Central PA Spring 2026 Discussion/Obs Thread

[canderson]

New day 3 is out

 

 

 Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0238 PM CDT Sat Mar 14 2026

   Valid 161200Z - 171200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SC TO
   SOUTHERN PA...

   ...SUMMARY...
   Scattered to widespread severe storms are likely on Monday for parts
   of the Mid-Atlantic States and Southeast. The greatest potential for
   strong tornadoes and significant damaging winds appears centered on
   parts of South Carolina to Maryland during the late morning to
   afternoon.

   ...Mid-Atlantic and Southeast...
   Primary changes this outlook are to add a 45 total severe
   probability along with minor northeast and southeast expansion to
   the categorical risk areas. Portions of the region, centered on SC
   to MD, may warrant an upgrade to a level 4/Moderate Risk in later
   outlooks.

   A large and deepening upper trough will eject east/northeastward out
   of the MS/OH/TN Valleys and across the Appalachians and into the Mid
   Atlantic/Northeast on Monday, with an expansive area of strong to
   intense wind fields aloft. A deep cyclone will move from Lower MI
   into QC, with an occluding cold front arcing southeast across the
   northern Appalachians, then south-southwest into the northern Gulf.
   This front will clear all but the FL Peninsula by Monday evening.

   Ahead of the front, seasonably rich low-level moisture characterized
   by 60s surface dew points will spread northward from the eastern
   Gulf/western Atlantic. Convection will likely be ongoing at 12Z
   Monday, low-topped along the Upper OH Valley to central Appalachian
   portion of the front to deep convection in the lee of the southern
   Appalachians to eastern FL Panhandle. A diurnal uptick in storm
   intensity, including potential for semi-discrete supercells ahead of
   the front, should occur from north FL to the Carolina Piedmont.
   Further intensification is anticipated midday into the afternoon as
   a confined corridor of moderate buoyancy likely develops just ahead
   of morning storms.

   Enlarged low-level hodograph curvature, in conjunction with
   favorable elongation of the mid/upper hodograph, should foster a mix
   of broken supercells south with line-embedded supercells in the
   reinvigorated QLCS north. With such intense 700-mb flow aptly timed
   with the diurnal heating cycle overlying rich low-level moisture,
   setup could yield an expansive severe weather day, including strong
   tornadoes and significant damaging winds. The degree of
   boundary-layer heating, as well as timing of convection that may
   outpace the front late D2 into early D3, will play key roles in how
   intense severe magnitudes may become. At present, the most likely
   corridor for significant/widespread severe appears centered on the
   eastern Piedmont to coastal plain from SC to MD around midday into
   the afternoon.

[canderson]

@Voyager

https://x.com/brody_wx/status/2032851932704886856?s=61&t=u98k6PBLbHMnYtCcWaeK4g 

[Voyager]

19 minutes ago, canderson said:

@Voyager

https://x.com/brody_wx/status/2032851932704886856?s=61&t=u98k6PBLbHMnYtCcWaeK4g 

Unbelievable. And here we (I anyway) freeze. I really hate that we've been "locked in" to this pattern all winter. 

[Blizzard of 93]

18z NAM likes the idea of back end snow Monday evening.

[canderson]

That’ll be bad for the crews who will be out trying restore power, cutting up fallen trees, helping those with roof damage and all 

[Itstrainingtime]

5 minutes ago, canderson said:

That’ll be bad for the crews who will be out trying restore power, cutting up fallen trees, helping those with roof damage and all 

Yes, snow and cold are about the worst things that could happen IF there is widespread damage/power outages which certainly seems possible.

[Yardstickgozinya]

The latest nws take on severe and snow. Plenty to be worked out yet ,but I get the feeling, this is all going  to work out for the best or the worst, depending on how you look at it. Exciting times ahead. 

Monday continues to be a period of high focus, as model
consensus zeroes in on the potential for significant convective
development. At this early juncture, confidence is quite high
on the synoptic-scale evolution (the approach of a negatively
tilted upper-trough, an associated sharp cold front, and
impressively strong wind fields at all levels). More uncertainty
still has to be dealt with, though, in terms of smaller-scale
factors, such as: exact timing of the cold frontal passage, can
any breaks develop in the overcast conditions that should
prevail to start the day (which would enhance instability)?, and
convective mode (will any discrete cells form ahead of a
probable intense squall line?). Bottom line, though, ultimately
we have increasing levels of confidence in high wind producing
thunderstorms Monday afternoon, with the best potential for
damaging gusts near and south of I-80, as well as east of I-99.
Please stay tuned for later updates over the next couple of
days.

