General Weather Discussion - December 2017

[SoonerDave]

The last GFS run is even drier still.

[SoonerDave]

Hey Anon.... any thoughts on the latest GFS run for the OKC/DFW area on 29 Dec..big winter blob suddenly showed up out of almost nowhere in last two runs....lots of folks heading to LA area from OK in that timeframe....too early to be concerned?

[Anonymous.]

Models ejecting the first piece of next week's storm much further north than previous runs. This essentially forces dry Canadian air down into the plains and cuts off any chance of wet snow. Potential for dry snow showers still exists Sunday/Monday, but any major storm is pretty much not possible in this scenario. Will have to keep watching to see if this holds.

In regards to SoonerDave's question. The GFS is basically predicting a closed-off low will develop out of the Rockies and strengthen directly over TX/OK on the tail end of the [would-be Christmas storm]. This is a very rare scenario and I wouldn't hang my hat on it, just yet. Especially since we haven't seen the cold air get into place. This Thursday into Friday things will become more legitimate as the cold, dry air will be in place.

By the way, if you were in OKC in 2009, this scenario described above is what happened on Christmas Eve where OKC recorded its 1-day snowfall record.

[LocoAko]

Tuttle is hyping highs in the low single digits and lows near -10, which will cause power outages and pipe bursts.

The GFS currently has lows in the low teens. Not sure what Tuttle's deal is or what he's basing that on but he'd probably not be my first source for forecast information...

[Anonymous.]

Chances of rain increasing for C and E OK heading into tonight. Models show rain spreading from N TX across the state, and then potentially heavy rain developing directly over C OK as it gets dark.

[Anonymous.]

In regards to the holiday storm for this weekend into the week. Models have begun trending back towards impacts to the state of OK. Like I keep mentioning, just keep monitoring the trends. I think by Friday afternoon, we will have a good shot @ a forecast.

[FighttheGoodFight]

In regards to the holiday storm for this weekend into the week. Models have begun trending back towards impacts to the state of OK. Like I keep mentioning, just keep monitoring the trends. I think by Friday afternoon, we will have a good shot @ a forecast.

I will try my best to make a highlight video of local news weather hype on Friday then!

[SoonerDave]

For the first time, I have really started studying each new run of the GFS and have been stunned at the run-to-run variability. I mean, I knew it was variable, but not THIS variable. One run it's a 2ft blizzard, the next run only 12 hours later, the same spot is dry.

[bchris02]

Tuttle, in his most recent blog post, is now predicting an ice storm instead of snow. Thoughts?

[Anonymous.]

I mean if he is going all-in with the Canadian model, then yes it currently shows an ice storm for a large part of OK.

[Anonymous.]

For the first time, I have really started studying each new run of the GFS and have been stunned at the run-to-run variability. I mean, I knew it was variable, but not THIS variable. One run it's a 2ft blizzard, the next run only 12 hours later, the same spot is dry.

Wonderful, right? Each model is swinging around all over the place. Remember not to pay attention to any single run (this far out). You can focus on single runs when the event is very imminent as the accuracy is exponentially better. But we are still 4+ days out of the beginning of the event, trends is what you need to watch. Over the weekend, models trended dry and further east track. Now they are trending wet and further west.

[SoonerDave]

Wonderful, right? Each model is swinging around all over the place. Remember not to pay attention to any single run (this far out). You can focus on single runs when the event is very imminent as the accuracy is exponentially better. But we are still 4+ days out of the beginning of the event, trends is what you need to watch. Over the weekend, models trended dry and further east track. Now they are trending wet and further west.

Well my mistake was looking at things even a bit farther than that - around the 28th/29th timeframe, and that's like playing darts blindfolded. In the last day or two, I've seen runs for a) bone dry, b) ice storm, c) snow storm, and d) heavy rain and sometimes changing that drastically in back-to-back runs.

[Anonymous.]

Oh yea trying to forecast storm #2 before #1 even unfolds is definitely going to be a rollercoaster. Also I am not sure if you are comparing forecast hour to forecast hour, but remember storms speed up and slowdown, so you may have to look @ other forecasting hours to find the storm you may have been looking @ in a previous run. Hope that makes sense.

