January 2013 Pattern Discussion

[nzucker]

I think it's pretty much a lock at this point, given the tropical convection signals and stratospheric signals, that the last 10 days of January are going to average significantly below normal, with perhaps an arctic outbreak. We've had the stratosphere on our side for a while, but the addition of the MJO pulse into Phases 7/8 should spike the PNA, which will cause the displaced PV to move further south. The main question is: will the month of January still finish below normal as a whole, with above normal snowfall, given the muted cold shot the first week, the missed overrunning event, and the extreme warmth mid-month?

[CooL]

12z EURO has a pretty massive greenland block showing up mid month

[NaoPos]

12z EURO has a pretty massive greenland block showing up mid month

And a pretty -PNA as the PAC ridge retros west. And a Never ending SE ridge.

[CooL]

And a pretty -PNA as the PAC ridge retros west. And a Never ending SE ridge.

 

 

Could be overdone with the SE ridge but the PAC is tearing us apart which is the norm this year 

[SnowGoose69]

Could be overdone with the SE ridge but the PAC is tearing us apart which is the norm this year 

 

The SE ridge is overdone if the NAO is that strongly negative.  Notice how much colder the Euro has gotten Days 6-8 now, it actually shows an ice storm for interior SNE and NRN NY with that first storm.

[CooL]

The SE ridge is overdone if the NAO is that strongly negative.  Notice how much colder the Euro has gotten Days 6-8 now, it actually shows an ice storm for interior SNE and NRN NY with that first storm.

 

Yeah the torch is really muted and brief now. I doubt that storm on the 13th cuts that far west with that big of a cutoff block moving west over greenland

[WeatherX]

I think today's MJO progs are probably influencing the operational model runs to some extent. 

 

You can see the GEFS are much quicker to move from torch phases 4,5,6 into 7 and 8 than the Euro...it still looks like a 15 day process at any rate, before the pattern becomes favorable for winter weather again. Not saying  there can't be anything interesting before a favorable MJO phase, but something to consider. 

 

 

[Stormlover74]

Yesterdays forecast highs for today was in the mid to upper 30s and I'm sitting at 43 right now.

[WeatherX]

I think today's MJO progs are probably influencing the operational model runs to some extent. 

 

You can see the GEFS are much quicker to move from torch phases 4,5,6 into 7 and 8 than the Euro...it still looks like a 15 day process at any rate, before the pattern becomes favorable for winter weather again. Not saying  there can't be anything interesting before a favorable MJO phase, but something to consider. 

 

NCPE_phase_21m_full.gif

 

ECMF_phase_MANOM_51m_full.gif

 

So, my assumption is that if the MJO suddenly jumps to a pretty robust amplitude as progged, it could very well overwhelm the pattern. Just throwing that out there....

[SnowGoose69]

So, my assumption is that if the MJO suddenly jumps to a pretty robust amplitude as progged, it could very well overwhelm the pattern. Just throwing that out there....

 

I've only recently read up on the MJO.  I do know the good/bad phases for this area now but what I don't have a good understanding of yet is what it means when it goes into the center circle.

[WeatherX]

I've only recently read up on the MJO.  I do know the good/bad phases for this area now but what I don't have a good understanding of yet is what it means when it goes into the center circle.

 

My understanding of the center circle is that tropical forcing is not really influencing the global circulation pattern, when it resides there. So no positive or negative signal. Obviously it makes forecasting the mid to long range a PITA, which is evident this winter so far. 

[bluewave]

I think it's pretty much a lock at this point, given the tropical convection signals and stratospheric signals, that the last 10 days of January are going to average significantly below normal, with perhaps an arctic outbreak. We've had the stratosphere on our side for a while, but the addition of the MJO pulse into Phases 7/8 should spike the PNA, which will cause the displaced PV to move further south. The main question is: will the month of January still finish below normal as a whole, with above normal snowfall, given the muted cold shot the first week, the missed overrunning event, and the extreme warmth mid-month?

 

My guess is that NYC will be running at least +5 to +8 degrees above normal through January 17th.

We may be able to knock down those departures to closer to normal with a cold enough pattern

between the 20-31st. But with the warmth in the forecast, it will be a big challenge to get a negative

departure on the month but it is still possible.

[nzucker]

My guess is that NYC will be running at least +5 to +8 degrees above normal through January 17th.

We may be able to knock down those departures to closer to normal with a cold enough pattern

between the 20-31st. But with the warmth in the forecast, it will be a big challenge to get a negative

departure on the month but it is still possible.

