Have we seen the last of the snow until next winter?

[Isotherm]

http://www.lightinth...om/archives/494

It’s been a struggle just to get the flakes flying this winter, nevermind a significant snowstorm. With the next 7-14 days likely to continue the above normal temperature regime, it’s highly unlikely the NYC metro area receives an accumulating snow event. Global teleconnectors remain unfavorable, with a similar pattern to what we saw most of this winter — low heights over the arctic and north atlantic (cold) and higher than normal heights (warm) across North America. Since the next couple weeks look shot, I thought I’d look beyond March 15th, at past weather patterns, to examine synoptic set-ups that yielded a snow event in the metro area.

March 2004 featured some moderate snows in the latter part of the month; below is the 500mb composite for that period:

We had a positive NAO, AO, but the positive PNA (western US ridging) was a major help, as well as good cold air supply in southern Canada. 850mb temperatures were well below 0c, and surface high pressure was well positioned in Quebec.

Surface air temperature anomaly for that same period – note the chill in Eastern Canada and the Northeast US:

The year prior to this, the metro area witnessed a very late season snowstorm on April 7th, 2003. Below is the 500mb pattern for that day:

Mid level riding in the Northeast and SE Canada, and check out the surface temp anomaly map – talk about some extreme negative departures:

March 15th, 1999, unlike the previous cases, had a strongly negative AO in March, and the event featured a nice 500mb block to the west of Greenland – near ideal orientation for a bomb of negative heights in the Eastern US.

The low pressure center was fairly intense, about 996mb on the mid atlantic coast, with plentiful surface cold in place; high pressure was present but not overly strong.

March 31st-April 1st 1997 was a minor event for NYC, but suburbia NJ recorded several inches to upwards of 10″ of snow in some locations. This was a major to historic snow for portions of southern New England.

Similar to our previous cases, the H5 pattern is far from the ideal that one would picture for the winter months of DJF. Positive heights in the northern latitudes, and a trough in the PAC NW. But shorter wavelengths in the spring allow an East Coast trough to be possible even w/ no Western ridge. What we did have – yet again – was mid level ridging to the N/W and thus plentiful surface high pressure, low level cold drainage into the storm system.

Surface temp anomalies — one word: Wow

April 9th-10th 1996 — a significant snow for NJ, to close out the snowiest winter on record for most. Once again, high pressure (1025mb approximately) situated to our west, plentiful cold air (850mb temps of -5c to -7c), and in this case, the most high latitude blocking we’ve seen of our cases thus far:

You’ve got a negative NAO, AO and positive PNA, negative EPO (Western US ridge, Alaska ridge) also known as the teleconnectors lined up perfectly for a significant late seaon snow event.

The surface temp anomaly – coincides nicely with the negative heights at 500mb – very cold:

March 18t, 1994, a 3-6″ snow event, had a set-up at H5 like this:

Big neg height anomalies from the PAC NW (again – generally unfavorable in winter, but not early spring) and a mid level ridge to the west of Greenland (conducive for east coast cyclogenesis)

I thought I’d examine one more, infamous Northeast late season snowstorm — April 12th, 1982 — the most significant of all late season events for NYC, with about 10″ (over a foot accumulated in NW suburbs).

The 500mb pattern, featured a PAC NW trough (low heights in the gulf of Alaska), a positive AO, and NAO probably negative. Nothing in the global teleconnectors would scream major snowfall – but in early spring, a strong West Coast trough actually teleconnects to the trough on the East Coast. Furthermore, we’ve got mid level ridging in the central US, plentiful surface cold air, and probably strong high pressure as well:

So the common denominator to all these snow events — unseasonably cold air, with mid level ridging (and surface high pressure) preferrably to the north/west of the storm. Some events had northern latitude blockings, others didn’t. Many featured a PAC NW trough and Central US ridge.

One thing we’ve seen very little of this winter in North America is unseasonably cold air – in fact we’ve had the opposite. Here’s the NAEFS week 2 forecast for the country (through March 18th):

Not a pretty look – very mild across Canada and the US, basically a repeat of the DJF pattern. If this verifies, which it should, an above normal temp regime does not bode well for late season snow events. Maybe we can see some cooling after March 20th, but I wouldn’t bet on it. Either way, the snow enthusiast can hold out hope until early-mid April for a pattern similar to one of the cases presented here. I’d say March will probably go snowless (or very close to it) in NYC. Once we make our way to the end of March, chances for accum snow fall off a cliff. But, we shall how the next several weeks play out.

