Okay here we go. Significant winter storm is increasing likely for this week. I'll do snowfall forecasts starting tomorrow.

GFS tonight has push cold air up into Thursday morning now. Freezing line should be from Hollis to Chickasha to Lawton to Purcell to Okemah to Fort Smith....give or take. Heavy precip now looks like it will arrive around the same time. Accumulations north of I-40 will be generally in the 1-3" range through 12PM. South of I-40 is another storm. Tricky gradient here since we'll likely see an idea of sleet between the snow and rain. We may see an area of 3-6" (isolated up to 8") from I-40 to the freezing line area. This is assuming 100% snow, which won't happen. So these are worst case scenario right now.

Moving into the 12PM to 6PM time frame, cold air is pushed through. Western OK will see roughly 1-3" of snow. Central OK will potentially have an enhanced area of snow drumping another 5-8" of snow with isolated amounts up to 9-10". Then a slight break of lower snow amounts and then the heavy rain/storms in SE OK.

6PM to 12AM Friday we'll see things taper off pretty quickly. Maybe another 1" of snow Central and West, another 1-3" East.

Wind will be 20-30 mph with gusts to probably 40 mph possible...nothing near the 09 Blizzard. This however will likely be a heavy wet snow with minimal drifting. As of right now, with the worst case scenario...

Ponca City: 1-3"
OKC/Edmond: 6-12"
Norman/Purcell: 8-14"
Ardmore: 5-8"

You all know the drill. Way far out. Things can't change. Storm track, speed of the cold front, and the availability of gulf moisture all are key here. If models stay on track, we'll probably see winter storm watches go up sometime Tuesday for all day Thursday.

Ponca City: 1-3"
OKC/Edmond: 6-12"
Norman/Purcell: 8-14"
Ardmore: 5-8"

You all know the drill. Way far out. Things can't change. Storm track, speed of the cold front, and the availability of gulf moisture all are key here. If models stay on track, we'll probably see winter storm watches go up sometime Tuesday for all day Thursday.

Venture, you do realize the typo? Highlighted in bold red. :LolLolLol

Your complete post brought a smile to me. Just try to keep it at that (prefer much more). :-)

I am also happy that this is my day off. :-D

It was late and typos happen. LOL

Hold the phone. Forecast soundings show a significant amount of warm air aloft and a shallow cold air mass when a lot of the precipitation falls Thursday. I'm thinking central Oklahoma gets considerable freezing rain and/or sleet. Generators fired up and ready?

Hold the phone. Forecast soundings show a significant amount of warm air aloft and a shallow cold air mass when a lot of the precipitation falls Thursday. I'm thinking central Oklahoma gets considerable freezing rain and/or sleet. Generators fired up and ready?

The Tulsa weather service (and some ST posters) seems to be fairly concerned with some ice with their forecast showing .25-.32" of ice before the snow. Which isnt terribly signicicant but could cause some power outages if the wind picks up. Granted thats for NE OK. OUN seems to be leaning towards a quicker changover to sleet. I tend to agree. I could do without the ice....the tress here never recovered from the last couple of ice storms. Be interesting to see what the next few model runs show. My generator is ready and I'll top off the gas can just in case..........

12Z GFS slows things down a bit...with the cold air not making it very far south until later Thursday. This, from what I can tell, it putting it a bit more inline with ECMWF.

Hold the phone. Forecast soundings show a significant amount of warm air aloft and a shallow cold air mass when a lot of the precipitation falls Thursday. I'm thinking central Oklahoma gets considerable freezing rain and/or sleet. Generators fired up and ready?

Sweet! I could finally use my hand cranked weather radio my parents bought me after the last ice storm! Although I could do without busted trees everywhere. That just might be the end of any sort of large tree cover this area has for a long time.

In all seriousness, I don't know how this relates but I'm thinking that right before the big Christmas snowstorm we were already in a pretty cold pattern, if my memory serves me right, so we didn't need some giant cold blast sweeping down from the artic. With this setup, we have been very warm lately. Doesn't it seem like we need a real kaunah of a cold front to bring in enough cold air into all layers of the atmosphere? Most news stations are predicting a high of 30-32 on Thursday, technically below freezing but not enough to make me think we are in for a huge snowstorm, but perfect for an icing event. Now whether thats the high at 1 am and the temp falls during the day or something similar, I don't really know. It could just be news stations are playing it conservative because winter weather in these parts is so hard to predict.

