Winter 2013-14 medium range discussion

[Ottawa Blizzard]

 

According to Environment Canada and the U.S. National Weather Service, Lake Michigan ice coverage reached 90 percent to 95 percent in the winters of 1903-04, 1976-77 and 1978-79.

Data indicate that three of the Great Lakes (Superior, Huron and Erie) have totally frozen over in a few of the very harshest winters since 1900, but Michigan and Ontario have never achieved complete ice coverage.

 

That's interesting to hear. I thought Lake Ontario had frozen over in February 1934.

[Ottawa Blizzard]

This is totally unscientific, but it's interesting how winters with a three and four in them often end up being cold: 1903-04, 1933/34, 1983/84, 1993/94, 2003/04 and now perhaps 2013/14?

[donsutherland1]

Not by Teleconnections Alone…

 

For North America, the possibility of one or two bouts of severe to extreme cold to open the first 7-10 days of January appears increasingly likely. Whether or not the 12/29 12z and 12/30 0z ECMWF’s idea of 1985- or 1994-style Arctic outbreaks verifies, the proverbial die has been cast that much of Canada, along with a large part of the eastern half of the CONUS will likely wind up colder than normal.

 

With blocking developing—the AO has now been negative for two consecutive days—one should typically expect to see cold develop over parts of Europe where temperatures have been downright toasty. Indeed, Muscovites have sweated through a November that averaged almost 8°F above normal and December appears poised to finish at least as warm. Certainly, if one runs the maps for the forecast teleconnections, one sees a colder outcome.

 

However, after a close look at the details beyond the teleconnections, the colder outcome appears unlikely. The persistent EPO- has led to an outcome in which almost all of the Northern Hemisphere’s anomalous cold has drained into North America. The EPO- regime is likely to persist for the foreseeable future. As a result, very little anomalous cold will be available to be tapped for Europe despite what would typically be the development of a favorable synoptic pattern for cold.

 

Below are maps illustrating global cold anomalies for December 29, 2013; the December 1-28, 2013 timeframe for the Northern Hemisphere, and those for Decembers 1984 and 1993 for the Northern Hemisphere. Maps for the forecast teleconnection indices and January 1994 are also included.

 

 

December 1984 saw widespread cold anomalies in the Northern Hemisphere. December 1993, not unlike December 1-28, 2013 featured less expansive cold anomalies centered near North America. January 1985 wound up very cold across much of North America and also Europe. In contrast, North America experienced cold anomalies in January 1994, while much of Europe wound up warmer than normal.

 

If one looks at the CFSv2’s forecasts since 12/20 (the beginning of its more skillful range), one finds a consistent theme of warmth in Europe. The GFS ensembles and ECMWF ensembles also indicate generally mild conditions through their extended range, with the GFS ensembles bringing about some cooling, particularly in southern Europe, Scandinavia, and extreme Western Europe at the end of their range. The 12/30 0z run of the ECMWF produces anomalies very similar to the January 1994 map by 240 hours.

 

In short, it appears that January 2013 could have warm anomalies centered near where they were centered in January 1994. The northern half of Scandinavia might wind up on the cool side of normal. Northern Africa and the Mideast might wind up near normal with perhaps some cool anomalies in the Mideast. But overall, one won’t see the kind of widespread cold one saw in January 1985 despite what the teleconnection indices might imply.

[cbmclean]

Interesting Don.  If I remember, back in the dreaded winter of 2011-2012, there were times when there was significant NAO blocking, but that year the other atmospheric dynamics were such that all the cold drained into Eurasia.  Is this the mirror image of that?

[Ottawa Blizzard]

Not by Teleconnections Alone…

 

For North America, the possibility of one or two bouts of severe to extreme cold to open the first 7-10 days of January appears increasingly likely. Whether or not the 12/29 12z and 12/30 0z ECMWF’s idea of 1985- or 1994-style Arctic outbreaks verifies, the proverbial die has been cast that much of Canada, along with a large part of the eastern half of the CONUS will likely wind up colder than normal.

