Winter 2013-14 medium range discussion

[The_Global_Warmer]

DISCUSS.  THE GRAPHICS WILL UPDATE EVERYDAY.  IF ANYONE WOULD LIKE TO ADD TO THE GRAPHICS IN THIS THREAD THAT UPDATE FREQUENTLY PLEASE DO SO.

 

 

 

 

 

 

 

 

 

[The_Global_Warmer]

[The_Global_Warmer]

 

 

 

 

[Amped]

Thanks Global warmer. I think we can do without the radar maps and warnings in a medium range thread.

[WidreMann]

Thanks Global warmer. I think we can do without the radar maps and warnings in a medium range thread.

How will you know what's coming?

[The_Global_Warmer]

Thanks Global warmer. I think we can do without the radar maps and warnings in a medium range thread.

 

Too much for your tmobile internet?

[ORH_wxman]

How will you know what's coming?

 

 

Radar images are irrelevant for medium range forecasting.

[Wow]

I need more maps

[WinterWxLuvr]

I need more maps

You've come to the right place, evidently.

[The_Global_Warmer]

At quick glance things are looking better going into mid to late November.

Northern plains, lakes, NE look to get some good cold shots/NW flow.

[The_Global_Warmer]

The GFS shows an event in the 7-9 day range.  Big hit for a large stretch of the forums.

 

 

[sniper88]

hi guys im a new in this forum, i love winter, it's a beatiful forum of weather, im leave in Italy, but i study the weather and forecasting for all north emisphere

[The_Global_Warmer]

Welcome to the forums

[donsutherland1]

Just to keep my thoughts in a single place, as they concern more than just a local region, I'll begin posting them in this thread. My very early thoughts about Winter 2013-14 were not pleasant.

 

My very early guess prior to data I look for in November for confirmation of some of my key assumptions is that odds favor a warmer than normal winter in the eastern third to half of the U.S./southern Canada (including Toronto and Montreal). The risk of warmth is lower for Ottawa and Quebec City. A warmer than normal outcome is perhaps a 70% probability in my thinking at this time and the risk of a much warmer than normal outcome is on or near the table.

 

Given some of the data, there is some prospect of near coast-to-coast warm anomalies this winter (perhaps 25%). Until some of the assumptions that would lead to that outcome are confirmed by subsequent data, it's too soon to make such a call (at least for me).

 

I'll have my final thoughts in late November.

 

http://www.americanwx.com/bb/index.php/topic/41578-very-early-winter-2013-14-thoughts/

 

At this point in time, the early data also seems to favor a warmer than normal December in large parts of North America.

I ran the maps for ENSO and Teleconnections last night to see what I'd come up with. The maps are for North America and for Europe. For purposes of comparison, I also included the 11/8/2013 0z run of the CFSv2.

 

The maps were as follows:

 

 

Although I didn't run the maps for Asia, the ENSO-Teleconnection analogs suggested that much of East Asia (including China, Japan, and parts of Siberia) would wind up cooler than normal in December. That's in contrast to the warm idea shown on the CFSv2.

 

It's important to note that from this far out, neither the ENSO-Teleconnection maps nor the CFSv2 have demonstrated much skill. But what might give somewhat higher confidence than normal in the idea of a warmer idea for December is the consistency of that idea based on the partial teleconnection analogs run daily since the beginning of November and the December cases following November AO peaks of +3 or above, as has occurred this year.

 

The December composite map based on Novembers with an AO peak of +3 or above was as follows:

 

 

Finally, today's partial analog years (excluding ENSO) for the extended forecast for the major teleconnection indices with the years rolled forward to December were: 1990, 1991, 1993, 1996, 1999, 2004, 2006, and 2008. That provided a map consistent with the idea expressed above.

[uncle W]

the mei continues to rise...latest index was in the plus side though barely...A neutral positive winter is now a possibility...

2013	.042	-.163	-.171	.009	.069	-.298	-.469	-.614	-.19	.094

[donsutherland1]

Arctic Warms...

 

During the summer into the early part of the fall, Arctic temperatures generally ran below to near normal. However, later in the fall, there had been a tendency toward warmer than normal readings outdueling colder than normal ones. In this battle between warmth and cold, the November 1-7 period proved colder than normal. However, since then there has been a dramatic rebound in temperatures.

 

 

The relevant question is whether the increasing tendency for warm anomalies and the largest deviation above normal so far this autumn, despite the normally colder AO+ regime, suggests that the Arctic is in a transition to yet another warmer than normal winter. If so, that will likely have downstream implications in terms of the magnitude and expanse of cold air masses.

