December 2018 Observations and Discussion

[Grizzcoat]

Interesting to note that Uncle Ukie is even further S with the L than the GFS-- in Southern Illinois. The FV3 lies in the middle of the 4. Obviously big differences for precip type and even precip at this range and unless the Euro is on to something- would be the outlier at this juncture. Will be fun to follow.

[Grizzcoat]

However- GEFS ensembles would suggest? that the Euro may be on to something .

[Clinton]

Good morning folks, the 6z FV3-GFS seems to have a good grasp of this very short LRC (36 to 38 days) at least through Tuesday.  Look out for a very strong storm late next week moving out of Texas over the top of a deep artic air mass that we will all be locked into(the return of the central plains trough). Models have had hints of this but have not locked on to this idea yet, but it should be a dominate feature in this years cycle.

[Tom]

00z EPS is really seeing snows with the first lead system across the Dakotas/MN/N NE into N WI.  In all honesty, this would be welcomed in my book bc these areas have zero snow OTG and if you want cold to "seed" future storms, you gotta have nature lay down the snow pack up north.  It's a catch 22 bc that'll mean my snow will be gone which I'll have to accept and move on to the next storm which the models, including the EPS and others, is seeing right after the first one that looks like another Plains/GL's cutter.

 

As for the GEFS, the snow shield looks a bit farther south and include parts of N IA, NE/MN/WI for the 1st storm...

[Tom]

Good morning folks, the 6z FV3-GFS seems to have a good grasp of this very short LRC (36 to 38 days) at least through Tuesday.  Look out for a very strong storm late next week moving out of Texas over the top of a deep artic air mass that we will all be locked into(the return of the central plains trough). Models have had hints of this but have not locked on to this idea yet, but it should be a dominate feature in this years cycle.

 

Regarding the bolded, the return of the Polar Vortex and seeding intense arctic air into North America and across our sub should be the first real chance some peeps may get their taste of sub zero cold if there is snow OTG.  Interestingly, I know you are utilizing a short cycle, but after doing some analyzing of the LRC, I'm also coming up with a longer cycle.  For instance, this past storm did not "look" like the early Oct 7th-10th system, esp if you compared the 500mb pattern in the NE PAC and along the EC back then to what just happened.  In early Oct, we had a stout NE PAC Ridge & EC Ridge in tandem which leads me to believe this coming system may be the beginnings of LRC #2 bc it def resembles that pattern quite well.  Also, of note, back in early Oct we had a series of waves come out of the SW and this is exactly what is happening now with back-to-back storms coming out of the SW with the 2nd wave being the potential bigger one.

 

 

 

 

 

Following these systems, the entire North American pattern resembles what happened post Oct 7th-10 when cold dominated and an amplified North American pattern locked in.  I'm really curious what Gary Lezak thinks about all of this.  It could be there are many "harmonic" or mini cycles repeating throughout this LRC which is why it's been so dang busy with storm systems galore.

 

 

 

 

GEFS are starting to see another bigger perturbed Polar Vortex as we open Decembrrrrr....this screams major arctic cold to invade the CONUS.

 

[Tom]

Early on in the LRC, there were parts of the LRC which showed a "La Nina" flavor and if you are to believe the overall pattern is cycling, then we are likely to see the central CONUS trough to open December through the first couple weeks of the month.  I've been using this techinique for a while and it has been rock solid in terms of predicting where troughs/ridges are to develop.  The big signal I read from the maps below is a signal to look for a ridge to develop near or close to the EC Week 2-3.

 

Look at the blossoming warming in the SE/EC at 10mb....while big cooling across NW NAMER....

 

 

 

http://www.cpc.ncep.noaa.gov/products/intraseasonal/temp10anim.gif

 

 

Same signal is showing up at 30mb which began around the 19th of Nov which correlates 2-3 weeks into the future....Dec 4th and beyond...

