December and January Pattern Discussion

[John1122]

00z a direct 180 from the 12z. Complete breakdown of the ridge in the West by 204, trough flies out of the east and heights rise quickly in the East. 

 

GFS has done this a few times over the past few weeks in the long range, but it never quiet comes true. 

[John1122]

I could be wrong, but it looks like there's a -AO, a -NAO, a +PNA but the cold doesn't go South at all, just slides across Eastern Canada and into the Northern Atlantic while HP spreads in from the West and moves across the country.

 

Not sure why the trough would lift out of the East with blocking in place.

[Reb]

I could be wrong, but it looks like there's a -AO, a -NAO, a +PNA but the cold doesn't go South at all, just slides across Eastern Canada and into the Northern Atlantic while HP spreads in from the West and moves across the country.

 

Not sure why the trough would lift out of the East with blocking in place.

Hopefully just a hiccup. Very strange look

[Carvers Gap]

I could be wrong, but it looks like there's a -AO, a -NAO, a +PNA but the cold doesn't go South at all, just slides across Eastern Canada and into the Northern Atlantic while HP spreads in from the West and moves across the country.

 

Not sure why the trough would lift out of the East with blocking in place.

 

The CPC ensembles support this pattern from yesterday 100%.  The NAO goes strongly positive w/ a weakly negative PNA around the end of the month.  To me the patterns depicted by many of the wx models seem to be at fault of "perpetuating" cold indefinitely, and that is always a red flag for me.  I have been wary of what the models are saying because of this.  A strong 10 day cold shot looks to be what is in store beginning now.  That has been the pattern all winter w/ a warm-up to follow w/ zonal flow.  This time, I think that a significant winter storm will precede the warm-up.  Now...most will also point out that a block that strong rarely breaks down that quickly.  And last time it got really cold, the models lost it for a day or two.  But nine times out of ten, when models show a pattern that is that severe...they will revert to a more reasonable outcome.  What is amazing is that all of them did it at the same time.  Now, I wouldn't throw the baby out w/ the bath water...let's see what the next day's model runs bring.  Truly, the 18z and 0z look more reasonable when considering the CPC ensembles from yesterday. 

 

edit:  Additionally, if I remember correctly 1994 is referenced as an analog year often, either on the main board or twitter - can't remember.  If that is the case, I lived in Knoxville then and don't remember 94' for much of anything at all.....Let's see what the ensembles and Euro say.

[Carvers Gap]

Midnight update...Through 192 the 0z 1/18 Euro is not backing down w/ the cold.  Several clippers.  No big storm.  Plenty of cold.

[John1122]

 January 1994 was spectacular for winter weather. It featured plenty of frozen precip, lots of Arctic air and a good cold snap that lasted basically a month straight. The PV parked on Ontario. It was cold and snowy on the 3rd and 4th, I had a low of 8 with a high of 19 on the 8th. It was 6 with a high of 32 on the 9th. There was light snow on the 14th. I had a high of 9 on the 15th with a low of -2, -3 up to 27 on the 16th, some freezing rain, topped by 6 inches of snow on the 17th, then another massive Arctic blast followed, it was -9 on Jan 18 and -14 on the 19th with highs in the lower 10s the 18th and lower 20s the 19th. It stayed with temps around freezing with lows in the single digits the next 4 days before finally warming up. We had 4 days of warmth and rain, followed by another cold shot with snow on on last two days of January and the first 3 days of February. It was 35 and 8 on February 2nd, after that it was mostly warm the rest of the winter and into spring.

 

NWS Louisville actually lists the Jan 17th-19th of 1994 as the #1 weather event to ever hit the Central Kentucky area.

 

 

[John1122]

Euro is favorable for snow before  it dumps the cold into the Southeast. Nice to see a potential snow even cropping up in under 192 hours, and on the Euro to boot.

