November 2012 Observations and Discussions

[CooL]

Euro backed off on the blocking. Looks pretty meh at day 10 with a ridge building in the east after a 3 day cold shot...keep in mind getting a good pattern set is going to take time so this is expected. The aleutian ridge is still beasting, only a matter of time before we get nao to coopertate

[blizzardof09]

Euro backed off on the blocking. Looks pretty meh at day 10 with a ridge building in the east after a 3 day cold shot...keep in mind getting a good pattern set is going to take time so this is expected. The aleutian ridge is still beasting, only a matter of time before we get nao to coopertate

id like to add to this statement with the aleutian ridge, if we can get it poleward and we get the -nao to cooperate we can be in business. but this all takes time and do not expect to really see a blocking pattern possibly setting up until maybe the first week of december or later

[bluewave]

The Euro and GFS ensembles agree on a -EPO/-NAO pattern near the end of the month.

[MJO812]

Euro backed off on the blocking. Looks pretty meh at day 10 with a ridge building in the east after a 3 day cold shot...keep in mind getting a good pattern set is going to take time so this is expected. The aleutian ridge is still beasting, only a matter of time before we get nao to coopertate

[MJO812]

AO

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

NAO

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

Trending negative

[kevbo81]

with Central Park being at -5 right now for their dept from normal this month, when is the last time we had a month where it was -3 or greater for such a negative? i'd say we have a fairly good shot at keeping the DFN solidly in the -3 to -4 category when all is said and done for Nov.

[kevbo81]

1/09 and dec 2010 had -4 DFN for Central Park. so it would be the coldest month we had in two years (if i'm right)

[MJO812]

It looks like a brief cold plunge after Thanksgiving and then a brief warmup and then the big cold comes in.

[MJO812]

Meteorologist Allan Huffman.

"Cold pattern to be in place it seem for December. Dont think Dec 89/10 levels just yet. But certainly to favor cold for Lakes/East"

[Guest Pamela]

with Central Park being at -5 right now for their dept from normal this month, when is the last time we had a month where it was -3 or greater for such a negative? i'd say we have a fairly good shot at keeping the DFN solidly in the -3 to -4 category when all is said and done for Nov.

12z GFS operational was not too good as the cold air has a hard time making it down to this latitude with the main storm track remaining along the US / Canadien border or up through the Great Lakes...if it verifed, you would probably not be far from a positive monthly departure in the Park for November.

[Isotherm]

12z GFS operational was not too good as the cold air has a hard time making it down to this latitude with the main storm track remaining along the US / Canadien border or up through the Great Lakes...if it verifed, you would probably not be far from a positive monthly departure in the Park for November.

Yeah, I think we'll eat away at the negative the rest of month w/ a mainly normal to slightly above normal pattern. This week will feature generally average temps in the 50s, strong but transient cold shot post Black Friday, then we could torch aheadof the next cold front for the end of Nov. Night time average lows are starting to get down there, so we're entering the time of year when high minima will really skew numbers upward even if daytime temps aren't all that warm. If we have a night or two that stays in the 50s, that's a major positive.

Either way, it's a virtual lock NOV will be colder than normal and the first widespread cold month in over a year for the NE US.

Of the 17 days thus far, only 3 have been above normal. The -5 right now in KNYC should be eaten away to at least -3 I think.

[nzucker]

12z GFS operational was not too good as the cold air has a hard time making it down to this latitude with the main storm track remaining along the US / Canadien border or up through the Great Lakes...if it verifed, you would probably not be far from a positive monthly departure in the Park for November.

There's no way Central Park will have a positive departure for November, even if the 12z GFS verified. Remember, lakes cutters right now don't produce such positive departures as later in the winter because average highs are still in the 50s. With a cloudy, rainy day, you're not going to get out of the 50s. The 12z GFS has one warm day: Black Friday. Next weekend is well below average with -5 850s, and then the pattern moderates with a cutter, but it's a chilly rain. Remember that climo for the end of November is for Boston to have 0C 850s, no colder. I think you're overestimating how warm it looks.

[Isotherm]

There's no way Central Park will have a positive departure for November, even if the 12z GFS verified. Remember, lakes cutters right now don't produce such positive departures as later in the winter because average highs are still in the 50s. With a cloudy, rainy day, you're not going to get out of the 50s. The 12z GFS has one warm day: Black Friday. Next weekend is well below average with -5 850s, and then the pattern moderates with a cutter, but it's a chilly rain. Remember that climo for the end of November is for Boston to have 0C 850s, no colder. I think you're overestimating how warm it looks.

