Mid to Long Range Discussion ~ 2022

[mclean02]

23 hours ago, BooneWX said:

Best advice I have for everyone to consider, if you get some spare time or a weekend where northwest flow is forecasted, don’t hesitate to head up with the family. A lot of people don’t realize it, but when they close the parkway for snow, it’s open to recreation. Take the sleds and enjoy. I know it’s never the same as snow in your backyard but it’ll satisfy the itch enough. I’m down in Burke County now, but always try to go up when a big flow event is forecasted. 

Y'all think Roanoke area will see a Inch in this case?

[Benjamn3]

3 hours ago, mclean02 said:

Y'all think Roanoke area will see a Inch in this case?

We are modeled to pick up a dusting to an inch. However backend snows are sometimes overdone. I’m hoping we can pick up an inch of powder but I’m not holding my breath for Friday AM. 

[Upstate Tiger]

Looking at today's models, teleconnections, and MJO, I am still thinking our next chance of significant winter weather in the SE is after 1/4.  NAO looks to go negative after 1/1, PNA is positive, lots of cold air has rebuilt in Canada, and ECMF has MJO moving into 7.  IF that all were to happen, it could be fun times in our area.  

[StantonParkHoya]

Euro might be cooking up something for mid next week

[GaWx]

 The period ~late 12/26 to early 12/27 still looks somewhat up in the air to me for the SE, especially near the coast, for wintry (mainly for ZR or IP) when seeing maps like the one below from the 12Z Euro. This shows very light rain for Jacksonville, FL, while the rain is just offshore GA/SC where temps are in the high 30s, wetbulbs are near 32, and 850s are still only ~+3 to +4 (cold enough to possibly support ZR). Though the odds remain pretty low, it wouldn't take too much of a change for this to instead be a stronger coastal storm with wintry precip:

[GaWx]

Further to the above, the 12Z EPS shows a rather strong signal (much stronger than earlier runs) for a surface low offshore the SE at 162 (1 AM 12/27). Keep in mind that this is about a week out, which is still plenty of time for significant changes on the models:

 

[Tyler Penland]

Further to the above, the 12Z EPS shows a rather strong signal (much stronger than earlier runs) for a surface low offshore the SE at 162 (1 AM 12/27). Keep in mind that this is about a week out, which is still plenty of time for significant changes on the models:
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The CMC has been harping on this for several runs now. It's the most amped and is mostly rain except some zr/ip in the mountains.

[Buddy1987]

I will not get overly invested.. I will not overly get invested.. I will not overly get invested.. I tell myself this time and time again and I’m a sucker for winter storms and tracking of systems. 

[eyewall]

51 minutes ago, Tyler Penland said:

 

The CMC has been harping on this for several runs now. It's the most amped and is mostly rain except some zr/ip in the mountains.

 

No cold air available.

[GaWx]

22 hours ago, GaWx said:

 Update for 12Z runs today for the highest SLP in mb in the lower 48 on 12/22 vs runs from 24 hours ago:

ICON 1068 (+3)
GFS 1067 (-1)   
JMA 1063 (-1)   
Euro 1061 (-1)
CMC 1061 (+2)
UKMET 1051 (-1)

AVG ~1062 (no change)

Record 1064

UKMET as it has been on the other days I've checked is a strong outlier on the low side. If I were to throw out the lowest and highest (UKMET and ICON), I'd get an average of 1063, which compares to 1062.5 from 24 hours ago.

 Update for 12Z runs today for the highest SLP in mb in the lower 48 on 12/22 vs runs from 24 hours ago:

GFS 1067 (0)   
ICON 1064 (-4)   
JMA 1064 (+1)   
Euro 1060 (-1)   
CMC 1059 (-2)   
UKMET 1051 (0)

AVG ~1061 (-1)

Record 1064

 If I throw out both the highest and lowest, the average is ~1062. We're still looking at a highly anomalous Arctic plunge coming up, something that the models will not be able to handle easily. Thus expect extra high model volatility and disagreement to continue for the SE, especially for 12/25-8. Also, 12/23 is going to be an amazing day for weather lovers as the extremely strong cold front plunges down, something not seen often.

