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Upstate NY/North Country + adjacent ON, QC, VT: Heading into December

Alpha5

By Alpha5,
in Upstate New York/Pennsylvania

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Logan11

Logan11

Posted
Posted

Looks likea stellar track and evolution for us in the hills west of KALB. This isn't to the level of the Xmas '02 storm or VD '07 because there is no capture and intense deformation like that...but a foot is very possible. Just a small risk of a few pingers for a time tomorrow morning as I see it. 98% snow. I think ALY was hedging their bets (due to last night's NAM) with that local point forecast mentioning snow/rain/sleet mix for a few hours tomorrow afternoon.

The following storm is more for the coast crowd, but we could get fringe snow amounts.

I'll hitch my wagon to this star instead. :snowman:

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Logan11

Logan11

Posted
Posted

I'm pretty close to tuning out models and going into "enjoy the stormmode." :) I'm not a pro met so it doesn't matter...it kind of spoils the event when you sit there the whole time scrutinizing model minutia.

My advice to you is to stop scrutinizing off hour model runs. The 6Z and 18z are typically head scratchers because they are lacking a lot of critical data parameters. Seriously, they aren't worth your time.

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champy

champy

Posted
Posted

Newest BGM discussion is interesting:

MAIN CHANGE FROM EARLIER DISCUSSION IS THAT THE EURO AND CMC CAME

IN COLDER. IN ADDTN...EVEN THE WARMER 12Z GFS HAS AN INTENSE

FRONT END WAA/ISENTROPIC LIFT PUTS A QUICK 6-7 INCHES DOWN IN

SCRANTON BY 00Z THU BEFORE CHANGING TO SLEET AND FREEZING RAIN.

THE GFS ALSO DEVELOPS A STRONG WAVE PATTERN IN THE QPF FIELDS BY

06Z THU WHICH CORRESPONDS TO WARMER AIR IN THE DRIER AREAS AND

COLDER AIR IN THE HEAVIER PRECIP AREAS IN SRN NY/NRN PA. THIS LOOKS

LIKE A MODEL INDUCED WAVE FROM THE CATSKILLS ON STRG LL EAST

WINDS WHICH EXAGERATES THE EFFECTS OF THE CATSKILLS. I DO BELIEVE

THAT THERE WILL BE SOME DOWNSLOPING BY NOT TO THE EXTENT THE GFS

AND EVEN NAM HAS. THE EURO IS SCARY FOR OUR AREA HAVE ALL SNOW

DOWN TO NE PA WITH 1 TO 1.5 INCHES QPF...SUGGESTING 12-18 INCHES

CWA WIDE. I STILL THINK THERE IS A CHANCE FOR SLEET/FREEZING RAIN

MIX UP INTO NE PA/CATSKILLS. IN ADDTN THERE IS A DRY SLOT BETWEEN

A WEAKENING UPR LVL WAVE MOVG N INTO WRN NY BY 12Z THU AS THE MAIN

UPR LVL LO GOES OFF THE COAST. THIS CUD HOLD SNOW AMNTS DOWN. THE CMC

ALSO IS COLDER AND AGAIN HAMMERS OUR FORECAST AREA. SO DECIDED ON

WINTER STORM WARNINGS FOR ENTIRE CWA...BUT HELD SNOW AMNTS DOWN S

AND E OF I-88 TO TOWANDA AND ESPECIALLY DOWN INTO NE PA. I DO

STILL BELIEVE THAT 2-3 INCHES PER HOUR POSSIBLE WITH THIS STORM

WITH THE TREMENDOUS DYNAMICS AND ALSO THE ANTICIPATED TRAVEL THE

DAY AFTER CHRISTMAS MAKES THIS A POTENTIAL HIGH IMPACT EVENT. SO

FEEL WARNINGS PRUDENTS ALL COUNTIES.

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wolfie09

wolfie09

Posted
Posted

THE NATIONAL WEATHER SERVICE IN ALBANY HAS ISSUED A WINTER STORM

WARNING FOR SNOW...WHICH IS IN EFFECT FROM 7 PM WEDNESDAY TO 7 PM

EST THURSDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* LOCATIONS...WESTERN MOHAWK VALLEY...SCHOHARIE VALLEY..EASTERN

CATSKILLS...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA REGION

AND SOUTHERN VERMONT.