I could be completely off but I just don't see the pieces coming together for a snowstorm.

Just curious in case anyone knows the answer. Whats the most snowfall OKC has recorded in one season?....I can't seem to find that info.

The Winter Storm Watch is officially up. (http://kamala.cod.edu/offs/KOUN/1001251736.wwus44.html) Nearly 3 days before the event, illustrating the potential significance of the storm. Still too early to be sure what areas get the significant icing, what areas get the most snow, and where it will be mostly rain.

Yeah, that's crazy. Though after I posted last night I did think to myself that I wouldn't be shocked if they did it today if the models kept looking insane. I'm going through things right now, and this is going to be right on the edge of going one way or the other. Both GFS and WRF are insane on precip amounts with this thing, and the Metro impact looks a bit...interesting.

Let's look at the first "interesting" time period...12PM Thursday. Everything before this will be south of I-40 and rain, so I'm not interested in it right now.

By 12PM Thurs the surface freezing line will be close to an Altus...Lawton...Pauls Valley...Eufaula...Tahlequah line. In some of these points, its north of these cities, but if I picked some random town most wouldn't know where I'm talking. :-) The freezing level at 850mb (couple thousand feet up) however is going to be from Elk City to Weatherford to Watonga to Enid to Ponca City. So the area south of the 850mb freezing line and north of the surface freezing line is here things will get tricky.

Precip amounts will be in a very tight gradient across this area. Wooward to Enid to Bartlesville and north will see little to no precip in this time frame. Areas from Elk City to Weatherford to Watonga to Enid...and to the north and west (but not north of the previous line) will see snowfall amounts generally 1-2". Sleet will then likely be occurring in a band just south of this around the I-40 area and north. Liquid accumulations with this area in the 0.25 to 0.5" range. South of this area it looks more likely for a freezing rain setup or just outright rain. It depends if surface temps can fall enough. Rainfall of 0.5 to 1.0" looks like a good bet in these areas and could pose significant icing issues if the surface temps fall fast enough and upper air temps evolve as forecasted.

Moving along...6PM Thursday.

850mb Freezing line is running from Wichita Falls to Duncan to Pauls Valley to McAlester to Tahlequah.

Surface freezing line is running from Childress to Lawton to Pauls Valley to Okmulgee to Muskogee to Tahlequah.

Situation transitions away from an icing threat to more of a snow or rain setup. Generally here in areas west of I-44 and west of I-35 (north of the city) snowfall amounts should be generally light in the 1-2" range. We'll then probably see a band somewhere of 3-6" along or near I-44. Then an enhanced area of snowfall or (snow/sleet/rain mix) in areas from Chandler to Broken Arrow down to Muskogee to McAlester to Ada to Shawnee and back up to Chandler. Depending on how things go, could see over 6" in that area, depending on how wet the snow is or how mixed with sleet/rain it becomes.

12AM Friday

All freezing boundaries are now aligned in extreme SE OK, so won't bother laying them out anymore. This will be a period of resurgent wrap around that will focus snowfall in areas where the upper system tracks. Heavy snow/sleet continues in Eastern OK. For the rest of the state the Central and Western 2/3rds will see a general 1-3" accumulation with some pockets of 3-5" general near and north of I-40. Focus right now is on the area to the NW Side of the Metro and out in Western OK between Woodward and Elk City.

6AM Friday

System is slowly moving away. The pocket of snow in Western OK is now moving through Central sections, with a general 1-2" accumulation with 3" amounts on the NW side by Watonga and Fairview. This activity should taper off by noon.

So that's pretty much how it looks, and of course will change a few more times as we get closer. :-)

By 12PM Thurs the surface freezing line will be close to an Altus...Lawton...Pauls Valley...Eufaula...Tahlequah line. In some of these points, its north of these cities, but if I picked some random town most wouldn't know where I'm talking. :-) The freezing level at 850mb (couple thousand feet up) however is going to be from Elk City to Weatherford to Watonga to Enid to Ponca City. So the area south of the 850mb freezing line and north of the surface freezing line is here things will get tricky.