It's the night time minima that do the dirty work at this time of year. Average lows by the end of November are near freezing for most suburbs, so lows in the 50s would be significant. Day time highs probably won't be impressively warm.

[bluewave]

While it will be on the Pacific side, the OP runs are hinting that we could see 500 meter positive anomalies showing

up in around a week or so. This is coming only around a month after we saw 400 meter positive anomalies during

Hurricane Sandy.

[famartin]

There's no way Central Park will have a positive departure for November, even if the 12z GFS verified. Remember, lakes cutters right now don't produce such positive departures as later in the winter because average highs are still in the 50s. With a cloudy, rainy day, you're not going to get out of the 50s. The 12z GFS has one warm day: Black Friday. Next weekend is well below average with -5 850s, and then the pattern moderates with a cutter, but it's a chilly rain. Remember that climo for the end of November is for Boston to have 0C 850s, no colder. I think you're overestimating how warm it looks.

Its not that hard for a cutter to send temps up into the 60s. Not in November, it isn't. Remember, even December averages a day or two in the 60s.

[Stormlover74]

I think we'll definitely see a stretch of +5 to perhaps +8 but as long as the last 10 days of the month don't end up that warm it will still end up below. But I wouldn't say its a lock that we'll end up -3 or greater

It's the night time minima that do the dirty work at this time of year. Average lows by the end of November are near freezing for most suburbs, so lows in the 50s would be significant. Day time highs probably won't be impressively warm.

[Isotherm]

Its not that hard for a cutter to send temps up into the 60s. Not in November, it isn't. Remember, even December averages a day or two in the 60s.

I think you meant 50s. December's average highs are around 50F for the first day or two but into the 40s thereafter.

[earthlight]

While it will be on the Pacific side, the OP runs are hinting that we could see 500 meter positive anomalies showing

up in around a week or so. This is coming only around a month after we saw 400 meter positive anomalies during

Hurricane Sandy.

That Aleutian ridge/block is the most anomalous feature on the globe, by far, on every model and ensemble. And according to the GEFS, by Day 8 it will have done its job of dislodging below normal height anomalies into the Northern 1/3 of the US.

[Stormlover74]

I think he meant most Decembers we see a 60 degree day or two not that the normal high is 60

I think you meant 50s. December's average highs are around 50F for the first day or two but into the 40s thereafter.

[Isotherm]

I think he meant most Decembers we see a 60 degree day or two not that the normal high is 60

Nevermind, I read it wrong.

[famartin]

I think you meant 50s. December's average highs are around 50F for the first day or two but into the 40s thereafter.

No, you misinterpret what I'm saying.

If you look at the number of days when the temperature reaches or exceeds 60 degrees in December from 1981-2010, the average at Central Park is 2. The average December absolute maximum temperature is 62.

YEAR MAXT #60
1981    58    0
1982    72    7
1983    59    0
1984    70    6
1985    55    0
1986    59    0
1987    60    1
1988    60    1
1989    53    0
1990    66    7
1991    66    3
1992    61    1
1993    62    1
1994    65    4
1995    55    0
1996    63    1
1997    54    0
1998    75    8
1999    63    3
2000    62    1
2001    71    7
2002    60    1
2003    58    0
2004    59    0
2005    55    0
2006    70    1
2007    61    1
2008    67    3
2009    66    1
2010    60    1

[SnoSki14]

December looks good I think, the gradual step down seems to be the way to go, which is fine. We aren't torching by any means and don't really expect to. Anything beyond Day 5 on the models is kind of a blur to me so I don't take those long range gfs forecasts that seriously.

Anything better than last winter is a huge improvement, the Aleutian ridge could very well be our savior this time.

[nzucker]

It's the night time minima that do the dirty work at this time of year. Average lows by the end of November are near freezing for most suburbs, so lows in the 50s would be significant. Day time highs probably won't be impressively warm.

Black Friday and next Wednesday are the only really warm days on the 12z ECM. Next weekend has a significant cold shot that probably gives us at least one double digit negative departure. 850s are -10 at Day 7 on the 12z ECM, which is really cold for mid November.

