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Winter storm threat disc 1/25/13-1/26/13


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This is why I said yesterday be careful what you wish for in terms of a less amplified track. People were so worried about changing to rain, now getting rain is the least of your worries.

The change to rain I personally don't feel was ever an issue. With that much cold air in place ahead of it, it would be very tough to turn to non frozen or even anything but snow. I knew this was over once the slight trend to the south started. We would WANT a NW trend because this storm is truly pushing into extreme cold air. The models in the end usually shift south with this type of cold airmass in place. I'm not sure who it was but someone made a GREAT post about a similar storm(s) that were literally ripped to shreds as they headed west to east with cold air funneling in. The trajectory of the precipitation, if development offshore and more south to north would make this vastly different than the west to east that we have

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This is why I said yesterday be careful what you wish for in terms of a less amplified track. People were so worried about changing to rain, now getting rain is the least of your worries.

Yes, because people saying they don't want rain caused this storm to shift south.

I think we are clearly downplaying the effects of our words on the model runs. Words can be like daggers. I know that the GFS is particularly vulnerable to emotional attacks. In addition, when ganged up on, the NAM tends to even cower in fear. It is usually juiced up, but when even the NAM is seen as weakening emotionally and quiet, the euro, UKmet, and Canadian even fall behind it. If we can keep some of our thoughts to ourselves we might positively influence the model runs, particularly at 6 and 18z, when they are most vulnerable and affected by positive reinforcement and guidance

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I wrote this on my blog on Sunday afternoon the 13th, about the possibility of s snowstorm here on Tuesday night into Wednesday morning of last week, only two days prior this is the way it looked, and look at which two models were correct. Maybe they will be again? Maybe they have a better handle on this pattern, maybe? We ended up getting 4 inches of snow.

Then there is a slight chance of more snow on Tuesday night into Wednesday morning. The European and American models keep this storm just to the south of us, but the British, Japanese and Canadian models all bring the storm far enough to the north to give us a significant snowstorm on Tuesday night into Wednesday morning, so this situation needs to be watched closely.

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The change to rain I personally don't feel was ever an issue. With that much cold air in place ahead of it, it would be very tough to turn to non frozen or even anything but snow.

 

There have been instances where severe cold was replaced by much warmer weather and rain within 24 hours or so.  Its a matter of whether the cold air has something to hold it in place. 

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The change to rain I personally don't feel was ever an issue. With that much cold air in place ahead of it, it would be very tough to turn to non frozen or even anything but snow.

There have been instances where severe cold was replaced by much warmer weather and rain within 24 hours or so. Its a matter of whether the cold air has something to hold it in place.

Yeah, true....but I feel like events that were sometimes thought to go from very cold to warm and rain as the storm worked its way up the coast ended up in much more frozen than non frozen...but you're definitely right...it's much more than just if there is "a lot of cold in place"

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This makes no sense. Storm coming up the coast? That is simply not the situation at hand. A low develops on the tail end of the front which is centered over the GL. A strong push of WAA over TN, KY, WV causes snow to fly. Wave remains open aloft which prevents much warming along the EC. Ultimately, latest runs have been keeping the mother low over the GL at about 1008 mb and not weakening, preventing any real coastal development, especially given the open wave nature.IMO, this is a rather typical weak Miller B situation where areas in the I-95 corridor miss out as the transfer occurs.

 

Yeah, true....but I feel like events that were sometimes thought to go from very cold to warm and rain as the storm worked its way up the coast ended up in much more frozen than non frozen...but you're definitely right...it's much more than just if there is "a lot of cold in place"

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This makes no sense. Storm coming up the coast? That is simply not the situation at hand. A low develops on the tail end of the front which is centered over the GL. A strong push of WAA over TN, KY, WV causes snow to fly. Wave remains open aloft which prevents much warming along the EC. Ultimately, latest runs have been keeping the mother low over the GL at about 1008 mb and not weakening, preventing any real coastal development, especially given the open wave nature.IMO, this is a rather typical weak Miller B situation where areas in the I-95 corridor miss out as the transfer occurs.

