E PA/NJ/DE Winter 2025-26 Obs/Discussion

[ChescoWx]

2 minutes ago, PhiEaglesfan712 said:

Just like I did on 3/29/2025, when in doubt, go the the NWS, which says too warm for snow:

Christmas Day

A chance of rain before 1pm. Cloudy, with a high near 44. Chance of precipitation is 30%.

Thursday Night

A chance of rain after 1am. Cloudy, with a low around 39. Chance of precipitation is 30%.

Friday

Rain likely. Cloudy, with a high near 57. Chance of precipitation is 70%.

Friday Night

A chance of rain before 1am. Mostly cloudy, with a low around 39. Chance of precipitation is 30%.

Saturday

Mostly cloudy, with a high near 51.

Saturday Night

A chance of rain. Mostly cloudy, with a low around 39. Chance of precipitation is 30%.

Sunday

A chance of rain. Mostly cloudy, with a high near 51. Chance of precipitation is 40%.

I suspect that high near 57 on Friday will be coming down significantly later today...

[ChescoWx]

Below normal temperatures look to continue through at least Christmas with some models now hinting at significantly colder weather than currently forecast for Friday. We do have a chance of some light snow, sleet and freezing rain arriving tomorrow morning. While amounts will be light the timing near rush hour could be a potential problem. We should dry out by tomorrow afternoon. Christmas Eve Day looks sunny. Plenty of uncertainty regarding both temperatures and precipitation by Christmas Day and Boxing Day.

[ChescoWx]

The latest European for Friday.....a wee bit different from prior model runs.

[ChescoWx]

From Meteorologist Bobby Martrich on these huge changes to Friday

"Last 4 runs of the GFS are comical... and it's not alone with this idea of a colder day Friday - just after Christmas. Much colder in fact, so instead of 50s you cut 25° off the high temps and get frozen precip, not rain. This goes back to the prior video discussions where I talked about models struggling in seasonal transition and being overzealous about the supposed "torch" pattern. If you're on the colder side of that thermal gradient, it's a much different outcome. This is the result of models completely whiffing on the extent of blocking in the Northern Atlantic and Atlantic Canada and a much stronger Quebec high providing the cold air damming. While we need to see this apparent trend to continue to alter the forecast, the Friday forecast could look much different if it does."

[PhiEaglesfan712]

80 degrees on 3/29/2025 was the best model forecast of the year: 

 

[RU848789]

Nice NWS-Philly discussion of the possible 12/26 event.  Would love to score a "surprise" snowfall on Friday.  

Area Forecast Discussion
National Weather Service Mount Holly NJ
546 AM EST Mon Dec 22 2025

Beyond Christmas Day, forecast uncertainty becomes very high.
Guidance indicates there will be a high over eastern or
southeastern Canada with low pressure moving eastward across the
Great Lakes and toward the Northeast or Mid Atlantic. This
setup will likely bring precipitation to our area. The 00Z suite
of guidance had a significant change in course, indicating a
much stronger high and weaker, more suppressed low. This
solution would introduce potential for wintry precip for our
region and much colder temperatures, quite the change from
widespread 50s and rain from before. The shift in guidance was
consistent between different models. GFS, ECMWF, and CMC all
showing this much colder, wintry solution now, however given
this *very* recent change in course, have stuck with NBM for now
until there is more consistency in a colder, more wintry
solution. Precipitation is still likely, with 50-80% PoPs,
however we could be dealing with all rain, a significant wintry
system, or anything in between. Remain alert for changes to the
forecast for the Friday timeframe.

[Duca892]

Not smart enough to definitively tell but i believe the GFS went north a bit?

 

[Ralph Wiggum]

Pretty notable shifts on the CMC past 4 runs:

[The Iceman]

I'm not confident to speak either way on Friday, good trends though. Gut thinks it's more mess than white though.

[penndotguy]

3 hours ago, ChescoWx said:

The latest European for Friday.....a wee bit different from prior model runs.

I’ll sacrifice Rain over Ice any day, Especially .25 and over. 

[Ralph Wiggum]

46 minutes ago, The Iceman said:

I'm not confident to speak either way on Friday, good trends though. Gut thinks it's more mess than white though.

I agree with this. Definitely not a clean flush hit, at least not appearing that way right now.

Ironically, the gefs mean is colder and snowier with a mean snowfall totals of 5" here in central bucks.

[jwilson]

13 UTC NBM still favors odds of rain-to-snow 55:20 at maximum rain potentiality, but it closed the gap a decent amount from a peak of 66:4 at 7 UTC.

In other words, there was a clear cold trend.  It also now favors snow early on the day Friday, 34:28, as opposed to the 66:13 rain-favored odds from the run before.

A mix is a good call right now unless the trend continues.

[Kevin Reilly]

1 hour ago, Ralph Wiggum said:

Pretty notable shifts on the CMC past 4 runs:

Hmm how about that 12z gfs

[LVblizzard]

GFS is really the only model showing a lot of snow for this area…most other guidance has a big mid-level warm nose and lots of IP/ZR. Trend has been our friend over the last day though, so we’ll see if that continues.

[Birds~69]

Ryan Hall, Y'all and the GFS...