 

With blocking developing—the AO has now been negative for two consecutive days—one should typically expect to see cold develop over parts of Europe where temperatures have been downright toasty. Indeed, Muscovites have sweated through a November that averaged almost 8°F above normal and December appears poised to finish at least as warm. Certainly, if one runs the maps for the forecast teleconnections, one sees a colder outcome.

 

However, after a close look at the details beyond the teleconnections, the colder outcome appears unlikely. The persistent EPO- has led to an outcome in which almost all of the Northern Hemisphere’s anomalous cold has drained into North America. The EPO- regime is likely to persist for the foreseeable future. As a result, very little anomalous cold will be available to be tapped for Europe despite what would typically be the development of a favorable synoptic pattern for cold.

 

Below are maps illustrating global cold anomalies for December 29, 2013; the December 1-28, 2013 timeframe for the Northern Hemisphere, and those for Decembers 1984 and 1993 for the Northern Hemisphere. Maps for the forecast teleconnection indices and January 1994 are also included.

 

 

December 1984 saw widespread cold anomalies in the Northern Hemisphere. December 1993, not unlike December 1-28, 2013 featured less expansive cold anomalies centered near North America. January 1985 wound up very cold across much of North America and also Europe. In contrast, North America experienced cold anomalies in January 1994, while much of Europe wound up warmer than normal.

 

If one looks at the CFSv2’s forecasts since 12/20 (the beginning of its more skillful range), one finds a consistent theme of warmth in Europe. The GFS ensembles and ECMWF ensembles also indicate generally mild conditions through their extended range, with the GFS ensembles bringing about some cooling, particularly in southern Europe, Scandinavia, and extreme Western Europe at the end of their range. The 12/30 0z run of the ECMWF produces anomalies very similar to the January 1994 map by 240 hours.

 

In short, it appears that January 2013 could have warm anomalies centered near where they were centered in January 1994. The northern half of Scandinavia might wind up on the cool side of normal. Northern Africa and the Mideast might wind up near normal with perhaps some cool anomalies in the Mideast. But overall, one won’t see the kind of widespread cold one saw in January 1985 despite what the teleconnection indices might imply.

It would appear that this winter, it is North America's "turn" so to speak to experience well below average temperatures. For the past few winters, it was Europe and Asia which experienced this, so perhaps this nature's way of evening the playing field?

[donsutherland1]

Afternoon thoughts...

 

For more than a week, the GFS and ECMWF ensembles have been indicating a period of severe cold for the first week of January (#388, #399) with only small timing differences on a run-to-run basis. As December comes to a close, the cold shot looks potentially even more impressive than first indicated. Below are the 12/30 12z ECMWF, GFS, and MEX MOS numbers for lowest temperatures for select cities (1/1-4/2014):

 

 

At the same time, much above normal December snowfall in parts of the Mid-Atlantic region has often occurred in past winters that ultimately went on to have above average snowfall in parts of the Middle Atlantic and New England areas. The charts for cases in which Philadelphia, New York City, and Boston all received 8" or more snowfall in December is below (NOTE: They were created on 12/17 #359).

 

[jbcmh81]

This is totally unscientific, but it's interesting how winters with a three and four in them often end up being cold: 1903-04, 1933/34, 1983/84, 1993/94, 2003/04 and now perhaps 2013/14?

 

1883-1884 had a very cold January.

[donsutherland1]

Interesting Don.  If I remember, back in the dreaded winter of 2011-2012, there were times when there was significant NAO blocking, but that year the other atmospheric dynamics were such that all the cold drained into Eurasia.  Is this the mirror image of that?

For now, it seems to be playing out that way.

[donsutherland1]

It would appear that this winter, it is North America's "turn" so to speak to experience well below average temperatures. For the past few winters, it was Europe and Asia which experienced this, so perhaps this nature's way of evening the playing field?

It will be interesting to see what happens after what appears likely to be an incredible stretch of winter weather. If the cold can reload afterward and more bigtime cold lies ahead later this month and at least part of February, a memorable winter might be in the making. Time will tell.