 

[olafminesaw]

1 hour ago, eyewall said:

No cold air available.

Definitely a thread the needle/depend on a stronger storm to produce it's own cold kind of setup. Not exactly our bread and butter, but what else do we have to track?

[GaWx]

1 hour ago, olafminesaw said:

Definitely a thread the needle/depend on a stronger storm to produce it's own cold kind of setup. Not exactly our bread and butter, but what else do we have to track?

 Besides the strong cold, itself, it looks like to me as of now that there are two packets of energy that the models are harping on after the cold arrives:

- one that hits the NW US coast late on 12/23 followed by a dive down to the Gulf compliments of the +PNA and with it affecting the SE to a quite unknown degree ~12/26-7, when it is still cold enough for potential wintry mischief 

- one that hits the NW US coast only one day later that also dives and then affects the SE to an unknown degree ~12/27-8, when the air modifies enough such that wintry mischief wouldn't be as easy to occur in the more southern areas
 

 And then we have a highly anomalously strong Arctic high (possibly the strongest since 12/1983) with Siberian origins in the mix. So, it isn't a simple pattern for the models to resolve over the next 8 days or so. Keep in mind that the two aforementioned packets of energy don't leave the relative data deprived ocean for still 3-4 more days.

[WinstonSalemArlington]

Longrange forecasting is hard

 

[BornAgain13]

Sure wish the GFS was right. Showing me getting a quick 2" when that front moves through with a heavy burst of snow. I highly doubt it.

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[wncsnow]

The fact we can't develop a superior computer weather model is pathetic. Even after multiple upgrades it still falls behind the Euro and lately the UK and Canadian too. The fact that many local weather stations and apps go off of GFS data is a sham. 

[GaWx]

 Based on the pre-Euro 0Z model consensus, I'd say we're no closer to eliminating the possibility of significant winter precip in the deep SE ~12/26-7. As a matter of fact, this GFS run was the closest call in several days. We're still 5-6 days out and lots can change on the modeling in this highly complex setup that likely includes the strongest SLP in decades. Keep in mind that the energy associated with the 12/26-7 threat is still thousands of miles offshore the US west coast and won't be coming ashore for nearly 3 days.

[WinstonSalemArlington]

 

[GaWx]

Fwiw regarding the first post frontal upper level disturbance, the 12Z GFS has on 12/26 snow virga over far S MS  at 6Z, S and C GA at 12Z, and at the NC/SC border near the coast at 18Z. This is not the first run doing something with this as several GFS runs on 12/14 and 12/15 had significant wintry precip deep into the SE late 12/25 into 12/26.
 
 Is this a sign that this disturbance could do more over land in future runs ~12/26 being that this is still 5 days out in a complex/highly anomalous pattern? FYI, this run has a 1067+ mb high over MT on 12/22. The alltime record is 1064. It is very likely overdone somewhat, but even so we're still looking at a good chance for the strongest lower 48 Arctic high since 12/1983. Any opinions?

*Edited for corrections regarding past GFS runs for 12/26

[BooneWX]

36 minutes ago, GaWx said:

Fwiw regarding the first post frontal upper level disturbance, the 12Z GFS has on 12/26 snow virga over far S MS  at 6Z, S and C GA at 12Z, and at the NC/SC border near the coast at 18Z. This is the first run doing this. Is this a sign that this disturbance could do more over land in future runs ~12/26 being that this is still 5 days out in a complex/highly anomalous pattern? FYI, this run has a 1067+ mb high over MT on 12/22. The alltime record is 1064. It is very likely overdone somewhat, but even so we're still looking at a good chance for the strongest lower 48 Arctic high since 12/1983. Any opinions?

