December Pattern Disco- 2013

[CoastalWx]

Very similar Will. All good months.

[CoastalWx]

As long as Canada keeps getting restocked like it shows and the cold stays on this side it's going to be a fun run.

 

No complaints from me on those maps. BTW, week 2 and week 3 had above normal QPF too. I just checked.

[ORH_wxman]

As long as Canada keeps getting restocked like it shows and the cold stays on this side it's going to be a fun run.

 

 

I don't think I've seen Canada as cold as it was on the weeklies the past few years. Double digit negative departures over a vast area. Pretty bullish/confident for a week 3 forecast. We'll see how it plays out.

[TauntonBlizzard2013]

As long as Canada keeps getting restocked like it shows and the cold stays on this side it's going to be a fun run.

Hey as long as we have chances I'll take a cutter or two if were going to get some appreciable snow. You take that trade off 10 times out of 10

[ORH_wxman]

No complaints from me on those maps. BTW, week 2 and week 3 had above normal QPF too. I just checked.

 

 

Its hard to have a gradient pattern without storm systems riding the baroclinic zone between the two airmasses. The composite precip anomalies for those years I showed illustrates that well:

 

[Ginx snewx]

The map reminded me of this composite:

could add 1995 and 2010 to that

[ORH_wxman]

could add 1995 and 2010 to that

 

 

No, it doesn't look like those years...those years were too cold in the southeast. 2010 was the coldest December on record for states like Gerogia and Florida...the weeklies are warm there like the years above.

 

 

edit: here is December 2010

 

[Ginx snewx]

No, it doesn't look like those years...those years were too cold in the southeast. 2010 was the coldest December on record for states like Gerogia and Florida...the weeklies are warm there like the years above.

 

 

edit: here is December 2010

 

Yea my bad, great look on your maps

[Ginx snewx]

The map reminded me of this composite:

Dec 1970 was my first year of recording daily weather and making hand drawn weather maps at age 13

[ORH_wxman]

Yea my bad, great look on your maps

 

 

The Aleutian ridge is similar to 2010, but the huge difference is we had an absolute monster -NAO...and this year is the opposite. So without the big -NAO to drive the cold anomalies southeastward, we generally get a gradient pattern...esp with a -PNA which will want to produce a SE ridge in conjunction with the +NAO. Dec 1970 had a -NAO (but 2008/2007 didn't), however, the -PNA in 1970 was stronger so it was able to overpower the -NAO and produce a SE ridge anyway....though it was weaker than the other two years.

[CoastalWx]

Its hard to have a gradient pattern without storm systems riding the baroclinic zone between the two airmasses. The composite precip anomalies for those years I showed illustrates that well:

Yep and it's why I told Brian987654321 that I was absolutely not worked at all about QPF. His worry may turn to ptype.

[CoastalWx]

No, it doesn't look like those years...those years were too cold in the southeast. 2010 was the coldest December on record for states like Gerogia and Florida...the weeklies are warm there like the years above.

edit: here is December 2010

Not hard to see what the height pattern may have looked like on that map.

[TauntonBlizzard2013]

Weeklies say gradient pattern here we come. For now we are just cool enough..like -1 to -2 avg for week 3 and 4. Strong dateline ridging.

Do gradient patterns usually swing one way or the other ( rain vs snow). Or will it differ week to week or even storm to storm?

You've said you've liked this look, so I just wanted to get a feel for which way it Tends to lean

[Ginx snewx]

The Aleutian ridge is similar to 2010, but the huge difference is we had an absolute monster -NAO...and this year is the opposite. So without the big -NAO to drive the cold anomalies southeastward, we generally get a gradient pattern...esp with a -PNA which will want to produce a SE ridge in conjunction with the +NAO. Dec 1970 had a -NAO (but 2008/2007 didn't), however, the -PNA in 1970 was stronger so it was able to overpower the -NAO and produce a SE ridge anyway....though it was weaker than the other two years.

Dec 70 was an epic month, seemed like it snowed every other day from about the 12 th on, lots of overrunning and redevelopers.

[CoastalWx]

Do gradient patterns usually swing one way or the other ( rain vs snow). Or will it differ week to week or even storm to storm?

You've said you've liked this look, so I just wanted to get a feel for which way it Tends to lean

I like the overall look, but I will say this...it's a gradient pattern because a strong thermal gradient will exist over the east and likely very near us. This means that we could be dealing with ptype issues, especially as one moves south. Gradient patterns sometimes favor latitude vs longitude which is why BOS beat out people like Kevin back in 2007 and 2008. Well 2007 may have been close but definitely 2008. In CT it wasn't the surface temps, but rather warm temps aloft that snuck in and changed many over to sleet.

So, don't get bummed out if that happens. If the ridge is poleward enough then you may not have much to worry about, but these nuances just cannot be determined this far out. A -NAO would also keep the storm track south, but we will have a +NAO just like in the composite Will showed. The storm track can change a bit from week to week, but what seems to happen is that we get a 10-14 day period where we get storm after storm. That's how BOS got near 30" in Dec 2007 and Dec 2008. This year seems like the cold will ooze down especially after week 1 in December to perhaps set the stage.