Yeh the euro and GFS don't allow the deepening to take place until east of Montauk they hold the primary longer. The JMA and ukie transfer earlier so they are more robust in the area and there in lies the differences

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This makes no sense. Storm coming up the coast? That is simply not the situation at hand. A low develops on the tail end of the front which is centered over the GL. A strong push of WAA over TN, KY, WV causes snow to fly. Wave remains open aloft which prevents much warming along the EC. Ultimately, latest runs have been keeping the mother low over the GL at about 1008 mb and not weakening, preventing any real coastal development, especially given the open wave nature.IMO, this is a rather typical weak Miller B situation where areas in the I-95 corridor miss out as the transfer occurs.

Yeah, true....but I feel like events that were sometimes thought to go from very cold to warm and rain as the storm worked its way up the coast ended up in much more frozen than non frozen...but you're definitely right...it's much more than just if there is "a lot of cold in place"

I'm not referring to this storm coming up the coast. In my previous post, I went in about how this storm has a west to east trajectory. If this WAS coming up the coast it would have better results I said. In my last post, I was clearly responding to famartin's post to me, and stating that in situations where models in preliminary runs before storms sometimes show the warm side of the storm winning out over the cold, which in many cases does not end up happening

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Upton offers some hope in its afternoon AFD - good write up :

LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/

THE STRETCH OF RATHER COLD CONDITIONS LINGERS FOR AWHILE, WITH EVEN

A DECENT POTENTIAL FOR A WIDESPREAD ACCUMULATING SNOWFALL FRIDAY AND

FRIDAY NIGHT.

THE MAIN SYNOPTIC SETUP IS COMPRISED OF A POLAR VORTEX ACROSS

EASTERN CANADA THAT WILL TEND TO KEEP A PRONOUNCED TROUGH ACROSS THE

GREAT LAKES AND NORTHEAST. AT LEAST ONE PIECE OF ENERGY ROTATING

SOUTHEASTWARD AROUND THE POLAR VORTEX LOOKS TO SLIDE ACROSS OUR AREA

WEDNESDAY NIGHT. WE THEN TURN TO ENERGY TOPPING THE RIDGE NEAR THE

WEST COAST, WHICH IS FORECAST TO DROP INTO THE PLAINS LATE THURSDAY

AND THIS IS WHERE THINGS GET MORE TRICKY. THE INITIAL POLAR VORTEX

MAY END UP LIFTING OUT WHILE A NEW ONE BECOMES ESTABLISHED NEAR

HUDSON BAY LATE FRIDAY. THIS MAY WORK IN TANDEM WITH THE PACIFIC

ENERGY DROPPING SOUTHEASTWARD WHICH CAUSES AMPLIFICATION TO OCCUR.

A LARGE SPREAD IN THE SOLUTIONS APPEARS PARTIALLY RELATED TO HOW

THE NORTHERN STREAM FLOW CROSSING THE GREAT LAKES INTERACTS WITH THE

APPROACHING SYSTEM. TOWARD FRIDAY NIGHT, THE LOW SHOULD BEGIN TO

REFORM NEAR THE BAROCLINIC ZONE NEAR SOUTHEASTERN VIRGINIA BEFORE

CONSOLIDATING NEAR THE NORTHEAST COAST. THIS WILL DETERMINE THE

TRACK AND STRENGTH OF THE SYSTEM AS IT SLIDES MAINLY JUST TO OUR

SOUTH LATE FRIDAY. GIVEN THE ARCTIC AIR AHEAD OF IT, ESPECIALLY IN

THE LOWER LEVELS AS THESE AIRMASS TYPES ARE MUCH MORE DENSE, IT

APPEARS THAT A DECENT OVERRUNNING EVENT SHOULD OCCUR. HOWEVER THE

DETAILS STILL NEED TO BE DETERMINED. ONE WOULD THINK THE ARCTIC AIR

WILL NOT BE ERODED EASILY, THEREFORE SOME WARMING ALOFT WILL HELP TO

STRENGTHEN THE THERMAL GRADIENT. MORE TRANQUIL CONDITIONS THEN

ARRIVE WITH A SHOT OF COLD AIR IN THE WAKE OF THE STORM, THEN SOME

AIRMASS MODIFICATION LOOKS TO TAKE PLACE EARLY NEXT WEEK.