Precip amounts will be in a very tight gradient across this area. Wooward to Enid to Bartlesville and north will see little to no precip in this time frame. Areas from Elk City to Weatherford to Watonga to Enid...and to the north and west (but not north of the previous line) will see snowfall amounts generally 1-2". Sleet will then likely be occurring in a band just south of this around the I-40 area and north. Liquid accumulations with this area in the 0.25 to 0.5" range. South of this area it looks more likely for a freezing rain setup or just outright rain. It depends if surface temps can fall enough. Rainfall of 0.5 to 1.0" looks like a good bet in these areas and could pose significant icing issues if the surface temps fall fast enough and upper air temps evolve as forecasted.



This is a stupid question, but what is the criteria for an Ice Storm Warning, and how much ice do you think it will take to start causing significant problems to the power lines and trees? I know the weather service recently came out with a new chart...that explains what damage 1/4", 1/2" of ice can do but I can't find it either. I'm having issues with research today I guess. I see on Meteogram they are expecting winds of around 20-30 during the precipitation. In all honesty would you expect major outages in the metro Thursday V?

I remember the very light icicng a few weeks ago caused some disruption along the north side of town......was that because of the wind or the harmonics of the lines that night?

I know....stupid question. I'm just trying to remember how prepared we should make ourselves in the event of say 1/3 inch of ice and 30mph winds? I have a tendency to over prepare and don't want to be a chicken little. I just get excited.......pre spring storm disorder maybe. lol

Ice Storm Warning from NWS:


This product is issued by the National Weather Service when freezing rain produces a significant and possibly damaging accumulation of ice. The criteria for this warning varies from state to state, but typically will be issued any time more than 1/4" of ice is expected to accumulate in an area.

Not sure what threshold Norman will use. If winds are up in the 20-30 mph range with more than a half inch of ice, I would save power outages would probably happen just from trees falling. I also give up understanding OGE's grid as power can go out for no reason some days and yet never went out during the blizzard or a severe storm.

We'll probably see a combination of warnings across the area...with some counties having more than one but in alternating time frames.

1/4" of ice accrual on exposed surfaces is the general rule for an "ice storm warning" for the reasons venture noted, but it can be modulated up or down at the forecasters' discretion based on the expected wind speed (higher winds mean more branches and power lines down) and may also be adjusted based on the expected accumulation on roads. Generally in storms like this one the band of significant icing is fairly narrow (maybe only 50-100 miles wide) and forecasting the right location of that is usually far more difficult than the forecast for winds and road surface temperatures.

Latest data suggest central Oklahoma will run the gamut of precip types during daylight hours Thursday, starting off rain, going to freezing rain for awhile, then to sleet, and finally to snow. In cases like that generally a blanket "winter storm warning" is used to cover the whole mess. It will be hard to tell how much of each type any given part of Oklahoma will get, but it should gradually become more clear the next couple of days.

KFOR has posted a storm totals map. I'm assuming this will change...

http://services.trb.com/kfor/fire.jpg

KFOR got it right on and of course, they will continue to change that map. A new one tonight, then so on for the next few days. This is something that we will expect, but the only thing left is the timing and storm tracks.

Note: That graphic above was not saved and reuploaded. It is linked from KFOR, so it will change each time they upload a new graphic.

KFOR got it right on and of course, they will continue to change that map. A new one tonight, then so on for the next few days. This is something that we will expect, but the only thing left is the timing and storm tracks.

Note: That graphic above was not saved and reuploaded. It is linked from KFOR, so it will change each time they upload a new graphic.

And you forgot to mention the key term 'dry slot'. We'll see what happens. Yes, I didn't save the image so that's cool that it will change ;-)

I swear, if a dry slot comes up, my brains gonna be all over the wall! That's how angry I get when dry slots ruin our amazing weather. Geez, I can be so dramatic.

I have a feeling there may be some rather wild snow predictions on the 10 o'clock news tonight. When you hear them, keep in mind that there are still a lot of things that could cut down on the snow totals, such as sleet/freezing rain mixing in, or the dry slot.

Evening NAM run has slowed WAAAAY down. Everything is rain until Thursday evening, except for some light snow on the north side in the NW 1/3rd of the OK. Accumulations are all less than 2". However, the forecast for the midnight period is interesting. Some pretty monster totals along (and north and south) of I-44. There is a large area of 1 to 1.50" of liquid precip forecast in this area...depending on the water content of the snow, this could push some pretty high amounts.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/00/images/nam_pcp_078l.gif

Through Friday Morning NAM has everything snow except far SE OK. Again, some extremely heavy precip amounts.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/00/images/nam_pcp_084l.gif

GFS is running now, we'll see where it sits when it spits out this timetable.