 

 

 

http://www.cpc.ncep.noaa.gov/products/intraseasonal/temp30anim.gif

[Clinton]

^{Unfortunately Gary isn't publicly confirming the cycle length for us right now.  There seems to be an issue with another meteorologist in Joplin, MO that is using his theory and claiming it as his own.  Tom your maps show a great point and very well may be right.  It is very possible that I picked up on a harmonic and the actual cycle length is much longer.  There are so many storms this year it can be quite confusing.}

[Grizzcoat]

Guy that filled in for PP on AccuwX Long Range thinks in early DEC will be cold followed by above avg temps and then maybe the Polar Vortex being dislodged for the end of the month. PP and his team have most of us reading this above avg for the month of DEC but they are concerned about exactly the length and strength of the warmup.  An update is supposed to be released today.

[Minny_Weather]

Guy that filled in for PP on AccuwX Long Range thinks in early DEC will be cold followed by above avg temps and then maybe the Polar Vortex being dislodged for the end of the month. PP and his team have most of us reading this above avg for the month of DEC but they are concerned about exactly the length and strength of the warmup. An update is supposed to be released today.

After seeing the Euro weeklies, I can see where he's coming from. It'll be above average while snowpack builds up to our North.

[CentralNebWeather]

NWS Hastings thinks the Friday/Saturday storm will be mostly rain here as the snow goes farther north.  However, they said the 2nd storm should be colder and snowy in the Central Plains according to that meteorologist.  

[Stormhunter87]

NAM just now starting to see the weekend storm. 540 line pretty far north 00z Saturday

[Tony]

With this current snowpack we have as well as the snow that's about to hit north of us, I believe the cold air in place will take longer to erode than what the models are currently seeing. I also don't see, as of now, a huge push north of WAA so temps should be tempered a bit.

[CentralNebWeather]

The NAM at 84 hours is showing a mixed bag of precipitation in the Central Plains and that is when it is just arriving.  Will be interesting to see how it evolves with the 2nd storm on its heels.

[St Paul Storm]

12z ICON with a 987mb in N/C MO., west of previous runs. Then the second low early Tuesday catches up with some leftover moisture and it crosses Chicago

[Minny_Weather]

Euro is pretty consistent in saying "What secondary wave?"

[Stormhunter87]

Euro is pretty consistent in saying "What secondary wave?"

So odd because even winter prediction center is seeing the second wave and like it better than the first storm for snow.

[East Dubzz]

Should we start a thread on this event? Seems reasonable at this time.

[CentralNebWeather]

Should we start a thread on this event? Seems reasonable at this time.

Sounds good to me.  

[Niko]

This system for the weekend looking really good for the plains and upper midwest. Great track. Heavy, soaking, rain for my area w temps in the 40s. Turns colder after the passage of the storm and looks like the cold air stays put afterwards.

[CentralNebWeather]

ICON is a decent shot around here for starters.  I'm sure there are many changes yet to come.  How much falls as rain vs. snow in the 1st storm and does a 2nd storm come up with colder air around or is there a 2nd storm at all.  

[Stacsh]

 Steady extremely light snow falling to fluff up the snow already on the ground.  Looks like a significant LES event following the next couple storms for the end of next week.  December will be pretty white around here. (Well after it disappears this coming weekend).  

[Minny_Weather]

Platte River crush job with the first wave on GFS. Models seem to be trending colder. NAM even has us at the freezing mark at the end of the run.

[Niko]

 Steady extremely light snow falling to fluff up the snow already on the ground.  Looks like a significant LES event following the next couple storms for the end of next week.  December will be pretty white around here. (Well after it disappears this coming weekend).  

December is looking great here in our neck of the woods. Unfortunately, this weekend, will be a soaker (especially Saturday) w temps in the 40s w hvy rain. It gets better thereafter.

[East Dubzz]

Well, 12z GFS was.. interesting. Actually does bring a decent amount of snow to my area, though the cutoff is sharp. Not sure how well it’s handling the temps, but at least there’s a chance of snow, I suppose.

[St Paul Storm]

12z GEM says two storms? Let’s combine them into one monster.

