys are calling for a High of 48.. I don't see it, at noon it is 35 and not rising very fast. RUC sees us getting up to 38-39 at the highest.

The snow line looks like it is quickly approaching the I-35 corridor, including the OKC metro from the southwest:

http://www.wunderground.com/radar/radbl ... rainsnow=0

Won't be too long now before the first few flakes start flying..

Light snow in south Grand Prairie.

An on air met just broke into news9 and said the following...

- Some parts of western Oklahoma have already reported 3-4" of snow

- A highway trooper under one of the heavier bands out west was reporting "whiteout conditions"

I cannot confirm these reports, but I thought they were interesting for sure. Definitely appears as though this storm could be a little worse than first thought in some locations.

8:08pm: I'm starting to receive a few light snow flurries

8:55pm: Flakes becoming a little more frequent. Still pretty hard to spot though since they are quite small.

9:03pm: Now a legitimate light "snow shower". Can easily see the tiny flakes dancing in the lights outside.

9:27pm: Tops of cars are starting to show a hint of white as intermittent light snow showers continue.

9:45pm: Coming down moderately now, everything gradually becoming coated.

10:18pm: Heaviest snow of the evening (so far) coming down right now. Grass has turned mostly white, and the snow is just starting to stick to the sidewalks and roads.

12:09am: Snow still coming down at a good clip, but it looks like it might be ending pretty soon. Haven't been out to measure, but grass, cars, and roof tops are all covered. Roads and sidewalks are white too. I would estimate that we probably have somewhere in the vicinity of 1-2" accumulated at this point.

12:25am: Looking at the radar and out my window, it appears as though this final 30-60 minutes of snow might be some of the heaviest of the event.

1:16am: Looks like the main show is winding down. There are a few more isolated bands out west, and a couple more could develop overnight (or even some freezing drizzle), but overall the main "meat" of the storm looks to be over. It was definitely a nice snowfall in the end. Nothing dramatic, or even close to a crippling winter storm/blizzard, but certainly more than just a run of the mill dusting. Based on visual estimation alone, I would say that we wound up with close to 1.5-2.5" here (on the grass). Just enough to cover everything and make it look like winter, but not enough to cause severe issues. Roads will still probably be a little messy for the morning commute though since they all have a nice layer of white on them (supposedly ~1" according to a friend that measured on a sidewalk), but they should clear up quickly once the temperature rises above freezing during the late morning hours.

8:21am: Looking at reports, there were a few more light snow/sleet showers overnight. Didn't add too much to the accumulation though. Right now we are actually getting another decent sleet shower moving through as I speak. I can hear it hitting the windows.

Ok so now that it has started to snow in OKC I am gonna try and do some 3D filming. Lets hope it looks good

First flakes finally flying after the atmosphere had to moisten up, didn't start slow either, good moderate snow right now.

Snow has completely covered the ground now, but the dry slot is coming in fast, should shut off the precip for a little while before more develops.

2.1 inches and coming down hard, but it is about to end for a bit. A pretty heavy band set up right over me.

I ended this even with over 4 inches, not bad. Sleeting right now before it ends.

Lots of freezing fog around here overnight and into this morning. Now that the sun has risen and the fog is starting to mix out, we are actually also getting some very small, fine snow flurries outside (at least where I am). Definitely ice crystals falling and not freezing drizzle, and they have actually lightly accumulated on my window sill.

update: It's pretty odd though, since ice nuclei usually need temperatures of at least -4C, but typically even colder than that to activate and become ice crystals. Temperatures at surface level at the time were only near 30F (-1C), and the 12z skew-t didn't show temperatures cold enough (below -4C) until well above the fog layer. hmmm. I'm going to have to think about this one for a little bit.

Update 2: just took a quick walk around outside, and it was snowing in some places and not in others. I think it might be related to the heating units on/around the buildings (perhaps they are helping to lift the ice crystals associated with the rime ice and seed additional flake development?). Definitely just a strange feeling morning out there. Foggy with scattered pockets of light snow. Crazy to think it should be in the 50s this afternoon!