Tarheel1
I TOLD YALL IT WASN’T GOING TO SNOW
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Bingo!
See 2002 December ice storm! Then winter was over
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Wintry Winter 2024-25 Discussion
- Thread starter SD
- Start date
See 2002 December ice storm! Then winter was over
Avalanche
Member
Yes, I like the idea of getting it over now with the holidays. January can warm up since we will all be ready for spring by then
iGRXY
Member
Who is we ?? lol
December Dud? More like Dynamite December.
Brent
Member
Don't jinx it. December still 10 days away
lexxnchloe
Member
Going to the store to get my emergency supplies ready.
What??? After the December 2002 Ice Storm, there were 3 more good storms in January and February 2003
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Only my absolute favorite snowstorm of all time
Webberweather53
Meteorologist
Updated this analog list to include things like Indian Ocean & Maritime Continent warmth, initialize w/ a +TNH in Dec (because when this happens oftentimes that TNH pattern persists throughout the winter), stronger than average zonal winds at 10mb in Dec, tweaked the weights, etc. I got a slightly different flavor to things, but the overall picture is generally the same as before, just amplified a bit more.
Here's how the gigantic (list of 350 years in total w/ weights) SST composite compares to observations in Oct-Nov. Of course only the first 25-30 or so are in the title, but there are a lot more in the background.
Here's the DJF 500mb mean pattern & 2m temp anomalies.
Interestingly, both this suite of analogs & the older set I came up with back in October sniffed out a cold December w/ a -EPO/+TNH. This new set is more amplified, in part because I explicitly looked for it this time, because a +TNH is likely going to happen.
Older analog set Dec 500mb pattern
Newer analog set Dec 500mb pattern.
Webberweather53
Meteorologist
I found it very interesting that these same 2 subsets of years, with the complete opposite mid-late winter temperature patterns over the CONUS, were all viable analogs for this upcoming winter!
When I took a closer look at the difference between these 2 subsets of years, I didn't notice anything out of the ordinary until I looked into the stratosphere.
The group w/ a colder Jan-Feb had a much cooler/stronger stratospheric polar vortex all the way up to 10mb. This allows the troposphere Hudson Bay Vortex to couple w/ and become "rooted" into the stratosphere, making it stronger/more persistent.
This seems to be one of the keys to getting this -EPO/+TNH pattern to "stick" into mid-late winter.
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Webberweather53
Meteorologist
When you compare -EPO and +EPO winters w/ cool neutral or La Niña ENSO like this year, some interesting things emerge.
EPO pattern difference
One of the things that really sticks out to me is the tendency for cool neutral - Nina years w/ -EPO to also be accompanied by a westerly QBO.
Piggy-backing off the previous post from a large-scale/dynamical point of view:
I suspect these cool ENSO winters w/ westerly QBO reduce upward/poleward wave activity onto the stratosphere polar vortex. This allows it to cool/spin-up over the Arctic & more specifically, Canada. If you can get a sufficient "trigger" to kickstart a -EPO/+TNH pattern in late fall or early winter, this pattern can effectively reinforce itself on longer time scales through positive feedbacks like wave driving & wave reflection, becoming increasingly more dominant as the winter wears on.
If you can further couple this stratospheric polar vortex w/ the Hudson Bay vortex in the troposphere, then you have the right recipe for potentially a very long-lived (& favorable) winter pattern.
Here are the 50mb zonal wind differences between -EPO & +EPO -ENSO years since the 1940s in ERA-5 & JRA-3Q:
This year is much more like the -EPO group of -ENSO winters, w/ a strong westerly QBO ~50mb.
EPO pattern difference
One of the things that really sticks out to me is the tendency for cool neutral - Nina years w/ -EPO to also be accompanied by a westerly QBO.
Piggy-backing off the previous post from a large-scale/dynamical point of view:
I suspect these cool ENSO winters w/ westerly QBO reduce upward/poleward wave activity onto the stratosphere polar vortex. This allows it to cool/spin-up over the Arctic & more specifically, Canada. If you can get a sufficient "trigger" to kickstart a -EPO/+TNH pattern in late fall or early winter, this pattern can effectively reinforce itself on longer time scales through positive feedbacks like wave driving & wave reflection, becoming increasingly more dominant as the winter wears on.
If you can further couple this stratospheric polar vortex w/ the Hudson Bay vortex in the troposphere, then you have the right recipe for potentially a very long-lived (& favorable) winter pattern.
Here are the 50mb zonal wind differences between -EPO & +EPO -ENSO years since the 1940s in ERA-5 & JRA-3Q:
This year is much more like the -EPO group of -ENSO winters, w/ a strong westerly QBO ~50mb.
Webberweather53
Meteorologist
This year so far is checking most of the boxes for the colder mid-late winter group w/ a westerly QBO & stronger early winter stratospheric polar vortex that would be more capable of coupling w/ the troposphere later on.
In fact, the polar vortex is forecast to be record strong at 10mb through at least mid-December on the extended GEFS & European weeklies.