[Carvers Gap]

 January 1994 was spectacular for winter weather. It featured plenty of frozen precip, lots of Arctic air and a good cold snap that lasted basically a month straight. The PV parked on Ontario. It was cold and snowy on the 3rd and 4th, I had a low of 8 with a high of 19 on the 8th. It was 6 with a high of 32 on the 9th. There was light snow on the 14th. I had a high of 9 on the 15th with a low of -2, -3 up to 27 on the 16th, some freezing rain, topped by 6 inches of snow on the 17th, then another massive Arctic blast followed, it was -9 on Jan 18 and -14 on the 19th with highs in the lower 10s the 18th and lower 20s the 19th. It stayed with temps around freezing with lows in the single digits the next 4 days before finally warming up. We had 4 days of warmth and rain, followed by another cold shot with snow on on last two days of January and the first 3 days of February. It was 35 and 8 on February 2nd, after that it was mostly warm the rest of the winter and into spring.

 

 

Are those Knoxville or Campbell Co records?  I ask because I thought I remember you mentioning being in Knoxville for a time.  I remember the cold and one decent snow...but nothing big in Knoxville during that time frame.  I am pulling from only memories though.  I was in Knoxville during college and early working years from 89-97'.  95-96 was obviously a great winter.  93' had the blizzard.  94 had an average snow.  Other than that, I was kind of disappointed not to see more.  Have any Knoxville data for that time frame? 

 

As for the 12z Euro, generally holds serve w/ the PNA ridge breaking down ever so slightly around 240.  Does pop a -NAO on days 9-10.  Looks east based.  'Bout all you can ask for. 

[Carvers Gap]

Euro is favorable for snow before  it dumps the cold into the Southeast. Nice to see a potential snow even cropping up in under 192 hours, and on the Euro to boot.

 

Time period has been consistently appearing as a time to watch.  I agree.  Remember those 1/26, 1/27 maps everyone was posting w/ snow on the ground and sub zero temps...

[Carvers Gap]

What a great site!  National Climatic Data Center

 

"Monthly Snow Totals" on the site is where the map below was pulled.  Knoxville's snow was not that great compared to points immediately north.  That might be why John and I have such different memories of January 1994.  I can see why the parts of the MW and NE love this analog year.  (edited). 

 

January 1994 Snow Totals

[John1122]

Are those Knoxville or Campbell Co records?  I ask because I thought I remember you mentioning being in Knoxville for a time.  I remember the cold and one decent snow...but nothing big in Knoxville during that time frame.  I am pulling from only memories though.  I was in Knoxville during college and early working years from 89-97'.  95-96 was obviously a great winter.  93' had the blizzard.  94 had an average snow.  Other than that, I was kind of disappointed not to see more.  Have any Knoxville data for that time frame? 

 

As for the 12z Euro, generally holds serve w/ the PNA ridge breaking down ever so slightly around 240.  Does pop a -NAO on days 9-10.  Looks east based.  'Bout all you can ask for. 

That was Campbell County, I've never lived in Knoxville. But Knoxville had similar weather, just warmer during the frigid spots. TYS is one of the warmest spots in the Knox area and it got down to -4 there with a high of 14. I recall that Knoxville had more ice and rain and less snow on the 17th. They picked up .18 of snow after zr all morning. Then the temp sat at 33.1 and they reported thunderstorm with snow, thunderstorm with rain in the same hour. I can remember watching the 12 pm news on Channel 6 and it was coming a storm in Knoxville with heavy rain and 33 degrees but from around Racoon Valley, north it was snowing. 

[John1122]

What a great site!  National Climatic Data Center

 

"Monthly Snow Totals" on the site is where the map below was pulled.  Knoxville's snow was not that great compared to points immediately north.  That might be why John and I have such different memories of January 1994.  I can see why the parts of the MW and NE love this analog year.  (edited). 