[bradh]

What's it looking like for Wichita? Driving down from MSP Friday and it looks like we've cleared out in the Twin Cities but south of us is looking poor, including a good chunk of our drive down 35

[jompster]

Tuttle, in his most recent blog post, is now predicting an ice storm instead of snow. Thoughts?

I think he needs to just calm down. I appreciate his scientific explanations, but I kind of get disgusted when he toots his own horn in his live broadcasts and blog. I had to close it when he said that the NWS was now getting behind his prediction. I don't chime in for the weather discussions much, but I really appreciate what you guys do on here. I get a lot more information out of your posts than anywhere else, really.

[Anonymous.]

All models continuing trend to shift this weekend's storm west and bring in more moisture.

We still need to wait for the cold air to arrive Thursday night for solid atmosphere sampling for the model data, but the signatures so far point to a classic OK winter storm.

[SoonerDave]

Anon, help me out on the GFS....the last run I saw appeared to have mostly a rain event focused on the southeast half of the state around the 23rd and moving out east and south, with nothing else for Christmas weekend...but you were just posting about a classic winter storm setup...what am I missing? Or is this a different model?

[Anonymous.]

GFS is appearing out-to-lunch as the other models are trending toward a similar solution. The real solution is likely somewhere in between. You can't just pick one and run with it because it creates the most hype (Tuttle).

The Canadian has been favoring a western track that puts ice potential along I-44 corridor.
The NAM has came all the way back and is mostly in line with the Canadian, but is favoring slightly further west impacts.
The GEM window doesn't have the full storm in it yet, but the lead-up is matching to the NAM/Canadian, but slightly colder.

From my experience, you have to take an average approach to the forecast and then begin weighing the more reliable models and their respective forecasting windows. A lot of meteorologist use past experiences to help determine which models they are going to rely on the most.

I mentioned classic winter storm due to the complexity of it. We could have a scenario where just south of I-44 is 30F with freezing rain, while NW OK is 34F and SE OK is 36F. Right now NAM paints an area from Lawton to Norman to south of Tulsa with heavy freezing rain. Then brief wrap-around heavy snow.

Using the information we have right now, it appears that scenario is plausible. But like I said, we still have a long ways to go. The next 6 runs could push everything back into Arkansas again.

[SoonerDave]

Thanks, Anon!

[SoonerDave]

Couple things as we roll toward the weekend...

If you like to read about weather, I found a nice little forum here (well, it's also a subforum for the OK area): https://www.americanwx.com/bb/topic/...ussion/?page=8

Second, some interesting discussion here that some of the models are starting to trend warmer and a bit drier going into Christmas. Won't pretend to understand ALL the things they go into there, but it seems the general sense among those in that forum were disappointed in a trend away from the harsher winter forecasts in some of the more recent models as we approach the weekend, especially with apparent increases in temperatures being seen. Interestingly enough, even though this is a national forum, they actually mention AT in there at one point, for "comic relief" I think they said.

[Anonymous.]

Models are all coming to a consensus of majority precipitation being in SE OK. What would have been the precip affecting south of I-44 corridor is expected to be mostly in the form of rain. Temperatures will be too warm for any significant winter scenario.

The is a chance of a brief period of moderate snow if a wrap-around zone forms on the backside, but dry air will dictate if that even occurs. If it does, OKC could get a quick dusting late overnight.


Next storm starts taking shape by Wednesday evening. At this time, it appears as a cold rain event for most of OK. Will monitor closely to see if this arctic air is actually going to come through or if it has been trolling this whole time.

[Bunty]

Thanks Anonymous for the weather info. I know Mike Morgan is worried about next week.

[Bunty]

I would imagine many people who went through it feel well blessed from the memory of the Christmas Eve blizzard of 2009 and also knowing what a White Christmas is really like and aren't anxious to be so richly blessed once again.

[foodiefan]

X2!!

[Pete]

There was one Christmas where we had a terrible ice / sleet storm a few days after and I could not get out of OKC to fly back to L.A.

After a couple of days, I ended up driving to Tulsa and taking a direct flight from there.

That was in the late 90's or early 00's I believe. It was a pretty big nightmare.