November 2017 Discussions & Observations Thread

[CIK62]

Next 8 days averaging 54degs., or +4degs.  KWO-35 seemed to have lower temps. predicted.

Ensembles show temperature predictions reliable for just 4 days.  Spread widens rapidly.  CMC likes 30degs. on the 12th., GFS likes 50degs., for example.

[bluewave]

EPS continues with a chance for a first freeze in NYC next Friday into Saturday. Longer range, the EPS finally builds the heights across the pole from the Aleutians to the Kara Sea in mid-November.  This means that we have a chance at seeing a -AO or -NAO later in November if the PV can get displaced. Skill can be low at these forecast times so we'll just have to wait and see what happens.

 

[Morris]

Models kept the weekend freeze on the overnight runs.

[bluewave]

It's been a while since we actually saw the EPS trend colder long range. All it took was that near record +500 meter Aleutian block and Arctic high.

 

 

 

[dmillz25]

16 minutes ago, bluewave said:

It's been a while since we actually saw the EPS trend colder long range. All it took was that near record +500 meter Aleutian block and Arctic high.

 

 

 

Models are now showing blocking in the high latitudes starting pretty soon actually. I take it as a good sign

[Morris]

The Canadian is the coldest of all. A bunch of freezes starting at the end of this week. Lots of well BN weather.

[bluewave]

25 minutes ago, dmillz25 said:

Models are now showing blocking in the high latitudes starting pretty soon actually. I take it as a good sign

Interesting things can happen when you get near record 500+ meter blocks near Alaska. Can't seem to get cold here anymore without some form of extreme blocking.

 

[SnoSki14]

3 minutes ago, bluewave said:

Interesting things can happen when you get near record 500+ meter blocks near Alaska. These extreme blocking events have been the only thing that have been able to bring colder temps here in recent years.

 

But is it temporary, that's the question. As of now it appears most of us will see our first freeze by next weekend including NYC.

[bluewave]

5 minutes ago, SnoSki14 said:

But is it temporary, that's the question. As of now it appears most of us will see our first freeze by next weekend including NYC.

It may represent the end of the extreme warm phase that began around September 10th. The record MJO and block that developed near Alaska have changed things up for the time being. How long it lasts remains to be seen.

[Stormlover74]

8 minutes ago, SnoSki14 said:

But is it temporary, that's the question. As of now it appears most of us will see our first freeze by next weekend including NYC.

It might be close, but I doubt NYC sees a freeze

[SnoSki14]

Just now, Stormlover74 said:

It might be close, but I doubt NYC sees a freeze

I would give it a couple days but if the EPS is correct then not only will they see a freeze but possibly a hard freeze with temps in the 20s. 

That's an Arctic air mass courtesy of the -EPO and record Aleutian block. 

[CIK62]

Next 7 days are averaging just 49degs. now (Normal or even BN and a 5 degree drop from the AM) now, with the current flip of the GFS.   Tomorrow could be the day the next 8 go BN for the first time in 2 months.

EPS Mean has next Sat/Sun as 20-30 degrees less than this weekend was.

[donsutherland1]

On 11/4/2017 at 4:55 PM, Isotherm said:

Thanks Don. Color not nearly as lurid as the past couple of years, but if you search for the right places, there are some beautiful spots still. We're probably about 90% changed at this point; peak probably occurring within a day or two, about a week behind schedule.

Even as the colors might not be as vivid as they were in some past years, they are still quite magnificent. Many areas have seen far less. Enjoy the peak before the leaves are all blown down.

[MJO812]

Upton has a possible mix even for the coast on sunday

 

"Sunday another shortwave with more energy is expected to pass through the area Sunday and Sunday night. With the cold airmass retreating and modifying Sunday precipitation could potentially begin as snow and/or rain inland with a mix possibly even down to the coast early Sunday."