 

January 1994 Snow Totals

1994knoxvillesnow(2).jpg

That is neat. The dot nearest me apparently has no data. I am pretty sure that was an old awos site in Elk Valley, but you can see the green 10-15 inch dot about 15 miles from me, around Williamsburg, Ky and another near there of 15-20. I didn't realize Knoxville had done quite so poorly with snow that January.

[Carvers Gap]

That was Campbell County, I've never lived in Knoxville. But Knoxville had similar weather, just warmer during the frigid spots. TYS is one of the warmest spots in the Knox area and it got down to -4 there with a high of 14. I recall that Knoxville had more ice and rain and less snow on the 17th. They picked up .18 of snow after zr all morning. Then the temp sat at 33.1 and they reported thunderstorm with snow, thunderstorm with rain in the same hour. I can remember watching the 12 pm news on Channel 6 and it was coming a storm in Knoxville with heavy rain and 33 degrees but from around Racoon Valley, north it was snowing. 

 

I got caught on the interstate in that mess.  Absolutely remember that one.  Lightning strikes.  Crazy business.  Crawled along on the interstate because of snow and people watching the electrical storm.  Posted a map above.  Snow wasn't great that January, but not terrible for Knoxville standards.  But we did have one winter storm that was decent depending on where you were, ranged from 4-5".  Good story.

 

...January 1994 does seem like a valid analog now that I look at the snow map.  Very similar to now. Would seem that it was a time w/ excellent cold, but very few events outside of elevation in TN.

[John1122]

I got caught on the interstate in that mess.  Absolutely remember that one.  Lightning strikes.  Crazy business.  Crawled along on the interstate because of snow and people watching the electrical storm.  Posted a map above.  Snow wasn't great that January, but not terrible for Knoxville standards.  but we did have one winter storm that was decent depending on where you were, ranged from 4-5".  Good story.

 

...January 1994 does seem like a valid analog now that I look at the snow map.  Very similar to now. Would seem that it was a time w/ excellent cold, but very few events outside of elevation in TN.

It was a wet snow on top of liquid, that night temps crashed fast, all the way down to the single digits, the next morning the snow was like a brick. That -14 morning was the only time my water ever froze and burst. Some animals had pulled the insulation off my pipes where they came out of the ground.

[John1122]

GGEM looks pretty good at 240. Ridge poking way up into Alaska with a big trough in the East still. After the 00z OP runs, the GFS broke the ridge early, the Euro broke it a bit later, the Canadian keeps it going, it actually pokes further up into Western Canada/Alaska post 192.

 

The Canadian Ens don't really start breaking the ridge down until hr 336, even then it's about 50/50 on those that have went zonal flow and those that still have a trough in the East.

 

The GFES individual members have mostly broken down the western ridge and lifted out the trough by 288, but several have it and some have a powerful southern storm during that time frame.

 

Historically, very cold January's do break down and lead to warm February weather. 1978 being a pretty large exception. But you can often get a major storm in this part of the country right before the pattern flips to warm. In 1996 we had a great January that was capped off by the big snow/arctic cold on February 1-5th. After that, spring sprung. 2010 was also nice in January and February but it was merely cold and not frigid with the below 0 lows.

[John1122]

JKL long range disco this morning.

 

 

 

THE MODELS STILL
HOWEVER...DO KEEP IN GOOD AGREEMENT WITH THE TROUGH OVER THE EAST
AND OVERALL...TEMPERATURES WILL BE ON THE COLDER SIDE OF NORMAL SO
BRIEF BOUTS OF SNOWFALL WILL BE POSSIBLE WITH EACH PASSING IMPULSE
IN THE LAST PORTION OF THE EXTENDED. IN FACT...TELECONNECTIONS AND
THE EURO...EVEN THE GFS FOR THAT MATTER...HAVE SHOWN A DEEPENING OF
THE TROUGH OVER THE EAST BY NEXT WEEKEND. JUST BEYOND THE EXTENDED
FORECAST PERIOD...ANOTHER POLAR AIR MASS MAY BE POISED TO MOVE SOUTH
OVER THE EASTERN CONUS...SIMILAR TO THE BITTER COLD TEMPERATURES
AFTER THE FIRST OF THE NEW YEAR.