 

I don't think the positive departures will be that large...we've started January somewhat below normal, and the torch has become more muted on recent model runs. The only days that look super warm to me are Friday and Saturday, and we're probably talking low 50s, not 60s. While a few days between 10-15 degrees above average will erase the negative departure we've accumulated, I don't think it will bring us to +5 and certainly not +8. 

 

Although the big cold has been in the Great Basin and Mountain West, January has started off below normal on the East Coast as well:

[PB GFI]

Warmth always seems to overpreform. We are probably looking a 10 to 14 day stretch that will finish above normal. If i had to bet it would b to the higher end of the range. But my hope is the last 10 days of jan r as harsh as the middle 10 will b nice

[MJO812]

 AO is forecasted to freefall

 

Nao is forecasted to go negative

 

PNA is forecasted to stay neutral to slightly negative

 

[bluewave]

I don't think the positive departures will be that large...we've started January somewhat below normal, and the torch has become more muted on recent model runs. The only days that look super warm to me are Friday and Saturday, and we're probably talking low 50s, not 60s. While a few days between 10-15 degrees above average will erase the negative departure we've accumulated, I don't think it will bring us to +5 and certainly not +8. 

 

Although the big cold has been in the Great Basin and Mountain West, January has started off below normal on the East Coast as well:

januarytempdepartures.png

 

NYC is pretty much guaranteed to be at least +5 through the 17th. it's very easy to do especially when

the mins will be so mild even if the clouds hold down maxes some days. We may be able to finish the month

0 to +2 if it gets cold enough at the end. A negative departure will be a challenge, but not impossible.

[IntenseBlizzard2014]

 AO is forecasted to freefall

 

Nao is forecasted to go negative

 

PNA is forecasted to stay neutral to slightly negative

 

Notice that the PNA isn't really going negative, but more of an approach to neutral.

[SnoSki14]

This whole pattern change thing is just what we've gone though in December where we kept waiting and waiting and we ended up with a few opportunities that we couldn't really bank on. Will we see the same result in the second half of this month, a few opportunities where we lose. 

 

I'm going to stay hopeful but I won't stress over the torch. If we can't have snow, then it might as well be mild right now. 

[nzucker]

NYC is pretty much guaranteed to be at least +5 through the 17th. it's very easy to do especially when

the mins will be so mild even if the clouds hold down maxes some days. We may be able to finish the month

0 to +2 if it gets cold enough at the end. A negative departure will be a challenge, but not impossible.

What is the exact departure right now? I know most stations in new england are -5 to -6 but we're probably not that cold.

[Isotherm]

What is the exact departure right now? I know most stations in new england are -5 to -6 but we're probably not that cold.

 

 

 

-2.5 at KNYC through 1/4. The next several days look 0 to +5, bringing us up to normal, and days 5-10 could be solidly above w/ +5 to +10s on the dailies. So we'll likely be running a fairly decent positive departure by mid month, but I think if the strongly negative EPO/AO/NAO pattern verifies, we have a good chance for colder than normal Jan in the Northeast. I'm very confident on a cold Mid-west/West/Lakes finish.

[rgwp96]

-2.5 at KNYC through 1/4. The next several days look 0 to +5, bringing us up to normal, and days 5-10 could be solidly above w/ +5 to +10s on the dailies. So we'll likely be running a fairly decent positive departure by mid month, but I think if the strongly negative EPO/AO/NAO pattern verifies, we have a good chance for colder than normal Jan in the Northeast. I'm very confident on a cold Mid-west/West/Lakes finish.

+1.3 for me so far through jan 4th

[tim]

...larry cosgrove is barking big time about d11 thru d15..

[bluewave]

If we can't get a decent rise in the PNA later this month, that SE Ridge may try to hold on enough

with the coldest temperatures staying over Upstate NY and New England.

 

You can see how the Day 10 Euro ensemble mean still has the look that we have been seeing all

winter so far.

 

 

 

 

Not a positive enough PNA would leave a remnant of the SE Ridge in place.

 

 

 

 

[Isotherm]

Well the major mid-winter warming of the stratosphere is ongoing as we speak, EP vectors are turning poleward through all levels of the atmosphere, so the vortex perturbing/disruption is certainly real. Consequently the AO will be going strongly negative; that is something I'm very confident about. However, we've seen a neg AO for the winter thus far, but not much Eastern cold. What I'm least confident about is the exact timing concerning when the Northeast sees sustained colder than normal temps. I guess you could say I'm bearish given how the teleconnections have not correlated to temps at all this winter, as the EPO has been overpowering the Arctic indices.