[mranger48]

From DT's Wxrisk Facebook page:

"*** ALERT *** POTENTIAL IS BUILDING FOR EARLY SEASON SIGNIFICANT WINTER STORM FOR PORTIONS OF THE OHIO VALLEY and the NORTHEAST NOV 28-30

right now data favors the Ohio valley and New England and PERHAPS the NORTHERN portions of then Middle Atlantic states -- say from PHILLY northward into NJ all of PA southern NY state NYC and Long island and of course ALL of New England..."

Just curious if anyone else can pinpoint what he's referring to and if anyone can extrapolate more. He's not usually a hypster when it comes to this sort of thing so I figured I'd ask. Any input would be appreciated.

[Isotherm]

Black Friday and next Wednesday are the only really warm days on the 12z ECM. Next weekend has a significant cold shot that probably gives us at least one double digit negative departure. 850s are -10 at Day 7 on the 12z ECM, which is really cold for mid November.

Not disagreeing with that - fully confident we'll be well below normal for Nov temps. Just saying we could have a couple very mild nights if the lakes-cutter scenario verifies. I recall many a December or even January night pushing 60-62F ahead of a strong cutter.

[Isotherm]

No, you misinterpret what I'm saying.

If you look at the number of days when the temperature reaches or exceeds 60 degrees in December from 1981-2010, the average at Central Park is 2. The average December absolute maximum temperature is 62.

YEAR MAXT #60
1981 58 0
1982 72 7
1983 59 0
1984 70 6
1985 55 0
1986 59 0
1987 60 1
1988 60 1
1989 53 0
1990 66 7
1991 66 3
1992 61 1
1993 62 1
1994 65 4
1995 55 0
1996 63 1
1997 54 0
1998 75 8
1999 63 3
2000 62 1
2001 71 7
2002 60 1
2003 58 0
2004 59 0
2005 55 0
2006 70 1
2007 61 1
2008 67 3
2009 66 1
2010 60 1

Yeah for the most part the first 10 days of December is more fall-like than winter-like in terms of temps. Rarely do we lock in significant cold/snow prior to the 10th, although there are exceptions. 2005 was quite cold early on, as was 1989.

[Guest Pamela]

Of the 10 coldest Novembers on record at Central Park, 9 were in the 19th century and the and the other one was in 1901. Through yesterday, KNYC was still 3.7 F warmer than the 10th coldest November; though that is obviously skewed by the fact that the 13 coldest days of the month climatologically have yet to be factored in.

[earthlight]

From DT's Wxrisk Facebook page:

"*** ALERT *** POTENTIAL IS BUILDING FOR EARLY SEASON SIGNIFICANT WINTER STORM FOR PORTIONS OF THE OHIO VALLEY and the NORTHEAST NOV 28-30

right now data favors the Ohio valley and New England and PERHAPS the NORTHERN portions of then Middle Atlantic states -- say from PHILLY northward into NJ all of PA southern NY state NYC and Long island and of course ALL of New England..."

Just curious if anyone else can pinpoint what he's referring to and if anyone can extrapolate more. He's not usually a hypster when it comes to this sort of thing so I figured I'd ask. Any input would be appreciated.

Models have been hinting at energy coming out of the Pac and digging into the Western US at that time. If it shoots northeast and amplifies, there could be a threat for frozen precip on the northern side. But without any blocking (models have trended away from it the last few runs) it will cut to the west or feature much more warm air. A blocking high to the north would bring wintry prospects that Dt describes so maybe he's hedging his bets on that development. You can see the threat here on the GEFS centered around 240 hr

http://www.meteo.psu.edu/~fxg1/ENSPRS_12z/ensloopmref.html

[andyhb]

Not sure the Northeast is going to see much of a wintry event from that, but as progged it would be a bigger threat for the Upper Midwest/GL for winter possibilities and also a warm sector severe threat (I'd like to see this get inside 192 hrs though to be a bit more confident). Moisture return looks good with the sub-tropical ridge in the position it is.

[nzucker]

Models have been hinting at energy coming out of the Pac and digging into the Western US at that time. If it shoots northeast and amplifies, there could be a threat for frozen precip on the northern side. But without any blocking (models have trended away from it the last few runs) it will cut to the west or feature much more warm air. A blocking high to the north would bring wintry prospects that Dt describes so maybe he's hedging his bets on that development. You can see the threat here on the GEFS centered around 240 hr

http://www.meteo.psu...nsloopmref.html

It looks as if a lot of the ensembles have an overrunning threat.