KEY MESSAGE 2: Following Monday storminess, a period of sharply
colder temperatures is expected through mid-week, with some
snow possible Monday night, as the cold air first builds in.

On Monday evening, once the surface cold front pushes through,
colder air should rush in. At issue is how much steadier
precipitation will linger behind the boundary. Given favorable
upper jet placement and the probability that some wrap-around
moisture will get steered into the Commonwealth, there is the
potential for a quick 1-3" of snow in some areas Monday night,
particularly over the higher terrain and northern sections of
the state. Again, this will come down to smaller details, so it
is advised that you stay tuned for later forecast updates

[Yardstickgozinya]

My best buddy is sending me  some pretty insane pictures and videos of flooding and mudslides on Maui  that are still in progress . According to him there's still plenty more to come.  He was out taking pictures and shooting video, but unfortunately, he's now in the process of trying to save his gym. Those cars are actually floating down the street in that video snapshot. 

[Voyager]

1 hour ago, Blizzard of 93 said:

18z NAM likes the idea of back end snow Monday evening.

So does CTP. My forecast says snowfall accumulation of less than one inch, which to me says that they think up to an inch could be possible.

[Voyager]

4 hours ago, canderson said:

@Voyager

https://x.com/brody_wx/status/2032851932704886856?s=61&t=u98k6PBLbHMnYtCcWaeK4g 

Actually, this wasn't good to bring to my attention. It made me look at the forecast for Sun City, and the highs for late next week will be around 105 degrees. It set my anger and depression into overdrive, and if my stubborn wife would have been willing to give it a chance out there, I wouldn't be here suffering this misery.

[canderson]

8 minutes ago, Voyager said:

Actually, this wasn't good to bring to my attention. It made me look at the forecast for Sun City, and the highs for late next week will be around 105 degrees. It set my anger and depression into overdrive, and if my stubborn wife would have been willing to give it a chance out there, I wouldn't be here suffering this misery.

Sorry

[Voyager]

55 minutes ago, canderson said:

Sorry

No don't be. Its ok, I'm just frustrated.

If we weren't so locked in since Thanksgiving I wouldn't be so upset. It's just been so relentless, both our cold and their heat.

I guess it didn't help that the two winters I spent out there with my mom were cool and somewhat wet. Both before and after my arrival and departure, the winters were warm and dry.

Gives merit to when I say that wherever I am, there too, shall the cold be.

[Yardstickgozinya]

Two extremely bright flashes over the last 15 minutes out this way, both followed by massive explosions. It shook everything. It actually happened during the day they other day here, and they never figured out what it was. Read about something like this happening in another part of Pennsylvania recently. 

[Blizzard of 93]

18 minutes ago, Yardstickgozinya said:

Two extremely bright flashes over the last 15 minutes out this way, both followed by massive explosions. It shook everything. It actually happened during the day they other day here, and they never figured out what it was. Read about something like this happening in another part of Pennsylvania recently. 

Is the Gap doing training drills this weekend?

[Yardstickgozinya]

27 minutes ago, Blizzard of 93 said:

Is the Gap doing training drills this weekend?

I don't think they can set off ordinance after the sunsets.

[Yardstickgozinya]

27 minutes ago, Blizzard of 93 said:

Is the Gap doing training drills this weekend?

Did you hear it too?

[Yardstickgozinya]

45 minutes ago, Blizzard of 93 said:

Is the Gap doing training drills this weekend?

Apparently, they can set off ordinance after sunset, but i've certainly never seen the flash from explosions that far away this lit everything up like it was daytime and seemed to come from the sky. It was also many times louder than any ordinance.I've ever heard from indian town gap. 

[Yardstickgozinya]

Back many years ago I was cat fishing the Marietta bend below chickies rock when a suspected meteoriite made impact somewhere in lancaster. Whatever tonight was was also many magnitudes, brighter and louder then that. 