WE USED A MODEL BLEND FROM WEDNESDAY NIGHT INTO FRIDAY, THEN

INCORPORATED HPC GUIDANCE THEREAFTER. HPC USED A BLEND OF THE ECMWF

MEAN/GEFS MEAN FOR FRIDAY NIGHT AND SATURDAY WITH A SMALL

PERCENTAGE OF THE OPERATIONAL ECMWF INCLUDED, THEN ANOTHER BLEND OF

THE AFOREMENTIONED MEANS TO ADD SOME DETAIL SUNDAY THROUGH TUESDAY.

SOME TWEAKS WERE MADE HOWEVER BASED ON ADDITIONAL COLLABORATION WITH

OUR NEIGHBORING OFFICES.

FOR WEDNESDAY NIGHT AND THURSDAY...AS THE POLAR VORTEX MEANDERS

SOUTHWARD SOME, ENERGY SLIDING SOUTHEASTWARD WITHIN THE CYCLONIC

FLOW WILL DIVE ACROSS THE MID ATLANTIC WEDNESDAY NIGHT. WHILE

MOISTURE AND LIFT DOES NOT APPEAR TO BE MUCH, THERE MAY BE A FAIRLY

SMALL RIBBON OF SNOW SHOWERS THAT ACCOMPANY THIS FEATURE. WE PLACED

LOW CHC POPS FOR NOW ACROSS PORTIONS OF THE DELMARVA FOR SCATTERED

SNOW SHOWERS AND THEN WENT WITH SCATTERED FLURRIES ELSEWHERE. THIS

SYSTEM SHOULD QUICKLY MOVE OUT TO SEA EARLY THURSDAY AS A SECONDARY

FRONT MAY DROP SOUTHWARD. THIS WOULD GENERALLY REINFORCE THE COLD

AIR ACROSS THE REGION FOR THURSDAY. A FAIRLY STRONG AREA OF HIGH

PRESSURE THEN SETTLES IN LATE THURSDAY AND THIS MAY SET THE STAGE

FOR A VERY COLD NIGHT AS WINDS DECOUPLE. SOME CLOUDS SHOULD START TO

INCREASE THURSDAY NIGHT, HOWEVER AS OF NOW THE THICKER CLOUDS LOOK

TO HOLD OFF. WE THEN TURN OUR ATTENTION TO THE WEST AND SOUTHWEST

FOR OUR NEXT STORM SYSTEM.

FOR FRIDAY AND SATURDAY...WHILE A STORM IS EXPECTED TO IMPACT THE

REGION, THERE CONTINUES TO BE UNCERTAINTY WITH THE DETAILS. THIS

REVOLVES AROUND THE ENERGY IN THE NORTHERN STREAM AND HOW MUCH IT

CAN AMPLIFY WHICH ULTIMATELY FACTORS INTO THE SURFACE LOW TRACK. IT

SEEMS LIKE THE GUIDANCE IS SLOWING THE NORTHERN STREAM ENERGY WITH

LESS EMPHASIS ON THE SOUTHERN STREAM SURFACE LOW. GIVEN THE TENDENCY

FOR ARCTIC AIR TO HOLD GROUND LONGER, ESPECIALLY NEAR THE SURFACE,

WE BELIEVE THE SURFACE LOW RUNNING UP TOWARD WESTERN PENNSYLVANIA

INDICATED BY SOME GUIDANCE IS TO FAR NORTH. WHILE IT SHOULD GET INTO

THE OHIO VALLEY, THE BAROCLINIC ZONE THAT WILL STRENGTHEN AS DECENT

WAA OCCURS SHOULD ALLOW THE LOW TO JUMP TO THE MID ATLANTIC COAST.

