December 2022

[PuraVida]

It depends on how strong the secondary low is. The EPS has several members with a primary into the Great Lakes and secondary in Eastern PA. The GEM has that scenario. So it has hurricane force gusts ahead of the storm and 60° to 8° in NYC behind the front. So a super front with a 50°+ drop.



 

Finally a fellow wind weenie!


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[LibertyBell]

4 minutes ago, SnowGoose69 said:

Models largely sucked with Miller B storms or redevelopers until the mid 90s, simpler setups like Miller As they often did much better...a storm like 12/30/00 would have busted 100 times worse on 12/30/90 than it did a decade later...as a whole a large area was modeled well with that despite the fact it was a tricky storm for models even in 2000 to get right.  

Yes I remember we were supposed to change to rain on western Long Island with that but it never happened.  It was a minor (positive) bust but I imagine that storm wouldn't even have been forecast to occur 10 years earlier.

Was January 2000 another bust? I remember that wasn't well forecast either.

 

[LibertyBell]

8 minutes ago, bluewave said:

The Euro has a weaker secondary in Eastern PA with 60-65 mph gusts. But the EPS has several members with a stronger secondary like the CMC. The CMC has widespread gusts over 70 mph. The stronger secondary would also turn the flow more NW behind the front with a chance of a super front producing a 50°+ drop from near 60° to single digits or low 10s. 

Thanks, I wonder what our largest temperature drops (and rises) are within a few hours.

 

[PuraVida]

Wind weenies unite!


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[LibertyBell]

12 minutes ago, bluewave said:

The Euro has a weaker secondary in Eastern PA with 60-65 mph gusts. But the EPS has several members with a stronger secondary like the CMC. The CMC has widespread gusts over 70 mph. The stronger secondary would also turn the flow more NW behind the front with a chance of a super front producing a 50°+ drop from near 60° to single digits or low 10s. 

It would be absolutely shocking to get to 8 degrees after a high of 62 like that graphic was showing.  That gradient would produce 70+ mph winds!

[Stormlover74]

1 hour ago, LibertyBell said:

Welp we didn't get much snow out of the -7.1 in Jan 1977 either lol

December 1989 should also be mentioned for being historically cold but very dry, that even had  a monumental "game time" bust of 6-8 inches being forecast and us getting nothing but rain and thunderstorms!  Warmed up right as the secondary developed and that was bust was just as big as the February 1989 bust where 6-8 inches were expected here and it was all virga lol.  That one dropped 19 inches in ACY, so we had both types of big busts in the same calendar year- a virga suppression cold bust and a rainy thundery mild bust!

 

89 had the Thanksgiving storm but December was brutal. Cold and nothing to show for it. The 15th was a cold cloudy day in the 20s with snow beginning in the early evening. Within an hour it was 40 and raining. I didn't even have weather Channel yet to figure out what the hell was going on and why it wasn't snowing as forecast. Then we warmed up just after Christmas with 3 days of rain and freezing drizzle

[LibertyBell]

8 minutes ago, Stormlover74 said:

89 had the Thanksgiving storm but December was brutal. Cold and nothing to show for it. The 15th was a cold cloudy day in the 20s with snow beginning in the early evening. Within an hour it was 40 and raining. I didn't even have weather Channel yet to figure out what the hell was going on and why it wasn't snowing as forecast. Then we warmed up just after Christmas with 3 days of rain and freezing drizzle

What I remember of that day in December 1989-- according to Craig Allen on WCBS radio who was on that evening-- the secondary formed too close to the coast?  I never knew what was going on in other parts of the country back then but found out later that DC had a very snowy December so I guess they did better than us because of suppression and Boston did better too because back then all the storms were either going south or north of us.

That Thanksgiving storm was the one bright spot that entire season-- it was a very cold and fluffy snow that started accumulating on the streets right away.