[Yardstickgozinya]

New update from the Spc . A zone of moderate risk has been added. Its definitely not looking good fellas, and I don't know that things will de escalate, at least on paper so let's hope for a thermodynamic failure at the lowest levels because the crazy, kinematics seem pretty eminent. Full discussion is in the link below the map.

   ...Carolinas into MD/PA and vicinity...
   Areas of showers may occur early in the day especially but should
   rapidly lift north, allowing areas of heating and gradual
   destabilization over the entire area. As the surface trough deepens,
   low-level wind will back and strengthen throughout the day.
   Supercells producing tornadoes appear most likely ahead of the cold
   front from SC into NC and southern VA. Models vary with degree of
   instability, but strong tornadoes do appear possible with effective
   SRH of at least 300-400 m2/s2. Fast storm motions over 50 kt suggest
   a long tracked tornado will be possible

https://www.spc.noaa.gov/products/outlook/day2otlk.html

[Yardstickgozinya]

Spc's new severe wind and tornado probability outlook.  

[canderson]

Schools should have easy dismissals as well as companies tomorrow early afternoon. 
 

Edit HRRR has this later - post 5 pm so maybe not. It also has a devastating updraft embedded line from DC north through York. 

Everyone in this thread should prepare for a QLCS with 85 mph winds. Yse today to make sure you have a safe space with water, pillows to cover your head and a hatchet of some type. 

[canderson]

From CTP

Within the line,
embedded supercells could support concentrated tornadic winds in
the midst of a potentially expansive area of damaging wind
gusts.

[Mount Joy Snowman]

Low of 36. All eyes on tomorrow for what should be an exciting, but hopefully not too destructive, weather day. 

[Itstrainingtime]

7 minutes ago, Mount Joy Snowman said:

Low of 36. All eyes on tomorrow for what should be an exciting, but hopefully not too destructive, weather day. 

I'll go against you on this one. There is nothing exciting about tomorrow to me. I'm very concerned 

[ChescoWx]

Today should be the calm before the storm. We see temperatures close to normal today in the lower 50's before rain arrives this evening. We have a chance to actually move to above normal precipitation for the year with between 1" to 1.75" of rain possible across the area. There will be a severe weather threat tomorrow especially with a strong cold frontal passage tomorrow evening. We could see temperatures fall by over 25 degrees over just a couple hours after highs well into 60's. Rain will possibly mix with or change to some brief snow before ending by Tuesday morning. We will see well below normal temperatures both Tuesday and Wednesday before we return to slightly below normal temperatures for the rest of the work week.

[anotherman]

I'll go against you on this one. There is nothing exciting about tomorrow to me. I'm very concerned 

I am as well.

[mahantango#1]

Tomorrow I'd just like to have a good thunderstorm consisting of good thunder and continuous lightning without wind over 25mph. But I guess we'll see what tomorrow brings.

[mahantango#1]

1 hour ago, canderson said:

From CTP

Within the line,
embedded supercells could support concentrated tornadic winds in
the midst of a potentially expansive area of damaging wind
gusts.

Seems quite unusual that CTP is strongly on board for this event. They are usually pretty conservative. 

[canderson]

11 minutes ago, mahantango#1 said:

Seems quite unusual that CTP is strongly on board for this event. They are usually pretty conservative. 

I moved to PA in 2006. I cannot recall a more favorable setup here than tomorrow for a QLCS packing 70-90 mph winds, hail and perhaps a tornado closer to the MD border. 

The fact it will be slower and later than it looked like a few days ago makes it even worse. It’s going to hit right after peak heating and soaring dews.

[TheDreamTraveler]

27 minutes ago, canderson said:

I moved to PA in 2006. I cannot recall a more favorable setup here than tomorrow for a QLCS packing 70-90 mph winds, hail and perhaps a tornado closer to the MD border. 

The fact it will be slower and later than it looked like a few days ago makes it even worse. It’s going to hit right after peak heating and soaring dews.

I was born here and still live in the same town and I can't really remember a setup where I was genuinely this worried. Normally severe weather excites me but I'm not really feeling it with this scenario. Definitely very concerning setup