[Coach B]

Knoxville's snow was not that great compared to points immediately north.  That might be why John and I have such different memories of January 1994.  I can see why the parts of the MW and NE love this analog year. 

OHX only recorded 4" total for the whole winter.  Again, just north into Kentucky it was massive.

[weathertree4u]

OHX only recorded 4" total for the whole winter.  Again, just north into Kentucky it was massive.

One of these years it will break - the snow drought - I just hope it is before I give up and move North!

[Carvers Gap]

The CPC's ensembles point to a big warm-up sometime around the beginning of February. Trough would switch to the west. But are they right? (To steal a tnweathernut phrase). The Euro hints at more Atlantic blocking. I lean towards a cold next 10-12 days and then some springlike weather for early-mid Feb followed by one last cold shot. Nothing set in stone. However, the current pattern does not seem like a snow producer. We need some energy to slide under that PNA ridge. Depending on northwest flow for wintry precip is a low probability endeavor in regards to snow. The pattern for this winter is cold/dry followed by warm/rain. Pattern appears to be locked in.

[Mr Bob]

Glad to see no cliff diving over the 12Z GFS. Remarkable how 24 hours ago it had below zero where it now has 50s.  The Euro continues to back the oncoming cold wave through then end of Jan...still no sign of a winter storm but still a long way to go. We can write off this run of the GFS.....for now....

[tnweathernut]

Models tend to kill blocking too quickly. I think we end up warming in early Feb sometime, but the GFS and its ensembles seems to act like a +400 mb anomaly block clear to the pole is just going to disintegrate in a couple of days. That is very likely an error.

We need the Pacific ridging to retrograde a bit though if we want a good snow opportunity.

If we can't score with the best "look" in the west and Pacific I have EVER seen modeled and such cold on our side of the globe .....it really will be bad luck.

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[tnweathernut]

I am an optimistic person, but what is being portrayed isn't a snow pattern. The biggest problem is the ridging that was projected to retrograde a few days ago isn't. It basically sets up our polar vortex to do one of two things, neither of which are good......unfortunately.

1. The vortex sits just to our northeast, basically creating a meat grinder for anything coming east (as shown by the 12z GFS)

Or

2. The PV is further north and/or east, allowing something to amplify better as it comes east, but also putting us into the situation where cold air isn't as available, meaning rain is as possible, maybe even more possible than snow/ice.

We need the whole setup to shift west over time. Unfortunately I am not seeing that right now.

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[Carvers Gap]

People, time to go look at the 12z Euro. Lots and lots of opportunity. Lost the pattern and picked it up again.

[suzbyrd]

Carvers, where do I go to look at the Euro?

[John1122]

The CPC 8-14 still has the East below normal, but for a change, most of the Tennessee Valley region is in the normal to above normal precip chances.

[tnweathernut]

DT posted the Euro 12z ensembles

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[Carvers Gap]

DT posted the Euro 12z ensembles

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I noticed this on the 18z GFS and thought it looked like a mess. Actually, it is a great set-up if true IMO. What do you think!?

[tnweathernut]

DT posted the Euro 12z ensembles

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I noticed this on the 18z GFS and thought it looked like a mess. Actually, it is a great set-up if true IMO. What do you think!?

I am cautiously optimistic, I guess anything to get away from clipper fest 2014. DT seems to think its a great setup for TN and KY, so we have that going for us.

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[tnweathernut]

Edit: I didn't even notice that was for the clipper on Tuesday. I thought that that ensemble map was for the weekend, crap.

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[Stovepipe]

GFS and Euro continue to show fun possibilities through the long range.  As long as they keep that up, my enthusiasm is above average.