StormChazer

I’ll agree the snow line confuses me.

No need to throw in the towel. It’s 1 run. This far out, so much is still subject to change. The Euro ensembles showed that the Euro master didn’t line up too well, it could very well dip back down tonight for all we know. I’d wait until Wednesday before getting too upset!

For those wondering, here is the current snow pack. It's going to stay cold up in Nebraska, so should be interesting to see if this has any affect in speeding up the cold air.

Tulsa thoughts on the upcoming system. "The strong system in the southern stream over the E Pac is forecast to move across the southern tier of states, and will tap a plentiful moisture source from the Gulf to produce widespread precipitation over the south central states. Coincidentally, a strong shortwave trough in the northern stream will force a cold front thru the region Thursday with colder air filtering into the region thru the weekend as surface high pressure settles south into the central Plains. This one-two punch on the separate streams of the westerlies tends to bring some of the bigger winter weather events for our part of the world. Using a blend of the thermal profiles aloft and the raw surface temps (which have trended warmer slightly) from the GFS/ECMWF, and using the latest QPF (the character of which is very similar between the GFS/ECMWF), this forecast will continue to suggest the potential for a winter storm across portions of NE OK and NW AR. Snow and sleet are expected to be the primary winter weather types, with some very light icing possible at precip onset down along the I-40 corridor. Rain will be predominant thru much of the event south of I-40, with a change over expected toward the end of the event Sat/Sat night and thus lighter accums. The details will continue to be refined in the coming days, especially as we get into the time frame of the NAM and its better handling of cold air in a day or so. Stay tuned for updates. Travel impacts across portions of the region are looking more likely."

GFS is up and running. Will post thoughts shortly!

My vote would go to #49; would make up these past few snowless years. If only! Haha

So the following is the 12Z members and what I found for the immediate Tulsa area... 16 members have Tulsa either missing out or under 1-2 inches. 8 members put Tulsa a hair away or right on the line on heavy totals. 26 members dump a heavy swath of snow across Tulsa and surrounding areas. So comparing the two, the biggest difference is that 5 members shifted from the middle and low column to the high column in Tulsa's favor. So I won't really complain too much about this. Lost ground on the master, but gained ground in the ensembles.

Now that I look at it, I think that may still be the 0Z, let me double check. If not, once it's updated I'll do the same thing to compare and contrast.

Well, I analyzed the 50 members for snowfall and at least for Tulsa, this is what I came up with. 17 members have Tulsa either entirely missing out on snow, or getting less than 1-2 inches. 12 members put Tulsa a hair away from the heavy totals, we're talking going from 1 to 10 inches in a span of one county. 21 members dump a heavy swath of snow across Tulsa(and most of NE OK), "heavy" being 5+ inches. Still just so much more time to go before zeroing in on the totals, but this run of the Euro has definitely made things much more cloudy. Midnight can come fast enough, haha.

Not sure how to interpret that one. I know we aren't supposed to focus on single model runs, but rather trends. But coldest to warmest has me wondering if this will end up as a run that went out to lunch, or if it's picking up on something. You would think if it was picking up on a warmer solution though that the GFS would have been even warmer.....looking forward to getting some shorter, higher res models into the fray soon. Also very curious now what tonight's Euro shows. I will say looking through the various members for snowfall, there is a very large number of models with high totals.

Here is every run of the Euro since the noon run on Thursday. I've adjusted the timing only slightly to try and visualize it better to get the frames matched up. This is more or less, Midnight Friday, so the frames following show a snowy scenario continuing into Saturday, but I thought this a pivotal point in the forecast to display. This is some fantastic run to run consistency, the only run that deviates anything meaningful is the 0Z Saturday run which depicts an icier solution with the colder air more north, before transitioning to snow. The other thing to notice is the precip shield moving more to the south and leaving KS and MO with less and less, although this hour in the storm doesn't highlight that aspect very well, I'd need to jump ahead 6 more hours for that. On the other side of things, the GFS has had some flip flopping issues. It'll go 2-3 runs agreeing with the Euro and then BOOM go another 2-3 runs keeping the cold air way north into Kansas, then cave again to the Euro, rinse and repeat. It's done that about 3 times now, and we'll see if the 12z run today brings it more in line with the Euro after seeing it inch southward on the 6Z. Point is, the Euro has been very consistent and handles these things quite well, so that's where I'm putting my faith for now.