 

Right now, it's still too soon to be sure about that, but spike in temperatures is not dissimilar from what happened during autumn in 2011. Once the warmer regime set in, the Arctic remained warmer to much warmer than normal throughout the entire winter with only a few slightly cooler than normal days. An unfavorable synoptic pattern contributed to the scarce supply of cold air's being dumped into Eurasia when blocking eventually developed. Winter 2011-12 and Spring 2012 proved abnormally warm across North America.

 

This situation bears watching. If, in fact, the current spike in temperatures marks the beginning of what would become the predominant temperature regime for the coming winter, cities such as New York, Philadelphia, and Washington could experience another winter without a single-digit reading. The last time the mercury fell below 10° in NYC and Philadelphia was January 24, 2011. The last time Washington, DC (DCA) registered a single-digit low was January 17, 2009.

[Ginx snewx]

Don a 2 day temp rise?

[donsutherland1]

Don a 2 day temp rise?

It's too soon for me to know whether this is a short-duration rise or the start of a predominantly warm pattern. FWIW, the CFSv2 forecasts a warmer than normal Arctic winter. October had a monthly average that was above normal. For now, it's something to be watched.

[donsutherland1]

To provide some context as to why I think the recent warming in the Arctic bears watching:

 

1. The CFSv2 forecasts the Arctic to become much warmer than normal for December and to remain that way through the winter, on average.

2. Recent winters have witnessed an abnormally warm Arctic region.

3. The Arctic is typically colder than normal during AO+ regimes. That the Arctic has suddenly warmed despite the AO's rising to +3 is a potentially large "red flag."

 

Below are the composite temperature anomalies for the Arctic region for all cases where the AO rose to +3 or above in the November 1-15 timeframe (1950-2012):

 

 

 

Hence, I believe the situation bears watching.

[Absolute Humidity]

Sounds like another less than 10" of snow dud winter for all of those cities experienced just two years ago.

[mrgolf]

Donsutherland, i have a few questions if you dont mind. Im from around memphis tn and try to follow you when i can. Keep up the good work! If we can manage a -epo or at least neutral through most of the winter, will that help us for the winter? Don, imo, the pacific looks better than it has in a while to allow that type of blocking, at times, during boreal winter and also perhaps some +pna ridging. Also, the pdo would support that possibility since its not as negative as its been. Next, what about the warming of the pacific to maybe allow a weak nino as time moves on, esp in enso regions 4 and 3.4? Lastly, a guy a week ago came out with this NAO chart to forecast the nao in the winter by taking the sst's in may and sept and came up with a -.77 for djf. Just curious on your thoughts. Would like to see a colder winter than the previous two. Thanks kevin

[donsutherland1]

Donsutherland, i have a few questions if you dont mind. Im from around memphis tn and try to follow you when i can. Keep up the good work! If we can manage a -epo or at least neutral through most of the winter, will that help us for the winter? Don, imo, the pacific looks better than it has in a while to allow that type of blocking, at times, during boreal winter and also perhaps some +pna ridging. Also, the pdo would support that possibility since its not as negative as its been. Next, what about the warming of the pacific to maybe allow a weak nino as time moves on, esp in enso regions 4 and 3.4? Lastly, a guy a week ago came out with this NAO chart to forecast the nao in the winter by taking the sst's in may and sept and came up with a -.77 for djf. Just curious on your thoughts. Would like to see a colder winter than the previous two. Thanks kevin

 

Assuming that the winter is a predominantly AO+ one, we'll need help from the Pacific. I'm not yet sure about the EPO's predominant state, but am fairly confident about the AO on account of the Snow Advance Index, new OPI, and my own statistical look.

 

With respect to the NAO, it tends to be positive when the AO is positive. Below is a table showing the percentage of days on which the NAO was negative when the AO was at various positive levels:

 

 

Given that historical relationship and my expectations of an AO+ winter, I believe the NAO- days could be limited. Of course, I could be wrong. It will be interesting to see how the NAO-related research fares this winter.

 

Overall, my early guess is that this winter could be warmer than 2012-13 but colder than 2011-12, but that's still preliminary, with the state of the Pacific being the largest area of uncertainty.

[cyclogent]

Hi all - I rarely post but if you're looking for extreme swings in temperatures then you're in luck.

• The HPC/WPC model blend of choice right now is the Euro/Canadian
• Take a glance at the day 7-10 from the last two 0z runs of the Canadian, and last 2 operational Euro runs
• Read the last paragraph from the midnight edition of the long range discussion from the HPC/WPC 

Enjoy.