 

The reason why I said it was the mirror image bust of February 1989 was because that "storm" was cloudy, windy and seemed like it was going to snow all day-- but never saw a flake here lol.  Found out later it was 19 incher in Atlantic City and eastern Long Island got like 2-5 but nothing west of there.

For me those two busts are even worse than March 2001 because in March 2001 at least we got a few inches of snow....4-5 inches here as the storm was pulling away.

 

 

[LibertyBell]

4 minutes ago, bluewave said:

It isn’t every day we get a 5 sigma block and a 5 sigma trough at the same time. So this could be an extreme event. I would make sure that your holiday decorations are secured. 
 

 

Thanks, so did this block get down to -5 SD....I thought it was hovering in the -4 SD range?

 

[Stormlover74]

4 minutes ago, LibertyBell said:

What I remember of that day in December 1989-- according to Craig Allen on WCBS radio who was on that evening-- the secondary formed too close to the coast?  I never knew what was going on in other parts of the country back then but found out later that DC had a very snowy December so I guess they did better than us because of suppression and Boston did better too because back then all the storms were either going south or north of us.

That Thanksgiving storm was the one bright spot that entire season-- it was a very cold and fluffy snow that started accumulating on the streets right away.

 

The reason why I said it was the mirror image bust of February 1989 was because that "storm" was cloudy, windy and seemed like it was going to snow all day-- but never saw a flake here lol.  Found out later it was 19 incher in Atlantic City and eastern Long Island got like 2-5 but nothing west of there.

For me those two busts are even worse than March 2001 because in March 2001 at least we got a few inches of snow....4-5 inches here as the storm was pulling away.

 

 

I was near Philly for Christmas in 89 and they had snow on the ground. And yes Feb 89 was equally bad as far as busts. When I left for school snow was on the doorstep but hour by hour went by and nothing. I was so pissed

[LibertyBell]

8 minutes ago, Stormlover74 said:

I was near Philly for Christmas in 89 and they had snow on the ground. And yes Feb 89 was equally bad as far as busts. When I left for school snow was on the doorstep but hour by hour went by and nothing. I was so pissed

Ha at least you didn't do what I did that day which was to stay home and think I was going to watch it snow.  I used to walk 30 min to school and then walk home 30 min and I was convinced that there would be 6-8 inches on the ground at the end of the day and I didn't want to walk home in that.

 

[Brian5671]

13 minutes ago, Stormlover74 said:

I was near Philly for Christmas in 89 and they had snow on the ground. And yes Feb 89 was equally bad as far as busts. When I left for school snow was on the doorstep but hour by hour went by and nothing. I was so pissed

I grew up in Philly-we were on the northern edge of all the storms that month so we had a few inches on the ground  almost the entire time

[EastonSN+]

1 hour ago, SnowGoose69 said:

 

It appears to be a transient change to me to a GOA low or semi vortex, the GEPS/GEFS show it too D12-15 or so but it begins retrograding at the end and the ridge is beginning to build back...the EPS just seems to be slower but it too looks like it may be retrograding the trof back to the Aleutians D15=16

Yeah I took a peak at the EPS, GEPS and GEFS. Only the EPS shows a full GOA Trough while the others show it being temporary.

GEPS seems to be a good middle ground this morning FWIW.

[eduggs]

3 hours ago, bluewave said:

This is probably the first time in December that we could get a 974 mb Great Lakes cutter following a few days after a -4 AO and +PNA. So my guess is that the warming climate is causing wavelength changes that would have produced a KU event in the past. Just goes to show how past analogs from a colder era don’t work anymore.

Climate indices aren't causally connected to weather. They are only loosely correlated to weather outcomes, particularly at the local level. So even if we could forecast their state 7 days in advance, we wouldn't know for sure if we were getting a coastal storm or cutter. But of course we can't forecast the state of climate indices that well 7 days out, especially the finer details like magnitude and orientation. So we are left using climate indices in hindsight to identify correlations instead of using them in advance for prediction.

Everybody wants it to be so simple... That we move from one stable, definable weather regime to the next, and that we can see the discrete change coming. But instead of existing as a pattern, weather is characterized by a continuously changing set of features. 