I know I sound like a broken record, but as of the 06Z GFS, it started trending south again, I suspect if it continues the pattern it's been on, the 12Z will have an even further south solution, and eventually it'll stop trying to keep the colder air north, this is all assuming the Euro is to be believed. Quite honestly, the Euro's run to run consistency since Thursday of last week has been quite impressive, the only changes in it's runs overall have been to bring the precipitation shield further south, causing MO and KS to miss out on the snow, but in terms of where the freezing line sets up, it has been very consistent. Today's runs are very important, we are only 4 days out now from the onset of the freezing precip depicted. If the Euro maintains, and the GFS creeps a little more south, I'd say that should lead to some moderate to high confidence in this storm, and by tomorrow night snow amounts can start to be discussed.

The GFS is known for not handing cold air very well, the Euro tends to have a better grasp. I think the snowpack could indeed have some impact on how far south it travels. If the Euro holds on like it has the last few days, then I’m going to trust it over the flip flopping gfs.

As if on queue the GFS has tried to go back to a more northern solution with the cold air. Which it will maintain for maybe 1 more run until going back towards the Euro again. I laughingly say that because it’s done that now that last few days. About 1 more day until the nam can start picking up on it.

The GFS so badly wants to do its own thing and for the past 3 days now, after 2-3 runs of keeping the cold air up north, it’ll cave to the Euro again for another 2-3 runs before trying to go north again. It’s quite funny actually. But this latest gfs run throws some very heavy snowfall and ice in OK.

I love it.

The gfs hasn’t yet settled in on the cold air coming over like the euro and Canadian, I thought it did yesterday, but then today’s runs went north again. We’ll see about the 18z. Euro is king most of the time and the gfs hasn’t been able to make up its mind, unlike the euro; its stuck to its guns the last few days. Someone is in for an ice storm if these models come to pass.

Yeah, you don't want to be in the bullseye 6-7 days out anyway, and that 32 degree line isn't going to be very accurate until a few days out, so the overall trend in the last 24 hours for all the models has been for a significant ice/snow storm in OK/AR/MO/KS, and I'm happy with that.

You beat me to it! That's two runs in a row that the GFS has gone more in line with the Euro, and this last GFS run puts up some big numbers for snow and ice as well. The Canadian unleashes an ice storm as well. Either way, all models at this moment seem to be in pretty good agreement. Let's see what the Euro does here shortly.

Could this be the GFS finally caving to the Euro?

NWS in Norman's first thoughts on the storm so far. "Temps will remain at least 3-5 degrees below average through most of next week. By Thu, though, increasing heights under a shortwave ridge axis and southerly low level flow will result in a brief warmup. Low rain chances will be possible Thu as WAA commences ahead of a main southern stream trough. Precipitation chances will then increase Friday-Sat with the mid to upper trough. The question then becomes in what form. The ECMWF continues to surge an arctic air mass southward Fri which would likely support all types of winter weather as far south as the Red River. For now, based on the fairly fast progression of this synoptic feature snowfall accumulations should remain on the light side. However, freezing rain and sleet may also be possible. This will be watched closely over the next several days." That's obviously the preliminary thoughts for just the Noman forecast area, but I'm guessing this weekend we will get a decent write up on it.

All in all, the Euro stuck to it's guns. I'd say the only major differences would be the precip isn't quite as heavy, but still moderate, and exact amounts this far out don't matter. The area of freezing rain has shifted more to the east, but other than that, the Euro maintains.

Yeah, I can't say that I have ever seen the freezing line approaching from the east and slowly retreating west.....that just doesn't make any sense to me, but ice storms muddle things up, so I guess there's always a chance? Yeah, when it grabs something a under a week out, it's such a nice surprise, tracking a storm 10 days out, only for nothing to happen is the absolute worst. But what counts is all the models show the moisture in place and the elements for a winter storm, so 7 days out, that is pretty good. Time to see what the Euro does.

The Canadian moved away from the GFS and came around more towards the GFS-FV3(which btw, has this model seen any kind of success so far?) as depicting an ice storm. Still waiting on the GFS-FV3 to finish up it's 12Z run, the GFS though maintains keeping the cold air just to the north and northeast of Oklahoma. I'm very intrigued to see if the Euro sticks to it's guns or relents some towards the GFS. I can see this being a very difficult one to forecast with the ice element to this one. This smells like an ice storm for someone and models just stink at judging that shallow layer of cold air.

I noticed that. Short and sweet, but they did say "this could be more significant." Nebraska and south Dakota are about to get slammed with " 9-14 inches of snow" according to the NWS in North Platte, NE, and it's going to remain below freezing the entire week leading up to our event, so that snowpack will potentially have an impact on the speed of the cold air. Yeah, should be an interesting one!