[Isotherm]

I had to remove a couple images from the post as there were too many; you can see them on my link I provided at the top.

[NEG NAO]

IMO can't rule out a snowfall here through the second week in April -regardless on how warm it was this year or might get before an event -- if we get in to a set up with good timing for a few days - example - Oct 29 and today down in WV and VA - impossible to predict to far in advance with those types of systems..............you are right though this year the odds are stacked against us but the last couple years have featured weird extreme weather at times -setting all time records - so can't rule out anything .....

[Brian5671]

Good post. Odds are we are done. Sure a fluky event is possible, but with little cold air on this side of the globe, and no blocking (Alot of the late season snow falls depend on blocking it seems from this post) it's a longshot.

[NEG NAO]

Good post. Odds are we are done. Sure a fluky event is possible, but with little cold air on this side of the globe, and no blocking (Alot of the late season snow falls depend on blocking it seems from this post) it's a longshot.

fluky events have been the norm the last couple of years - just look at a all the records set for heat - precip - snowfall - earliest snowfall - most snowfall in one month on record - etc etc - very unusual so many records set in such a short period of time - several all time seasonal records - maybe UncleW can compile a list of them for the last few years for NYC and don't forget that fluky 108 degrees at newark last July 22

[Analog96]

I would probably rule out anything major. But you probably can never rule out a little event like April 9, 2000.

[NEG NAO]

I would probably rule out anything major. But you probably can never rule out a little event like April 9, 2000.

Some folks in the NYC metro area were not happy with that event since they got next to nothing while others were quite happy in NJ - wasn't the previous day close to 80 degrees ? Also April 6 - 10th has featured several events over the years

http://www.njfreeway.../09-Apr-00.html

[Analog96]

Some folks in the NYC metro area were not happy with that event since they got next to nothing while others were quite happy in NJ - wasn't the previous day close to 80 degrees ? Also April 6 - 10th has featured several events over the years

http://www.njfreeway.../09-Apr-00.html

At my personal location, it was 77 degrees the day before, and I received 2 inches of snow, as the temperature fell to 29.

[bluewave]

My guess is that Central Park finishes up the season with 7.4 but there is the outside chance of seeing a trace

like 4/6/2002.

http://www.wunderground.com/history/airport/KNYC/2002/4/6/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA

[Analog96]

My guess is that Central Park finishes up the season with 7.4 but there is the outside chance of seeing a trace

like 4/6/2002.

http://www.wundergro...eq_statename=NA

IMO, a trace is likely. Hard to remember a March and April without even a trace.

[uncle W]

the way this year is going I'd say no but we have seen snow in late March or April after a warm winter...1972-73 and 1997-98 had measurable snow on 3/22...2000 had snow on 4/9...1990 had some snow in April after 85 degrees in mid March...

[bluewave]

IMO, a trace is likely. Hard to remember a March and April without even a trace.

it's a toss up for getting a trace or better in April since 1995.

The real rarity is if you could go traceless past March 1st.

We were able to squeak out a trace for March and April 2002.

No April trace in NYC...98...99..01..04..05..08..10...

2001-02 0 0 0 0 0 T 3.5 T T T 0 0 3.5

[NEG NAO]

it's a toss up for getting a trace or better in April since 1995.

The real rarity is if you could go traceless past March 1st.

We were able to squeak out a trace for March and April 2002.

No April trace in NYC...98...99..01..04..05..08..10...

2001-02 0 0 0 0 0 T 3.5 T T T 0 0 3.5

2 examples of winters with less then 10 inches through March then April snows

1941-42 0 0 0 0 0 0.3 6.4 1.9 0.5 2.2 0 0 - total 11.3

1937-38 0 0 0 T 0.8 0.7 6.5 T 0.7 6.4 0 0 total 15.1

here is an example where April saved the winter snowfall from being well below normal

1914-15 0 0 0 0 0 2.6 3.8 4.5 7.7 10.2 0 0 total 28.8

If you look back at the snowfall records for NYC there have been 13 Aprils out of 26 ( Aprils with at least 1 inch) where there has been at least 1 inch of snow in April and the seasonal total ended up below normal - so all in all even in below normal to well below normal seasonal snowfall years there is still a chance of at least 1 inch in April

[uncle W]

here is a list of snowstorms after March 15th in NYC...3.2"+...