However, going forward, it's pretty apparent that the EPO turns strongly negative w/ major height rises from south of AK upward to the pole. Problem is initially, the -AO, -EPO, -PNA pattern will favor the Plains/West due to the magnitude of the -PNA/Western trough.

Good news:



Bad news:



And so there will be SE ridge resistance UNTIL we can get a NAO, west based, of strong enough magnitude to overwhelm the entire United States with cold air. The NAO magnitude and position is where my confidence is lowest, and thus, my confidence on timing the cold to the East Coast is low.

What should happen over the coming week:

1) MMW induced vortex disruption/breaking and warming into the troposphere, AO becomes negative
2) EPO turns strongly negative with height rises significant AK region
3) PNA reverses, tanking negative, pumps the SE ridge for days 5-10 in the East

NAO goes negative but how negative and where? This will determine the extent and timing of eastern cold for JAN 15-30.

If the NAO ends up being another BS NAO, we'll be looking at a 2006-07 type winter where we torch DEC/JAN and maybe save FEB.         

[IntenseBlizzard2014]

Well the major mid-winter warming of the stratosphere is ongoing as we speak, EP vectors are turning poleward through all levels of the atmosphere, so the vortex perturbing/disruption is certainly real. Consequently the AO will be going strongly negative; that is something I'm very confident about. However, we've seen a neg AO for the winter thus far, but not much Eastern cold. What I'm least confident about is the exact timing concerning when the Northeast sees sustained colder than normal temps. I guess you could say I'm bearish given how the teleconnections have not correlated to temps at all this winter, as the EPO has been overpowering the Arctic indices.

However, going forward, it's pretty apparent that the EPO turns strongly negative w/ major height rises from south of AK upward to the pole. Problem is initially, the -AO, -EPO, -PNA pattern will favor the Plains/West due to the magnitude of the -PNA/Western trough.

Good news:

Bad news:

And so there will be SE ridge resistance UNTIL we can get a NAO, west based, of strong enough magnitude to overwhelm the entire United States with cold air. The NAO magnitude and position is where my confidence is lowest, and thus, my confidence on timing the cold to the East Coast is low.

What should happen over the coming week:

1) MMW induced vortex disruption/breaking and warming into the troposphere, AO becomes negative

2) EPO turns strongly negative with height rises significant AK region

3) PNA reverses, tanking negative, pumps the SE ridge for days 5-10 in the East

NAO goes negative but how negative and where? This will determine the extent and timing of eastern cold for JAN 15-30.

If the NAO ends up being another BS NAO, we'll be looking at a 2006-07 type winter where we torch DEC/JAN and maybe save FEB.

If the ESRL is right, we'll be looking at an excellent opportunity by the 21st.

[SnowGoose69]

LOL GFS breaks the entire pattern down again late in the run, if we lose this one I think I'll be ready to pull the plug on this winter.

[IntenseBlizzard2014]

LOL GFS breaks the entire pattern down again late in the run, if we lose this one I think I'll be ready to pull the plug on this winter.

Something seems familiar with this. Remember the last time when the GFS was the Polar Opposite of the EURO? Also, when was the last time when the EURO and the GFS ever agreed upon under 96 HRS?

[uncle W]

LOL GFS breaks the entire pattern down again late in the run, if we lose this one I think I'll be ready to pull the plug on this winter.

 

the plug was pulled after the warm December we just had...Last year we had a snowfall around the 20th...it came when the January thaw usually comes...February and March became warm again...If we get another snowfall when we should be getting the January thaw February might turn out warm again...

[bluewave]

the plug was pulled after the warm December we just had...Last year we had a snowfall around the 20th...it came when the January thaw usually comes...February and March became warm again...If we get another snowfall when we should be getting the January thaw February might turn out warm again...

 

I think that we have to go back to 92-93 to get above 20 inches on the season after a December below 2 inches.

[nzucker]

I was looking at the correlations last night, and the AO only has a minor correlation to temperatures as far north as New York City...much less of a correlation than in the Southeast, and MUCH MUCH less than in Russia and Europe, where a -AO has turned this winter into a brutal one. What's really important here is the EPO, and the AO's impact on 500mb heights is much less in Alaska than Greenland.