[frosty]

Not by Teleconnections Alone…

 

For North America, the possibility of one or two bouts of severe to extreme cold to open the first 7-10 days of January appears increasingly likely. Whether or not the 12/29 12z and 12/30 0z ECMWF’s idea of 1985- or 1994-style Arctic outbreaks verifies, the proverbial die has been cast that much of Canada, along with a large part of the eastern half of the CONUS will likely wind up colder than normal.

 

With blocking developing—the AO has now been negative for two consecutive days—one should typically expect to see cold develop over parts of Europe where temperatures have been downright toasty. Indeed, Muscovites have sweated through a November that averaged almost 8°F above normal and December appears poised to finish at least as warm. Certainly, if one runs the maps for the forecast teleconnections, one sees a colder outcome.

 

However, after a close look at the details beyond the teleconnections, the colder outcome appears unlikely. The persistent EPO- has led to an outcome in which almost all of the Northern Hemisphere’s anomalous cold has drained into North America. The EPO- regime is likely to persist for the foreseeable future. As a result, very little anomalous cold will be available to be tapped for Europe despite what would typically be the development of a favorable synoptic pattern for cold.

 

Below are maps illustrating global cold anomalies for December 29, 2013; the December 1-28, 2013 timeframe for the Northern Hemisphere, and those for Decembers 1984 and 1993 for the Northern Hemisphere. Maps for the forecast teleconnection indices and January 1994 are also included.

 

 

December 1984 saw widespread cold anomalies in the Northern Hemisphere. December 1993, not unlike December 1-28, 2013 featured less expansive cold anomalies centered near North America. January 1985 wound up very cold across much of North America and also Europe. In contrast, North America experienced cold anomalies in January 1994, while much of Europe wound up warmer than normal.

 

If one looks at the CFSv2’s forecasts since 12/20 (the beginning of its more skillful range), one finds a consistent theme of warmth in Europe. The GFS ensembles and ECMWF ensembles also indicate generally mild conditions through their extended range, with the GFS ensembles bringing about some cooling, particularly in southern Europe, Scandinavia, and extreme Western Europe at the end of their range. The 12/30 0z run of the ECMWF produces anomalies very similar to the January 1994 map by 240 hours.

 

In short, it appears that January 2013 could have warm anomalies centered near where they were centered in January 1994. The northern half of Scandinavia might wind up on the cool side of normal. Northern Africa and the Mideast might wind up near normal with perhaps some cool anomalies in the Mideast. But overall, one won’t see the kind of widespread cold one saw in January 1985 despite what the teleconnection indices might imply.

Happy new year to everyone on the American weather forum.

I have been viewing this forum for a good while now and thought I would sign up

and add the odd post now and again.

During late December 84 their was a SSW which played a big part in the cold outbreaks that

Europe and the UK saw during that winter.It appears to me as if Europe is more reliant on

Stratospheric warming to produce the goods so to speak.

This theory would hold up when looking back at the LIA and low solar which affected Russia

and Europe more than elsewhere I believe but that is a another story.

It does appear now as if a warming perhaps even a SSW will occur later in January. It is

already showing up on the extended range of the stratosphere runs on GFS and the

stratosphere charts on instant weather maps. To early to say about the SSW at the moment

but this could turn the UK and Europes winter on its head especially when you look at where

the warming is occurring, over Greenland and to the north of the UK.

[Ottawa Blizzard]

Happy new year to everyone on the American weather forum.

I have been viewing this forum for a good while now and thought I would sign up

and add the odd post now and again.

During late December 84 their was a SSW which played a big part in the cold outbreaks that

Europe and the UK saw during that winter.It appears to me as if Europe is more reliant on

Stratospheric warming to produce the goods so to speak.

This theory would hold up when looking back at the LIA and low solar which affected Russia

and Europe more than elsewhere I believe but that is a another story.

It does appear now as if a warming perhaps even a SSW will occur later in January. It is

already showing up on the extended range of the stratosphere runs on GFS and the

stratosphere charts on instant weather maps. To early to say about the SSW at the moment

but this could turn the UK and Europes winter on its head especially when you look at where

the warming is occurring, over Greenland and to the north of the UK.