12.0" 3/15-16/1896...

..6.4" 3/16-17/1956

..5.5" 3/16/2007

..7.2" 3/18/1892

..3.8" 3/18/1949

11.6" 3/18-19/1956

..6.2" 3/19/1992

..6.0" 3/19/1890

..5.0" 3/19/1906

..4.8" 3/19-20/1944

11.8" 3/20-21/1958

..9.8" 3/21-22/1967

..4.9" 3/21-22/1964

..5.0" 3/22/1998

..3.5" 3/22/1914

..3.2" 3/22/1992

..3.2" 3/22/1940

..4.5" 3/23/1896

..3.3" 3/28-29/1984

..4.1" 3/28-29/1996

..4.0" 3/29/1970

..3.4" 3/29/1974

..4.5" 3/30/1883

..8.5" 4/1/1924

10.2" 4/3-4/1915

..6.5" 4/5/1944

..9.6" 4/6/1982

..6.4" 4/6-7/1938

..4.0" 4/7/2003

..4.2" 4/8/1956

..3.3" 4/8-9/1916

..6.5" 4/9/1917

..5.0" 4/9/1907

10.0" 4/13/1875

[Analog96]

Only the following winters had NO snow at all in March OR April, not even a trace:

1877-78

1902-03

It has been 110 years since there has been no snow in March or April in NYC, not even a trace.

[Analog96]

Here's a list of Marches and Aprils in NYC after less than one inch of snow fell in NYC in February.

1877-- Feb: 0.4"

Mar 6.5"

Apr:0

1892-- Feb 0.1"

Mar 12"

Apr 1"

1909-- Feb 0.8"

Mar 4.3"

Apr 0"

1919-- Feb 0.5"

Mar 2.7"

Apr T

1938-- Feb T

Mar 0.7"

Apr 6.4"

1953 Feb 0.4"

mar 0.9"

Apr T

1954 Feb 0.5

Mar 0.1

Apr 0.3

1959 Feb 0.4

mar 6.7

Apr 0.6

1971 Feb T

Mar 1.3

Apr 0.4

1973 Feb 0.8

Mar 0.2

Apr T

1981 Feb T

Mar 8.6

Apr 0

1982 Feb 0.4

Mar 0.7

Apr 9.6

1984 Feb 0.2

Mar 11.9

Apr 0

1989 Feb 0.3

Mar 2.5

Apr 0

1998 Feb 0

Mar 5

Apr 0

2004 Feb 0.7

Mar 4.8

Apr 0

[Stormlover74]

I assume you mean less than 1" falling in February?

In that case you should add 2002. February had a trace, March had 3 days with a trace and April had one day (just 10 days before it reached the mid 90s).

Here's a list of Marches and Aprils in NYC after less than one inch of snow fell in NYC.

1877-- Feb: 0.4"

Mar 6.5"

Apr:0

1892-- Feb 0.1"

Mar 12"

Apr 1"

1909-- Feb 0.8"

Mar 4.3"

Apr 0"

1919-- Feb 0.5"

Mar 2.7"

Apr T

1938-- Feb T

Mar 0.7"

Apr 6.4"

1953 Feb 0.4"

mar 0.9"

Apr T

1954 Feb 0.5

Mar 0.1

Apr 0.3

1959 Feb 0.4

mar 6.7

Apr 0.6

1971 Feb T

Mar 1.3

Apr 0.4

1973 Feb 0.8

Mar 0.2

Apr T

1981 Feb T

Mar 8.6

Apr 0

1982 Feb 0.4

Mar 0.7

Apr 9.6

1984 Feb 0.2

Mar 11.9

Apr 0

1989 Feb 0.3

Mar 2.5

Apr 0

1998 Feb 0

Mar 5

Apr 0

2004 Feb 0.7

Mar 4.8

Apr 0

[mattinpa]

It seems like everything would have to be well timed (like later this week) to have a chance, unless the pattern changes late in March. I'd bet against much more than a trace, but we'll have to see.