Ill pay dearly for a dry slot to ruin this. I dont feel like sliding 23 miles to work only to have to stay 32 hours working with no sleep. Well hopefully it stays all liquid through thursday evening.

GFS is agreeing with NAM at this point. Above freezing with mostly rain into Thursday evening. After change over, precip will start to fall off pretty past. Looks like mostly 3-6" accumulations in areas west of I-35. Higher amounts east of I-35 and especially in NE OK.

As usual...thing swill bump around a bit.

Venture, I hope you watched Mike's forecast tonight. He was pretty much being a professional and not "over hype" this storm. He compared this storm potential to the last blizzard. He kept stating that it is unknown at this time what exactly we will get at certain times.

I don't see the comparison to the Christmas Eve Blizzard except for a high impact storm. This isn't setup to be pure snow storm with extreme winds. However, with the changes to the evening models, it does tend to limit the potential for widespread severe icing.

That may be the best news I have heard all year.

The morning NAM model run is still insisting on considerable warm air aloft, any my experience is when this is predicted it usually happens, so freezing rain and sleet is still my expectation for the dominant precipitation type. It looks like we don't get cold enough for significant travel impacts until afternoon Thursday. Event ends as snow Friday morning. My current expectation is 1/4 to 1/2 inch of ice and 1-2 inches of sleet in the OKC area Thursday afternoon and night, with snow ranging from an inch or two south of Norman to 4-6" Guthrie/Stillwater late Thursday night into Friday morning. Bigger snow totals up around Enid/Woodward.

I'm leaving work at noon on Thursday to beat the mess this storm is going to create on the roads.

Venture, tell us that we'll still see lots of the white stuff.

Rick Mitchell is coming around to the ice event in his blog.

Mmmk, here is my take. Going to go by time period and compare NAM and GFS since they do have some slight differences. Biggest one is going to be GFS is a little faster with cold air moving in, and NAM is a bit slower and as stated above...if slower moving cold air is almost always the case. The tricky part is getting the liquid to snow ratio down for this, for which I think we'll have a wetter snow and there for we'll probably see a 1" to 6-8" liquid to snow ratio.

Thursday 12PM

Rain is moving in and will generally be along and south of I-40 from border to border. Surface temps should be above freezing most areas where precip is occurring, except for an area around Weatherford, Elk City, and Sayre. Those areas may see a transition to freezing rain this early. GFS has the cold air a bit further south from Mangum to Chickasha to Norman to Okmulgee. It also has heavier precip in Central OK at this time - over 1" of liquid. NAM is much more on the light side with generally less than a quarter inch liquid in most areas except for heavier rain in South Central and SE OK where amounts could hit an inch.

Metro Impact: Light to Moderate Rain around 0.25"


Thursday 6PM

Let the fun begin. Surface freezing line pushes near a Frederick - Lawton - Norman - Muskogee line...unless you are GFS and it is already from Ardmore - Atoka - and east into Arkansas. We'll go with NAM on this for now, precip values are pretty equal between the two, so we are good there. Areas of moderate to heavy snow will be occurring in the TX Panhandle into sections of extreme Western OK around Woodward and north of I-40. This snow should be expanding east into areas around Fairview, Enid, Ponca City, and close to Stillwater. It should be noted that far Northern OK may not see a whole lot in this time period. South of the snow area will be warmer temps aloft and freezing temps at the surface. We'll have a transition from Sleet to Freezing rain as you go farther south. Watonga, Kingfisher, near Stillwater should see mainly sleet. Areas from SW OK between I-40 and I-44 and into the Metro area and NE along I-44 will see mainly moderate to heavy freezing rain. Liquid accumulations in these areas will be between a half inch to an inch of rain...so we could see near or more than a half inch of ice in most locations.

Metro Impacts: Moderate to Heavy Freezing Rain, >0.50" of accumulation possible.