[Jonger]

Arctic Warms...

 

During the summer into the early part of the fall, Arctic temperatures generally ran below to near normal. However, later in the fall, there had been a tendency toward warmer than normal readings outdueling colder than normal ones. In this battle between warmth and cold, the November 1-7 period proved colder than normal. However, since then there has been a dramatic rebound in temperatures.

 

 

The relevant question is whether the increasing tendency for warm anomalies and the largest deviation above normal so far this autumn, despite the normally colder AO+ regime, suggests that the Arctic is in a transition to yet another warmer than normal winter. If so, that will likely have downstream implications in terms of the magnitude and expanse of cold air masses.

 

Right now, it's still too soon to be sure about that, but spike in temperatures is not dissimilar from what happened during autumn in 2011. Once the warmer regime set in, the Arctic remained warmer to much warmer than normal throughout the entire winter with only a few slightly cooler than normal days. An unfavorable synoptic pattern contributed to the scarce supply of cold air's being dumped into Eurasia when blocking eventually developed. Winter 2011-12 and Spring 2012 proved abnormally warm across North America.

 

This situation bears watching. If, in fact, the current spike in temperatures marks the beginning of what would become the predominant temperature regime for the coming winter, cities such as New York, Philadelphia, and Washington could experience another winter without a single-digit reading. The last time the mercury fell below 10° in NYC and Philadelphia was January 24, 2011. The last time Washington, DC (DCA) registered a single-digit low was January 17, 2009.

I thought a warmer arctic brought on a colder winter? Longer and more amplified troughs, there are so many conflicting theories and ideas right now, its hard to know what to belief outside of realtime observations.

[roardog]

If the arctic has been generally at or below normal overall for awhile now then why the very sudden jump in temps during a time when a positive AO would make us expect the opposite to occur? There has to be a short term mechanism to cause this, what is it?

[Jonger]

If the arctic has been generally at or below normal overall for awhile now then why the very sudden jump in temps during a time when a positive AO would make us expect the opposite to occur? There has to be a short term mechanism to cause this, what is it?

 

I wonder how much the huge block is affecting short term arctic temps.

[WidreMann]

I thought a warmer arctic brought on a colder winter? Longer and more amplified troughs, there are so many conflicting theories and ideas right now, its hard to know what to belief outside of realtime observations.

If there is no cold air in the source regions, then even when the cold airmasses do move south, they aren't that cold. That's what Don's talking about.

[Jonger]

If there is no cold air in the source regions, then even when the cold airmasses do move south, they aren't that cold. That's what Don's talking about.

 

Maybe, Don's one of the best we got, but the science is really tough to perfect.

 

Keep in mind, those anomalies today are only 1-3C above normal (based on eyeballing the map)... When a -40F airmass is running -37F, the deciding factor will still be jet dynamics. If the arctic is slightly warmer, the jet should relax south a bit more according the arctic amplification sciences, so I have to wonder if it will help or hurt us.

 

I'm only a hobbyist, but I'm really a big pacific index follower, the PNA is going to make or break our winter.

[CoastalWx]

You'd have to fire up the H5 composite. For instance in '11-'12 we had a very strong +AO also with a Bering Sea trough. Not a textbook loading pattern, hence why we were warm in NAMR and may have helped keep part of the arctic a bit warmer than normal.

[donsutherland1]

Maybe, Don's one of the best we got, but the science is really tough to perfect.

 

Keep in mind, those anomalies today are only 1-3C above normal (based on eyeballing the map)... When a -40F airmass is running -37F, the deciding factor will still be jet dynamics. If the arctic is slightly warmer, the jet should relax south a bit more according the arctic amplification sciences, so I have to wonder if it will help or hurt us.

 

I'm only a hobbyist, but I'm really a big pacific index follower, the PNA is going to make or break our winter.

I strongly agree that extended range forecasting is extremely difficult. There are no slam dunks when it comes to monthly or seasonal forecasting. The level of difficulty is even higher when it comes to precipitation and snowfall ideas.

 

As for the Arctic observation, areas subjected to a direct discharge can and will get very cold. However, when source regions for Arctic air masses are milder and/or such cold air is less expansive, there can be some downstream impact. It's still too early to tell if the shift to widespread warm anomalies in the Arctic is temporary or is a development in line with modeled ideas for the winter up there. That the warming occurred during a synoptic pattern that should produce widespread cold is a sort of "red flag." But one still needs to wait. I believe we'll have our answer by near or at the end of this month.