[Analog96]

I assume you mean less than 1" falling in February?

In that case you should add 2002. February had a trace, March had 3 days with a trace and April had one day (just 10 days before it reached the mid 90s).

Of course! How did I overlook 2002?

2002 Feb T

Mar T

Apr T

[Stormlover74]

Like this winter it was pretty easy to forget

Of course! How did I overlook 2002?

2002 Feb T

Mar T

Apr T

[Analog96]

Like this winter it was pretty easy to forget

Pretty much. Based on my stats, it will snow again. May not accumulate, but it will snow before this so-called winter ends.

[green tube]

3 of the last 6 winters will have produced less than 9" of snow IMBY.

6 year ave: 26.5" (matches the historical ave almost exactly).

one hell of a way to have a "normal 6 years."

[Analog96]

3 of the last 6 winters will have produced less than 9" of snow IMBY.

6 year ave: 26.5" (matches the historical ave almost exactly).

one hell of a way to have a "normal 6 year period"

That's because the other three were blockbusters.

[green tube]

That's because the other three were blockbusters.

yes... that goes without saying.... that's why i didnt say it.

it's actually 2 blockbusters.

3 duds.

1 average.

but it is comical with 5 out of 6 winters being "extreme" (for better or worse), yet the 6 year average is exactly normal.

[bluewave]

2 examples of winters with less then 10 inches through March then April snows

1941-42 0 0 0 0 0 0.3 6.4 1.9 0.5 2.2 0 0 - total 11.3

1937-38 0 0 0 T 0.8 0.7 6.5 T 0.7 6.4 0 0 total 15.1

here is an example where April saved the winter snowfall from being well below normal

1914-15 0 0 0 0 0 2.6 3.8 4.5 7.7 10.2 0 0 total 28.8

If you look back at the snowfall records for NYC there have been 13 Aprils out of 26 ( Aprils with at least 1 inch) where there has been at least 1 inch of snow in April and the seasonal total ended up below normal - so all in all even in below normal to well below normal seasonal snowfall years there is still a chance of at least 1 inch in April

The years where we accumulated in April didn't have the kind of warmth that we have had in North America this winter.

[bluewave]

Only the following winters had NO snow at all in March OR April, not even a trace:

1877-78

1902-03

It has been 110 years since there has been no snow in March or April in NYC, not even a trace.

I think that this December was only the third one to go without a trace of snow.

I wonder if parts of the park may have picked up a trace yesterday but was not

registered in the official data. I know there were posts reporting flurries yesterday.

[jm1220]

Pretty much. Based on my stats, it will snow again. May not accumulate, but it will snow before this so-called winter ends.

The fact there was heavy snow today right down to Ocean City, MD gives me some hope that we have some chances yet.

[Stormlover74]

92-93 and 08-09 are the only 2 in the last 20 winters that had between 20 and 32" of snow, or between 80 and 120% of normal. It's either feast or famine around here (at least half the winters from 78-92 were close to normal, none significantly above, a few were quite below though)

yes... that goes without saying.... that's why i didnt say it.

it's actually 2 blockbusters.

3 duds.

1 average.

but it is comical with 5 out of 6 winters being "extreme" (for better or worse), yet the 6 year average is exactly normal.

[NEG NAO]

The fact there was heavy snow today right down to Ocean City, MD gives me some hope that we have some chances yet.

Exactly - we could have easily been the ones picking up the heavy snow if the clipper and the system north of us was aligned and tracked differently further north a couple hundred miles - guaranteed sometime between now and the second week in april another intrusion of cold enough air and a storm will give someone on the east coast another opportunity for frozen precip

[Isotherm]

3 of the last 6 winters will have produced less than 9" of snow IMBY.

6 year ave: 26.5" (matches the historical ave almost exactly).

one hell of a way to have a "normal 6 years."

My 6 year average is 31.1" in Monmouth County.

06-07: 12"

07-08: 8"

08-09: 29.5"

09-10: 72"

10-11: 57.5"

11-12: 7.5"

Even though though this winter sucked, I'm not complaining. Since 2000 has generally been phenomenal, with only 4 below average winters (01-02, 06-07, 07-08, 11-12).