Friday 12AM

Colder air is moving in up stairs, so a change over to snow is pushed into motion. The tricky part here is how much water content the crystals will half and this could send snow fall amounts from a 3-6 to a 6-12 situation. Freezing Rain/Sleet/Mix will be primarily in SW OK from around Duncan up through Ada, McAlester, Okmulgee, Eufaula, Muskogee, and to the east. Significant icing is still probably in these areas. North and West of these areas we'll see primarily snow. Generally a swath of 3-6" in most areas is pretty on target, lower amounts as you get closer to the TX Panhandle. It does appear we'll have a heavy snow band setup somewhere around Central and NE Oklahoma. Best guess right now is for this to setup from Enid to Kingfisher to Lawton up to Norman to Chandler to Tulsa and Bartlesville back to Ponca and Enid. A dumping of around 6-12" is a good possibility in this area, but there is no way to say who is going to get the 6 and who will get the 12. Also if any residual sleet is mixing in or the water content is higher than expected, snow fall amounts will be lower.

Metro Impacts: Moderate to Heavy Snow, some Sleet; 6" of snow, maybe up to 10-12" in spots.

Friday 6AM

Dry slot is well on its way in pushing through. Most snow from the first push will be coming to an end. Could still see sleet/freezing rain in areas east of Ada and south of I-40 in SE OK. NE OK will likely still be seeing some light to moderate snow, with light snow still possible Along I-40 to the west and North and along I-35 both north and south.

Metro Impacts: Light Snow maybe another 1-2"

Friday 12PM and later

GFS and NAM differ here. GFS has most precip ended, while NAM wants to develop snow under the upper low as it tracks across the state. This part of the forecast is pretty low confidence right now, but if NAM verifies we can see a swath of 1-3" in SW to Central and NE OK through Friday. Some areas, where any bursts in convection appear, could see over 3".

Metro Impacts: Light Snow, maybe another inch or two if snow develops.

Rick mentioned that the storm is slowing down. Maybe that is what the NAM is picking up on. How are they able to know the speed of a storm? GFS will probably pick up on that soon. If the storm is indeed slowing down, then that will give the cold air time to arrive. Thoughts?

http://www.srh.noaa.gov/images/rtimages/oun/fxc_Hazardous_Weather_Outlook.jpg?timestamp=126452 9659

OUN's first stab.

Hmmm, interesting map.....

I don't know if they are trying to alarm people into watching, but Channel 9 says this storm is forming together in a way very similar to the December 2007 ice storm.

Hmmm, interesting map.....

I don't know if they are trying to alarm people into watching, but Channel 9 says this storm is forming together in a way very similar to the December 2007 ice storm.

In a totally sarcastic way....lovely!

Just curious in case anyone knows the answer. Whats the most snowfall OKC has recorded in one season?....I can't seem to find that info.

I found the answer to my own question :irule:

25.2" 1947-48

http://downloads.newsok.com/knowit/okcsnowfall.pdf

Next question.....anyone remember how much freezing rain was responsible for the 12/07 ice storm in the metro.....I'm thinking it was about 1/2-3/4"?........with hardly any wind!!!!! That could make a huge difference this time.

I found the answer to my own question :irule:

25.2" 1947-48

http://downloads.newsok.com/knowit/okcsnowfall.pdf

Next question.....anyone remember how much freezing rain was responsible for the 12/07 ice storm in the metro.....I'm thinking it was about 1/2-3/4"?........with hardly any wind!!!!! That could make a huge difference this time.

Bit higher than that. :) Most areas were well over 1" of ice with some having nearly 3" of ice.

National Weather Service - Norman, OK Forecast Office (http://www.srh.noaa.gov/oun/climate/get_f6.php?city=okc&month=12&year=2007&fontsize=3)

Oklahoma Department of Emergency Management - Winter Weather Event 20071209 - Master (http://www.ok.gov/OEM/Emergencies_&_Disasters/2007/Winter_Weather_Event_20071209_-_Master/index.html)

Okay so here is my doomsday forecast. LOL This is the best blend that I can go with right now. The snowfall forecast, i can state this clearly enough, is a max potential if we see the cold air in the upper levels move south as projected. If it slows any, we'll see higher ice amounts and lower snow amounts. The one key to take away, where the heavy snow fall amounts are, that could easily mean another inch of ice if the transition doesn't take place fast enough. As for the ice accumulation forecast, I am pretty conservative here. There will probably be some thunderstorms around as well, so if the temps are below freezing - the amounts will increase a ton.

