John1122
Member
The most common occurrence in these situations is that the North American models soon cave to the Euro, which then two runs later drops the threat.
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Ostrich December
- Thread starter SETNwx
- Start date
The most common occurrence in these situations is that the North American models soon cave to the Euro, which then two runs later drops the threat.
I sure would like to see better ensemble support today.
I mean really just any ensemble support would be nice. EPS last night had 3 members with any snow for my area and GEFS was completely blanked. Not great.
I mean really just any ensemble support would be nice. EPS last night had 3 members with any snow for my area and GEFS was completely blanked. Not great.
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Webberweather53
Meteorologist
Well, looks like the -NAO wants to save us after all. I thought last week it would probably dissipate & hence I was getting pretty keen on a warm-up by the Winter Solstice, but I did mention if we get managed to get a strong -NAO, we might be able to thwart it at least thru Christmas. Good to see it's fighting back in a big way inside day 7-10 on most guidance.
AJ1013
Member
Disappointing forecast bust here. Only made it down to 48F imby, 50F at the airport. Wind was probably the culprit.
Webberweather53
Meteorologist
Using data from this forum, social media, CoCoRaHS, mPING, SERCC's NWS NOWData, & other personal communication, I made a map of the flizzard event we had earlier this week in north-central NC & have stored it on my website:
http://www.webberweather.com/2020s-winter-storms-nc.html
http://www.webberweather.com/2020s-winter-storms-nc.html
I’m also noticing that the AO is wanting to stay negative as well which is big difference from the last couple years. Is this something that will help keep warm ups in check?
Webberweather53
Meteorologist
It's a favorable indicator in a hemispheric-scale sense that cold air is being distributed fairly generously into the mid-latitudes, it doesn't say anything specifically about N America however. The NAO & EPO help describe the pattern here over N America. As @Myfrotho704_ & myself alluded to last week, if we can get the Alaskan vortex to retrograde towards the Aleutians/Bering Sea we open up the door for a +PNA to develop and coupled w/ the -NAO, it opens up the door for significant bouts of cold air to get discharged into the east-central CONUS and also provides a relatively stormy pattern for the US east coast.
I got stuck at 26. Still though I can't complain about the last couple of weeks, some warm, some cold
I will say that even though we got the 00z Euro on board, the 06z run looks arguably much worse, but it's not done yet, the ICON looks worse too. There's still a lot of room for shifting, with little support from its ensembles, the GFS and CMC. I wouldn't get my hopes up, since this pattern is really threading the needle.
In Huntsville, we've already had as many lows below freezing this December as we had all of December 2019.
SnowNiner
Member
Wouldn't be poetic if we finally get our long coveted season long -NAO.....but only to block the AK vortex warm pacific flow? It looks like the AK low wants to move a touch west, but not really doing it overnight. We're sooo close here. My hope is come January it'll find it's way west.
I'm not the biggest fan of the setup but I'm not going to tell myself that
You might could change that for all winter. Last year was touch here.
The last four runs don’t look too promising for anybody. The eastern Canadian ridge has been retreating in every run allowing our system to continue to cut further north sooner.
On the upside the god awful AK is looking better and our NAO looks better on the long run. Webber is on to something around late next week and possible Christmas week in the se. If we gradually see improvements over the LR the next couple of days.
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On the upside the god awful AK is looking better and our NAO looks better on the long run. Webber is on to something around late next week and possible Christmas week in the se. If we gradually see improvements over the LR the next couple of days.
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Webberweather53
Meteorologist
Unlike so many -NAO/+EPO regimes we've seen in the past, the one that's coming around the corner could have much easier access to true Arctic air thanks to this week's -WPO that'll deposit air from NE Siberia (the coldest place in the entire N hem) straight into Alaska & NW Canada. I'm legitimately going to be interested in what this pattern holds thru Christmas if the -NAO doesn't dissipate.
AJ1013
Member
Beautiful morning here!
