December 2025 OBS and Discussion

[RockawayRowdies]

Any updates for Tuesday system?

[SACRUS]

51 / 36 here.

[Brian5671]

1 hour ago, RockawayRowdies said:

Any updates for Tuesday system?

Models not great for next week-warmer and wetter but wait 6 hrs it'll change.   On a serious note we might have to wait until the 28th-29th for the pattern to fully set up

[jconsor]

1 hour ago, SACRUS said:

The NWS map looks underdone to me for eastern/central LI and eastern Connecticut. I would expect widespread gusts of 55+ mph and scattered 65-70 mph gusts.  HREF *mean* has 70 mph hugging the South Shore of Suffolk County and the Twin Forks, and HRRR is similar.   We often overperform in southerly windstorms in the winter ahead of cold fronts.


 

[wthrmn654]

1 minute ago, jconsor said:

The NWS map looks underdone to me for eastern/central LI and eastern Connecticut. I would expect widespread gusts of 55+ mph and scattered 65-70 mph gusts.  HREF *mean* has 70 mph hugging the South Shore of Suffolk County and the Twin Forks, and HRRR is similar.   We often overperform in southerly windstorms in the winter ahead of cold fronts.


 

They have dramatically upped wind amounts from Max of 40-45 mph gusts to gusts over 60 mph now. 

[wthrmn654]

SHORT TERM /MIDNIGHT TONIGHT THROUGH SATURDAY NIGHT/...

-- Changed Discussion --

Key Messages: * A strong cold front will move through near noontime on Friday, bringing strong to locally damaging winds and moderate to heavy rain, along with isolated thunderstorms. * Potential tying or record breaking temperatures early Friday fall back into the 20s Friday night, to below normal levels. Any leftover moisture may freeze if drying does not occur. Rain ahead of a cold front becomes more likely as the nighttime progresses with most of the area likely seeing rainfall by sunrise Friday. Strong low level jet lift and moisture convergence, plus a potential convective element with elevated instability, could cause the rain to be heavy at times. The heaviest rainfall likely occurs starting around sunrise with some impacts to the morning commute with the threat continuing until the cold front passes through late morning/early afternoon with a line of convectively-enhanced showers. Areas of minor/poor drainage flooding are anticipated. Flash flooding is not a concern at this point with the system pushing through fairly quickly and the liquid equivalent of any remaining snow pack is probably no more than a tenth of an inch. Still a chance of a shower in the afternoon behind the cold front, an maybe even some snow mixed in well NW of the city towards sundown. Regarding winds, an 80-90kt low level jet at 925mb shifts through much of the coastal area during Friday morning. Forecast soundings however show a strong low level inversion, so it appears that winds are going to have a tough time mixing down to the surface. It might take surface temps reaching 60 degrees to get mixing deep enough to bring down gusts strong enough for high wind warning consideration, and some spots may warm up close to this. Thinking is that about 50% of the 925mb jet winds could still mix down anyway, which translates to higher-end wind advisory gusts, but cannot completely rule out a gust or two that reaches warning criteria. Not enough confidence that the occurrence would be widespread enough to warrant a high wind warning, but will keep messaging the threat of isolated 60mph gusts in the advisory. No change to the end time of the advisory, but can`t rule out 46mph+ gusts for a couple of hours after midnight. High temperatures likely occur in the morning right ahead of the rain - generally in the mid to upper 50s. This is close to record high temperatures for the day. See the climate sections below for these records. Temps then fall somewhat with the rainfall, then fall more steadily in the afternoon with the start of cold air advection behind the front. A more rapid drop in the temperatures then happens this evening as the advection strengthens behind the front. Depending on how much winds can dry out surfaces before temps fall below freezing in the evening, there could be spots where freezing of standing water occurs. Dry weather for Friday night with high pressure building in. Winds will gradually diminish overnight. The high pressure ridge then shifts through the region Saturday afternoon and keeps us dry through Saturday night. Any precip with weak warm advection at night should remain to our north. Saturday`s high temperatures are expected to be just below normal.

 

[wthrmn654]

.TIDES/COASTAL FLOODING...