THE PLACEMENT OF THE UPPER-LEVEL TROUGH/POLAR VORTEX SHOULD ALSO

KEEP THE SURFACE LOW MORE SOUTH. WHILE THIS IS HOW WE ARE PLAYING

THE SURFACE LOW TRACK, OTHER FACTORS COME INTO PLAY AS WELL. THE

AMOUNT OF WAA WILL TRY AND TOSS A WARM LAYER NORTHBOUND, BUT THIS

MAY BE REDUCED GIVEN THE SURFACE LOW REFORMING TO OUR SOUTH BEFORE

SLIDING NORTHEASTWARD. THIS STORM SHOULD BE A FAIRLY QUICK MOVER

THOUGH AS THE FLOW DOES NOT REALLY SUPPORT A SLOW DOWN OFF OF OUR

COAST. THIS SETUP IS LOOKING MORE AND MORE LIKE A PRONOUNCED

OVERRUNNING ONE WHICH IS DRIVEN BY WAA AND A RIBBON OF DEVELOPING

FRONTOGENETIC FORCING AS THE THERMAL GRADIENT MAINLY WEST TO EAST

TIGHTENS UP.

SINCE THINGS CAN CERTAINLY CHANGE THIS FAR OUT, WE TENDED TO STAY

CLOSER TO CONTINUITY. WE DID HOWEVER SLOW DOWN THE POPS SOME DURING

THE DAY FRIDAY AS THE MAIN SYSTEM LOOKS TO ARRIVE SOMETIME FROM

ABOUT MIDDAY ON. REGARDING PRECIPITATION TYPES, IT LOOKS MOSTLY ALL

SNOW ACROSS THE AREA, HOWEVER SOME SLEET MAY OCCUR ACROSS THE SOUTH

IN THE EVENT THE WARM LAYER MAKES ITS PRESENCE FELT. IF THE SYSTEM

STAYS WEAK ENOUGH, THE WAA WOULD TEND TO BE WEAKER AND THEREFORE A

COLDER PROFILE EVERYWHERE. THE STRONGER WAA INDUCED LIFT THOUGH INTO

AN EXISTING ARCTIC AIRMASS COULD OFFSET THE LOWER LEVEL WARMING. FOR

NOW, WE FAVORED MORE FROZEN PRECIPITATION GIVEN THE SYNOPTIC SETUP

WHICH WOULD LEAD TO THE POTENTIAL FOR A WIDESPREAD PLOWABLE

SNOWFALL. LOTS OF THINGS TO BE IRONED OUT, HOWEVER WE ARE

ANTICIPATING A SWATH OF ACCUMULATING SNOW ACROSS A GOOD PART OF THE

AREA. IT IS A BIT EARLY TO TIE DOWN SPECIFIC SNOW AMOUNTS ESPECIALLY

WITH LOWER CONFIDENCE IN THE DETAILS AND QPF. WE WILL CONTINUE TO

MENTION THIS SYSTEM IN THE HAZARDOUS WEATHER OUTLOOK, AND A BRIEFING

PACKAGE HAS BEEN POSTED.

THE SYSTEM MOVES AWAY DURING SATURDAY WITH A COLD AND GUSTY

NORTHWESTERLY WIND IN ITS WAKE. THERE COULD BE SOME FLURRIES OR SNOW

SHOWERS MAINLY IN THE POCONOS DUE TO SOME EASTERN GREAT LAKES

RESPONSE.

 

That's Mt. Holly's discussion, not Upton's, but, yes, it's still pretty upbeat about seeing a "decent overrunning event" which produces a "plowable snow."  They don't include snowfall amounts, but that kind of language is not 1-3" - it's at least 3-6" language. 

 

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

 

Upton is much less bullish, which is not surprising as most of their CWA is further north, meaning a more southerly track could have more of an impact on their area receiving a plowable snow.  That's why they're favoring more snow/precip near the coast.  Way too early for people to posting "storm cancel" but it happens every time, since most people around here simply have a limited understanding of the limitations and uncertainties associated with global forecast models being able to accurately predict localized weather outcomes several days in advance. 