AJ1013
Member
Some issues with heaters in the Miami area https://www.local10.com/news/local/...um=social&utm_campaign=snd&utm_content=wplg10
Webberweather53
Meteorologist
We're gonna be rebuilding the glacier in Canada
Tarheel1
I TOLD YALL IT WASN’T GOING TO SNOW
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TWC for me this weekend! I think they use the GFS verbatim! Euro shows more than this, I think
The ICON is no good. It lacks in wave separation. Right now, I'd lean towards things not separating, only because the Euro has a bias to hold things back in the SW.
We weep for Wilkes County and Birdman.
If the Euro holds for the 3rd run in a row, we really might be on to something significant (maybe not Winter weather) but some sort of big time dynamic system. I feel like this coming Euro run & ensembles might be one of the most important ones as far as sniffing out a storm so far this season.
12z will probably not be as good given that euro looked worse at 06z but we’ll see
Webberweather53
Meteorologist
The coldest air in the entire N hemisphere settles into the NW Territories by day 10 on the Euro.
If we can keep the -NAO gravy train going past mid-month, and force a few transient waves in the northern branch of the jet to slide underneath it into SE Canada & the Great Lakes, we might be able to tap into some of that.
If we can keep the -NAO gravy train going past mid-month, and force a few transient waves in the northern branch of the jet to slide underneath it into SE Canada & the Great Lakes, we might be able to tap into some of that.
So the indices don't look bad:
PNA - Looks to go slightly negative, but then go slightly positive in the LR.
NAO - Is currently slight negative, but actually looks to go father negative in the LR.
AO - Is currently moderately negative but looks to go farther negative in the LR.
CPC - Climate Weather Linkage: Teleconnections (noaa.gov)
PNA - Looks to go slightly negative, but then go slightly positive in the LR.
NAO - Is currently slight negative, but actually looks to go father negative in the LR.
AO - Is currently moderately negative but looks to go farther negative in the LR.
CPC - Climate Weather Linkage: Teleconnections (noaa.gov)
Webberweather53
Meteorologist
A sneaky, fast-moving MJO wave looks like it's gonna propagate thru the Pacific later this week & beyond.
This particular wave looks like it's going to be forced almost exclusively by wave breaking in the N Pacific storm track (as there's no corresponding signal in U850 or OLR). Hence, lacking a significant moist convective component, this particular subseasonal wave had more limited predictability than what typically accompanies the MJO.
I bring this up because interference with &/or a reprieve from Indian Ocean-Maritime Continent convection in early winter is a win in my book and may be why some NWP are more gung-ho about the -NAO this week sticking around past mid-month.
This particular wave looks like it's going to be forced almost exclusively by wave breaking in the N Pacific storm track (as there's no corresponding signal in U850 or OLR). Hence, lacking a significant moist convective component, this particular subseasonal wave had more limited predictability than what typically accompanies the MJO.
I bring this up because interference with &/or a reprieve from Indian Ocean-Maritime Continent convection in early winter is a win in my book and may be why some NWP are more gung-ho about the -NAO this week sticking around past mid-month.
Per Maxar’s -AO/+EPO analogs, the SE actually averaged colder than normal with a +PNAish look to the US temperature anomalies. The same can be said for MJO phase 4 with a -AO fwiw.
*Corrected
Looks like the energy in the Western Gulf has been trending N on the GFS.
I guess the gfs is gonna take its time 
It was a step toward the Euro. It's trending toward the Euro across the Rockies and southern Canada around d3/4 which is where the divergence occurs
We need 2 days of temps near 70...most of our winter storms come after big swings. NC style. Looks like we get some warm air this weekend.
RVD
Meteorology Student
Hmmm... maybe something else to watch further down the road, too.
Thanks for the update mountains brick
Webberweather53
Meteorologist
Historically, in -NAO/-AO/+EPOs, the +EPO backs off some and the AK vortex retrogrades towards the Aleutians, opening up the door for +PNA
I played around w/ a few composites, I think this is as close as I can get at a monthly scale for the hemispheric scale pattern in a -AO/-NAO/+EPO during Dec.
I even used an older, cooler base period to try and bias the temperature composite warmer but it's still arguably vodka cold.
