WINTER STORM NOW 12/08-11/2007: KS, OK, NE, MO, IA, CO, among others

[Jeff Snyder]

I continue to see mixed freezing rain and sleet. Most of the day, I'd say the predominant precipitation type at my house (on Waterloo E of I35 along the Oklahoma / Logan county border) has been sleet (IP), though we did have heavy enough liquid precip about 30 minutes ago that it started overflowing the gutters (granted, they're clogged with leaves that I haven't had time to remove, but it's interesting nonetheless). I'd say there's ~0.4" of glaze on the grass and branches, but the solid surfaces (i.e. my concrete driveway) has a good deal of sleet on it, so walking isn't too bad (the sleet acts to bite into the glaze ice a bit, giving a little bit of traction).

The Missing or Calm wind obs on the Mesonet can most likely be attributed to frozen anemometers. I just took a stroll down the road, and I'd say sustained winds are 5-10 mph.

I'm quite fascinated by the persistance of the quasi-stationary band of precip that started about 24 hours ago along I44. Asphalt roads are still largely just wet, not surprising given 2" and 4" bare soil temps in the 34-36F range (see http://agweather.mesonet.org/soil/default.html ). The freezing of the roads will be slowed a bit as the freezing process itself, as I'm sure we all know, releases energy (i.e. latent heat of fusion slows the freezing process). I'm still looking to get out tomorrow morning to take some pictures. Some of my favorite winter landscape pics involve glaze ice.

FWIW, news is reporting 100 auto crashed since last night, with 8 fatalities (a count that doesn't include a multi-fatality collision in Okemah along I40 that closed that interstate). Enhanced rainrates expected given possibility of convection yet again tonight. The 00z OUN sounding (http://www.spc.noaa.gov/exper/soundings/07121000_OBS/OUN.gif ) showed ~700 j/kg MUCAPE, with a very impressive warm nose (~10 C at 850mb... in December!). Interestingly, there's also ~45-50 kts of effective shear (~35kts at updraft base / 850mb / increasing to 85kts at the equilibrium level / ~300mb) which may promote a little organization to some of the storms.

EDIT: KTLX base velocity data indicate that the cold air is back down to near 2800-2900 feet in depth. If I recall correctly, the cold air deepened earlier this morning to near 4000 feet, so it's decreased in time lately. This is not surprising given the strength of warm air advection just above the cold dome. Eventually (most likely by tomorrow afternoon), the freezing line should move back northward. Of course, it's important to note that models have a strong tendency to underforecast the speed and intensity of these shallow arctic air intrusions, so I wouldn't be surprised to see subfreezing temps hold on a little longer than models forecast.

 

[Robert Rohloff]

No power lots of ICE

My power at the house has been out since 0430 hours, inside temp is down to 52 degrees. I have heard trees snapping all day last couple of hours my back yard tree is not sounding good. Have some power poles bent or breaking just NE of Owasso.

Last check I have seen about 3/4 to 1 inch of ice on some areas. If I did not state it before I HATE ICE STORMS............

 

[Jonathan Whitehead]

Well this isnt 2002. Some limiting factors here, one which OUN pointed out on their evening update, is light winds. Its one thing to get trees and powerlines covered in ice but they need help in going all the way over and that just isnt there. ALSO something i noted earlier and Jeff just did as well is ground temps. Unfortunately there was no extended period of 35 or below air temps prior to the beginnings of this storm in central OK, which means the ground/soil/roads have been slow to cool. Roads are obviously beginning to ice up but ground is not cooperating as such. Also doesnt help that area is expected to actually warm over the next 24.
So not a major ice storm event that will be remembered but a winter storm that will be the most notable of the year I believe.

 

[Dan Dawson]

The warming trend is interesting, given that the winds are still light out of the north. Since temperatures drop off toward the north, there should still be some weak CAA. I imagine that both sensible heating from the warm raindrops and latent heating as they freeze on contact with the surface are contributing to the slight warmup.

 

[Dan Dawson]

I am seeing some very strange flashes going on to the south. It's greenish in color: not sure if it is lightning or power flashes, but it is nearly continuous.

EDIT: The flashes have stopped, but I saw a few more off to the NE. I'm pretty sure they are power flashes, probably from trees falling on power lines. It was just particularly long-lasting.

 

[Jonathan Whitehead]

I am seeing some very strange flashes going on to the south. It's greenish in color: not sure if it is lightning or power flashes, but it is nearly continuous.

Dan you had me running outside and upstairs.
You sure your not seeing the reflection off the cloud of the beacon from Goldsby airport?
I live on campus, not sure what part of Norman your in as far as looking south goes

EDIT: my apartment face east so I have no way of seeing this even if i knew about it, unless i walked out door.

 

[Brett Roberts]

I thought I saw some strange flashes outside my window about 10 minutes ago (~12:20 CST) as well.

 

[Billy Griffin]

Still hearing an occasional clap of thunder and seeing a distant flash or two of lightning over here in SE Norman, OK. Streets here in the neighborhood continue wet, ice-free! However, everything else has about 1/4 - 1/2" of ice and it's still raining! Had one power hit about 30 minutes ago that made us all think, "this is it," but power came right back on (15 seconds or less).

