February/March 2021 - Frigid or Flop? Pattern/Longterm Forecast Thread.

[Carvers Gap]

1 minute ago, Blue Moon said:

The Euro's having a hard time right now. A run with 32" of snow in Clarksville, TN followed by zilch must mean it's juggling mixed signals.

Nah, it's just mid to LR forecasting - just all kinds of gremlins in play.  I actually feel today's run was a big improvement to 0z.  Yesterday's run was more for fun - no way we are seeing 36" in ten days.   Honestly, since we still  have cold in play and an active southern jet...I am encouraged.  I doubt we have seen the last of the big snow runs though.  I could be wrong, but with that much cold around and an active southern stream....like gasoline on a fire.

[Carvers Gap]

Here are the anomalies in MT.  I like front range cold in MT.  That has a tendency to move SE.  I am woefully low on my account memory, but here is the Euro at 240.  It is simply slower with the cold - and way colder.  Very difficult to find anomalies this cold.  This is Siberia type stuff in February in NA.  These are BN temp anomalies in MT during the middle of winter.....

 

[Carvers Gap]

Really, after 100...The Euro is not too dissimilar to this 240 slide.   Again, no reason to take a 240 slide verbatim.  Simply showing the potential.  The 12z UKMET was pretty much this cold at 144. I am just showing this so you all can see an expanded view of the MT cold with actual temps and not anomalies.  That set-up is why we had such huge snow totals on yesterday's run at 12z on the Euro.  The setup is still there, but the timing is different due to the range.  D5-10 stuff is absolutely going to have lots of variability.  However, when we look at modeling during winter, this is a great setup.   Been a while since we have seen this on modeling inside of d10 .

[Carvers Gap]

This is 144 on the 12z UKMET.  That is -47F stuff in Iowa.  Models "seem" to be signaling a major cold outbreak.  Timing is EVERYTHING in regards to if/when the cold arrives and if it the southern stream will attack it(which I think it would).  The Euro is pretty much the best solution as I look at the 12z suite.  Yes, it is slower with the cold...but it holds the cold in the Plains.  If that cold slides into the Midwest - it will be a major news story because of the cold and not snow.  If it holds in the front range of MT and slowly heads SE(key being SLOW), that gives multiple piece of energy a chance to attack that incoming cold.  Pretty much all modeling is showing severe cold...UKMET, Euro, GFS, and CMC.  Duration, location of the worst of it, and extremes TBD.

Sorry for the small thumbnail...had to resize it.  Pivotal has the actual model run.  

[Carvers Gap]

Pretty much a cage match between the MJO vs the NAO vs the SSW vs changing wavelengths of the season.  MJO phase 7 centered on JFM is warmish over the East.  Notice the severe cold over MT which fits the above maps.  Thing is, the NAO is going to try to press that cold eastward with suppressed flow - will agitate that MT cold if you will. 

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/

 

[Carvers Gap]

Here is the 12z EPS MSLP(mean sea level pressure for 240).  So, just trying to see if the ensemble matches the operational.  Looks pretty good, but more eastward with the core of the cold.  The ensemble supports the UKMET operational actually.  It does not bottle the cold up in MT.  This is a great winter storm pattern IF it verifies, and IF we can get precip to time with the onset of the cold.  Again, the slower this front moves...the better chance we get OR we get a higher frequency of systems from the southern stream.  The ideal situation is that the front sages south of our area and stalls.  If the SER fights(and it should), that would send multiple waves of precip along this cold air boundary - reference the blue arrow.  My interest is in getting the pattern right - for now.  I know we all love great snow maps, but that is a good look below.  IF we can reel that in, that is the key... I think yesterday's snow map on the 12z Euro was just a warning shot by the model that things might get interesting.   FTR, this might be 240 on the EPS, but the actual pattern(not to this extreme) begins about 132.  We have seen this look past d10 multiple times this winter and it did not verify.  I like right now that we are seeing this now in a 5-10 day depiction.

[Carvers Gap]

One quick correction.  The most severe cold on the EPS does indeed bank briefly along the front range of MT before heading south and east.  So, while we thought the Jan25-30 time frame might have some similarities to 95-96, we are now actually within 100 hours of a similar temp configuration (NW to SE band of cold temps across NA) coming to fruition.   IF the EPS is correct, that temp configuration lasts from Feb 5 to Feb 18.  We really can't ask for a better look on modeling and it is well within range now.  We have noted often how this La Nina has elements of both '89 and '96.  January at TRI finished 2.7 AN re: temps.  What is being modeled is nearly opposite of that warm spell during January.  Exciting times.  This is why we do this.  Might we strike out?  Sure!  That is just life in the Upper South.  But history does show that sometimes we can do well with this type of pattern.  Time will tell.  Just enjoy the ride.

[Math/Met]

Carver,  Just wanted to say that you do a great job with these pattern discussions. It always makes for a good read.