 

http://forecast.weather.gov/product.php?site=OKX&issuedby=OKX&product=AFD&format=CI&version=1&glossary=1&highlight=off

[PB GFI]

3 hours ago, bluewave said:

It's been a while since we actually saw the EPS trend colder long range. All it took was that near record +500 meter Aleutian block and Arctic high.

 

 

 

I like the look of the day 15 EPS as the heights rise from Alaska over the pole into Siberia.

That should allow the trough to get caught up in the N Hemisphere.

The week 4 CFS makes sense , so that by day 20 we could see the start of a trough migrate into the east and stay for a bit.

 

Unlike the in and out nature of this weekends trough.

[EasternLI]

2 hours ago, bluewave said:

It may represent the end of the extreme warm phase that began around September 10th. The record MJO and block that developed near Alaska have changed things up for the time being. How long it lasts remains to be seen.

 

That MJO (along with recent modeling) has me a bit interested in prospects for a neg. NAO. Here is a paper on the subject, some interesting tidbits here. Some other reading I've done suggests it could be narrowed down more to phase 3 and 7, but I'm not certain about that right now.

http://journals.ametsoc.org/doi/full/10.1175/2008JCLI2515.1

Quote

In general, the probability results are consistent with the composites of the NAO index itself of Table 2. When the NAO leads the MJO, there is a high probability that a negative NAO leads phases 2 and 3 by 3∼5 pentads, whereas a positive NAO leads phases 6 and 7 by 2∼5 pentads. On the other hand, a systematic connection between the NAO and MJO is found when the MJO leads the NAO. Significant large probabilities of the NAO index in the upper tercile are observed for phases 2–4 and large probabilities in the lower tercile for phases 6–8. Hence, a positive (negative) NAO is likely to happen 5–15 days after the MJO is detected in phases 2–4 (phases 6–8), which correspond to an enhanced (reduced) precipitation over the Indian Ocean and Maritime Continent and a reduced (enhanced) convective activity near the tropical central Pacific (Fig. 3).

[Tatamy]

3 hours ago, Snow88 said:

Upton has a possible mix even for the coast on sunday

 

"Sunday another shortwave with more energy is expected to pass through the area Sunday and Sunday night. With the cold airmass retreating and modifying Sunday precipitation could potentially begin as snow and/or rain inland with a mix possibly even down to the coast early Sunday."

 

http://forecast.weather.gov/product.php?site=OKX&issuedby=OKX&product=AFD&format=CI&version=1&glossary=1&highlight=off

0z NAM 12K is indicating that we do not have to wait until Sunday.  It is stronger with the wave for Tuesday evening and shows rain changing to accumulating snows across northern and western NJ and eastern PA to the tune of 2 - 4".  This is from the Pivotal Wx maps.  NAM 3K has a warmer solution.

[swamplover56]

3 hours ago, PB GFI said:

I like the look of the day 15 EPS as the heights rise from Alaska over the pole into Siberia.

That should allow the trough to get caught up in the N Hemisphere.

The week 4 CFS makes sense , so that by day 20 we could see the start of a trough migrate into the east and stay for a bit.

 

Unlike the in and out nature of this weekends trough.

Please continue to post as we move into the beginnings of winter weather season I think I speak for everyone your posts are always greatly appreciated always enjoy your opinions

[psv88]

14 minutes ago, swamplover56 said:

Please continue to post as we move into the beginnings of winter weather season I think I speak for everyone your posts are always greatly appreciated always enjoy your opinions

Don't worry, he'll be posting

[snowman19]

5 hours ago, EasternLI said:

 

That MJO (along with recent modeling) has me a bit interested in prospects for a neg. NAO. Here is a paper on the subject, some interesting tidbits here. Some other reading I've done suggests it could be narrowed down more to phase 3 and 7, but I'm not certain about that right now.

http://journals.ametsoc.org/doi/full/10.1175/2008JCLI2515.1

The MJO phases have completely different effects on the longwave pattern based on whether we are in a La Niña or an El Niño. There are sites to look it up on, but the MJO phases are all adjusted for each phase for a Niña or a Niño 

[Eduardo]

6 hours ago, PB GFI said:

I like the look of the day 15 EPS as the heights rise from Alaska over the pole into Siberia.

