Mid to Long Range Discussion ~ 2023

[BooneWX]

Mood

[GaWx]

6 hours ago, CAD_Wedge_NC said:

If the MJO is in phase 4,5 or 6 during February, then you can forget about it being cold. That is pretty much guaranteed in a La Nina.

Yeah, it is hard to have a cold Feb in a Niña as only 15% of them have been cold. So, having the indices favoring cold is crucial.
 

 However, the MJO so far this season has not correlated well with tendencies. (I say tendencies because that's all they are.) This winter's strongest cold to date, 12/23-7, was during phase 5. Also, I just took a look at the MJO/temps during Niña Febs since 1975. What I discovered is that whereas cold Febs were infrequent as expected, I saw virtually no correlation of temps and MJO! For example, the six warmest Febs (1976, 1989, 2000, 2012, 2018, and 2022) had few or no days in phases 4-6! Moreover, two of the coldest Febs (1985 and 2009) had many days in those phases.

 
This is enough data to tell me to not place much emphasis on the MJO to predict how this Feb will turn out.

MJO data (see it for yourselves):

http://www.bom.gov.au/climate/mjo/

[Coach McGuirk]

Maybe we'll have better luck in late January/February.  The Pac Jet can't maintain this dominance all winter long, especially in a non el-nino winter.

[Met1985]

If you don't like the looks of the weeklies or trust them then look at the ensembles currently.  All three of the major long range models have a positive PNA and a negative epo pattern setting up around the 20th of this month. To me that's some pretty good signs but to others the damn sky is falling everyday....

[CAD_Wedge_NC]

It does give us some hope, but it is too far down the road to put any faith in right now. Like to see it inside 7 days.

[Coach McGuirk]

4 hours ago, CAD_Wedge_NC said:

It does give us some hope, but it is too far down the road to put any faith in right now. Like to see it inside 7 days.

Unless we get some major changes, there is nothing inside two weeks.

[GaWx]

 Today's GEFS based forecast for day 14 has slight improvements vs yesterday's forecast from the perspective of someone who prefers that a colder pattern return in late January:

- gets back to a weak +PNA after a -PNA that starts ~1/15

- AO rises to neutral but then falls back to moderately negative; very strong Dec -AO favors sub -1 AO in January. To have a good shot at that, a mainly sub -1 will likely be needed for 1/22-31

- The current moderate to strong +NAO falls back toward neutral

 Regardless of whether or not a BN dominated period returns at some point during the last 10 days of the month, January will almost certainly end up quite a mild month for the SE as a whole and much of the E US. It has a good shot at being one of the warmest nationwide since 1950 from a population weighted heating degree perspective. So, a near normal Dec and a mild January in the SE US. What will February bring? That's the big question. Any educated guesses?

 

[TARHEELPROGRAMMER88]

31 minutes ago, GaWx said:

 Today's GEFS based forecast for day 14 has slight improvements vs yesterday's forecast from the perspective of someone who prefers that a colder pattern return in late January:

- gets back to a weak +PNA after a -PNA that starts ~1/15

- AO rises to neutral but then falls back to moderately negative; very strong Dec -AO favors sub -1 AO in January. To have a good shot at that, a mainly sub -1 will likely be needed for 1/22-31

- The current moderate to strong +NAO falls back toward neutral

 Regardless of whether or not a BN dominated period returns at some point during the last 10 days of the month, January will almost certainly end up quite a mild month for the SE as a whole and much of the E US. It has a good shot at being one of the warmest nationwide since 1950 from a population weighted heating degree perspective. So, a near normal Dec and a mild January in the SE US. What will February bring? That's the big question. Any educated guesses?

 

Flowers blooming and birds singing. February? Nah, early May more like it. 

[Daniel Boone]

17 hours ago, Met1985 said:

If you don't like the looks of the weeklies or trust them then look at the ensembles currently.  All three of the major long range models have a positive PNA and a negative epo pattern setting up around the 20th of this month. To me that's some pretty good signs but to others the damn sky is falling everyday....

That's that meltdown I was talking about brother, lol. 

[Met1985]

23 minutes ago, Daniel Boone said:

That's that meltdown I was talking about brother, lol. 

For sure!

[franklin NCwx]

1 hour ago, GaWx said:

 Today's GEFS based forecast for day 14 has slight improvements vs yesterday's forecast from the perspective of someone who prefers that a colder pattern return in late January:

- gets back to a weak +PNA after a -PNA that starts ~1/15

- AO rises to neutral but then falls back to moderately negative; very strong Dec -AO favors sub -1 AO in January. To have a good shot at that, a mainly sub -1 will likely be needed for 1/22-31

- The current moderate to strong +NAO falls back toward neutral

 Regardless of whether or not a BN dominated period returns at some point during the last 10 days of the month, January will almost certainly end up quite a mild month for the SE as a whole and much of the E US. It has a good shot at being one of the warmest nationwide since 1950 from a population weighted heating degree perspective. So, a near normal Dec and a mild January in the SE US. What will February bring? That's the big question. Any educated guesses?