[iluvsnow]

Carver, that 1058 HP over Montana triggered a thought that the set-up mirrors the great Arctic outbreak of Feb 8th - 13th of 1899. If you check out this excellent analysis of what is considered the most severe cold event to ever hit this nation....it is eerily similar to what some of the models currently project for the same time period....only 122 years later......

http://www.heidorn.info/keith/weather/almanac/arc2009/alm09feb.htm

[Carvers Gap]

1 hour ago, Math/Met said:

Carver,  Just wanted to say that you do a great job with these pattern discussions. It always makes for a good read.

Thanks, Math/Met!   Thankfully, the actual content(potential cold wx) is interesting right now.  Honestly, just really thankful to see our board expand and still maintain such great content.  We have so many great posters.  I am always hugely appreciative of the contributions of the meteorologist on this forum.   Just a small example, I had almost no idea that we had mountain wave events in this area until you started posting about them.  Great team effort here by so many.  Thank you again!

[Carvers Gap]

2 hours ago, iluvsnow said:

Carver, that 1058 HP over Montana triggered a thought that the set-up mirrors the great Arctic outbreak of Feb 8th - 13th of 1899. If you check out this excellent analysis of what is considered the most severe cold event to ever hit this nation....it is eerily similar to what some of the models currently project for the same time period....only 122 years later......

http://www.heidorn.info/keith/weather/almanac/arc2009/alm09feb.htm

Will give it a read!  I know very little about weather events during that time.   I have done a little bit of reading about the Great Blizzard of 1888 and some blizzards in the Plains during that time.  MT and WY have some crazy cold winters.  If the cold comes down the front range, there is nothing to stop it.  It just banks up against the mountains.   Really enjoy the climate in that part of the world.  One of these days, I am spending a winter out there!

[John1122]

The Control is still shooting for the moon. 

[Stovepipe]

3 hours ago, iluvsnow said:

Carver, that 1058 HP over Montana triggered a thought that the set-up mirrors the great Arctic outbreak of Feb 8th - 13th of 1899. If you check out this excellent analysis of what is considered the most severe cold event to ever hit this nation....it is eerily similar to what some of the models currently project for the same time period....only 122 years later......

http://www.heidorn.info/keith/weather/almanac/arc2009/alm09feb.htm

This is fascinating, thank you for sharing!

[TellicoWx]

6 hours ago, Carvers Gap said:

Phase 7 may be colder...but the cold that is on the table on the UKMET is unreal.  Now, it seems like 95-96 or one of those Nina winters, the MJO had virtually no influence on the pattern - meaning it rotated through the warm phases and remained cold in the East.  The snow from the past two days has been right in the middle of phase 6.  Last winter was phases 5-6 - was awful.  @TellicoWx I want to revisit a QBO conversation that we had last winter(I may have been wrong in retrospect) where you noted that the falling of the QBO was not as correlated to the bottoming out and rising of the QBO.  I am too lazy to dig back through the thread, but makes me wonder(even if the QBO is positive) if maybe the current phase of the QBO is actually helping us.  It may just be as simple as the -NAO has been a good card for eastern areas of the sub-forum.  

Basically, as more studies are being conducted (we understand very little of the exact why's/how's everything is linked), the number reading (+/-) doesn't mean exactly what it was thought to mean per se. A strong -QBO doesn't necessarily translate to cold East. The reading can be misleading..while we are currently at a +10..we are actually in a QBOE descending phase...Easterlies are beginning to work their way down thru the atmosphere. In last couple years there is strong evidence that depending how the whole column is moving (QBOE des/asc..QBOW asc/des), it can amplify or mute the effects of the MJO. Since we are currently in QBOE des...it should amply whatever phase the MJO is in. If we were in QBOW...even if the MJO was moving into the cold phases, it would not have as much effect as what we would think here. Everything is linked (solar flares/wind has an effect on QBO...which it's multi phases effects how the MJO reacts downstream...and so on)...Top-Down approach. One day we may be able to hopefully tie all the links together.

[PowellVolz]

The Control is still shooting for the moon. 

That’s perfect for ETn. Got a hundred miles of wiggle room


.

[TellicoWx]

@Carvers Gap while the data set is limited..a big question now is why 2 of the last 3 cycles of QBO has featured a double dominant Westerlies (very little descending propagation of the Easterlies).

[Carvers Gap]

The 12z/18z GEFS and 12z GEPS look decent in the LR regarding the 500 pattern.  Thinking back just a few days, that is a pretty big move in the LR.  

[Carvers Gap]

1 minute ago, TellicoWx said:

@Carvers Gap while the data set is limited..a big question now is why 2 of the last 3 cycles of QBO has featured a double dominant Westerlies (very little descending propagation of the Easterlies).

Great question.  Makes me wonder if the abnormally warm Pacific (due to a decadal trend which features a lack of moderate to strong Ninas balancing surface temps) has created a lack of gradient which is affecting global wind patterns.  Just spitballing, but I know Typhoon Tip has talked about ENSO analogs being less effective due to the lack of gradient.  Maybe this La Nina will add some balance to the force so to speak.  

