December 2016 Discussion & Observations

[Morris]

Park 38/15 at 0z.

 

Some models had us down to close to freezing by now.

[Morris]

Dew point down 40 degrees already. From 55 to 15 in a few hours.

[dmillz25]

36 now here

[Rtd208]

Temp has fallen to 38 here.

[JerseyWx]

28° 

[Morris]

34 in the park before 10 pm. We might still sneak in a freezing day today for the monthly statistics.

[Morris]

45 minutes ago, Morris said:

34 in the park before 10 pm. We might still sneak in a freezing day today for the monthly statistics.

And we have a freeze!

32 in the park at 10:51 pm.

 

Today's massive positive departure is also getting slaughtered.

[doncat]

Sunday also saw a wide range in barometric pressure, rising from an am 29.69" to 30.49" by midnight.

[Rtd208]

Current temp down to 29

[Allsnow]

Current temp 25 

-12 in Chicago 

[Rtd208]

Current temp 25, looks like we will have to close the shades for the next couple of weeks unless something changes with the pattern in the shorter term.

[Morris]

25 in the park.

GFS was correct. Euro/Nam overdid the cold.

[PB GFI]

27 minutes ago, bluewave said:

Ensembles going with another warm up within several days of Christmas. This would make the 6th year in a row with 50's or greater

temperatures near Christmas.

NYC highs temperatures within several days of Christmas since 2011:

2015...72....2014....62....2013....71....2012...56...2011...62

 

 

Wheels up through the 10 th maybe even the 15th .

The torch is cometh.

[dmillz25]

7 minutes ago, PB GFI said:

 

Wheels up through the 10 th maybe even the 15th .

The torch is cometh.

I take it for now. Working outside in sub 25 degree is no joke. Anyways sounds like a typical January thaw to me although it's happening earlier 

[Morris]

24 in the park.

[donsutherland1]

21 minutes ago, Morris said:

24 in the park.

The December anomaly through this morning (31-24 split) is 1.6° below normal. There remains a distinct possibility that the entire cold anomaly could be wiped out by the end of the month, as the EPO+/AO+/PNA- pattern argues for warmer than normal conditions to predominate during the closing 7-10 days of the month.

[Morris]

Just now, donsutherland1 said:

The December anomaly through this morning (31-24 split) is 1.6° below normal. There remains a distinct possibility that the entire cold anomaly could be wiped out by the end of the month, as the EPO+/AO+/PNA- pattern argues for warmer than normal conditions to predominate during the closing 7-10 days of the month.

The last 10 days of the month will have to average +4.8 for the month to be N.

[donsutherland1]

3 minutes ago, Morris said:

The last 10 days of the month will have to average +4.8 for the month to be N.

That's a real possibility. Indeed, the GFS MOS MEX brings the anomaly to normal within 10 days. We'll see what happens.

[donsutherland1]

This morning, the Arctic Oscillation (AO) was +2.233. The monthly average is +0.799.

To date, 68% of days this meteorological winter have seen a positive AO and 58% of days have seen the AO at or above +1.000. Only 32% of days have seen a negative AO and 5% of days have seen the AO at -1.000 or below.

The AO remains forecast to reach +3.000 or higher in coming days. That points to a diminished likelihood of blocking in January. In years in which the second half of December saw the AO peak at +3.000 or above, positive AO days in January were 30% more frequent than climatology and days with the AO of +1.000 or above were 33% more frequent. Days with an AO of +3.000 or above were more than 60% more frequent than climatology. In contrast, days with an AO of -1.000 or below were 35% less likely than climatology and days with an AO of -3.000 or below were 55% less frequent than climatology.

In terms of numbers, December will very likely finish with 24-25 days on which the AO was positive. Based on past cases when the second-half December AO peaked at +3.000 or above, January will likely see an additional 12-20 days with an AO+. If this is representative, 36-45 of the first 62 days of meteorological winter could have a positive AO.

[doncat]

Pressure impressive at 30.75" currently.

[thunderbolt]

25 minutes ago, donsutherland1 said:

This morning, the Arctic Oscillation (AO) was +2.233. The monthly average is +0.799.

To date, 68% of days this meteorological winter have seen a positive AO and 58% of days have seen the AO at or above +1.000. Only 32% of days have seen a negative AO and 5% of days have seen the AO at -1.000 or below.

The AO remains forecast to reach +3.000 or higher in coming days. That points to a diminished likelihood of blocking in January. In years in which the second half of December saw the AO peak at +3.000 or above, positive AO days in January were 30% more frequent than climatology and days with the AO of +1.000 or above were 33% more frequent. Days with an AO of +3.000 or above were more than 60% more frequent than climatology. In contrast, days with an AO of -1.000 or below were 35% less likely than climatology and days with an AO of -3.000 or below were 55% less frequent than climatology.

In terms of numbers, December will very likely finish with 24-25 days on which the AO was positive. Based on past cases when the second-half December AO peaked at +3.000 or above, January will likely see an additional 12-20 days with an AO+. If this is representative, 36-45 of the first 62 days of meteorological winter could have a positive AO.

so what you're basically telling us Don that we should put a fork in January

[thunderbolt]

hay Don  how long do you anticipate this cycle lasting for?

