December Obs & Discussions

My my. 7 degrees this morning

19* for my low tis morning - BRRRRR - deep winter feel with a majorly snow covered landscape

24* low for this morning..

Was 27 here not sure we have been that low at 8am yet here. Still pretty cold now.

At mid month we are running at or slightly BN temps.  I expect BN for the month and think that will hold.  The snowfall of at least 4" I was saying for NYC very much in jeopardy as it stands at nothing along with a lot of the I95. I'm not sure there's a recorded case of -4 sigma AO in December and no measurable snowfall at Central Park during December.  

Finally some sun. 37 degrees. Looks like 22nd will be s high impact rain snd wind storm. I just can't get over that no one on this board is likely to.see snow except light snow posdible on the back end. I'm hoping that it is not being sampled properly yet but I'm 90% sure we sol.

Hoping that there is actually some backend snow with the artic front

phil155 wrote:Hoping that there is actually some backend snow with the artic front

yeah but with the Temps and several inches rain it likely won't stick.

From Donald Sutherland on American Weather referring to NYC Central Park snowfall when the AO in December averaged <= -2.0 which is probably going to be this month.  It's not huge sample sets, but enough that this would be very unusual to not have decent December snowfall totals.  Still have time in December but models ATTM are saying more likely than not to break this. Possible shutout or close to shutout.  We shall see.

The lowest December snowfall when the AO averaged -2.000 or below was 5.1" in 1976. Total seasonal snowfall was 24.5". There is a chance that the December 1976 record futility could be surpassed this month.

jmanley32 wrote:

phil155 wrote:Hoping that there is actually some backend snow with the artic front

yeah but with the Temps and several inches rain it likely won't stick.

Agreed but still hoping

phil155 wrote:Hoping that there is actually some backend snow with the artic front

In this frame we got this mid-level energy that's offshore and the 500mb trough hasn't cleared the coast.  If we can get a stronger wave then maybe some enhanced snow can fall from that. I am not a believer in any front end snow with this threat whatsoever due to the ridge being pulled down from the NAO block. The issue with these as usual is the speed at which they move at.  

While it looks increasingly like a sure-thing that this Thursday storm will be rain, I think there is a slight chance with that very potent cold air pouring into the region Friday into Saturday that we could see some snow flurries/showers. It wouldn’t be much, but maybe some Christmas Eve mood flakes?
One thing is for sure, the weather next weekend -snow or no - will be much colder than is typical at Christmas, so it will feel plenty wintry.

billg315 wrote:While it looks increasingly like a sure-thing that this Thursday storm will be rain, I think there is a slight chance with that very potent cold air pouring into the region Friday into Saturday that we could see some snow flurries/showers. It wouldn’t be much, but maybe some Christmas Eve mood flakes?
One thing is for sure, the weather next weekend -snow or no - will be much colder than is typical at Christmas, so it will feel plenty wintry.

Cold without snow I would rather have warm temps. Bring the cold with the snow.

Hi... Introducing myself as Walt Drag-retired NWS and private sector AQWX, WSC,WXCORP.  I'd like to add info about the recent GFS change on 11/30.  

I want to make sure this gets noticed: by all who have interest in GFS model snow fall in the United States.  The model update on 11/30/22 I think is resulting in improved snowfall prediction. It certainly was a cyclically very good performer here in the I84 corridor coverage for 12/15-16. It's picking up on warm ground and elevations better.

I'd like to attach some snapshots of a recent NCEP meeting but can't seem to find the method.  In short: 10x1 snow ratios don't work very well in 1000-500MB thickness above 540 DM,  and not very well in snow-sleet (both greatly inflated). Instead it is recommended for the GGS to now consider Positive Snow Depth Change as a potential better ballpark solution.

Note: Using 10 to 1 is not going to be a consistently good approach, especially warm thickness (1000-500MB 540DM or higher) snows and/or temps 32-34F. This presentation also references Tropical Tidbits Positive Snow Depth Change (SNOD in NCEP language).

Hi Walt!  Great to see you post here as many have seen you from American Weather Forums.  The positive snow depth on the GFS was spot on for last storm.  The 10:1 showed 1' of snow in some of the LHV areas, but the positive snow depth was a few inches and verified for the most part.  This is the post that showed the maps.

WDrag wrote:Hi... Introducing myself as Walt Drag-retired NWS and private sector AQWX, WSC,WXCORP.  I'd like to add info about the recent GFS change on 11/30.  