That should allow the trough to get caught up in the N Hemisphere.

The week 4 CFS makes sense , so that by day 20 we could see the start of a trough migrate into the east and stay for a bit.

 

Unlike the in and out nature of this weekends trough.

Was wondering when we could expect your return, Paul.

I understand it's only November 6th, but any December thoughts just yet?

Great to have you back!!

[CIK62]

We do it!  Next 8 days averaging just 47degs., or 2degs. BN.  Saturday is almost a Bona Fide mid winter day supposedly.

Most weather regimes last 45 days or so.  Related to MJO complete cycle period or something.  This one is going to total 55 days.

Evidence that this is a new regime of mostly BN temps. is thin right now.  Next 45 days keeps bouncing around.

[EasternLI]

6 hours ago, snowman19 said:

The MJO phases have completely different effects on the longwave pattern based on whether we are in a La Niña or an El Niño. There are sites to look it up on, but the MJO phases are all adjusted for each phase for a Niña or a Niño 

That's not what I'm referring to here. I have the link for that. I'm pointing out a lag relationship of approx. 2 weeks to those phases.

[bluewave]

12 hours ago, EasternLI said:

 

That MJO (along with recent modeling) has me a bit interested in prospects for a neg. NAO. Here is a paper on the subject, some interesting tidbits here. Some other reading I've done suggests it could be narrowed down more to phase 3 and 7, but I'm not certain about that right now.

http://journals.ametsoc.org/doi/full/10.1175/2008JCLI2515.1

 

This record MJO pulse was first associated with the record California warmth during late October as the Western ridge began to ballon rapidly up toward Alaska. The key will be getting this near record ridge to build back across the pole like the day 10-15 EPS is showing. Check out the 500 mb animation below and you can see the ridge really take off right as the MJO was going into 6.

http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_nh_anim.shtml

[NEG NAO]

[Morris]

Finally enjoying reading the OKX weather discussion.

[bluewave]

The EPS is showing an ideal cold air drain down the Hudson Valley right into NYC Saturday morning. The Arctic high is so strong on the EPS that is forecasting a record low tie of 28 degrees. This would be a big deal for NYC should it verify since the last November record low or tie was way back in 1976.

 

[Animal]

48 minutes ago, NEG NAO said:

 

Is this legit. Saw a few post about snow possible mid week and sunday.

Mt Holly NWS has not mention of it.

[NJwx85]

3 minutes ago, Animal said:

 

Is this legit. Saw a few post about snow possible mid week and sunday.

Mt Holly NWS has not mention of it.

The Euro and the GFS have a suppressed look. The GGEM is further North but much too warm. It seems likely that the NAM is throwing too much lift into the cold, dry air coming down from the North with a relatively weak shortwave that moves off the Delmarva.

[PB GFI]

1 hour ago, bluewave said:

Yeah, the 0z connects the Aleutian ridge to the Kara ridge. This allows the AO to drop in the long range EPS as the PV finally gets displaced form the Arctic. It would be a good sign if the long range EPS is onto something here. Be interesting to see if the AO can drop to -2 or lower November 20th to 30th. Every winter since 2000 when this has occured has had it least 1 negative -AO month between December and March. These are the years since 2000 with a -2 or lower AO close to Thanksgiving....2012...2010...2009...2008...2002.

 

I like 08 and 10 , I think we get off to a fast start in late November through December.

To your point , you see that exact set up on the 6z GEFS day 11 thru 15.

"if" we connect the ridge all the way to the Kara sea then I believe the net drainage of that air will funnel into the lakes and NE.

 

Canada and Greenland look to building a very nice snow pack early on and thats always a good sign for cold in the N Hemisphere.