[donsutherland1]

1 minute ago, thunderbolt said:

so what you're basically telling us Don that we should put a fork in January

Not necessarily for all of January. The first week and perhaps first half, unless the EPO and/or PNA become more favorable. There are a few cases with strongly positive AO regimes in the second half of December e.g., winter 2004-05, that saw strong blocking develop int he second half of January.

Unfortunately, the predominant seasonal AO cannot be forecast reliably. The appearance of severe blocking in December (or the opposite) often provides some insight for the month ahead.

[thunderbolt]

Just now, donsutherland1 said:

Not necessarily for all of January. The first week and perhaps first half, unless the EPO and/or PNA become more favorable. There are a few cases with strongly positive AO regimes in the second half of December e.g., winter 2004-05, that saw strong blocking develop int he second half of January.

Unfortunately, the predominant seasonal AO cannot be forecast reliably. The appearance of severe blocking in December (or the opposite) often provides some insight for the month ahead.

thank you for your answer greatly appreciate it

[WEATHERBUFF]

With the indices the way are seems like the coast will have a rough time with snow, being a few above average is not good...the interior is a different story.

[nzucker]

3 hours ago, Allsnow said:

Current temp 25 

-12 in Chicago 

It's -11F at Aurora Airport outside Chicago right now, they had a low of -18F last night. 

Much of Oklahoma and Texas was also in the single digits and low teens. We missed the extreme cold by a few hundred miles; it was coldest to the northeast last Thurs/Fri as the PV passed over Quebec and Maine, then coldest in the Southern/Central Plains this weekend. 

[psuhoffman]

52 minutes ago, WEATHERBUFF said:

With the indices the way are seems like the coast will have a rough time with snow, being a few above average is not good...the interior is a different story.

The indices were looking at are not good for the interior either, unless  your talking interior new england and upstate NY MAYBE, and even there it will be dicey in this pattern with some storms cutting enough to rain there.  But anyone in the east south of upstate NY this patter sucks.  Remember some of the places in the Interior average much more snow, so yea they might get some snow as opposed to nothing on the coast but if a place in the Poconos that averages 60" ends up with 30" that's just as bad as if NYC ends up with 13" for the season with regards to averages.  Bottom line this pattern pretty much sucks interior or coast. 

[nzucker]

2 minutes ago, psuhoffman said:

The indices were looking at are not good for the interior either, unless  your talking interior new england and upstate NY MAYBE, and even there it will be dicey in this pattern with some storms cutting enough to rain there.  But anyone in the east south of upstate NY this patter sucks.  Remember some of the places in the Interior average much more snow, so yea they might get some snow as opposed to nothing on the coast but if a place in the Poconos that averages 60" ends up with 30" that's just as bad as if NYC ends up with 13" for the season with regards to averages.  Bottom line this pattern pretty much sucks interior or coast. 

Binghamton, NY already has 53" snowfall this season; they only need about 30" more to reach average. With the November 20th cold front and subsequent lake effect event, the Dec 15-16 arctic front/LES, and the Dec 17 SWFE followed by the 1040mb high last night, it's been a very active winter for much of the interior. It's quite unlikely that the interior will not reach average snowfall this season due to the strong start. Things might slow down for a while but it's only December 19th. I'd imagine the pattern flips back to cold around January 10th; the late winter could be snowy, too, as all models start to weaken the La Nina. That could shift us towards a more Niño-like Pacific with a -EPO/Aleutian Low pattern. 

[WEATHERBUFF]

40 minutes ago, psuhoffman said:

The indices were looking at are not good for the interior either, unless  your talking interior new england and upstate NY MAYBE, and even there it will be dicey in this pattern with some storms cutting enough to rain there.  But anyone in the east south of upstate NY this patter sucks.  Remember some of the places in the Interior average much more snow, so yea they might get some snow as opposed to nothing on the coast but if a place in the Poconos that averages 60" ends up with 30" that's just as bad as if NYC ends up with 13" for the season with regards to averages.  Bottom line this pattern pretty much sucks interior or coast. 

Poconos and northeast Pa will be ok, especially elevations over 1000 ft. There is I agree chances of mixed precipitation and snow to rain scenario. Some parts of northeast Pa average over 80 inches of snow a year, although last year it was less than 30 inches. We had over 25 inches of snow already while Binghamton has had close to 50 inches.while Philly had had an inch or less so far.

[WEATHERBUFF]

40 minutes ago, nzucker said:

Binghamton, NY already has 53" snowfall this season; they only need about 30" more to reach average. With the November 20th cold front and subsequent lake effect event, the Dec 15-16 arctic front/LES, and the Dec 17 SWFE followed by the 1040mb high last night, it's been a very active winter for much of the interior. It's quite unlikely that the interior will not reach average snowfall this season due to the strong start. Things might slow down for a while but it's only December 19th. I'd imagine the pattern flips back to cold around January 10th; the late winter could be snowy, too, as all models start to weaken the La Nina. That could shift us towards a more Niño-like Pacific with a -EPO/Aleutian Low pattern. 

My feelings also about the pattern. It may get better for coastal areas and south of 40 crowd, but I feel they at best will end up near average.