General rule of thumb. This is a broad brush of where things may end up, but only a few areas in the zones may actually hit these maximum values. Just like with the 09 Blizzard...the extreme snow totals were isolated to specific areas, this is no different. I'm also not 100% ready to bite on calling for nearly all sleet/freezing rain for everywhere but the northern tier of counties in OK (see News 9's forecast at noon).

http://www.anvilcrawlers.com/coppermine/albums/userpics/10001/okstorm-jan2010-ice.png

http://www.anvilcrawlers.com/coppermine/albums/userpics/10001/okstorm-jan2010-snow.png

How about a minimum potential forecast? Haha.

Going to get the Live Blog thing going again for us. I'll see if it will let me leave it open for an extended period of time. I won't be available all the time, but something to use as the storm gets closer.

Live Severe Weather Coverage Dis (http://www.anvilcrawlers.com/livechat.html)

Supposed Jed CAstles quote:

Remember me saying we will never see another storm like this in our
life time after the Christmas Eve Blizzard?....This one will make us
forget about that one. This is turning into a catastrophic ice storm
then snow storm. Honestly, I almost am in disbelief?! I am as serious as
I can be: For those across central OK, prepare yourselves to be without
power for a while starting late Thursday..

Ugh, causing panic will do no good.

18Z NAM continues the trend - more ice, less snow. I'm going to bump my freezing rain forecast for OKC up a bit, now 1/2 to 3/4" ice, 1-2" sleet, and around 2" snow.

Okay so here is my doomsday forecast. LOL This is the best blend that I can go with right now.

Just like always my pc isn't picking up on the two images you have posted. I think it doesn;t like ".png" images. Could you give me a text version of what you think the westside (Bethany) area will recieve. In general of course.......and again thanks. I'm trying to decide if I need to go get a second gas can for the generator before the storm hits so I don't have to get out once it starts.......council groves can be a nightmare when the trees start crashing.

I'll start putting them up at JPGs. :-P

That part of town, taking into consideration the 18Z NAM which still has a significant amount of precip falling (oknacreous, trying to go as conservative as possible?)...Ice probably 0.5 to 0.75, though do not be shocked to see over an inch in areas especially with thunderstorms in the area. Snow, I'm sticking with the 6-12" for the metro as a good estimate right now with the amount of Sleet expected. Less sleet, we have the potential to be pushing the top of the scale. This will be a close one for the Metro. Some of us will be right on, the others will be way off. The boundary between frz rain/sleet/snow is going to be so close, it would be shocking to see the North Metro have a ton of snow and South Metro a lot of freezing rain.

I'll start putting them up at JPGs. :-P

That part of town, taking into consideration the 18Z NAM which still has a significant amount of precip falling (oknacreous, trying to go as conservative as possible?)...Ice probably 0.5 to 0.75, though do not be shocked to see over an inch in areas especially with thunderstorms in the area. Snow, I'm sticking with the 6-12" for the metro as a good estimate right now with the amount of Sleet expected. Less sleet, we have the potential to be pushing the top of the scale. This will be a close one for the Metro. Some of us will be right on, the others will be way off. The boundary between frz rain/sleet/snow is going to be so close, it would be shocking to see the North Metro have a ton of snow and South Metro a lot of freezing rain.

Venture, Do you have a Twitter feed? I'd subscribe sooo fast! Putting all your stuff along with your cohorts with a hashtag of say #OKWX would be awesome.

Venture, I'm using the NAM forecast soundings (http://tinyurl.com/y8ojjtt) which indicate a warm nose persisting up around 750 mb until at least late evening on Thursday. It's right on the melting line for several hours, so your prediction about a sharp gradient in snow totals across OKC is very plausible. This strongly reminds me of an event a couple of years ago where 10-15" of snow was predicted for OKC and the sounding was "oh so close" but the nose of warm air advection aloft won out in the end and we ended up with 3" of sleet and very little snow.

@Mike - I have venturewx (venturewx) on Twitter (http://twitter.com/venturewx) setup. Going to try to work in some more things through anvilcrawlers.com to try to have a more focused location to find any information. Something we really didn't have for the Blizzard.

@oknacreous - Okay, we are both looking at the same thing then. Yeah I agree that this is very similar to that event from a few years back. Hopefully things get a bit more clear later this evening with the next set of runs.

Thanks V....