Although we have fleeting cold air, that timeframe has been a signal on the models for a week now. It seems like it has some merit. Like I said the other day, you know what they say about the tail end of patterns 

[GaWx]

31 minutes ago, BooneWX said:

Although we have fleeting cold air, that timeframe has been a signal on the models for a week now. It seems like it has some merit. Like I said the other day, you know what they say about the tail end of patterns 

 Thanks. My statement about this being the first run like this was incorrect and I'll edit it out. I had a brain fart as you're correctly pointing out that this timeframe has had a signal on the models for a week now. On the GFS, the 0Z 12/14, 0Z 12/15, and other 12/15 runs had significant wintry precip going deep into the SE late 12/25 through 12/26 and I even posted clown maps for three of these runs lol.

[GaWx]

 The 12Z Euro (and last few runs) is trending to somewhat more robust at H5 with the lead post frontal disturbance for early 12/26, but it still has nothing to show for it (too dry) at the surface. 
 

  This run then has a more robust follow up disturbance at H5 (it is quite impressive) along with it being colder over the SE vs prior runs meaning a later ending window for possible wintry precip.  It is faster moving than on the 0Z run and has light snow over N AL from this late on 12/26 to early 12/27. It also has cold rain (39F) as far north as Daytona Beach early 12/27 as a weak surface low forms just NE of the Bahamas.

 These disturbances are still 5-6 days away from the SE and are still well out in the Pacific with a huge Arctic high to precede them. Thus, the uncertainty level for what the SE will or wont experience on 12/26-27 is still high and higher than normal for 5-6 days out.

[GaWx]

The 12Z UKMET has light accumulating snow over far N AL/GA on 12/26 followed by light accum snow over part of C GA, SC, and SE NC that night.

[GaWx]

21 hours ago, GaWx said:

 Update for 12Z runs today for the highest SLP in mb in the lower 48 on 12/22 vs runs from 24 hours ago:

GFS 1067 (0)   
ICON 1064 (-4)   
JMA 1064 (+1)   
Euro 1060 (-1)   
CMC 1059 (-2)   
UKMET 1051 (0)

AVG ~1061 (-1)

Record 1064

 If I throw out both the highest and lowest, the average is ~1062. We're still looking at a highly anomalous Arctic plunge coming up, something that the models will not be able to handle easily. Thus expect extra high model volatility and disagreement to continue for the SE, especially for 12/25-8. Also, 12/23 is going to be an amazing day for weather lovers as the extremely strong cold front plunges down, something not seen often.

 

 Well, we're now only one day away. Here's the 12Z run update for today for the highest SLP in mb in the lower 48 on 12/22 vs runs from 24 hours ago (1064 is all-time lower 48 record back to late 1800s):

GFS 1067 (0)   
JMA 1065 (+1)   
ICON 1063 (-1)   
Euro 1059 (-1)   
CMC 1059 (0)   
UKMET 1052 (+1)

AVG ~1061 (no change)

The UKMET is either going to shine or fail with their continued much lower SLP vs other models. If I throw out the highest and lowest, the average is 1061.5 mb.
 
 Friday is going to be one of the most dramatic days in a long time for the entire SE!

  *Edit: The 12Z NAM runs have 1067-8 mb depending on the resolution!

[olafminesaw]

8 minutes ago, GaWx said:

 Well, we're now only one day away. Here's the 12Z run update for today for the highest SLP in mb in the lower 48 on 12/22 vs runs from 24 hours ago (1064 is all-time lower 48 record back to late 1800s):

GFS 1067 (0)   
JMA 1065 (+1)   
ICON 1063 (-1)   
Euro 1059 (-1)   
CMC 1059 (0)   
UKMET 1052 (+1)

AVG ~1061 (no change)

The UKMET is either going to shine or fail with their continued much lower SLP vs other models. If I throw out the highest and lowest, the average is 1061.5 mb.
 
 Friday is going to be one of the most dramatic days in a long time for the entire SE!

And it's sandwiched up against a bomb that could produce LP records in that region (don't have time to research, but could drop into the 960s). The wind field is incredible 

[GaWx]

 The 18Z GFS has nothing wintry over the SE from either post frontal H5 disturbance. However, similar to the 12Z Euro, it does have from the 2nd disturbance a surface low that forms well offshore the SE coast. If there were to actually be a low that tracked, say, 200 miles west of that track, with about the same amount of cold air, there'd probably be a significant winter event 12/26-27 deep into the SE.