[EastonSN+]

56 minutes ago, wdrag said:

and now the guidance:  Click the maps and note the further east trend in the last 12 hours and also greater consensus in the GEFS at 06z/17. Sunday morning call me wrong if the EPS warm wind south flow is still valid.  I am definitely thinking GEFS/GFS are going to be more accurate with EC and CMC to follow: That doesn't mean I'm reading this correctly.  I get leery of dismissing the GEFS. 

Thanks Walt!

Made a visit to the MA forum and the 6Z EPS definitely shifted east a bit. 

IMBY (coastal CT) already had 1.5 inches. Would gladly take a 1 to 3 incher before the rain to pad the December snowfall stats.

[eduggs]

All the degreed or professional meteorologists who study 10+ day anomaly charts and climate indices have contributed nothing to local weather prediction so far this winter. We've experienced average to below average snowfall, mostly above average precipitation, and average temperatures with slightly more extreme highs than lows but no big extremes either way.

Maybe this is a fruitful endeavor if you're forecasting drought in the western US and even if you're an energy trader... but if you're a medium range forecaster along the highly baroclinic east coast, I see very little utility studying the charts at day 10 and beyond. Maybe in the future, model skill will improve to the point of usefulness. But right now it only serves to create false expectations.

[Stormlover74]

17 minutes ago, LibertyBell said:

Ha at least you didn't do what I did that day which was to stay home and think I was going to watch it snow.  I used to walk 30 min to school and then walk home 30 min and I was convinced that there would be 6-8 inches on the ground at the end of the day and I didn't want to walk home in that.

 

I wish I could have. Or Jan 87..bare ground on the way in and nearly a foot to walk home in

[EastonSN+]

1 hour ago, EasternLI said:

If you loop the ensembles, you can see a CWB cyclonic wave break near Alaska. And the trough retrograding back towards the sea of Okhotsk. But need to see how this week plays out first I think. 

While the ensembles continue to vary on the PAC progression, all continue the blocking straight through.

[JTA66]

2 hours ago, LibertyBell said:

Welp we didn't get much snow out of the -7.1 in Jan 1977 either lol

December 1989 should also be mentioned for being historically cold but very dry, that even had  a monumental "game time" bust of 6-8 inches being forecast and us getting nothing but rain and thunderstorms!  Warmed up right as the secondary developed and that was bust was just as big as the February 1989 bust where 6-8 inches were expected here and it was all virga lol.  That one dropped 19 inches in ACY, so we had both types of big busts in the same calendar year- a virga suppression cold bust and a rainy thundery mild bust!

 

Thanks for mentioning this, should serve as a good lesson for our current pattern/snow chances. Dec '89 was probably the coldest December of my lifetime. Blocking so strong and storm track so surpassed, didn't it snow in Jacksonville FL for Christmas? And yet we still managed a rainstorm in the midst of it.

Just saying there's always a path to failure no matter how epic the pattern. On to 12z... 

[EasternLI]

20 minutes ago, EastonSN+ said:

While the ensembles continue to vary on the PAC progression, all continue the blocking straight through.

Right. And these wave breaks help reinforce it. So I think it matters what happens with this week as well. 

[Franklin0529]

Icon is 60° rainstorm 

[SnoSki14]

3 minutes ago, Franklin0529 said:

Icon is 60° rainstorm 

At this point I'll take the extreme cold front. At least it would be interesting 

[Franklin0529]

Gfs is slowly caving. Writing has been on the wall since yesterday.  This sucks man. This epic pattern we were supposedly getting is gonna yield 2 driving rain storms 

[LibertyBell]

34 minutes ago, Stormlover74 said:

I wish I could have. Or Jan 87..bare ground on the way in and nearly a foot to walk home in

I have a bad memory of that storm lol.  Got locked out of my house!  Both my parents were working and we had moved into a new house and the door was stuck frozen shut.  I was out there waiting from 3 PM to 6 PM waiting for them to come home.  I didn't know anyone in the area since we had just moved there so I just waited it out in the driveway and on the steps.

