December 2021 Weather Discussion

[tron777]

We have a lot of dry air to overcome before any flakes hit the ground tonight, but I am watching radar trends. An area of light snow is developing across the St. Louis area which models have shown to occur. It's just happening faster then what the models have indicated. That usually does happen anyway with these quick hitting systems. Any snow we get should be out of here before the AM Rush tomorrow.

[tron777]

The timing from the 12Z GFS looks good with light snow arriving this evening probably after 7pm or so should this be correct. Just a narrow band coming thru the heart of the Tri-state is all we've got. The band shifts south more into KY later this evening then in the wee hours of the morning into SE KY. Temps are good, below freezing for this event so we've got that in our favor. The lack of deeper moisture is the primary issue from something good occurring. If you see a dusting or car topper at your location, then consider it a win.

[tron777]

12Z GFS has 0.06" of QPF at CVG, HAO 0.05", MGY - 0.05" DAY and CMH around 0.02" FGX - 0.07" for our SE Crew.

[tron777]

Looks like the possible back end snow idea is fading on the guidance today as well for this weekend. Models (including the new 12z GFS) are more progressive with the front blowing it on thru here faster like by early Sat morning. I'm also not seeing the secondary low idea quite as much either. Just a classic case of the moisture already being gone by the time the cold gets here which is usually what we see most of the time anyway. Still... heavy rain with this system, wind, and possible strong storms are on the table.

Next week continues to look much quieter and mild so that'll give us time to track the period around Christmas and the period following it. The arm chair mets on twitter continue to beat the drum of the MJO favoring the development of a -EPO and a more colder pattern kicking in late this month and to kick off 2022. We've seen head fakes with this before, so the wise thing to do is proceed with caution as we normally do on here anyway.

[tpweather]

Great Posts this morning guys. I try and look at the positive for us winter lovers and yes I can be to far ahead with a pattern change. This week I was okay with the cold shot and minor snow event but I really thought a trend more towards winter would happen this weekend. Sure we get cold but once again 24-48 hours and back to above normal temps.

The good news is some of the record cold in the polar regions. Parts of Sweden have recorded their lowest temp in 35 years with temps nearing -50, Saint Peterburg hit -20 the other day. Alaska which had record cold in parts of the state in November remains cold but not quite the record cold some areas especially in the southwest part of the state saw last month. Back in Oct areas in northeast China including Beijing had very cold temps with some of the earliest snowfall in history. Areas like Northern Canada took awhile longer to get cold and yes they are frigid but nothing that is not seen every winter season along with Siberia which is having their normal cold winter but nothing unusual. This tells me a very strong PV which is happening and we just need something to disrupt the cold temps as we know cold dense air will sink. The one thing that I have noticed though is when we just grab a very small piece of the cold in Canada it has been rather cold for the pattern we are in but does not last long and with little snow cover in the lower 48 temps warm up very quickly. My guess some folks in the southern plains have not had any frost where folks in Northern Florida have because if some decent troughs in late November. For us locally not getting much snow at this point in the season is nothing new but the Rockies is the one place that is so far behind and it drives much of the economy in the winter and they need the heavy snows for much needed water once it melts in the spring. Again very early in the season but the southwest ridge has been a bigger issue than the normal southeast ridge that we dread quite often.

[tron777]

Tim... great post! The Rockies should start to see things change coming up as we turn warmer and quieter next week. We need that snow cover to build to our NW as well to assist us later in the season when, and if, the pattern does change more favorably for us.

[Bgoney]

Did they do away with a daily WPO index. ? I can't find it

[tron777]

Did they do away with a daily WPO index. ? I can't find it

ftp://ftp.cdc.noaa.gov/Public/gbates/te ... resent.txt

This link will take you directly to the daily index reading from 1948 to present using Internet Explorer as the web browser.

Main webpage: https://psl.noaa.gov/data/timeseries/daily/WPO/

EDIT: The nice webpage that we used to use for both the WPO and EPO, remember the cool charts? It was done by ESRL and unfortunately, it went bye bye in Sept of 2020 I believe. I've been missing it ever sense.

[tron777]

WPO has been mainly negative since November (was positive over the summer) based on the daily index readings I am seeing on the above links.

Here's the daily index reading for the EPO: ftp://ftp.cdc.noaa.gov/Public/map/telec ... resent.txt

Main site: https://psl.noaa.gov/data/timeseries/daily/EPO/

Looking at these numbers, the EPO has been mainly positive of course since Alaska has been so cold. 12/3 to 12/5 it has averaged negative but 3 days doesn't really tell us a trend. I do not know how NOAA calculates these indices. I was so used to the ESRL site for such a long time. I'm still sad that it's gone.

[Bgoney]

Did they do away with a daily WPO index. ? I can't find it

ftp://ftp.cdc.noaa.gov/Public/gbates/te ... resent.txt

This link will take you directly to the daily index reading from 1948 to present using Internet Explorer as the web browser.

Main webpage: https://psl.noaa.gov/data/timeseries/daily/WPO/

EDIT: The nice webpage that we used to use for both the WPO and EPO, remember the cool charts? It was done by ESRL and unfortunately, it went bye bye in Sept of 2020 I believe. I've been missing it ever sense.

Boy , can they make it any more difficult . Those pages are a bridge to nowhere

[tron777]

Did they do away with a daily WPO index. ? I can't find it

ftp://ftp.cdc.noaa.gov/Public/gbates/te ... resent.txt

This link will take you directly to the daily index reading from 1948 to present using Internet Explorer as the web browser.