Welcome to the forum! Great to have you!

[wxmx]

To add to the SSW discussion, there's currently wave 2 activity that should lead to stratospheric PV weakening. Wave 1 or 2 activity is a requirement prior to any significant stratospheric warming, wave 2 activity is preferred for a better setup (PV split odds increase). Still, even it's a requirement, it doesn't mean that a major warming is in the works, but could set the table for something later on.

 

[frosty]

Big upgrade this morning on the stratosphere warming with a potential SSW according to

the 06z GFS run.

1mb temperature at t336                                      

 

1mb GPH at t384       

10mb temperature at t394                                  

10mb GPH at t384

This would almost certainly have major tropospheric effects I would have thought on the

northern hemisphere weather pattern going into the second half of winter.

[Amped]

Still can't believe how little rain California is and has been getting.

[donsutherland1]

Severe Great Lakes/Ohio Valley Cold Shot of January 5-8, 2014:

 

A significant winter storm will bring 4"-8" of snow across the northern Mid-Atlantic, 6"-12" across parts of Long Island, and 8"-16" across parts of southern New England today and tomorrow. It will also pull down cold air that will likely result in the coldest minimum and maximum temperatures in several years in parts of that region.

 

Afterward, the big focus will be the potential super cold air mass that the ECMWF and to a lesser extent the GFS has been suggesting could impac an area from the Great Lakes region to the Middle Atlantic states in the January 5-8 timeframe. The coldest anomalies relative to normal are forecast to occur in the Great Lakes Region and Ohio Valley.

 

The latest GFS ensembles show an area of cold 2-3 standard deviations below normal. If that verifies, some parts of the Great Lakes region and Ohio Valley could see their coldest readings since 1994. The likely absence of snow cover will likely modify the air mass farther south and east, with the big cities of the Middle Atlantic region likely have cold in the 1.5 to 2.5 sigma range. However, should the precipitation end with a period of snow sufficient to cover the ground, somewhat colder readings would be possible.

 

Below are tables showing the GFS ensemble mean 850 mb anomalies forecast for January 7 0z and low temperatures associated with the standardized anomalies for select cities:

 

 

In terms of the coldest readings forecast for the 1/5-8 timeframe, the 1/2/2014 0z run of the ECMWF has forecast a low temperature of -20° in Chicago, -18° in Columbus, and -19° in Indianapolis. The 1/2 0z MEX MOS output for lowest temperatures for those three cities is -12°, -11°, and -15° respectively.

 

The last time the temperature fell to -10° or below in Chicago was January 16, 2009 (-18°). The last time the temperature fell to -10° or below in Columbus was January 17, 2009 (-11°). The last time the temperature fell to -10° or below in Indianapolis was January 16, 2009 (-12°).

 

The last time the temperature fell to -15° or below in Chicago was January 16, 2009 (-18°). The last time the temperature fell to -15° or below in Columbus was January 21, 1994 (-15°). The last time the temperature fell to -15° or below in Indianapolis was January 21, 1994 (-16°).

 

Finally, for perspective, the three coldest readings on record for select cities are below:

 

Chicago:

-27°, January 20, 1985

-26°, January 10, 1982 

-25°, January 16, 1982 and December 24, 1983

 

Columbus:

-22°, January 19, 1994

-19°, January 17, 1977 and January 20, 1985

-17°, December 22, 1989 and January 18, 1994

 

Indianapolis:

-27°, January 19, 1994

-25°, January 5, 1884

-23°, December 22, 1989

[Hoosier]

Thanks for the input, Don.  We've been watching this with interest out here.  Given the growing snowpack in this region in the days to come, this airmass will be further enhanced.

[donsutherland1]

From NWS State College:

 

000
NOUS41 KCTP 021945
PNSCTP
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-022345-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
245 PM EST THU JAN 2 2014

...FRIGID TEMPERATURES WILL ACCOMPANY AN ARCTIC OUTBREAK EARLY
NEXT WEEK...