 

Warm February,  below normal March,  April,  and May

[Met1985]

14 minutes ago, franklin NCwx said:

Warm February,  below normal March,  April,  and May

Bye bye spring especially for us.

[CAD_Wedge_NC]

9 minutes ago, Met1985 said:

Bye bye spring especially for us.

Maybe we can dodge most of the severe outbreaks. 

[Upstate Tiger]

2 minutes ago, CAD_Wedge_NC said:

Maybe we can dodge most of the severe outbreaks. 

I hope.  Reminds me of 1983/84.  Was a freshman in college.  We had the brutal cold snap at Christmas with no snow.  Mild January.  A  mild February with one little 2” snow event. Bad tornado outbreak end of March in South Carolina. 

[Met1985]

14 minutes ago, CAD_Wedge_NC said:

Maybe we can dodge most of the severe outbreaks. 

Heck I hope we get both. 

[GaWx]

1 hour ago, franklin NCwx said:

Warm February,  below normal March,  April,  and May

 I prefer BN/lower than average dewpoints for all months of the year. Just add Feb in and this forecast would be perfect for me!

 The 12Z EPS progressed well vs the last 4 runs. So far so good for cold lovers! Let's see if an actual pattern change in January can hold on the EPS for a change. The prior two attempts (1/9-10 and midmonth) have apparently since failed with the overall mild pattern still not breaking on the models til at least 1/21 or so.

 The end of the 12Z run shows a solid +PNA with 10-12 dm AN H5 heights Pacific NW and 8-10 dm BN centered over the lower Midwest. BN at the ground is coming into the SE near the end. It still doesn't look very cold yet as there still aren't more than a few members with big Arctic highs coming down, but it is a start and would mean much colder than the preceding warmth if it were to verify.

[franklin NCwx]

5 hours ago, Met1985 said:

Bye bye spring especially for us.

Unfortunately it's been that way for a few years.  Mean reversion after those great winters we had a decade ago.

[GaWx]

 Since 1950 at KATL, there have been five La Niña Febs at one BN or colder out of 21 (2009, 2006, 1996, 1985, and 1971). I decided to check out the PNA, AO, NAO, and EPO for these five to see if there were any tendencies:

 

PNA: -1.0, -0.1, -0.3, -0.5, +0.1; AVG -0.4

AO: -0.7, -0.2, +0.2, -1.4, -0.9; AVG -0.6

NAO: +0.1, -0.5, -0.1, -0.5, +0.2; AVG -0.2

EPO: -24, -34, -20, +75, +85; AVG +16

 The coldest Feb (2006) had a PNA of -0.1, an AO of -0.2, an NAO of -0.5, and an EPO of -34.

 Surprisingly, there was no +PNA tendency for the colder five. The most significant tendency was a  -AO.

 Now I'll compare these averages of the indices for the five colder Febs with that for the warmer 16 Febs:

PNA: 

+0.7, -0.3, -1.0, +0.8, -1.6, +0.5, -0.2, +1.1, -0.1, -1.1, -1.5, -0.2, -0.9, -1.0, -1.7, -1.0

AVG PNA for warmer: -0.5

 

AO:

+1.6, -1.2, +0.1, -0.0, +1.6, +0.9, -0.6, +1.1, +0.5, +3.3, +1.7, +0.2, -0.5, -2.0, -1.5, +0.6

 AVG AO for warmer: +0.4

 

NAO: 

+1.7, +0.1, +1.6, +0.4, +0.7, +0.7, +0.5, +1.7, +0.3, +2.0, +0.9, -0.6, -0.1, -1.1, -1.1, +0.4

AVG NAO for warmer: +0.5

EPO: 

-16, +50, -70, +48, -16, +86, -41, +34, +194, -232, +89, +44, +135, +51, +6, +101

AVG EPO for warmer: +29

---------------

The warmest Feb (2018) had a PNA of -1.0, AO of +0.1, NAO of +1.6, and EPO of -70.

 The average PNA was ~same for warmer vs colder. The average AO was significantly higher at +0.4 vs -0.6 while the average NAO was also significantly higher at +0.5 vs -0.2. The average EPO was just a little bit higher at +29 vs +16.