[Stormhunter87]

Okay this GFS run is very odd. Starts off warm and then changes quickly, which that 540 line seems to far north to happen. Then that second storm comes through and dumps a ton, but it appears way to south for me to by it. Very odd indeed. I don't mind it but I'm hard pressed to buy it

[East Dubzz]

Started a new thread for the storm: http://theweatherforums.com/index.php/forum/9-the-great-lakes-and-great-plains/

[Stacsh]

Okay this GFS run is very odd. Starts off warm and then changes quickly, which that 540 line seems to far north to happen. Then that second storm comes through and dumps a ton, but it appears way to south for me to by it. Very odd indeed. I don't mind it but I'm hard pressed to buy it

 

It seems to have a fairly strong High to the north in place by the time the second wave comes in. Not sure I buy it yet either.  

[Tony]

After the weekend rain it looks like a nice LES setting up for Northeast IL for a good 24hrs for Monday into Tuesday. Most of the models have been showing this for the past couple days. At least it will be snowing to start the 1st week of December.

 

The 12z ICON has it going for about 48hrs. Should be an interesting setup.

[Niko]

@Jaster

 

1st week of December looks cold and some snow chances. Depending on track. You will likely get LES, so heads up there buddy.

[Stormhunter87]

Seeing another storm around the 12th >.> Definitely going to get cold.

[james1976]

Seeing another storm around the 12th >.> Definitely going to get cold.

Yeah that thing has been showing up for a while. Anyone remember which system it would have been in the first cycle?

[Tom]

I took a gander at the Euro Weeklies and overall agree with a somewhat pullback during the middle of the month.  I've seen this type of pattern before during the development of the LRC this Autumn.  I will say, this type of pattern is known to deliver a favorable storm track across the sub as ridging forms across Canada while the jet cuts underneath across the CONUS.  While this ridging develops, I believe we will see a big SSW event over the pole mid month.  As is typical during these events, we usually see a relaxation of extreme cold while it reloads during the later half of the month.  I think right around the Winter Solstice or Christmas week there will be a very active period that should lay down the snow right before the extreme cold begins to invade Canada and the eastern CONUS.

[Niko]

December looks cold during the 1st week. End of week looks interesting. Have to watch that piece of energy

[Tom]

Alright guys, I think I figured out the cycle length and I'm pretty convinced of it now knowing where this weekends system is tracking and deepening.  Earlier on, I though the pattern around Thanksgiving resembled what we saw in early Oct or even this past weeks Blizzard, but at 500mb it didn't make sense to me.  With that in mind, check out this 500mb at 12z Sat and it clearly has all the details we saw back in early Oct (7th-10th).  Of note, notice the NE PAC ridge, the ridge out ahead of the storm system near the EC and most importantly, the closed low centered right over KC.

 

 

 

The Oct 7th-10 storm system was a slow mover and first targeted the 4 corners on the 7th and ejected out slowly over the TX Panhandle which brought flooding rains into the S plains and a similar pattern is shaping up across the Arklatex region this weekend.  This SLP tracked from the TX Panhandle while going neg tilt across KC/C IA/N WI, all awhile, a blocking HP was centered due north of the system across S Canada.  This is why, earlier on, I was really paying attention to this blocking signal and the models did in fact correct to this as we got closer in time.  

 

With that being said, this year's cycle may be closer to the 55 day range, give or take a few days.  Now, what happens next???  Well, we should see a light/mod precip event break out into the Plains/MW/GL's a couple days later around the 6th/7th.  After that???  We will likely see another trough target So Cal/4 corners region a couple days after that (7th/8th).  There will also be a deep trough knifing down the leeward side of the Rockies while the trough hits the 4 corners region and this will prob be our next Winter Storm potential.  Fun times.

[Niko]

December has potential for a lot of posters on here in terms of snow. Some big dogs are on the table.

[Clinton]

Alright guys, I think I figured out the cycle length and I'm pretty convinced of it now knowing where this weekends system is tracking and deepening.  Earlier on, I though the pattern around Thanksgiving resembled what we saw in early Oct or even this past weeks Blizzard, but at 500mb it didn't make sense to me.  With that in mind, check out this 500mb at 12z Sat and it clearly has all the details we saw back in early Oct (7th-10th).  Of note, notice the NE PAC ridge, the ridge out ahead of the storm system near the EC and most importantly, the closed low centered right over KC.