AN OUTBREAK OF VERY COLD AIR IS EXPECTED ACROSS THE REGION EARLY
NEXT WEEK. MANY LOCATIONS COULD SEE THEIR COLDEST TEMPERATURES IN
NEARLY TWO DECADES. A SUMMARY OF SIGNIFICANT COLD WEATHER FOR
SELECTED SITES ACROSS CENTRAL PENNSYLVANIA IS INCLUDED BELOW:

CITY                JANUARY 7/8         LAST DATE       LAST DATE
                    RECORD (YR)         BELOW ZERO      BELOW -10F

HARRISBURG       5 (1942)/ 0 (1970)     2/6/1996        1/21/1994
WILLIAMSPORT    -2 (1942)/-10 (1942)    2/11/2011       1/17/2009
STATE COLLEGE   -1 (1988)/-9 (1942)     1/24/2011       1/20/1994

$$

EVANEGO

[Mikehobbyst]

 

From NWS State College:

000
NOUS41 KCTP 021945
PNSCTP
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-022345-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
245 PM EST THU JAN 2 2014

...FRIGID TEMPERATURES WILL ACCOMPANY AN ARCTIC OUTBREAK EARLY
NEXT WEEK...

AN OUTBREAK OF VERY COLD AIR IS EXPECTED ACROSS THE REGION EARLY
NEXT WEEK. MANY LOCATIONS COULD SEE THEIR COLDEST TEMPERATURES IN
NEARLY TWO DECADES. A SUMMARY OF SIGNIFICANT COLD WEATHER FOR
SELECTED SITES ACROSS CENTRAL PENNSYLVANIA IS INCLUDED BELOW:

CITY                JANUARY 7/8         LAST DATE       LAST DATE
                    RECORD (YR)         BELOW ZERO      BELOW -10F

HARRISBURG       5 (1942)/ 0 (1970)     2/6/1996        1/21/1994
WILLIAMSPORT    -2 (1942)/-10 (1942)    2/11/2011       1/17/2009
STATE COLLEGE   -1 (1988)/-9 (1942)     1/24/2011       1/20/1994

$$

EVANEGO

I bet we have a harsh winter like '94, followed by a very slow beginning and mid spring with tons of 40's and drizzle followed by a hot June with SVR thunderstorms.  I remember June1994 being torrid for NYC area with sweltering heat and SVR.  May 1994 has backdoor swings from low 80's to 50's a few times.   Could we have upper 90's in five months ?  Probably.

[Heisy]

What is this stratospheric warming event people are talking about, and what could its effects be for this winter? 

[donsutherland1]

Already, one has seen some impressive cold temperatures today. For parts of the East, tonight and tomorrow morning will likely see the coldest readings so far. For some of those cities, this might be the winter's coldest air mass. In the Great Lakes region and Ohio Valley, an even colder air mass is likely to produce extreme readings early next week.

 

For today, some highlights:

 

Boston: 2° (coldest reading since 1/24/2011 when the temperature fell to -2°)

Chicago: -12° (coldest reading since 1/16/2009 when the temperature fell to -19°)

Columbus: 1° (coldest reading since 1/22/2011 when the temperature fell to -2°)

Detroit: -5° (coldest reading since 2/10/2011 when the temperature fell to -5°)

Harrisburg: 10° (coldest reading since 2/11/2011 when the temperature fell to 9°)

Indianapolis: -3° (coldest reading since 1/21/2011 when the temperature fell to -3°)

New York City: 10° (coldest reading since 1/24/2011 when the temperature fell to 6°)

[donsutherland1]

Today saw numerous cities in the Northeast post their lowest high temperatures in several winters. Highlights included:

 

Albany: 5° (lowest since 1/24/2011 when the temperature only reached 5°)

Allentown: 15° (lowest since 1/16/2009 when the temperature only reached 13°)

Boston: 14° (lowest since 1/24/2011 when the temperature only reached 13°)

Bridgeport: 14° (lowest since 1/15/2004 when the temperature only reached 13°)

Burlington: -3° (lowest since 1/21/2005 when the temperature only reached -3°)

