Central PA Winter 25/26 Discussion and Obs

[paweather]

1 minute ago, Itstrainingtime said:

WTF?

He had too much to drink 

[pasnownut]

18 minutes ago, paweather said:

He had too much to drink 

I'm just getting started. lol

 

[pasnownut]

well boys n girls how happy will the next hour(ish) be?

we'll start off by adding the ICON to the thursday party.  Mostly northers....but its now popped a SLP and norther 1/2 gets snow. Pops around somerset and traverses pa to Mt. Pocono.  

as we are almost approaching mid term w/ models it'd be nice to get them all to show something for thursday....or not.  Headed out shortly w/ the mrs for some grub.  Will check in later.

 

[paweather]

18z GFS took a bit of a step back but not bad.

 

[Blizzard of 93]

Just now, paweather said:

18z GFS took a bit of a step back but not bad.

 

Yes, but I would still gladly sign for it.

[mahantango#1]

DT: WILL DO A NEW SHORT VIDEO THIS EVENING ABOUT JAN 15-16.

 

The last few runs on the operational GFS continued develop a huge snowstorm for the middle I thank New England coast. the model not me but the model is showing something like the January 2016 blizzard or Something like the 1909 or 1922 blizzards on the Mid-Atlantic coast. it's a very extreme solution. it's not out of the question but most of the data is against that kind of massive system.

 

 on the other hand the upper level energy on the 12z Saturday midday European model has taken a big step towards the GFS idea of a big Mid-Atlantic winter storm on January 15

[paweather]

3 minutes ago, Blizzard of 93 said:

Yes, but I would still gladly sign for it.

I would sign as well

[paweather]

CTP won’t update 

[mahantango#1]

13 minutes ago, paweather said:

CTP won’t update 

6pm they will.

[Blizzard of 93]

Decent 18z Euro run for the 15th chance.

[paweather]

18z EURO and GFS one in the same it appears. Both are decent

[Blizzard of 93]

1 hour ago, mahantango#1 said:

6pm they will.

Lol, they updated it with No update. Their forecast discussion says updated 723 pm, but it must have been just a short term update. 
No mention in the discussion or grids of Thursday or Friday storm chances.

It’s going to be a shock to some of the general population if the GFS or Euro were to verify.

[pasnownut]

2 hours ago, mahantango#1 said:

6pm they will.

6pm Wednesday. 

[Blizzard of 93]

Thankfully Mt. Holly had a good update this evening on their discussion…

KEY MESSAGE 3...Potential for a coastal storm Thursday and/or
Friday. Impacts/details are very uncertain as these will depend on
how close to the coast the low tracks.

For Thursday and Friday, the upper air pattern is forecast to become
more amplified across the East. The sharpening of an upper-level
trough will develop a storm, however the details are much less
certain at this time. The model consensus is pointing toward a
storm, however whether this will become a coastal storm or one that
simply goes out to sea is the forecast challenge. Some guidance
suggests a significant winter storm while others are a miss. If the
southern energy can remain out ahead of the northern stream energy
along with a trough axis more neutral or becoming negatively tilted,
then the surface low would tend to be closer to the coast. The
guidance that has more of a positive tilted upper-level trough shear
the system northeastward and keeps it out to sea. The closer to the
coast scenario would favor more precipitation westward across our
region, with the timing either Thursday or Friday. Given the wealth
of uncertainty in the details, did not alter the forecast away from
the NBM guidance. This continues to show low chances for now of rain
and/or snow Thursday and Thursday night, however it currently is dry
for Friday. If some of the guidance is correct, then PoPs would need
to be added/increased for Friday. A colder air mass is forecast to
be in place at the of next week and to start next weekend.

[paweather]

9 minutes ago, Blizzard of 93 said:

Thankfully Mt. Holly had a good update this evening on their discussion…

KEY MESSAGE 3...Potential for a coastal storm Thursday and/or
Friday. Impacts/details are very uncertain as these will depend on
how close to the coast the low tracks.