* HAZARD TYPES...MODERATE TO HEAVY AMOUNTS OF SNOW...SLEET...AND

LIGHT FREEZING RAIN WEDNESDAY NIGHT INTO THURSDAY.

* ACCUMULATIONS...BETWEEN 8 AND 14 INCHES OF SNOW AND SLEET IS

POSSIBLE WEDNESDAY NIGHT INTO THURSDAY.

* MAXIMUM SNOWFALL RATES...BRIEF INTERMITTENT BURSTS OF 1 TO 2

INCHES OF SNOW PER HOUR WEDNESDAY NIGHT AND EARLY THURSDAY

MORNING.

* ICE ACCUMULATIONS...LIGHT ICE ACCRETION...A TENTH OF AN INCH OR

LESS OF ICE...IS POSSIBLE IN THE SCHOHARIE VALLEY...EASTERN

CATSKILLS...SARATOGA REGION AND SOUTHERN VERMONT. LATE WEDNESDAY

NIGHT INTO THURSDAY.

* TIMING...SNOW IS EXPECTED TO BEGIN WEDNESDAY NIGHT...HEAVY AT

TIMES LATE WEDNESDAY NIGHT. SLEET AND FREEZING RAIN IS EXPECTED

TO MIX IN AROUND DAYBREAK THURSDAY MORNING AND CONTINUE

THURSDAY MORNING...THEN END AS SNOW SHOWERS THURSDAY AFTERNOON.

* IMPACTS...HEAVY ACCUMULATIONS OF SNOW...SLEET AND LIGHT

ACCUMULATIONS OF ICE WILL MAKE FOR DANGEROUS TRAVEL ON LATE

WEDNESDAY NIGHT INTO THURSDAY.

* VISIBILITIES...FREQUENTLY BELOW 1 MILE IN MODERATE TO HEAVY

SNOW...WITH INTERMITTENT PERIODS BELOW ONE HALF MILE.

* TEMPERATURES...TEMPERATURES WILL BE IN THE MID 20S WEDNESDAY

NIGHT...WARMING TO THE LOWER 30S THURSDAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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kulaginman

kulaginman

Posted
Posted

Interesting to see blizzard warnings posted all the way up to the Erie County PA lakeshore. Similar conditions will of course transpire along the Erie and Ontario shorelines in western NY as well. Actually, that northeasterly LLJ is forecast to be quite intense throughout Western NY from 00z-06z tomorrow night. I wouldn't be surprised if KBUF experiences 40 mph gusts along with the heavy snowfall.

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heavy_wx

heavy_wx

Posted
Posted

Interesting to see blizzard warnings posted all the way up to the Erie County PA lakeshore. Similar conditions will of course transpire along the Erie and Ontario shorelines in western NY as well. Actually, that northeasterly LLJ is forecast to be quite intense throughout Western NY from 00z-06z tomorrow night. I wouldn't be surprised if KBUF experiences 40 mph gusts along with the heavy snowfall.

It seems likely that many areas along the south shores of Lake Erie and Ontario will experience blizzard conditions. The Buffalo NWS doesn't like to issue blizzard warning though, I think because the sensible weather of a blizzard is very similar to a lake effect snow event. It could also be because of the severe connotations the term blizzard has in the Buffalo area as a result of the Blizzard of 1977.

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lakeeffectkid383

lakeeffectkid383

Posted
Posted

Are the media stations here in Buffalo retarded or just scared its gonna be another bust? Channel 2 is calling for 3-5" for everyone north of buffalo for this event and channel 4 is calling for 4-8". Both mighty conservative if you ask me and IMO stupid, when they show the banner at the top that says WINTER STORM WARNING than shows 3-5" underneath it. Just makes the public think a warning will be issued whenever we get 3-5" of snow which isn't even near warning criteria.

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WestWind

WestWind

Posted
Posted

Are the media stations here in Buffalo retarded or just scared its gonna be another bust? Channel 2 is calling for 3-5" for everyone north of buffalo for this event and channel 4 is calling for 4-8". Both mighty conservative if you ask me and IMO stupid, when they show the banner at the top that says WINTER STORM WARNING than shows 3-5" underneath it. Just makes the public think a warning will be issued whenever we get 3-5" of snow which isn't even near warning criteria.

Historically, Buffalo does not tend to get extreme snowfall amounts out of synoptic events, at least not without lake assistance. Lake assistance will not occur here because winds will be from the east. Only time I can recall a foot or more from synoptic was a spring storm one March. Not to say snowfall will be insignificant, but probably the 4-8" is a reasonable estimate.