 

.LONG TERM /FRIDAY THROUGH TUESDAY/...

 

AS HIGH PRESSURE SLIDES OFFSHORE EARLY FRIDAY...A LOW PRESSURE IS

FORECAST TO TRACK FROM THE OHIO VALLEY INTO THE MID ATLANTIC REGION

ON FRIDAY. THERE IS STILL PLENTY OF UNCERTAINTY REGARDING THE EXACT

TRACK OF THE LOW AND INTENSITY...BUT THE ATMOSPHERE WILL BE COLD

ENOUGH TO SUPPORT MAINLY A SNOWFALL EVENT AT THIS TIME. THE BEST

CHANCE FOR WARNING LEVEL SNOWS RIGHT NOW STILL APPEARS TO BE ALONG

THE COAST...HOWEVER...ANY SUBTLE CHANGE IN STORM TRACK/INTENSITY CAN

HAVE A SIGNIFICANT IMPACT ON AMOUNTS AND PTYPE.

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

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I'm definitely going to give up on snow threats if we get practically nothing from this. Things are just not in our favor this winter and that could very well continue, the lack of blocking is hurting us big time and all your going to get with a PV nearby is cold air but little in terms of snow it seems. 

 

Even after the reload, there is little evidence of blocking so we would still be dry. Minor events from clippers are the best we might be able to do. 

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I'm definitely going to give up on snow threats if we get practically nothing from this. Things are just not in our favor this winter and that could very well continue, the lack of blocking is hurting us big time and all your going to get with a PV nearby is cold air but little in terms of snow it seems. 

 

Even after the reload, there is little evidence of blocking so we would still be dry. Minor events from clippers are the best we might be able to do. 

 

 

That's kind of a weenie comment to make. In the winter of 2008-09, I had to wait until March 1st-2nd to get a snow event greater than 6", and I managed to make it slightly above normal in snowfall that year (the storm produced 13.5"). In 2004-05, our first real / significant event came around now. We've seen plenty of winters where the bulk of the snow fell after mid winter.

 

1955-56 is another example. Nothing over 3" storms through February, then NYC recorded 21" in March 1956.

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I'm definitely going to give up on snow threats if we get practically nothing from this. Things are just not in our favor this winter and that could very well continue, the lack of blocking is hurting us big time and all your going to get with a PV nearby is cold air but little in terms of snow it seems. 

 

Even after the reload, there is little evidence of blocking so we would still be dry. Minor events from clippers are the best we might be able to do. 

 

Hopefully, we can at least bump NYC snowfall for the 12-13 season from the 5.1 inch level above 10 inches.

I don't think that anyone wants to see a back to back single digit seasons. We came close between 96-98

but were able to get to 10.0 inches exactly one out of the two years. With the reloading pattern in early

February I'll be bold and say we finish with 10.0 or higher. Fingers crossed...

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Hopefully, we can at least bump NYC snowfall for the 12-13 season from the 5.1 inch level above 10 inches.

I don't think that anyone wants to see a back to back single digit seasons. We came close between 96-98

but were able to get to 10.0 inches exactly one out of the two years. With the reloading pattern in early

February I'll be bold and say we finish with 10.0 or higher. Fingers crossed...

I think most places in the NYC area are already above 10" minus the park and areas with in the core of the urban heat island. Lets not forget the 12Z nam did bring the .25 line a hair south of the city and it had more to go past h84. The CMC also had around .30 for the city, the Ukie and JMA had solid hits. So despite not seeing last nights Euro bomb today, it doesn't mean we can't get a 4 to 6+ snowfall.
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Hopefully, we can at least bump NYC snowfall for the 12-13 season from the 5.1 inch level above 10 inches.

I don't think that anyone wants to see a back to back single digit seasons. We came close between 96-98

but were able to get to 10.0 inches exactly one out of the two years. With the reloading pattern in early

February I'll be bold and say we finish with 10.0 or higher. Fingers crossed...

 

 

I'd be shocked if they finish in the single digits. It's going to take a decent amount of bad luck given the colder pattern going forward.