For Thursday and Friday, the upper air pattern is forecast to become
more amplified across the East. The sharpening of an upper-level
trough will develop a storm, however the details are much less
certain at this time. The model consensus is pointing toward a
storm, however whether this will become a coastal storm or one that
simply goes out to sea is the forecast challenge. Some guidance
suggests a significant winter storm while others are a miss. If the
southern energy can remain out ahead of the northern stream energy
along with a trough axis more neutral or becoming negatively tilted,
then the surface low would tend to be closer to the coast. The
guidance that has more of a positive tilted upper-level trough shear
the system northeastward and keeps it out to sea. The closer to the
coast scenario would favor more precipitation westward across our
region, with the timing either Thursday or Friday. Given the wealth
of uncertainty in the details, did not alter the forecast away from
the NBM guidance. This continues to show low chances for now of rain
and/or snow Thursday and Thursday night, however it currently is dry
for Friday. If some of the guidance is correct, then PoPs would need
to be added/increased for Friday. A colder air mass is forecast to
be in place at the of next week and to start next weekend.

Lots of time things will change 

[canderson]

At least something to track 

A very windy Sunday ahead

[MAG5035]

5 hours ago, mahantango#1 said:

DT: WILL DO A NEW SHORT VIDEO THIS EVENING ABOUT JAN 15-16.

 

The last few runs on the operational GFS continued develop a huge snowstorm for the middle I thank New England coast. the model not me but the model is showing something like the January 2016 blizzard or Something like the 1909 or 1922 blizzards on the Mid-Atlantic coast. it's a very extreme solution. it's not out of the question but most of the data is against that kind of massive system.

 

 on the other hand the upper level energy on the 12z Saturday midday European model has taken a big step towards the GFS idea of a big Mid-Atlantic winter storm on January 15

 

It’s certainly a bit of a long shot but the big storm option is definitely on the table. There’s a lot of energy dropping in amplify this trough and it’s darn near an all out phase and explode type east coast storm. I have the 18z solutions below and you can see the distinct shortwaves lined up, but still on a positive trough axis. The trough eventually goes negative but it’s takes time and doesn’t seem to phase features cleanly/completely, which still yields some kind of event but not a storm of the nature that has occasionally been thrown out by mainly the GFS. 

Some things to consider, regardless of any eventual storm evolution this looks to be a fairly potent trough and closed 500mb low that develops over or just under PA. I think that alone will probably generate a swath of snows somewhere in central and/or eastern PA as the trough goes negative. 

Another thing to consider is temps. Tomorrow will be cold and windy but this is a quick cold shot that moderates rapidly for the first half of the week. Temps will likely be mild (5-10ºF above normal) first half of the week right up to the early stages of this digging trough and associated coastal potential. If we do get a storm it will be preceded by mild to marginal temps, esp in the Sus Valley. So when it’s probably 50ish there the day before, don’t be surprised. 

[pasnownut]

here you go.  Fresh off the CTP press.  Boy their distain for snow/cold is slightly obvious.

Area Forecast Discussion
National Weather Service State College PA
1035 PM EST Sat Jan 10 2026

.WHAT HAS CHANGED...
* Added mention of SNSQs in the wx grids for 14-19Z Sun

&&

.KEY MESSAGES...
1) Snow accumulation /and possibly a few squalls/ expected
across the western highlands Sunday. A few snow showers could
even make it into eastern Pennsylvania Sunday afternoon. Wind
picks up behind a broken line of snow showers/squalls.

2) Quieter wx for Mon-Tues. Warmer than normal for Tues-Wed.

3) Still a possibility for a low pressure area to develop later
in the week over the Mid-Atlantic. But, many factors are in
question.

[paweather]

0z GFS holds serve

[pasnownut]

11 minutes ago, paweather said:

0z GFS holds serve

im liking the trough axis and see the 500 lp looking a little sharper/neg tilt. this delays the real deal a bit, but might be worth the wait moving forward (if this look continues to hold).  

gnight all.  