I know these things can be really difficult. esp. this far out. And I know how much difference a few miles can make. We had a crippling icestorm (can't rmember if it was the 2001 or 2002 storm on the west side of OKC while the east side and Norman got off very lightly. To this day that one storm did the most damage to our property (more than even the 2007 storm....maybe because all the trees were already trashed) and we were without power for over a week. I appreciate the updates.....looking forward to the live blog....least til we lose power. :-( Starting to think I'm going to miss the old battery operated tv's...

18Z GFS has gone colder it appears. Ugh.

So I should panic right now. No power = Dead fish. My heat comes from 2 portable electric heaters. :-(

Guys at stormtrack say there is a dry slot showing up. Any chance that can move in keep us from ice? Also Venture, you say it has become colder, would that suggest more snow than ice?

18Z GFS has gone colder it appears. Ugh.

Does this enhance the probability of an icing event?

Also, I'm really curious as to what data these news stations are using as they are all over the place right now. KFOR is prediciting hardly any ice but 6-12 inches of snow, KWTV is showing a dusting of snow but a "cataclysmic" amount of ice, KOCO is in between the two but leaning towards more snow now.

My secretary watched Jeff Castles on her computer at lunch today as was downright startled.

EDIT: My cousin who is a night stocker at Wal Mart tells me they are already bracing for extra shipments of ice melt, shovels, etc. So no fighting and panicing tonight at the store people!

Guys at stormtrack say there is a dry slot showing up. Any chance that can move in keep us from ice? Also Venture, you say it has become colder, would that suggest more snow than ice?

Do...not...say...the...two...words. :beaten_fi

Do...not...say...the...two...words. :beaten_fi

Yeah, I hear ya. If there was no mention of an ice storm, I wouldn't mind the foot of snow. But........... I would take a dry slot any day over an ice storm. Ice storms are terrible, I don't wish them on any town/city.

OMG!! Is anyone watching channel 4 news right now? Mike Morgan is hilariously over-dramatic!! I know this storm looks like it'll be a doozy, but mike just makes it seem like its the end of the world!

Colder upper air temps would push us more to a sleet or snow event and away from Freezing Rain. Which I think most of us would prefer. LOL

The dry slot...couple things that show it well from the NAM 18Z that the guy on StormTrack was talking about:

http://grib2.com/nam/CONUS_NAM218_ATMOS_BRF_57HR.png
http://grib2.com/nam/CONUS_NAM218_ATMOS_BRF_60HR.png

Dry slots typically well stop most of the significant precip for a time (depending on wrap around) and you'll normally see light freezing rain or freezing drizzle then. It doesn't look like the dry slot will get north of I-44 at this time, but this goes back to what was said early. We can end up seeing a tight gradient in precip amounts just across the Metro.

WTF is a dry slot!? :)

WTF is a dry slot!? :)

It is when the storm starts to wrap in drier air on the back side. It'll move up into the circulation and start to cut the precip off in the areas it moves over, and eventually start to weaken the storm if it gets pulled in far enough.

Gotcha.

We're all amateur meteorologist in the 405. :D

Does anyone know if the Norman NWS office (or any one else) has a link to a Sperry-Piltz ice forecast map for central Oklahoma like this one for northeastern Oklahoma from NWS Tulsa?

Sperry Piltz Utility Ice Damage Index (http://www.srh.noaa.gov/tsa/?n=badice)

00Z model runs are basically status-quo. NAM is still warmer aloft so more ice and less snow (in general). GFS gets cooler faster and throws OKC over to snow early enough to get quite a lot. The million dollar question is whether 1) the difference lies in the fact that the NAM's vertical and horizontal resolution is better so it is able to depict the nuances of the thermodynamic structure of the system, or 2) the GFS is simply depicting something different. Based on the SREF output it's probably a combination of both.

I should have mentioned earlier I was being Norman-centric in my forecast so I'll be more generic for all of central OK here. Best chance of significant icing (3/4 to 1") and power problems is in the band from Lawton/Wichita Falls and Duncan to Purcell/Pauls Valley to Henryetta. Best chance for significant snow is in the band from Cheyenne to Enid and Ponca City with a foot of snow possible (and near-blizzard conditions). In between I still think the dominant precip type will end up being sleet, but with a significant gradient in snow totals across OKC - 1 to 2" southeast of Norman and 5 to 7" up around Piedmont. Things start going downhill rapidly midday Thursday.