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I'd be shocked if they finish in the single digits. It's going to take a decent amount of bad luck given the colder pattern going forward.

the winters that started out mild and snowless that had a good February or March are...

1949-50...

1971-72...

1985-86...

1992-93...

1994-95...

2006-07...

None of these were great but at least had a cold snowy February/March...

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I think most places in the NYC area are already above 10" minus the park and areas with in the core of the urban heat island.

 

I find it unfortunate that despite 8 million citizens, there are only 3 active CoCoRaHS stations in the city of New York.  OK, I realize many of them don't have a good place (or any place) to put a rain guage, but still... surely there would be more than 3???

 

Anyway, only 1 of those 3 has something resembling reliable snowfall measurements, a station in Queens, which lists a seasonal total of 8.1".  Certainly much higher than the Park, JFK and LaGuardia.

 

The four stations I found in Westchester County list totals of 13-17".

 

The one station I found in Nassau lists a total of 8.1", though there appear to be some instances where they didn't measure so I'm not sure that's accurate.

 

Now the CoCoRaHS website decided to take a nap so I can't look up NJ, but EWR has 8.9" and I'm sure most Monmouth stations are over 10"...  probably most Bergen stations too. 

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I just would like to see this get east of the rockies before i worry. Mayb its a whiff but sampling is not the same til on the grid so i dont give up on solutions until the models hav absorbed sufficent data. If and when that happens we will all be back replaying this with the next scenerio.

18z 264hr ant.

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I think it's quite foolish to look at the SREF's at this point... Lets see what comes of the models tonight.

If nothing has changed by tomorrow night then it's time to give up on anything more than an inch or two.

 

True. I was just posting them considering how good they have been in the nearer term. If you look at the individual members of the SREF, there's a lot of disagreement, so it's best to disregard them atm.

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I just would like to see this get east of the rockies before i worry. Mayb its a whiff but sampling is not the same til on the grid so i dont give up on solutions until the models hav absorbed sufficent data. If and when that

happens we will all be back replaying this with the next scenerio.

18z 264hr ant.

That looks beautiful

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Two things, one that I won't give up until the British and Japanese models do because they were the models that got the last snowstorm right here while GFS and Euro missed to the south, and that was only 48 hours before the storm, and two is that the pieces to this puzzle won't even be onshore and in the models until 0z tomorrow night.

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the winters that started out mild and snowless that had a good February or March are...

1949-50...

1971-72...

1985-86...

1992-93...

1994-95...

2006-07...

None of these were great but at least had a cold snowy February/March...

 

If memory serves, 1982-83 was also fairly snowless until the Blizzard of 83.

 

One more point.  I've been browsing these weather boards for so long now that I think that those whose frame of reference is mid 90s to present don't realize how rare a 10" storm had been for such a long stretch.  My frame of reference goes back to 1978.  Growing up, between 1978 and 1992, on LI we had:

 

- An unusual but not that giant storm in April 82

- Blizzard of 1983

- A decent storm in 1987 which ended as rain

- That's it.

 

Of course 93/94 was great, as was 95/96, and then in the 2000s, starting with 12/30/2000, things were great despite the great variablity and some snow droughts.  Still though if the mid 90s to 2000s are your frame of reference, you'd be suprised to see that for quite a long stretch, 10" snowstorms happened on average once every five years.  I remember in 1999 doing some quick research and finding that LI had a grand total of six or 10"+ snow storms between the late 70s and 1999.

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the winters that started out mild and snowless that had a good February or March are...

1949-50...

1971-72...

1985-86...

1992-93...

1994-95...

2006-07...

None of these were great but at least had a cold snowy February/March...

Did we get two sleet storm in 2006-2007?

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Im at 10 inches on the season now after yesterdays 3 inch surprise! I can see the bay from my bedroom in NASSAU. So there is hope at the end of the rainbow. We actually have a nice crusty 2 inch covering here currently in the land of now snow. Overrunning after arctic can kick serious A. I was at school in bmore for pd2 wow is all i have to say. This is not pd2 but i think allot of surprises are in the semi short term.

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