[Mount Joy Snowman]

Packers have me a broken man. I need snow to lift me up. 

[anotherman]

Packers have me a broken man. I need snow to lift me up. 

It reminded me of some of the Eagles games this year. Dominating first half, and then the offense is completely garbage in the second half and the defense eventually gets tired and loses the game.

[Voyager]

5 hours ago, MAG5035 said:

If we do get a storm it will be preceded by mild to marginal temps, esp in the Sus Valley. So when it’s probably 50ish there the day before, don’t be surprised. 

I remember from the past, that some of biggest storms followed absolutely beautiful days which were sometimes almost spring-like.

[mahantango#1]

READ THIS AFTER YOU WATCH THE VIDEO

The new 0z Sunday operationally European model is quite impressive. For the first time it not only develops a CLOSED UPPER LOW but it now forms a closed in southwest ILL , drops into the deep Longwave Trough on the East Coast Wednesday night. From there the closed 500 UPPER LOW deepens and drops SE into the Carolinas by Thursday night. If this solution is correct it matches the GFS solution in developing a significant Coastal storm Nor'easter along the Delmarva Coast with rain initially along the coastal areas and heavy snow in the Piedmont and Appalachian Mountains of the Middle Atlantic and the Ohio Valley .

If we were to Take verbatim the 0z sunday European model run, the surface LOW Pounds the hell out of western NC/ far southeast KY/ southwest VA the entire Shenandoah Valley/ Western MDd and most of WV On Thursday and Thursday evening the coastal LOW intensifies and rain changes the snow in I-95 and coastal areas Thursday night . Snow continues through Friday dawn in the eastern half of VA/ c central and eastern MD/ and the Delmarva and possibly Hampton roads.

The European model has a break in the snow shield from Baltimore to NYC while Southeast New England sees some moderate accumulating snow.

As I mentioned in the video the key to the January 15 event is the formation of the closed UPPER LOW -- this feature HAS to drop into the Carolinas in order for there to be a significant Middle Atlantic winter storm.

If that UPPER LOW never forms or let's say the orms over PA that would be great for NY state and New England but it would be complete Miss for a new the southern Middle Atlantic.

[paweather]

Looks like a chase again

[ChescoWx]

Here in EN we have received 0.77" of rain since Friday. We turn back to near normal temperatures for January with highs both today and tomorrow near 40 degrees. We turn a bit milder for both Tuesday and Wednesday before we turn colder on Thursday with increasing chances of our 9th winter event towards the end of this work week. I would also keep an eye on some possible snow showers or a heavier snow squall this afternoon not too long before Eagles kick off - go birds!

[mahantango#1]

Had .43 rain from Friday and Saturday.

[mahantango#1]

I see looks like CTP already changed. 

Starting Jan 12 at 12pm, we’re transitioning our Area Forecast Discussion (AFD) to a "Key Message" format.

This impacts-first approach streamlines communication, reduces redundancy, and ensures the most critical hazard info is front and center. Details: https://www.weather.gov/chs/newAFD

[ChescoWx]

We have only recorded 11 snowstorms over 6" here in the last 10 years in Chester County. On average based on history we should have seen 15 such storms in a 10 year period. Below are the 11 snowstorms recorded here in Chester County over the last 10 years with greater than 6" of accumulation at a Chester County Station.

1/23/16 - 27.4" / 2/3/21 - 16.6" / 3/22/18 - 13.5" / 3/7/18 - 11.5" / 2/13/24 - 10.5" / 12/17/20 - 9.3" / 12/14/25 - 8.8" / 3/14/17 - 8.0" / 2/18/21 - 7.5" / 11/16/18 - 7.3"

[Voyager]

29 minutes ago, mahantango#1 said:

Had .43 rain from Friday and Saturday.

Beat me by a hundredth. I had .42 from .15 on Friday and .27 yesterday.