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Polarbear

Polarbear

Posted
Posted

Got a question for the red-taggers... I recall in some storms within the past few yrs, where it seemed as though we were primed for a good amount of snow that in the end didn't happen due to convection that formed down through the mid-atlantic. If i remember correctly it seemed to absorb the moisture that was progged to stream N into our area and instead greater convection in that area form.. As I see there seems to be fair amount of severe weather with this, is there any sign of that being an issue in this storm?

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BuffaloWeather

BuffaloWeather

Posted
Posted

Historically, Buffalo does not tend to get extreme snowfall amounts out of synoptic events, at least not without lake assistance. Lake assistance will not occur here because winds will be from the east. Only time I can recall a foot or more from synoptic was a spring storm one March. Not to say snowfall will be insignificant, but probably the 4-8" is a reasonable estimate.

On average about every 3-4 years Buffalo receives a synoptic snowstorm that produces a foot or more. The anomaly was in March of 2008 when we had two events within a 3 week period that dropped nearly 30 inches from both.

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kulaginman

kulaginman

Posted
Posted

Got a question for the red-taggers... I recall in some storms within the past few yrs, where it seemed as though we were primed for a good amount of snow that in the end didn't happen due to convection that formed down through the mid-atlantic. If i remember correctly it seemed to absorb the moisture that was progged to stream N into our area and instead greater convection in that area form.. As I see there seems to be fair amount of severe weather with this, is there any sign of that being an issue in this storm?

This is something I had mentioned the other night. It has long been hypothesized that warm frontal convection will rob moisture from the LLJ and decrease snowfall amounts farther northward because convection takes moisture out of the warm conveyor belt (WCB) and deposits it as rain just north of the warm front. There actually has been very little research conducted to back up this hypothesis.

I did come across a case study conducted in 2009 that analyzed a Midwestern snowstorm that occurred in February 2003. The case study found that the large release of latent heat associated with convection can cause a diabatic potential vorticity (PV) anomaly to form in the mid-troposphere, which can impact the location of heavy precipitation downstream. It isn't so much that convection absorbs moisture that was progged to stream north, but it can cause a re-distribution of precipitation which will cause model QPF to be exaggerated in some locations and underestimated in others.

This is the case study if you're interested:

https://ams.confex.com/ams/23WAF19NWP/techprogram/paper_153425.htm

The convection down South is one of the many reasons why I have been hesitant to pull the trigger on widespread 12"+ snowfall amounts. It certainly does complicate the picture.

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blizzard1024

blizzard1024

Posted
Posted

This is something I had mentioned the other night. It has long been hypothesized that warm frontal convection will rob moisture from the LLJ and decrease snowfall amounts farther northward because convection takes moisture out of the warm conveyor belt (WCB) and deposits it as rain just north of the warm front. There actually has been very little research conducted to back up this hypothesis.

I did come across a case study conducted in 2009 that analyzed a Midwestern snowstorm that occurred in February 2003. The case study found that the large release of latent heat associated with convection can cause a diabatic potential vorticity (PV) anomaly to form in the mid-troposphere, which can impact the location of heavy precipitation downstream. It isn't so much that convection absorbs moisture that was progged to stream north, but it can cause a re-distribution of precipitation which will cause model QPF to be exaggerated in some locations and underestimated in others.

This is the case study if you're interested:

https://ams.confex.c...aper_153425.htm

The convection down South is one of the many reasons why I have been hesitant to pull the trigger on widespread 12"+ snowfall amounts. It certainly does complicate the picture.

I don't know if I quite agree with this. I can see it having some effect...but with this storm, the upper level trough/low moves east from the lower ohio valley into the middle atlantic states Wednesday it goes slightly negative, and leads to significant upper level divergence over NY and PA. In addition, related to this, is a strong upper level jet streak rounding the base of the trough. This supports a tremendous southeasterly low-level jet which goes directing up the isentropes right into upstate NY and northern PA. Meanwhile...related to the upper divergence is the movement of the upper level wave which will raise the isentropes as well...so you have isentropes rising over NY/PA as the air ascends up the isentropes. This is a tremendous large scale set up. I don't think convection to the south will do anything except maybe disrupt exactly where the surface low is. But this is immaterial relative to the strong dynamics. There will be moisture and with the ascending air way up into the mid troposphere it won/t take much for saturation w.r.t ice to occur. I can easily see a band of 12-18" somewhere in wrn ny...possibly to nc ny. The only issue is that this cyclone will be occluding rapidly as it reaches off the NJ coast by 12z thu. This will limit any wrap around snowfall. So I see an intense burst of heavy snow in wrn/cntrl ny wed evening/erly thu am possibly 2-3 inches per hour for 3-5 hours...then snow will lighten up some. The convection offshore in the WCB likely won/t have any effect on what happens inland this far north. I think someone in NY...especially western to nrn NY will get slammed by this storm.