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A new moon occurring Friday evening will result in as little as 1 3/4 ft of surge causing minor coastal flooding and 2 1/2 ft causing moderate impacts. A high end gale south-southeast flow ahead of a strong frontal system will bring likelihood for widespread minor coastal flooding during the Friday morning high tide cycle for our Tri-State south facing coasts and even tidally affected rivers (Hackensack and Hudson R), with localized moderate along the southern bays of Queens and W LI. Models are in good agreement with peak winds occurring during the time of high tide for much of the region, with frontal passage occurring after high tide. This has increased the potential for widespread minor coastal flooding across vulnerable coastal locales along NY/NJ harbor, Jamaica Bay, great South Bay, twin forks of LI, and coastal Westchester/CT. Water levels will likely get close to moderate flood levels along Jamaica Bay and western Great South Bay, combined with rain and wave impacts, during morning commute, a coastal flood warning has been issued for exacerbated flood impacts. Otherwise, coastal flood advisories have been expanded into southern CT (wave action of 3-5 ft during high tide), E Bergen County and NE Suffolk County for similar reasoning as above/below. With S/SE gales ramping up through the time of high tide (favorable direction for surge along south facing coasts), high wave action onto open water coasts, and potential coincidence of heavy rain, this forecast has been leaned towards the higher end of plausible scenarios. A blend between SNAP-EX 50th percentile (NYHOPS 95th percentile), ETSS and STOFS was used. Offshore winds behind the cold front will end the coastal flood threat with subsequent high tides.

-- End Changed Discussion

[wthrmn654]

8 minutes ago, jconsor said:

The NWS map looks underdone to me for eastern/central LI and eastern Connecticut. I would expect widespread gusts of 55+ mph and scattered 65-70 mph gusts.  HREF *mean* has 70 mph hugging the South Shore of Suffolk County and the Twin Forks, and HRRR is similar.   We often overperform in southerly windstorms in the winter ahead of cold fronts.


 

They updated there afd, rather early today, and say there not confident enough to issue high wind Warnings but will be vocal of the potential. 

[wthrmn654]

Just was talking to a guy from nws on slack, his standpoint is as follows. 

Hello Michael. Current thinking is that this is a high-end advisory wind event. An isolated gust to warning thresholds is not out of the question, but a widespread warning-level event is not likely in spite of the strong winds aloft. These winds from aloft would have a tougher time reaching the surface vs some strong/high wind events we had a month or so ago. Regarding its speed. It looks like it will cross your area at roughly 1pm give or take an hour.

[wthrmn654]

In regards to a potential storm later end of month,  I need some historian help, how many times has there been some sort of snow storm around new years day/ eve? 

[winterwx21]

53 degrees here right now. Beautiful day. The cold and snow was nice, but it's also nice to have a warmer day for running outside. 

[[email protected]]

At least seven straight year of it raining at some point on NYE! Last time it snowed, I believe, was 2009.

[donsutherland1]

51 minutes ago, wthrmn654 said:

In regards to a potential storm later end of month,  I need some historian help, how many times has there been some sort of snow storm around new years day/ eve? 

[TheClimateChanger]

19 hours ago, donsutherland1 said:

Winter 2025-2026 is off to the 37th best start in terms of cold and snow in New York City. Records go back to 1869-1870.

Don, I don't put as much stock in the temperatures from the first order sites since the transition to the Vaisala sensors earlier this year. They have consistently been running between about 1-2F cooler relative to cooperative stations in every month since that change.

[donsutherland1]

7 minutes ago, TheClimateChanger said:

Don, I don't put as much stock in the temperatures from the first order sites since the transition to the Vaisala sensors earlier this year. They have consistently been running between about 1-2F cooler relative to cooperative stations in every month since that change.

I wasn't aware of that disparity. That's a pretty sizable change.

[TheClimateChanger]

1 minute ago, donsutherland1 said:

I wasn't aware of that disparity. That's a pretty sizable change.

Well, I don't have exact numbers. As far as I can find, no analysis was performed before the change. Some sort of pre-switch testing, but no systematic analyses like they had done back in the 1990s.

Just very suspicious IMO. Why are all of the airport stations (with the exception of Islip-Macarthur) so much cooler this December (so far) relative to last compared to the cooperative stations? Upton NWS office used to be the coldest by far... Shirley Brookhaven AP was always significantly warmer, now they are almost the same? Westchester even colder now?