[ORH_wxman]

Dec 70 was an epic month, seemed like it snowed every other day from about the 12 th on, lots of overrunning and redevelopers.

 

Here was the pattern during the epic 14 days where BOS picked up most of their 27.9" of the month

 

 

 

 

 

 

 

 

Now here is the epic periods in 2007 and 2008 that produced the big snows:

 

 

 

 

 

 

 

It's actually pretty creepy how similar those two composites are.

[TauntonBlizzard2013]

I like the overall look, but I will say this...it's a gradient pattern because a strong thermal gradient will exist over the east and likely very near us. This means that we could be dealing with ptype issues, especially as one moves south. Gradient patterns sometimes favor latitude vs longitude which is why BOS beat out people like Kevin back in 2007 and 2008. Well 2007 may have been close but definitely 2008. In CT it wasn't the surface temps, but rather warm temps aloft that snuck in and changed many over to sleet.

So, don't get bummed out if that happens. If the ridge is poleward enough then you may not have much to worry about, but these nuances just cannot be determined this far out. A -NAO would also keep the storm track south, but we will have a +NAO just like in the composite Will showed. The storm track can change a bit from week to week, but what seems to happen is that we get a 10-14 day period where we get storm after storm. That's how BOS got near 30" in Dec 2007 and Dec 2008. This year seems like the cold will ooze down especially after week 1 in December to perhaps set the stage.

Cool, appreciate you taking the time. Interesting how such small changes in latitude and longitude in this type of pattern can have such huge effects.

Living in taunton I know it'll rain at points during the winter. I'm okay with that, as long as we get our fair share of snow.

[mahk_webstah]

If we get that pattern, you can keep the -NAO away.  That would seem to be a big winner up here with regular snow events, every few days.  That is the kind of weather I like vs. the more rare big coastal.  I like repeated snow on snow, even if its only 4-8 at a time.  Once you have 15 inches on the ground an 8 inch feels and looks like a big storm to me.

[Ginx snewx]

Here was the pattern during the epic 14 days where BOS picked up most of their 27.9" of the month

Now here is the epic periods in 2007 and 2008 that produced the big snows:

It's actually pretty creepy how similar those two composites are.

split PV

[Heisy]

Ouch. Road trip to Oregon anyone? 

 

The Euro ensembles say that OP is way too overdone, but this would add some + anomalies for December. 

 

[Damage In Tolland]

Looks like 00z runs still have the light snow Sunday into Monday..Thoughts from mets? Can we sneak an inch or 2?

[CoastalWx]

It's possible. It does warm aloft during that time but if we can get some light snow from what may be a Cstl front moving west and moisture from the south....perhaps.

[Harry]

Here was the pattern during the epic 14 days where BOS picked up most of their 27.9" of the month

 

 

 

 

 

 

 

 

Now here is the epic periods in 2007 and 2008 that produced the big snows:

 

 

 

 

 

 

 

It's actually pretty creepy how similar those two composites are.

 

 

The huge difference can be found out this way.. As far as snowfall goes anyways.. Dec 07 with 20 inches while Dec 08 with about 40 inches vs 1970 with only 4.0... The main difference between Dec 07 vs 08 was the lake helped out a bit more in Dec 08 and less mixed/more snow events.. Both were hyper active though.. Dec 08 was the coldest of the 3 around here.

[Damage In Tolland]

It's possible. It does warm aloft during that time but if we can get some light snow from what may be a Cstl front moving west and moisture from the south....perhaps.

How do Ens look Dec 1-15?

[CoastalWx]

How do Ens look Dec 1-15?

Gradient like. We walk the line here. GEFS were colder.

[Damage In Tolland]

Gradient like. We walk the line here. GEFS were colder.

But nothing like the Euro op right? That's really importnt

[CoastalWx]

But nothing like the Euro op right? That's really importnt

It does support a mild period like the op but the signal is a little more muted.

[weathafella]

The op extremes though are silly. Now often do we see costa OR/WA that cold and potentially snowy. It does happen bit usually more into the heart of winter.

I remember December 1993 with a cold plunge I to the west like that progged. In the end a much more favorable pattern (for us) developed. Also, the big warmth progrged frequently over this past month failed. I'm liking where we're sitting today.

[Damage In Tolland]

The op extremes though are silly. Now often do we see costa OR/WA that cold and potentially snowy. It does happen bit usually more into the heart of winter.

I remember December 1993 with a cold plunge I to the west like that progged. In the end a much more favorable pattern (for us) developed. Also, the big warmth progrged frequently over this past month failed. I'm liking where we're sitting today.

Yeah i have a feeling some of these "mild forecasts" we're seeing popping up for next week are going to end up incorrect..I know yesterday Will said the Euro ens had trended colder for the wintry threat early/middle of next week

[ORH_wxman]

Yeah i have a feeling some of these "mild forecasts" we're seeing popping up for next week are going to end up incorrect..I know yesterday Will said the Euro ens had trended colder for the wintry threat early/middle of next week

 

 

00z run trended back warmer...but its still one to keep an eye on. But I wouldn't expect anything out of it right now. Dec 2-6 is going to be the mildest period most likely of the next 10-12 days after tomorrow.