Concord: 7° (lowest since 1/24/2011 when the temperature only reached 6°)

Hartford: 12° (lowest since 1/18/2005 when the temperature only reached 11°)

Islip: 18° (lowest since 1/16/2009 when the temperature only reached 17°)

New York City: 18° (lowest since 1/16/2009 when the temperature only reached 16°)

Newark: 17° (lowest since 1/18/2005 when the temperature only reached 17°)

Providence: 17° (lowest since 1/23/2013 when the temperature only reached 16°)

White Plains: 14° (lowest since 1/27/2005 when the temperature only reached 12°)

Worcester: 9° (lowest since 1/24/2011 when the temperature only reached 8°)

[Hailstorm]

Thanks for all your insightful analysis and facts, Don. What are your thoughts about the January thaw that is modeled to happen by the middle of the month after next week? How long do you think the duration of it will be? I heard a rumor that the EPO is going positive and the MJO having a strong phase 6, but the AO and NAO does show some promise of being slightly negative. 

[donsutherland1]

Thanks for all your insightful analysis and facts, Don. What are your thoughts about the January thaw that is modeled to happen by the middle of the month after next week? How long do you think the duration of it will be? I heard a rumor that the EPO is going positive and the MJO having a strong phase 6, but the AO and NAO does show some promise of being slightly negative. 

The thaw looks quite likely. My early thinking is that it could last 1-2 weeks, but that the cold will return before January is finished. I'm not sure that we'll see cold as severe as the current shot and the one forecast for early next week, though.

[SnoSki14]

The thaw looks quite likely. My early thinking is that it could last 1-2 weeks, but that the cold will return before January is finished. I'm not sure that we'll see cold as severe as the current shot and the one forecast for early next week, though.

 

My fear is that the cold and snow never return and we have an early end to Met winter. What teleconnections point to a return of cold before January ends? I see the PNA looks to be mostly positive through mid January and the AO definitely looks more negative than we've seen with perhaps more negativity after mid January. The EPO is going to be positive, however, and that's my biggest worry. 

[donsutherland1]

This morning saw numerous cities in the Mid-Atlantic and New England areas record their lowest temperatures in recent winters. Some highlights:

 

Albany: -12° (lowest since 1/24/2011 when the temperature fell to -13°)

Allentown: -4° (lowest since 1/24/2011 when the temperature fell to -4°)

Atlantic City: -3° (lowest since 2/6/1996 when the temperature fell to -3°)

Baltimore: 6° (lowest since 1/17/2009 when the temperature fell to 2°)

Boston: 2° (lowest since yesterday when the temperature fell to 2°; yesterday was the coldest since 1/24/2011 when a low of -2° occurred)

Bridgeport: 3° (lowest since 1/24/2011 when the temperature fell to 0°)

Burlington: -15° (lowest since 1/24/2011 when the temperature fell to -19°)

Concord: -17° (lowest since 1/16/2009 when the temperature fell to -24°)

Danbury: -7° (lowest since 1/24/2011 when the temperature fell to -12°)

Harrisburg: 5° (lowest since 1/24/2011 when the temperature fell to 3°)

Hartford: -9° (lowest since 2/5/1996 when the temperature fell to -13°)

Islip: 0° (lowest since 1/15/1988 when the temperature fell to -7°)

New Haven: 2° (lowest since 1/24/2011 when the temperature fell to -2°)

New York City: 8° (lowest since 1/24/2011 when the temperature fell to 6°)

Newark: 6° (lowest since 1/24/2011 when the temperature fell to 5°)

Philadelphia: 8° (lowest since 1/24/2011 when the temperature fell to 8°)

Portland: -14° (lowest since 1/16/2009 when the temperature fell to -16°)

Providence: -3° (lowest since 1/16/2004 when the temperature fell to -6°)

Westhampton: -13° (lowest since 1/17/2009 when the temperature fell to -15°)

White Plains: 0° (lowest since 1/24/2011 when the temperature fell to -1°)

Wilmington, DE: 5° (lowest since 1/17/2009 when the temperature fell to 5°)

Worcester: -4° (lowest since 1/24/2011 when the temperature fell to -9°)

[JamieOber]

My fear is that the cold and snow never return and we have an early end to Met winter. What teleconnections point to a return of cold before January ends? I see the PNA looks to be mostly positive through mid January and the AO definitely looks more negative than we've seen with perhaps more negativity after mid January. The EPO is going to be positive, however, and that's my biggest worry. 