 Keep in mind that this as well as the Euro low were generated by a disturbance currently 7,000 miles away from us and 4,000 miles off the Pacific NW coast where data is relatively limited and that isn't going to cross the Pacific coast for another 3 days. The pattern is quite complex with the huge Arctic high and another H5 disturbance ahead of this one by just one day. When considering all of this, a 200 mile west shift for something 5 days out isn't hard to fathom. So, though the odds favor no big deal 12/26-7 over the bulk of the SE from either disturbance based on model consensus continuing to keep it mainly quiet, a change to a big deal would not be the least bit shocking.

[SouthWake33]

22 minutes ago, GaWx said:

 The 18Z GFS has nothing wintry over the SE from either post frontal H5 disturbance. However, similar to the 12Z Euro, it does have from the 2nd disturbance a surface low that forms well offshore the SE coast. If there were to actually be a low that tracked, say, 200 miles west of that track, with about the same amount of cold air, there'd probably be a significant winter event 12/26-27 deep into the SE.

 Keep in mind that this as well as the Euro low were generated by a disturbance currently 7,000 miles away from us and 4,000 miles off the Pacific NW coast where data is relatively limited and that isn't going to cross the Pacific coast for another 3 days. The pattern is quite complex with the huge Arctic high and another H5 disturbance ahead of this one by just one day. When considering all of this, a 200 mile west shift for something 5 days out isn't hard to fathom. So, though the odds favor no big deal 12/26-7 over the bulk of the SE from either disturbance based on model consensus continuing to keep it mainly quiet, a change to a big deal would not be the least bit shocking.

Really appreciate all of your updates!  I continue to check in regularly. Hopefully things break our way soon.

[Tyler Penland]

 The 18Z GFS has nothing wintry over the SE from either post frontal H5 disturbance. However, similar to the 12Z Euro, it does have from the 2nd disturbance a surface low that forms well offshore the SE coast. If there were to actually be a low that tracked, say, 200 miles west of that track, with about the same amount of cold air, there'd probably be a significant winter event 12/26-27 deep into the SE.
 Keep in mind that this as well as the Euro low were generated by a disturbance currently 7,000 miles away from us and 4,000 miles off the Pacific NW coast where data is relatively limited and that isn't going to cross the Pacific coast for another 3 days. The pattern is quite complex with the huge Arctic high and another H5 disturbance ahead of this one by just one day. When considering all of this, a 200 mile west shift for something 5 days out isn't hard to fathom. So, though the odds favor no big deal 12/26-7 over the bulk of the SE from either disturbance based on model consensus continuing to keep it mainly quiet, a change to a big deal would not be the least bit shocking.

A 200 mile west shift at 5 days should almost be expected. Look what happened with the current system.

This could easily NW trend itself into a decent storm.
Or NW trend itself into a cutter.

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[GaWx]

Latest highest SLP in MT is ~1053 mb. Keep in mind that this isn't based on station measured pressures as they have to be converted to SLP and much of MT is up several thousand feet.

 These SLPs will be rising considerably tonight. I can already say that the UKMET is going to verify way too low. This makes me wonder about how it converts to SLPs. Something's off bigtime.

 Map with current SLPs:

 https://www.spc.noaa.gov/exper/mesoanalysis/new/viewsector.php?sector=11&parm=pmsl&underlay=1&source=1#

[GaWx]

 Although the 0Z Euro still doesn't give the SE wintry precip, the 2nd disturbance is stronger (more closed off) and a little further west for the same timeframe vs the 12Z. This results in the sfc low forming near the Bahamas on 12/27 being a little further west. As a result, rain gets further north in FL to St. Augustine vs Daytona on the 12Z run and to the coastal waters of the Carolinas vs 100 miles offshore on the 12Z. This run does nothing to sway me away from the possibility of later runs giving the SE wintry precip from this.

[BooneWX]

It’s so close.