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Winter 2022/23 Short/Medium Range Discussion


Chicago Storm
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2 hours ago, Chambana said:


You know winter has sucked when your focus has shifted to a potential snowstorm 7+ days out. Even michsnowfreak can’t polish this turd (still love your endless optimism) 

Im not trying to polish anything. The mild first half to two thirds of January was well advertised. I mean there's really nothing you can do but wait it out. 

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18 minutes ago, michsnowfreak said:

Im not trying to polish anything. The mild first half to two thirds of January was well advertised. I mean there's really nothing you can do but wait it out. 

There's plenty we can do, bitch and whine about it on here without having to deal with you telling us winters gone as advertised, like that helps lol. 

Usual SEMI donut hole, least amount this far north.

https://www.washingtonpost.com/weather/2023/01/10/below-average-northeast-snow/

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6 minutes ago, Stevo6899 said:

There's plenty we can do, bitch and whine about it on here without having to deal with you telling us winters gone as advertised, like that helps lol. 

I never said Winter's gone as advertised. A mild, gross January pattern was seen way back when we were shivering on Christmas.  It became clear there was no avoiding it. I'm just glad the light at the end of the tunnel is finally showing.

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3 minutes ago, cyclone77 said:

The difference between yesterday's 12z and today's 12z GFS is truly lol worthy.  Apparently it's the best model though.

Dude I was literally sitting on the toilet about to write that exact same thing a few minutes ago but I decided not to double post and beat a dead horse. 

Seriously though, is this how it'll always be? The weak/SE trend has quite literally been by far the most dependable thing in snow forecasting the last several years imo. It's always the same. I'm sure there will be a couple golden runs coming up and then the whole thing really collapses to shit once we're under 80 hours. 

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4 minutes ago, cyclone77 said:

The difference between yesterday's 12z and today's 12z GFS is truly lol worthy.  Apparently it's the best model though.

I guess it's good that the gfs is showing a weak turd slider for next weekend. Lately when it's shown a more wound up storm in this range, it's ended up as a weaker low, per the norm the last several years. Maybe we can break the shitty progressive turd slider slide we're on...

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13 minutes ago, Malacka11 said:

Dude I was literally sitting on the toilet about to write that exact same thing a few minutes ago but I decided not to double post and beat a dead horse. 

Seriously though, is this how it'll always be? The weak/SE trend has quite literally been by far the most dependable thing in snow forecasting the last several years imo. It's always the same. I'm sure there will be a couple golden runs coming up and then the whole thing really collapses to shit once we're under 80 hours. 

you forgot to add "no pun intended."

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Euro has been pretty consistent with that system for the last several major runs - actually came NW a little with the overnight suite. GFS has been bouncing on either side of it. EPS has been fairly consistent as well. All that said, I'm not buying shit until Sunday or Monday.

image.png.9a6d5bd5fafc2108cf68323003a3a358.png

 

eps_lowlocs_us_27.png

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44 minutes ago, Malacka11 said:

Wasn't this almost the exact same setup model wise that the pre-Christmas snowstorm did? The Euro was farthest north and amped, the GFS was farthest SE and weakest, and the CMC was dickin around in the middle, right?

Someone will correct me but I think the large scale pattern is a little different than the pre-christmas storm so probably not fair to compare the model performance.

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Yeah by setup wise I meant how the models resolve compared to one another, not the physical storm setup. My bad. I don't know shit but I know at least that much
I think a better way think of that comparison is the relative run to run consistency, since the setups are quite different. The GFS has exhibited much larger variability over a period of a few model cycles vs. the ECMWF, similar to the pre Christmas storm. It certainly doesn't mean the operational ECMWF will be right (ie. the ECMWF runs about 4-5 days out from pre-Xmas were much too early to rapidly deepen the synoptic system).

However,at this range I'm leaning toward the more consistent guidance from a probabilistic perspective in terms of whether we see meaningful precip over a good chunk of the CWA.

There are EPS members with a similar evolution to the last 2 runs of the GFS, which is to be expected at day 5-6 on a 51-member ensemble. A majority of the 12z EPS members and the mean support the general idea of the operational run though. Given the tendency of the GEFS members to more often hug closer to the operational, I consider the GEFS members less useful relative to the EPS members, which do a better job of capturing the full spectrum of plausible outcomes.

For today's afternoon forecast package, with the above thinking in mind, felt comfortable with likely PoPs for much of the LOT CWA Wednesday night into Thursday, but that still gives a ~30-40% chance of a miss south, which is reasonable this far out.



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51 minutes ago, RCNYILWX said:

I think a better way think of that comparison is the relative run to run consistency, since the setups are quite different. The GFS has exhibited much larger variability over a period of a few model cycles vs. the ECMWF, similar to the pre Christmas storm. It certainly doesn't mean the operational ECMWF will be right (ie. the ECMWF runs about 4-5 days out from pre-Xmas were much too early to rapidly deepen the synoptic system).

However,at this range I'm leaning toward the more consistent guidance from a probabilistic perspective in terms of whether we see meaningful precip over a good chunk of the CWA.

There are EPS members with a similar evolution to the last 2 runs of the GFS, which is to be expected at day 5-6 on a 51-member ensemble. A majority of the 12z EPS members and the mean support the general idea of the operational run though. Given the tendency of the GEFS members to more often hug closer to the operational, I consider the GEFS members less useful relative to the EPS members, which do a better job of capturing the full spectrum of plausible outcomes.

For today's afternoon forecast package, with the above thinking in mind, felt comfortable with likely PoPs for much of the LOT CWA Wednesday night into Thursday, but that still gives a ~30-40% chance of a miss south, which is reasonable this far out.


 

Models aside, do you take into consideration/mention the trends the past few years of storms ending up weaker/se in your afd's/write ups/forecast pops.

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Models aside, do you take into consideration/mention the trends the past few years of storms ending up weaker/se in your afd's/write ups/forecast pops.
I take each setup on a case by case basis pretty much. I don't think we can necessarily hinge on a general trend to play out each time. The above said, part of the perception is related to the difficulty in getting systems to phase as far west as the guidance sometimes shows. Or in the case of pre- Xmas, to get the PV (potential vorticity) anomaly to fully close off and rapidly deepen as far west as some of the runs 4-5 days out.

I think for the specific scenario of phasing of short waves, it is worth noting in AFDs that the guidance has a tendency to overdo phasing (either too early to phase or phasing occurring at all).

The pre-Christmas storm was a unique evolution. In hindsight, the very sharp angle of approach from where the wave started digging was sensitive to downstream changes, and being skeptical of the aggressively far west bombing out and closing off of the cyclone would have been warranted. That's one of my takeaways from that event.

Next week's setup doesn't involve phasing, with it mainly related to the track and strength of the main southern stream wave, and the wave has been forecast to develop a closed 500 mb low fairly early. Magnitude of confluence downstream will be a factor that modulates the track and strength of the wave, which makes it a little less complex and conditional (vs. needing a well timed phase).

Finally, our PoPs (at Central Region WFOs) are initialized out beyond 36 hours using the NBM. We already had likely PoPs in the forecast, so there wasn't really any discussion of lowering PoPs. In a vacuum, I probably would have capped them at 50% and trended up or down as needed from there. Anything higher than likely (55-74%) this far out would be too high.

Sent from my SM-G998U using Tapatalk

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^

that can be construed as a potentially white period for some areas as has been relayed by RC, OH Weather, and Chistorm. Normal to slightly above temps during a wet period in mid-late January is hardly a deal breaker for many. Or a transition period.The Minneapolis snow train may be out to edge south and east.

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