Main webpage: https://psl.noaa.gov/data/timeseries/daily/WPO/

EDIT: The nice webpage that we used to use for both the WPO and EPO, remember the cool charts? It was done by ESRL and unfortunately, it went bye bye in Sept of 2020 I believe. I've been missing it ever sense.

Boy , can they make it any more difficult . Those pages are a bridge to nowhere

I know it isn't the best but it's been the only thing I have been able to find. The FTP links work using IE on a PC. No idea if you are using a mobile device if it'll work or not. I wish I could find something much easier, but since Sept of 2020, I haven't been able to.

[cloudy72]

Currently 26 with a dew of 10 here.

[dce]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

[tron777]

12Z Euro has shown the least amount of QPF for this light snow maker moving our way, and it still is. No need to post any QPF totals because they are pretty sad. The model is in good agreement with the rest of the data for the Fri / Sat system as well.

[Bgoney]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

Most likely due to it moving through 5/6 , plus lag time. 7 phase is a transitory phase , so I think it needs to get at least mid way of 7 and beyond to start a.meaningful pattern change

[cloudy72]

12Z Euro has shown the least amount of QPF for this light snow maker moving our way, and it still is. No need to post any QPF totals because they are pretty sad. The model is in good agreement with the rest of the data for the Fri / Sat system as well.

Perhaps the Euro is picking up on all the dry air at the surface and thinks it will mostly be a virga storm (well maybe just a virga shower). LOL

[tron777]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

There is a lag between the MJO phase and the impacts on our sensible weather. So assuming the GFS is right... we don't get into Phase 7 until Dec 18th at the earliest. It would be closer to Christmas before you'd see any impacts. So the warmth makes perfect sense to me. At this point, we don't even know if the GFS, Euro, etc. are going to even be correct. But assuming they are, we won't see any huge changes IMO until we get closer to Christmas. Maybe even beyond Christmas. These junk patterns are so tough to break. We've got to see changes in the Pacific especially in the EPO domain if we're going to have a chance here.

[tron777]

12Z Euro has shown the least amount of QPF for this light snow maker moving our way, and it still is. No need to post any QPF totals because they are pretty sad. The model is in good agreement with the rest of the data for the Fri / Sat system as well.

Perhaps the Euro is picking up on all the dry air at the surface and thinks it will mostly be a virga storm (well maybe just a virga shower). LOL

That is possible Mike! Good thing that we're not looking to get much out of it anyway.

[tron777]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

Most likely due to it moving through 5/6 , plus lag time. 7 phase is a transitory phase , so I think it needs to get at least mid way of 7 and beyond to start a.meaningful pattern change

Exactly, which would put us near or just shortly after Christmas, again assuming the GFS is correct.

[dce]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

There is a lag between the MJO phase and the impacts on our sensible weather. So assuming the GFS is right... we don't get into Phase 7 until Dec 18th at the earliest. It would be closer to Christmas before you'd see any impacts. So the warmth makes perfect sense to me. At this point, we don't even know if the GFS, Euro, etc. are going to even be correct. But assuming they are, we won't see any huge changes IMO until we get closer to Christmas. Maybe even beyond Christmas. These junk patterns are so tough to break. We've got to see changes in the Pacific especially in the EPO domain if we're going to have a chance here.

Maybe I'm not seeing something on that MJO forecast map, but it appears as if the GFS has it to phase 7 in about two days? Am I missing something on there?

[dce]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

There is a lag between the MJO phase and the impacts on our sensible weather. So assuming the GFS is right... we don't get into Phase 7 until Dec 18th at the earliest. It would be closer to Christmas before you'd see any impacts. So the warmth makes perfect sense to me. At this point, we don't even know if the GFS, Euro, etc. are going to even be correct. But assuming they are, we won't see any huge changes IMO until we get closer to Christmas. Maybe even beyond Christmas. These junk patterns are so tough to break. We've got to see changes in the Pacific especially in the EPO domain if we're going to have a chance here.

Maybe I'm not seeing something on that MJO forecast map, but it appears as if the GFS has it to phase 7 in about two days? Am I missing something on there?

Ok. Now I see it. That is the GFS Ensemble forecast that has it going to 7 in about 2 days. The GFS has it there around the 15th or 16th.

[Bgoney]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

Most likely due to it moving through 5/6 , plus lag time. 7 phase is a transitory phase , so I think it needs to get at least mid way of 7 and beyond to start a.meaningful pattern change

Exactly, which would put us near or just shortly after Christmas, again assuming the GFS is correct.

Sorry about that Les , I didn't see your earlier post

[tron777]

WOW! Euro says to get out the BBQ's , golf clubs, shorts and flip flops next Wed and Thurs! 500 MB heights peak at 585 DM with 850 MB temps around 15C! I wonder if 70 degrees is attainable? That would be record highs. The record high at CVG for that period is 66 and 67 degrees respectively so 70s would shatter that! With such an anomalous ridge being shown, I wouldn't be surprised to see this happen unfortunately.

[tron777]

I find it interesting that the GFS is predicting this kind of warmth at the same time it is predicting the MJO to be in this position.

Most likely due to it moving through 5/6 , plus lag time. 7 phase is a transitory phase , so I think it needs to get at least mid way of 7 and beyond to start a.meaningful pattern change

Exactly, which would put us near or just shortly after Christmas, again assuming the GFS is correct.

Sorry about that Les , I didn't see your earlier post

All good! We are both saying the same thing.

[tron777]

Decent band of light snow from Central IN extending back to the SW over areas just S of STL. I checked surface obs and I cannot find any reports of snow until you get to St. Louis. So most of that appears to be virga at this time.