1:25 AM CST - We're sure flirting with that magic 32 degree mark! 30 here in Norman, but I see just down the road, Pauls Valley, OK reports 34 degrees.
Wonder how much longer we'll stay at or below freezing? Coming a downpour here at the house as I type, and radar looks to be filling in with pockets of moderate to heavy rain all over southwest and south-central Oklahoma...... W O W !!!!!

 

[Angie Norris]

So much fun...watched some power flashes while helping a friend chip through about 1/2" of ice on her car so we could get home from work, then saw a few more in the vicinity of NE Moore/SE OKC on the drive to Norman. Got in about 10 minutes ago, accompanied by some thunder and another round of light freezing rain. Like Billy said, streets are just wet, but the trees and everything else look like they're encased in crystal. Temperature is 29 (per mesonet data) and radar is lighting up.

 

[Joey Ketcham]

2:30AM.. on and off freezing rain, been watching branches falling as well as seeing some power flashes.. power blinked for a moment. Everything is literally covered in ice here in Pittsburg, KS.

 

[Jonathan Whitehead]

3:15am: Awaken by loud clap of thunder....look at radar shows things have taken turn for worst. Instead of widespread scattered cells, now its a constant line with no breaks and lots of convection....not good for power, this now is becoming serious in terms of power

EDIT: BANG!!!!!!!! CG

EDIT: EDIT: see http://www.spc.noaa.gov/products/md/md2200.html (SPC MD 2200)

 

[Ben Prusia]

Just got home from work and EAX/TWX WFOs just issued an ice storm warning for just about their entire CWA for ice accumulations possibly exceeding one inch! Both the NAM and GFS 0Z models are indicating QPF of near 2" in and near the KC Metro Area; I am hoping it is not 2002 all over again...

 

[Rob Satkus]

In Norman, about 4:30am, light to moderate freezing rain ongoing. Have been hearing branches snap and crash to the ground for about the last hour or so, sounding like a gunshot followed by the sound of shattering glass. Just had a very large branch snap and bounce of the roof, landing on the walkway just in front of the door. Good thing no one was stopping by...(not that anyone would at 4:30am) but this was a big enough branch to cause serious injury. Amazed the power is still on. A few flickers but thats it. Can only imagine what this would have been like if temps were colder than what they have been. Very surprised to see streets are pretty much just wet. Several close cg's very early Sunday morning and again early this morning...enough to set off car alarms and knock the cable out for a few minutes. Hope to get some pics later...maybe I'll finally figure out to how to get them on here...I am such a technological simpleton.

Rob

 

[Mike Peregrine]

1-2" of ice is definitely enough to be concerned about. I don't even want to think about this being anything like 2002, but it sure looks that way. Woke up worried about what's coming today and noticed the warnings. EAX has a new web briefing on the event here. I was hoping to avoid this, but it looks like we're going to get nailed. Surface temps here have been in the low 20s for several days now, so when rain falls, there will be no wet pavement. It's pretty much going to freeze instantly. I doubt if many of us will be posting online after tonight. Bye bye electricity. It was nice having you -

 

[Anthony Silver]

1-2" of ice is definitely enough to be concerned about. I don't even want to think about this being anything like 2002, but it sure looks that way. Woke up worried about what's coming today and noticed the warnings. EAX has a new web briefing on the event here. I was hoping to avoid this, but it looks like we're going to get nailed. Surface temps here have been in the low 20s for several days now, so when rain falls, there will be no wet pavement. It's pretty much going to freeze instantly. I doubt if many of us will be posting online after tonight. Bye bye electricity. It was nice having you -

Not looking good at all for the KC area!....from the latest EAX AFD:

A SIGNIFICANT AND POTENTIALLY DAMAGING WINTER STORM APPEARS LIKELY LATE TODAY THROUGH TUESDAY. AN UPPER LEVEL LOW WAS NEARLY STATIONARY OVER THE BAJA OF CALIFORNIA WITH A WEDGE OF TROPICAL MOISTURE SURGING NE AHEAD OF THE SYSTEM. AT THE SFC...THE COLD FRONT WAS ACTUALLY STILL PRESSING SLOWLY SOUTHEAST INTO EXTREME SRN ARK AND SERN TX. THE BOUNDARY MOVEMENT AND THE AMOUNT OF WARM AIR THAT CAN RETREAT NORTH IS CRITICAL FOR DETERMINING ICE ACCUMULATIONS...ESPECIALLY FOR THE SRN GRIDS. GIVEN THE DEPTH OF THE COLD AIR...AROUND 125MB..AND CURRENT PLACEMENT OF THE FRONT...MODELS APPEAR MUCH TOO EAGER TO WARM SFC TEMPS THROUGH TUESDAY...ESPECIALLY GIVEN THE FACT THAT A REINFORCING SHOT OF COLDER AIR SPREADS SOUTHEAST DURING THE DAY ON TUESDAY. THIS IN RESPONSE TO THE NORTHERN BRANCH SHORTWAVE OVER THE NRN PLAINS SHIFTING EAST.

Might as well call KCPL now and tell them my power is out, that way I'll have it back on by Friday and not have to wait 2 1/2 weeks like I did in '02!