[TellicoWx]

25 minutes ago, Carvers Gap said:

Great question.  Makes me wonder if the abnormally warm Pacific (due to a decadal trend which features a lack of moderate to strong Ninas balancing surface temps) has created a lack of gradient which is affecting global wind patterns.  Just spitballing, but I know Typhoon Tip has talked about ENSO analogs being less effective due to the lack of gradient.  Maybe this La Nina will add some balance to the force so to speak.  

Solar~QBO~MJO~ENSO~rest of the teleconnections is what is being studied..As the solar winds/flares hit the upper tropo (QBO), it propagates downward effecting the MJO. Depending how the MJO reacts to the descending phase of the winds, it effects the upwelling of the ocean (effecting the ENSO),which in turn effects where the ridges/troughs are most likely to form..something happened to the solar influence around 2015/16...throwing the sequence out of balance. Think of how badly the analogs cold/warm LR outlooks have performed the last 5 yrs.

[TellicoWx]

18z GEFs..while the run/run has ebbed back and forth...the last couple days has seen the overall mean slowly get better for the central/western areas as well..decent trend for the entire forum.

[Carvers Gap]

1 hour ago, TellicoWx said:

Solar~QBO~MJO~ENSO~rest of the teleconnections is what is being studied..As the solar winds/flares hit the upper tropo (QBO), it propagates downward effecting the MJO. Depending how the MJO reacts to the descending phase of the winds, it effects the upwelling of the ocean (effecting the ENSO),which in turn effects where the ridges/troughs are most likely to form..something happened to the solar influence around 2015/16...throwing the sequence out of balance. Think of how badly the analogs cold/warm LR outlooks have performed the last 5 yrs.

Solar has been way, way off.  That last cycle was weak(as predicted due to the sun going so quiet around 2010 I think).  That definitely coincides with a lack of moderate/strong La Ninas.  I always think moderate to strong La Ninas reset the temp gradient in the equatorial Pacific.  For those of you who don't know what I am speaking of(I know Tellico does), we are used to weak El Ninos being great winter weather signals.  However, for the El Nino to be a strong winter wx signal in the East, the Sea Surface Temps(SSTs) need to be colder in the places which are not part of the El Nino.  The stronger that temp differential(the gradient) between the Nino and the rest of the Pacific, the more likely the El Nino behaves as normal.  With SSTs above normal in much of the Pac for the past 4-5 years, the Nino climatology was been washed out.  I am hoping that this La Nina will allow the next Nino to have a stronger gradient and behave more as a Nino would.   As Tellico notes, all of this is likely tied together.  And again, the AMO cycle is only about 2/3 of the way through - maybe it will end early?  I do hold out hope that this year's unexpected -NAO cycle this winter might well be a harbinger of better winters to come.    

[Dsty2001]

The solar aspect has always intrigued me, 2009/2010 winter when I lived in Delaware was epic.  Coincidentally, from my understanding solar activity at the time was super low.  

[John1122]

The GFS is very cold but just Uber dry the next 10 days.  If it came to pass it would be the driest stretch in my back yard since the flash drought in September 2019.  It has me with about .2 qpf over 10 days. 

I just don't swallow that happening. 

[Wurbus]

6 minutes ago, John1122 said:

The GFS is very cold but just Uber dry the next 10 days.  If it came to pass it would be the driest stretch in my back yard since the flash drought in September 2019.  It has me with about .2 qpf over 10 days. 

I just don't swallow that happening. 

I would take the uber dry run if we could lock in the storm it has on Valentine's Day. CMC also has a little storm for East TN toward the end of it's run.

[Matthew70]

15 minutes ago, John1122 said:

The GFS is very cold but just Uber dry the next 10 days.  If it came to pass it would be the driest stretch in my back yard since the flash drought in September 2019.  It has me with about .2 qpf over 10 days. 

I just don't swallow that happening. 

Somehow it would not surprise me it happening.  Seems here in mid TN that is usually what ends up happening.  Get the cold air but turns dry.  Hopefully not but not holding my breath. 

[Stovepipe]

[John1122]

Euro is folding to the GFS and just crushing the weekend system that has been snowing on the eastern valley. It will likely affect everything after as well. 

[John1122]

Yep, 20 degrees warmer valley wide on Sunday on the Euro vs 12z.  Instead of dropping snow here and turning into a noreaster it heads for Bermuda. So the cold isn't pulled down into our area like it was before. 

 

[John1122]

Big storm coming out by Tuesday that wasn't there at all at 12z. But likely a rainer here. Very warm in advance of it. 

[John1122]

Low is just north of Savannah with almost no precip associated with it. Cold front is undercutting the precip in middle Tennessee by early Tuesday morning.  Freezing rain developing west. Fizzles moving east.