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WestWind

WestWind

Posted
Posted

On average about every 3-4 years Buffalo receives a synoptic snowstorm that produces a foot or more. The anomaly was in March of 2008 when we had two events within a 3 week period that dropped nearly 30 inches from both.

Agreed, it does happen - but once every three to four years is is not very often and therefore I don't have a lot of confidence in this particular event being one of those rare cases. It could be - but I feel the odds are well below 50% just given the above statistics. I have to ask myself - is this particular event really different enough from the norm that it only occurs once every 3 or 4 years? I think that is what the NWS is doing by being conservative in their predictions. They are likely looking at climatology for this type of event.

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blizzard1024

blizzard1024

Posted
Posted

It looks like the nam downslopes the area just west of the catskills

http://forums.accuwe...=post&id=183044

I think the downsloping is exaggerated by the models due to the coarser representation of

the mountains. There will be some downsloping but not to this extent over such a wide

area. Plus,in the low-levels the air is very stable which tends to minimize the impact

of the valleys and hills. The flow is smoother over terrain and as such is not as sharp of an upslope/downslope

couplet because of the stability. It is related to a low froude number...suggesting strong winds aloft

don't flow down into the valleys...hence the downsloping is less than for a more unstable layer.

In addition and more importantly, at the onset of the storm between 21z and 06z...the lift is maximized

between 10 and 15 kft well above the Catskills. There is descent on the models down low at KBGM on BUFKIT

for example but it is a very shallow later around 3000 feet. I don't think this will make enough of a difference

to explain the huge differences in the precip amounts as per the gfs and nam from this apparent downslope.

The 12z euro did not show this as much...neither did the cmc. There will be some affect...but I think it

will be minimal.

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snowgeek

snowgeek

Posted
Posted

I think the downsloping is exaggerated by the models due to the coarser representation of

the mountains. There will be some downsloping but not to this extent over such a wide

area. Plus,in the low-levels the air is very stable which tends to minimize the impact

of the valleys and hills. The flow is smoother over terrain and as such is not as sharp of an upslope/downslope

couplet because of the stability. It is related to a low froude number...suggesting strong winds aloft

don't flow down into the valleys...hence the downsloping is less than for a more unstable layer.

In addition and more importantly, at the onset of the storm between 21z and 06z...the lift is maximized

between 10 and 15 kft well above the Catskills. There is descent on the models down low at KBGM on BUFKIT

for example but it is a very shallow later around 3000 feet. I don't think this will make enough of a difference

to explain the huge differences in the precip amounts as per the gfs and nam from this apparent downslope.

The 12z euro did not show this as much...neither did the cmc. There will be some affect...but I think it

will be minimal.

Are your thinking the same applies for the Hudson Valley? I have noticed that the stronger the high to the north, and the thicker that low level cold air, the less we downslope. I was worried because I wasn't to impressed with the surface cold air here.

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LakeEffectKing

LakeEffectKing

Posted
Posted

The simulated NAM radar from the latest run for 03z is pretty slow and weak with the ongoing convection over AL....none of the models have the eastern precip shield covered well at all....not sure of what it means....

As for the qpf min that many of the models are showing nosing up early Thurs. morning....I think it may be a combo of compressional surface heating, along with the skinny surface ridge that is associated with CAD signatures (ie drying)....just happens in this case that the flow is orthogonal to both the orientation of both the mountains and the CAD signature (as opposed to a more northerly component in many other nor'easter type setups).

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Ottawa Blizzard

Ottawa Blizzard

Posted
Posted

nam destroys WNY up through eastern ontario once again....the SREFs are supportive but of course there is a large variability.

NAM is 2 inches of qpf in ottawa!

LOL.

NAM always overdoes the qpf though.

Still, it's looking better for Toronto and Ottawa than it was this time yesterday. I'm hoping for at least 6" in Toronto, although I think 4" is more likely.

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