January '10 Weather Discussion

[drum4no1]

Well they are screaming snow around the 28th and 1st of Feb. If im looking at the GFS correctly the 28th seems to be to warm for snow and the first looks possible for us maybe more towards the east. Either way it looks to be back in a colder pattern starting in a few days.

[Thunder]

Remember when Mike warned us all about that Blizzard? He saw something the rest of the others did not. Fair enough, that Blizzard came and went.

[Bostonfan]

Remember when Mike warned us all about that Blizzard? He saw something the rest of the others did not. Fair enough, that Blizzard came and went.

Remember the numerous times when Mike warned us, and we ended up getting nothing? Fair enough, those fake storms came and went.

[drum4no1]

All Morgan did was went out on a limb by predicting a snowstorm earlier than everyone which happened to be correct.

As mentioned earlier he has cried wolf quite a few times... but thats the nature of TV weather

[Thunder]

Remember the numerous times when Mike warned us, and we ended up getting nothing? Fair enough, those fake storms came and went.

Dry slot's fault. No one can predict it until the actual day and hours leading up to it.

[venture]

Hmm k. Time for me to start posting stuffs. :-)

There is some consistency starting to show in the GFS for a Jan 28th event. The positioning and location though are still uncertain. It is up to roughly a 50% shot now that somewhere in the state will see snow. How much and exactly where...yeah I'm not biting yet. Over the last day GFS has gone from a northern setup, to a central one, to a southern one. Here is how it is playing out right now, and this will change about 4000 times.

Morning of the 28th will see areas of moderate to heavy rain around to the state...mainly southern 2/3rds. Some areas could see up to an inch of rain in the morning hours. Cold front will dive south through the day, switch to a mix or snow by early afternoon. The timing on the change over is key. There is an enhanced band of 0.75 to 1.00" of liquid precip running just south of I-40 from roughly Clinton to Norman to Fort Smith. If this goes snow, its a lot of snow. If the cold air can't mix in fast enough, its a lot of rain, sleet or very wet snow. Upper levels show that it should be all snow, but we know how well that plays out. By evening snow will taper off fast, though a 2-4" accumulation in SE OK is still possible. Too many variables right now to say yes a foot of snow or an inch of rain. I would not be shocked to see a change over struggle a bit and take well past 1PM to occur. If it stays a wetter snow, it'll melt pretty fast on very wet ground from the earlier rain.

That'll do it for January. I'll go more into detail on this in the Feb thread when we get that going, but its too early now.

Snow for the Feb 1 to 2nd period is still on schedule. This will be a generally light snow. Mostly 1-3" amounts across the state, except SE which will stay rain. Maybe some higher amounts in Western OK or in areas where you get a good burst of snow. I would not expect to see amounts over 5 inches for this, so not a big deal.

Nothing else showing up except maybe some light rain around the 6th. Another system moves on shore on the 8th in CA, will bring more heavy rain to them and may impact us a couple days later.

[westsidesooner]

I'm thinking it'll be to warm for any heavy snowfall....especially with the preceeding rain Venture mentioned soaking the ground, but heres the latest forecasts from GFS and meteogram.


Earl's GIS Radar Site Overlays Page

Meteogram Generator

[venture]

06 and 12Z GFS are sticking with the same solutions now for the most part. The main bug in the ointment here is how fast will the front bring in the colder temps. 12Z temps are expected to be around freezing at 6AM and fall below by 12PM. However, temps around 850 to 750 mb are going to be just above freezing. This tends to indicate that we may see a rain to sleet/freezing rain to snow transition. Precip amounts from 6AM to 12AM are light in N OK, between a quarter to half inch in C OK and over an inch in S OK. This should mostly be all rain except far north.

By 12PM transition to frozen precip should be done or well in progress...in all areas except SE OK. General accumulations look like up to 1" in NW OK, 0.5 to 0.75 in West of I-35 and north of I-40. Then 0.375 to 0.5 to the east of I-35 and south of I-45...with a pocket of lower precip values in SE OK.

I'm still not 100% sold on a typical 10 to 1 conversion on this due to higher temps prior to the period, and also higher ground temps with wet ground.

By Thursday evening, all should be snow with some wrap around. Generally another 1-3" across the state with up to 4 inches in NE OK and over 6" in SE OK.

Something we need to watch. OUN is going to start mentioning the possibilities for a winter storm.

[bandnerd]

I just found myself making a rude gesture at my computer screen when I checked both weather.com and koco for the 7 day.

I'm ready for things to be GREEN.

[venture]

I just found myself making a rude gesture at my computer screen when I checked both weather.com and koco for the 7 day.

I'm ready for things to be GREEN.

Move to Florida or South Texas? lol

[venture]

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.

[Thunder]

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.

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

[venture]

It was late and typos happen. LOL

[oknacreous]

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?

[westsidesooner]

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..........

[venture]

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.

[adaniel]

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.

[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.

[oknacreous]

The Winter Storm Watch is officially up. 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.

[venture]

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. :-)

[westsidesooner]

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

[venture]

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.

[oknacreous]

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.

[OKCisOK4me]

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

[Thunder]

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.