[TheClimateChanger]

This is even more egregious, and it's been like this month after month. The airport sites (WBAN stations) were uniformly the warmest until the switch and now they are not. Notice especially PIT goes from the warmest station in the entire climate district to middle of the road, dropping from about 3F warmer than the nearby Moon Township NWS office site last December to only about 0.5F warmer this December. Note that the Emsworth site had a lot of missing data in 2024, and that's the only one warmer than the two airports. That's an unexplained 2.5F variance at the first order site versus a reliable cooperative station with no change. It's been like this every single month since the change.

[TheClimateChanger]

Just now, TheClimateChanger said:

This is even more egregious, and it's been like this month after month. The airport sites (WBAN stations) were uniformly the warmest until the switch and now they are not. Notice especially PIT goes from the warmest station in the entire climate district to middle of the road, dropping from about 3F warmer than the nearby Moon Township NWS office site last December to only about 0.5F warmer this December. That's an unexplained 2.5F variance at the first order site versus a reliable cooperative station with no change. It's been like this every single month since the change.

The crazy thing is since they switched all the airports at the same time, you wouldn't even notice a problem [except relative to your personal station] unless you compared to cooperative station data.  If you only compare to other airports, it looks legitimate. PIT is similar to AGC in both months, and warmer than BTP and AFJ. But if you look into the data, you notice PIT/AGC went from warmest by far to middle-of-the-road. BTP and AFJ went from warmer half of the distribution to among the coldest sites.

[qg_omega]

5 hours ago, MJO812 said:

[Krs4Lfe]

1 minute ago, qg_omega said:

Literal blowtorch for nearly the entire CONUS for rest of forseeable future. Absolute abysmal prospects for any cold or snow anywhere in country for next few weeks. Doesn’t show any signs of reversal either. Don’t buy BAM’s hype 

[qg_omega]

3 minutes ago, Krs4Lfe said:

Literal blowtorch for nearly the entire CONUS for rest of forseeable future. Absolute abysmal prospects for any cold or snow anywhere in country for next few weeks. Doesn’t show any signs of reversal either. Don’t buy BAM’s hype 

 

[Krs4Lfe]

3 minutes ago, qg_omega said:

 

Absolutely abysmal for any winter weather prospects. Only storminess will be heading to west coast because of the -PNA. I don’t think we should discount a January 2023 scenario. Cold and snow across conus for most of December 2022, and then late in the month we flipped to a torch and the east stayed like that for rest of winter. The west got record snowfall because of a deep -PNA

[wthrmn654]

1 hour ago, donsutherland1 said:

Shocking no major storms enough to put a damper or stop festivities in NYC area. 

[wthrmn654]

1 hour ago, [email protected] said:

At least seven straight year of it raining at some point on NYE! Last time it snowed, I believe, was 2009.

You are more annoying then Tony saying every winter storm threat will snow and "we track".

@MJO812

[Brian5671]

19 minutes ago, Krs4Lfe said:

Absolutely abysmal for any winter weather prospects. Only storminess will be heading to west coast because of the -PNA. I don’t think we should discount a January 2023 scenario. Cold and snow across conus for most of December 2022, and then late in the month we flipped to a torch and the east stayed like that for rest of winter. The west got record snowfall because of a deep -PNA

it's one run, but it's certainly possible.  Winters like 2005-06 had something similar.  Need to see if it holds or not...

[wthrmn654]

Non the less,  if the 1 met who says there's a chance of a L forming of the coast giving most east snow, is correct then snow not rain.  But I believe what he says with a grain of salt lol

 

Around new years*

[wthrmn654]

1 hour ago, [email protected] said:

At least seven straight year of it raining at some point on NYE! Last time it snowed, I believe, was 2009.

What happened?  You said 9 before, now we're down to 7?! 

[MJO812]

34 minutes ago, qg_omega said:

 

32 minutes ago, Krs4Lfe said:

Literal blowtorch for nearly the entire CONUS for rest of forseeable future. Absolute abysmal prospects for any cold or snow anywhere in country for next few weeks. Doesn’t show any signs of reversal either. Don’t buy BAM’s hype 

You two love being wrong . Keep it up. 

[MJO812]

Normal

[wthrmn654]

Big changes coming to the gfs model, new datasets, etc including AI stuff. 

 

Talking about it right now on weather channel with new guy in charge of noaa