In fact, the polar vortex is forecast to be record strong at 10mb through at least mid-December on the extended GEFS & European weeklies.
lexxnchloe
Member
From LC
However, when you look at the rebuild of the vast ridge complex along the entirety of the West Coast (AK and southward across Baja California), combined with renewed moderate -NAO ridging below Iceland), the CFS scenario of a new James Bay vortex suggests a cold December 23 - January 8 period to the right of the Rocky Mountains and above the Gulf Coast. If it sounds like late 1995, you would be right. This being a La Nina with a still-warm Gulf of Mexico, I lean toward a sudden January Thaw in the second week of the New Year. But a difference may be that as the 500MB features start going into their "peak of the season" positions, I lean toward more widespread cold with snow and ice possibilities to the right of the High Plains after mid-January.
However, when you look at the rebuild of the vast ridge complex along the entirety of the West Coast (AK and southward across Baja California), combined with renewed moderate -NAO ridging below Iceland), the CFS scenario of a new James Bay vortex suggests a cold December 23 - January 8 period to the right of the Rocky Mountains and above the Gulf Coast. If it sounds like late 1995, you would be right. This being a La Nina with a still-warm Gulf of Mexico, I lean toward a sudden January Thaw in the second week of the New Year. But a difference may be that as the 500MB features start going into their "peak of the season" positions, I lean toward more widespread cold with snow and ice possibilities to the right of the High Plains after mid-January.
Brent
Member
Whatever happens this winter no more snow donut holes
I refuse to watch that again. I'd rather have no snow anywhere
I refuse to watch that again. I'd rather have no snow anywhere
lexxnchloe
Member
Brent
Member
Webberweather53
Meteorologist
This is one of those winters where I think a strat warm event would actually hurt us (potentially). I just don't want to lose the stratosphere support over top of the Hudson Bay vortex.
lexxnchloe
Member
Sounds good
Meaning
NCSNOW
Member
La nina conditions. Or scale tipped in La nina favor as opposed to a neutral state (no el nino or la nina)
The exact position east based verse west based el nino, and la nina matter most for our downstream effects, then strength of each.
Its a dice roll no matter what is cooked up for our sakes it seems. So Id prefer a dice roll of neutral state and take my chances with other drivers of the pattern.
NCSNOW
Member
I still say the winter of 13/14 seem to be matching most closely from my non expert eyes. I stand to be corrected. Most in NC would take a redux. Also I beleive 1985 was a neutral to weak sauce la nina.
Why I thought GSO could hit a 0 for a low this winter as a pre season highlight. Both those winters had some cold punches come down. We are in the midst of one now this week. Doesnt mean we avoid some Good Golf weather days, as next 2 weeks appear on warm side, but wet as well to a degree.
Why I thought GSO could hit a 0 for a low this winter as a pre season highlight. Both those winters had some cold punches come down. We are in the midst of one now this week. Doesnt mean we avoid some Good Golf weather days, as next 2 weeks appear on warm side, but wet as well to a degree.
NCSNOW
Member
The last 3 month runing ONI value I saw was for Aug-Oct 0.22. Love to see the 3 month runing value for Sept Oct Nov.
You can use chart in link below to see which year resembles current state of affairs out in the pacific.
You can use chart in link below to see which year resembles current state of affairs out in the pacific.
NCSNOW
Member
December 2013 Greensboro had 4 seperate days with highs above 70. They where spread out an came in pairs of 2 on 2 seperate weeks.
Maybe we don't get stuck in the warmer phases after all?
GolfishardIknowit70
Member
Better hope it's correct. 4-6 are very warm phases
Webberweather53
Meteorologist
Takes 20 days to get to phase 7. Oof
NCSNOW
Member
Didn't GaWx do a study for Atlanta. Best phases where inside circle phase 1 @ 2, Outside phase 7
Just in time for Santa moving to January. Let's hope so.
tennessee storm
Member
Nothing certain yet
Webberweather53
Meteorologist
RMM MJO Phase 7-8 in cold ENSO is usually the hot spot for getting a winter storm in NC.
January phase 7 in general is the true hot spot for getting a winter storm in NC, with a 1 in 6 chance per day of seeing snow/ice. This is about 3x higher than climo
Just out of curiosity, what are you considering a winter storm here? Any precipitation with a temp at or below 32, measurable snow, snow > 1” or something else? Also, do these stats include the mountains?
Webberweather53
Meteorologist
Any storms that are archived on my website where measurable snow/ice occurred outside the mountains, (>Trace snow or T or greater ZR) or cases where measurable snow or ice occurred at RDU, CLT, GSO, ILM, FAY, or ECG (when I don’t have a storm archived).
I made these a few years ago and posted them right before Jan 2022 happened
Good deal. I did a similar study myself around 2018 and found the same results so I was curious if your methodologies were similar, which they were.
Webberweather53
Meteorologist
NOAA ESRL has provided an OLR based MJO index that goes back to 1940 using ERA-5 reanalysis. Might be worth giving that a try when I get a chance and have some time on my hands
NOAA ESRL MJO indices
I remember when I used to have “professional development” days where I could do fun SQL-based studies like this. Apparently I developed too much, because I don’t have much free time anymore lol.
rburrel2
Member
Is there a reason you like the Hudson Bay vortex? Maybe historically speaking that can produce here?, but I feel like the last 10-15 years it has been absolute garbage for getting wintry weather.
I guess if it’s transient then good patterns can sprout up around it, but just seems like when it’s there, it stays there for weeks and never leads to anything when it’s around or when it goes away.
Let's hope he's right about the period post-holidays. Seems reasonable.
Tarheelwx
Member
It's nice to see that cold air sitting over the northern plains and most of Canada moving south at the end of the AI run.
TW
TW