Week 4 on the Euro weeklies show a negative EPO.

[White Gorilla]

I have nothing empirical to back this prediction, but I think Feb will deliver a KU storm after some mid weather mid to late Jan. In winters where we have a strong start lie we have now, Feb-March usually are interesting, exceptions of course.

[donsutherland1]

The recent snowstorm that brought 9.0" snow to Philadelphia, 6.4" to New York City, and 15.1" to Boston has brought seasonal totals to 20.2" in Philadelphia, 15.0" in New York City, and 26.8" in Boston. Snowy winters have often seen a snowy December followed by additional snowfall within the first 10 days of January.

 

Taking the cases provided in #359 in this thread for which Philadelphia, New York City, and Boston each received 8" or more snowfall in December and refining them for cases in which at least a trace of snow fell in all three cities in the January 1-10 period, the idea of a snowy winter is maintained.

 

 

At this point in time, it appears very likely that Philadelphia and New York City will see 30" or more snowfall this winter and Boston will see 50" or more. In short the thaw that will unfold beginning later next week will not mark the end of winter so to speak.

[GaWx]

Folks,

 When I last posted about this in Dec., the strat. was cool. However, the strat. has been warming per the attached. At 1 mb, it has risen to ~+10C anom. (orange) as of 1/3. It has risen there at ~3C/day since 1/1 (+4 to +10). At 2 mb, it has risen from -1C to +7C or 4C/day since 1/1. At 5 mb, it has risen from -5 to +3C in the last 2 days or 4C/day. It still is nowhere near where it needs to get to be noteworthy. Based on the past, it would be best if it warmed to +28 or warmer (brown and gray) to put it solidly into the strong SSW cat. At the rate of 4C/day, it would take about 6-7 more days to get there should that rate continue. Based on this and past durations (usually it takes no more than 7-10 days to reach peak heat), we should know by ~1/10 if this is likely going to reach into the solidly strong SSW event cat.

 

 Link: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_JFM_NH_2014.gif

 

 

 

 Past strong SSW's have had periods of at least 8C/day of warming. Here's one example from 1/2009, which warmed 8C/day for 4 days to get it to +32+ anom. (tiny area of gray near 10 mb; brown is +28-32):

 

[Amped]

Folks,

 When I last posted about this in Dec., the strat. was cool. However, the strat. has been warming per the attached. At 1 mb, it has risen to ~+10C anom. (orange) as of 1/3. It has risen there at ~3C/day since 1/1 (+4 to +10). At 2 mb, it has risen from -1C to +7C or 4C/day since 1/1. At 5 mb, it has risen from -5 to +3C in the last 2 days or 4C/day. It still is nowhere near where it needs to get to be noteworthy. Based on the past, it would be best if it warmed to +28 or warmer (brown and gray) to put it solidly into the strong SSW cat. At the rate of 4C/day, it would take about 6-7 more days to get there should that rate continue. Based on this and past durations (usually it takes no more than 7-10 days to reach peak heat), we should know by ~1/10 if this is likely going to reach into the solidly strong SSW event cat.

 

 Link: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_JFM_NH_2014.gif

 

time_pres_TEMP_ANOM_JFM_NH_2014.gif

 

 

 Past strong SSW's have had periods of at least 8C/day of warming. Here's one example from 1/2009, which warmed 8C/day for 4 days to get it to +32+ anom. (tiny area of gray near 10 mb; brown is +28-32):

 

time_pres_TEMP_ANOM_ALL_NH_2009.gif

 

 

 

Agreed this isn't progged by any model to reach into the strong category.  At least the vortex is remains pretty elongated and is not a circle of death directly over the pole. This gives some potential for a  Negative AO in the troposphere.