January '10 Weather Discussion

[OKCisOK4me]

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 ;-)

[Thunder]

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.

[oknacreous]

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.

[venture]

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/nwp...m_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/nwp...m_pcp_084l.gif

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

[drum4no1]

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.

[venture]

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.

[Thunder]

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.

[venture]

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.

[drum4no1]

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

[oknacreous]

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.

[sacolton]

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

[Thunder]

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

[rod4soonrs]

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

[venture]

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.

[Thunder]

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?

[venture]

OUN's first stab.

[adaniel]

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.

[OKCisOK4me]

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!

[westsidesooner]

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

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.

[venture]

I found the answer to my own question

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

Oklahoma Department of Emergency Management - Winter Weather Event 20071209 - Master

[venture]

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).

[silvergrove]

How about a minimum potential forecast? Haha.

[venture]

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

[OKCMallen]

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..

[venture]

Ugh, causing panic will do no good.