Conclusion: The biggest drivers to determine warmth vs chill for La Niña Febs appear to be AO and NAO.

 If we could get a sub -1 AO, a sub -0.5 NAO, a PNA of no lower than -0.5, and an EPO no higher than +100, I'd feel there'd be a decent shot at a Feb at one BN or colder.

[LakeNormanStormin]

So you're saying there's a chance....

[GaWx]

 The 0Z EPS is still consistent with its prior runs as regards the developing +PNA late in the run. It actually looks a touch colder thanks to a few more members with pretty strong Arctic highs. Baby steps. Let's see if it remains over the next few runs. If it does and looks like a real deal, the next question will be about its longevity prospects.

[eyewall]

We are going to be fast approaching "sun angle and soil temp" season by the time there is even a remote chance it feels like. Being completely blanked on the season is on the table.

[Bevo]

On 1/7/2023 at 8:54 PM, Coach McGuirk said:

Maybe we'll have better luck in late January/February.  The Pac Jet can't maintain this dominance all winter long, especially in a non el-nino winter.

Why not? It has definite historical precedence to do so. Again, we've seen this movie a hundred times.

[franklin NCwx]

1 hour ago, eyewall said:

We are going to be fast approaching "sun angle and soil temp" season by the time there is even a remote chance it feels like. Being completely blanked on the season is on the table.

That started Dec 22.

[CaryWx]

1 hour ago, eyewall said:

We are going to be fast approaching "sun angle and soil temp" season by the time there is even a remote chance it feels like. Being completely blanked on the season is on the table.

That almost sounds like a troll post.  And believe me, I'm a dreaded sun angle guy.  However I'm also astute enough to know sun-angle has little bearing on winter storm occurrence opportunities. At least during the season.  It is more an issue with staying power for snow cover and the like.  By the way in our red neck of the woods it's not really relevant until about 2/15 or so.

[PackGrad05]

Climatologically, February is not that far off from January for RDU in amount of snow.  

Yes, January is the best chance, but February has produced great events.  Once we get to February 20 is when I start getting more concerned.

Being completely blanked is still on the table for sure.  But so is getting a 10" storm.

[NorthHillsWx]

On 1/7/2023 at 4:40 PM, BooneWX said:

Mood

This may be the post of the winter 

[NorthHillsWx]

30 minutes ago, PackGrad05 said:

Climatologically, February is not that far off from January for RDU in amount of snow.  

Yes, January is the best chance, but February has produced great events.  Once we get to February 20 is when I start getting more concerned.

Being completely blanked is still on the table for sure.  But so is getting a 10" storm.

Agree with this. I think the problem is all of us want to enter February with “money in the bank” (at least one event in the December-January period). Getting blanked through 2-3 of our best climo doesn’t sit well with anyone and relying on February for all of our winter weather threats doesn’t work out well. So far, any pattern change or threat remains more than 2 weeks down the road and the period until then is absolutely garbage with cutter after cutter and zero cold air anywhere near the east coast. That’s a fact. 

[olafminesaw]

1 hour ago, NorthHillsWx said:

Agree with this. I think the problem is all of us want to enter February with “money in the bank” (at least one event in the December-January period). Getting blanked through 2-3 of our best climo doesn’t sit well with anyone and relying on February for all of our winter weather threats doesn’t work out well. So far, any pattern change or threat remains more than 2 weeks down the road and the period until then is absolutely garbage with cutter after cutter and zero cold air anywhere near the east coast. That’s a fact. 

Persistence persists until proven otherwise.

[Upstate Tiger]

You can clearly see the ridge begin to build out west after the 21st.  One thing is for sure.  The reservoirs and snow pack in the west should have benefited from the ongoing pattern.  

[GaWx]

 The Dec 2022 AO ended up way down at -2.7. That's the second lowest AO on record back to 1950 with only 2009's -3.4 lower! Here is the subsequent Jan AO for the strongest Dec -AOs:

 

Strongest Dec -AO/Jan AO

2009: -3.4/-2.6 6th strongest

2022: -2.7/???

2010: -2.6/-1.7 top 20%

2000: -2.4/-1.0

1995: -2.1/-1.2 top 25%

2005: -2.1/-0.2

1976: -2.1/-3.8 strongest

1985: -1.9/-0.6

1950: -1.9/-0.1

1969: -1.9/-2.4 9th strongest

1952: -1.8/-1.0

 

  The above tells me that there's a good shot at a sub -1 this month though that would probably require a sub -1 for the last week of this month.

  Implications for February? Not much per these analogs. Whereas a -AO could be argued to be slightly favored over neutral or +, Feb of 2011 went strongly + with a +1.6!