 

 

 

The Oct 7th-10 storm system was a slow mover and first targeted the 4 corners on the 7th and ejected out slowly over the TX Panhandle which brought flooding rains into the S plains and a similar pattern is shaping up across the Arklatex region this weekend.  This SLP tracked from the TX Panhandle while going neg tilt across KC/C IA/N WI, all awhile, a blocking HP was centered due north of the system across S Canada.  This is why, earlier on, I was really paying attention to this blocking signal and the models did in fact correct to this as we got closer in time.  

 

With that being said, this year's cycle may be closer to the 55 day range, give or take a few days.  Now, what happens next???  Well, we should see a light/mod precip event break out into the Plains/MW/GL's a couple days later around the 6th/7th.  After that???  We will likely see another trough target So Cal/4 corners region a couple days after that (7th/8th).  There will also be a deep trough knifing down the leeward side of the Rockies while the trough hits the 4 corners region and this will prob be our next Winter Storm potential.  Fun times.

 

Tom, you may be right but when I look at the 500mb level I come up with a shorter cycle.  I believe the pattern began to change or mix in back in Sept.  I believe it may be around 34-38 days with an average cycle of 36 days.

Compare these 3 maps

https://www.spc.noaa.gov/obswx/maps/500_180919_12.gif

https://www.spc.noaa.gov/obswx/maps/500_181023_12.gif

https://www.spc.noaa.gov/obswx/maps/500_181130_00.gif

[jaster220]

Alright guys, I think I figured out the cycle length and I'm pretty convinced of it now knowing where this weekends system is tracking and deepening.  Earlier on, I though the pattern around Thanksgiving resembled what we saw in early Oct or even this past weeks Blizzard, but at 500mb it didn't make sense to me.  With that in mind, check out this 500mb at 12z Sat and it clearly has all the details we saw back in early Oct (7th-10th).  Of note, notice the NE PAC ridge, the ridge out ahead of the storm system near the EC and most importantly, the closed low centered right over KC.

 

 

 

The Oct 7th-10 storm system was a slow mover and first targeted the 4 corners on the 7th and ejected out slowly over the TX Panhandle which brought flooding rains into the S plains and a similar pattern is shaping up across the Arklatex region this weekend.  This SLP tracked from the TX Panhandle while going neg tilt across KC/C IA/N WI, all awhile, a blocking HP was centered due north of the system across S Canada.  This is why, earlier on, I was really paying attention to this blocking signal and the models did in fact correct to this as we got closer in time.  

 

With that being said, this year's cycle may be closer to the 55 day range, give or take a few days.  Now, what happens next???  Well, we should see a light/mod precip event break out into the Plains/MW/GL's a couple days later around the 6th/7th.  After that???  We will likely see another trough target So Cal/4 corners region a couple days after that (7th/8th).  There will also be a deep trough knifing down the leeward side of the Rockies while the trough hits the 4 corners region and this will prob be our next Winter Storm potential.  Fun times.

 

Nice work amigo. Did you tell Gary yet? 

[Tom]

Tom, you may be right but when I look at the 500mb level I come up with a shorter cycle. I believe the pattern began to change or mix in back in Sept. I believe it may be around 34-38 days with an average cycle of 36 days.

Compare these 3 maps

https://www.spc.noaa.gov/obswx/maps/500_180919_12.gif

https://www.spc.noaa.gov/obswx/maps/500_181023_12.gif

https://www.spc.noaa.gov/obswx/maps/500_181130_00.gif

The only problem I see with this is that you are using maps from late Sept and according to Gary’s theory, you can only start a cycle during the 1st week of Oct.

[Clinton]

The only problem I see with this is that you are using maps from late Sept and according to Gary’s theory, you can only start a cycle during the 1st week of Oct.

 

He has recently said that there is a transition phase in the pattern that most likely begins in late August and Sept.  The pattern doesn't go old/new over night, in Sept there is the old pattern still cycling and some of the new features developing for the new patteren.  By the first week of Oct the new pattern is cycling with no influence from the old pattern.  I hope this make since.