I want to make sure this gets noticed: by all who have interest in GFS model snow fall in the United States.  The model update on 11/30/22 I think is resulting in improved snowfall prediction. It certainly was a cyclically very good performer here in the I84 corridor coverage for 12/15-16. It's picking up on warm ground and elevations better.

I'd like to attach some snapshots of a recent NCEP meeting but can't seem to find the method.  In short: 10x1 snow ratios don't work very well in 1000-500MB thickness above 540 DM,  and not very well in snow-sleet (both greatly inflated). Instead it is recommended for the GGS to now consider Positive Snow Depth Change as a potential better ballpark solution.

Note: Using 10 to 1 is not going to be a consistently good approach, especially warm thickness (1000-500MB 540DM or higher) snows and/or temps 32-34F. This presentation also references Tropical Tidbits Positive Snow Depth Change (SNOD in NCEP language).

Welcome and thank you very much for sharing this important piece of information with us. I personally was not aware of the change but it looks like it could have a big impact.

heehaw453 wrote:Hi Walt!  Great to see you post here as many have seen you from American Weather Forums.  The positive snow depth on the GFS was spot on for last storm.  The 10:1 showed 1' of snow in some of the LHV areas, but the positive snow depth was a few inches and verified for the most part.  This is the post that showed the maps.

Although it’s good to see the model verify, I never believed in those ridiculous amounts…H5 ULL was to our N&W.

28 degrees, clear, calm winds.
In a final insult by this terrible pattern, NWS has removed the 40% chance of snow showers for Friday night thereby eliminating any chance of a White Christmas.
"You're a mean one, Mr.Grinch......."!

docstox12 wrote:28 degrees, clear, calm winds.
In a final insult by this terrible pattern, NWS has removed the 40% chance of snow showers for Friday night thereby eliminating any chance of a White Christmas.
"You're a mean one, Mr.Grinch......."!

lol I was looking forward last week for snow on Christmas with our luck it would probably snow on Easter

Walt!! Welcome aboard and thaks so much for posting here and bringing us your insight!
Love to hear your coments and outlooks down the road my man!!

This is just unreal:

Snow lovers in the East hearing this in their heads as we watched the trend west past few days pic.twitter.com/gLs5gblSHB

— Ralphs Weather OBS (@WeatherNut27) December 20, 2022

And that Cape May will be in the mid 20's whilst up in NNJ it'll be in the mid to upper 40's. This is really wild and an arctic front that swings SW to NE is something I HAVE NEVER SEEN in my 40 plus years of following weather.


Arctic front keeps speeding up which the models are starting to pick up  on and may bring some back end snow showers with temps crashing 30 degrees in ~ 3 hours. May stick to colder surfaces...any snow is good snow peeps.

It's not impossible for some to have a white Christmas.  The GEFS is showing that possibility consistently further west.  Anything that falls will stick around.  

Big time temperature drop associated with this late week cold front - temperatures falling as much as 30° F in 3 hours as the front sweeps eastward. Impressive stuff. pic.twitter.com/RimnO6tl94

— John Homenuk (@jhomenuk) December 20, 2022

Cool visual

heehaw453 wrote:It's not impossible for some to have a white Christmas.  The GEFS is showing that possibility consistently further west.  Anything that falls will stick around.  

The secondary that pops coould surprise some in the far Western areas and maybe N areas as teh storm deepens and wraps up. This secondfary LP needs to slow up by a few more hours and allow that arctic front to press in quicker!! It keeeps making ticks east, we'll see by mood flakes are always welcomed!!!

Real possibility for our shore folks

With the new moon and increasing SE winds, we will have to monitor high tides along around NY Harbor and other south/east facing shores on Friday morning. Moderate to locally major coastal flooding is possible. #nywx #njwx #ctwx pic.twitter.com/1pmqtSc3wX

— Miguel Pierre (@mpierre19) December 20, 2022

Currently 33* low of 28* this morning. Welcome Walt.

Welcome, Walt.

The temps will go down fast on Fri thus wind. What are we looking at?30-40 mph gusts?

I don't think the possibility of snow showers on the back-side of this system is off the table at all with the cold air that will be crashing in. May not accumulate much in some areas, but I think you could see some scattered flakes flying at the end even down to the coast.

If the GFS is to be believed there's a lot of mid-level energy swinging through as the 500mb trough is pushing through and crashing temps.

The temps won't be an issue at the mid and lower levels.  The surface would be the last to crash and of course that's the one that affects accumulations.  This is a lot of mid-level moisture that would have to swing through.  No question there would be minor accumulations NW of 95 with this setup.