 

[Franklin0529]

[LibertyBell]

27 minutes ago, JTA66 said:

Thanks for mentioning this, should serve as a good lesson for our current pattern/snow chances. Dec '89 was probably the coldest December of my lifetime. Blocking so strong and storm track so surpassed, didn't it snow in Jacksonville FL for Christmas? And yet we still managed a rainstorm in the midst of it.

Just saying there's always a path to failure no matter how epic the pattern. On to 12z... 

Yes, we've seen it all, a favorable pattern is no guarantee of everything.

Besides the two busts from the 80s and March 2001 we also had the January 2008 bust.  I think that might have been our most recent bust where we didn't receive anything at all when we were forecast to receive heavy snow right up until the day the storm was supposed to happen.  Maybe there was something more recent-- but I don't remember it.  

[LibertyBell]

51 minutes ago, eduggs said:

Climate indices aren't causally connected to weather. They are only loosely correlated to weather outcomes, particularly at the local level. So even if we could forecast their state 7 days in advance, we wouldn't know for sure if we were getting a coastal storm or cutter. But of course we can't forecast the state of climate indices that well 7 days out, especially the finer details like magnitude and orientation. So we are left using climate indices in hindsight to identify correlations instead of using them in advance for prediction.

Everybody wants it to be so simple... That we move from one stable, definable weather regime to the next, and that we can see the discrete change coming. But instead of existing as a pattern, weather is characterized by a continuously changing set of features. 

So frustrating it almost makes you want to control the weather to create a guaranteed outcome.

[bluewave]

3 hours ago, eduggs said:

Climate indices aren't causally connected to weather. They are only loosely correlated to weather outcomes, particularly at the local level. So even if we could forecast their state 7 days in advance, we wouldn't know for sure if we were getting a coastal storm or cutter. But of course we can't forecast the state of climate indices that well 7 days out, especially the finer details like magnitude and orientation. So we are left using climate indices in hindsight to identify correlations instead of using them in advance for prediction.

Everybody wants it to be so simple... That we move from one stable, definable weather regime to the next, and that we can see the discrete change coming. But instead of existing as a pattern, weather is characterized by a continuously changing set of features. 

There are solid statistical relationships from the past when certain combinations of teleconnections were met and storm outcomes that accompanied them or lagged by weeks or even months. But the limit of these in the forecast range is about 8-10 days before we lose the useful skill. New features like the record warm pool to our east that didn’t exist when these relationships worked out have changed the equation. So marine heatwaves are altering ENSO, MJO, and teleconnection expectations in a warming climate. A -4 SD -AO and +1 PNA would produced a much colder and potentially snowy scenario rather than such a deep low tracking to our west. We get a different wavelength response now from the older days when the same numerical index values were met.

[romba]

As expected GFS puts on a collar and admits it’s all other models’ B

[LibertyBell]

3 minutes ago, bluewave said:

There are solid statistical relationships from the past when certain combinations of teleconnections were met and storm outcomes that accompanied them or lagged by weeks or even months. But the limit of these in the forecast range is about 8-10 days before we lose the useful skill. New features like the record warm pool to our east that didn’t exist when these relationships worked out have changed the equation. So marine heatwaves are altering ENSO, MJO, and teleconnection expectations in a warming climate. A -4 SD -AO and +1 PNA would produced a much colder and potentially snowy scenario rather than such a deep low tracking to our west. 

Aside from that why is it so hard to predict tracks with a reasonable degree of accuracy?  Haven't we launched multibillion dollar GOES satellites to help assist in obtaining data from data sparse regions or do we need to have regular dropsondes in those regions to obtain any kind of reasonable accuracy on storm tracks 5-7 days out?  I won't ask for beyond 7 days because that may be nearly impossible-- but 5-7 days sounds reasonable.

 

[MJO812]

Over