Central PA - Spring 2020

[Blizzard of 93]

33 minutes ago, Atomixwx said:

Everything you've posted this season has been a total fluke. 

Ha ! You are right!

Nothing has worked out for snow this year except one Advisory level event during PA Farm Show week in January.

I am hoping that we get just a couple hours of snow that maybe coats the grass on Wednesday morning.

It would be like losing a baseball game by 20 runs and then scoring 1 pitiful run in the 9th inning just to get on the scoreboard.

[canderson]

17 minutes ago, Itstrainingtime said:

Is the primary threat tomorrow from a squall line, discreet supercells or a combination?

Kinda a combo. Squall line is def an issue but the S and E areas can easily have storms fire ahead of it given parameters. 

This setup is a very common one in Texas and the SE - it’s pretty rare to get it up here. 

[Itstrainingtime]

7 minutes ago, canderson said:

Kinda a combo. Squall line is def an issue but the S and E areas can easily have storms fire ahead of it given parameters. 

This setup is a very common one in Texas and the SE - it’s pretty rare to get it up here. 

Thanks...sounds like an ominous setup. I don't feel any better knowing that our Texas guy is playing this up.

[canderson]

11 minutes ago, Itstrainingtime said:

Thanks...sounds like an ominous setup. I don't feel any better knowing that our Texas guy is playing this up.

We tend to almost always strike out with CAPE and shear here, so we’ll see what transpires. 

[daxx]

36 minutes ago, canderson said:

We tend to almost always strike out with CAPE and shear here, so we’ll see what transpires. 

We seem to always miss out on at least one of them. I’ll take good shear over a high cape. 

[canderson]

4 minutes ago, daxx said:

We seem to always miss out on at least one of them. I’ll take good shear over a high cape. 

Agreed. It’s actually the opposite of East Texas, give me sky high CAPE and you’re off to the races. Environmental factors mage a huge, huge difference. 

[Blizzard of 93]

Remember, I’m just the messenger...

Here is the 18z NAM for the Wednesday snow chance.

 

[MAG5035]

That's quite a satellite loop:

https://weather.cod.edu/satrad/?parms=meso-meso1-truecolor-96-1-50-1&checked=map&colorbar=undefined

[canderson]

If you see sun tomorrow for more than a few minutes before noon, pray if you’re religious.

[Jns2183]

If you see sun tomorrow for more than a few minutes before noon, pray if you’re religious.

I understand the parameters are pretty out there, but that statement feels more in line with “if you see sun before noon, say hello, you are now in Wheatland, Pennsylvania; it’s may 31st, 1985, enjoy the unique clouds on offer today”.


. Pro

[canderson]

Just now, Jns2183 said:

I understand the parameters are pretty out there, but that statement feels more in line with “if you see sun before noon, say hello, you are now in Wheatland, Pennsylvania; it’s may 31st, 1985, enjoy the unique clouds on offer today”.


. Pro

Had to look that one up. What a crazy setup THAT was. Truly once-in-a-lifetime stuff. 
 

I don’t think we see tornados tomorrow but I’m very concerned about straight-line winds mixing down above 70 mph.

[Jns2183]

So exactly what parameters do we even need in place for their to be a legit possibility of a 70 mile long tornado rated at F4 and I believe 1-2 miles wide for the majority of its track to blaze across the mountains west to East laughing at everyone lulled into complacency at seeing countless squall line poop, puke, and decapitate themselves on the same track?

Exactly how many times have we seen parameters that at least roughly equal that days ones for our area throughout the entire period where it’s possible to compare?

Surely this had to be some PSU MET PhD dissertation or research project in the last 30+ years.

Whose got access to PSU library that can check?


. Pro

[canderson]

3 minutes ago, Jns2183 said:

So exactly what parameters do we even need in place for their to be a legit possibility of a 70 mile long tornado rated at F4 and I believe 1-2 miles wide for the majority of its track to blaze across the mountains west to East laughing at everyone lulled into complacency at seeing countless squall line poop, puke, and decapitate themselves on the same track?

Exactly how many times have we seen parameters that at least roughly equal that days ones for our area throughout the entire period where it’s possible to compare?

Surely this had to be some PSU MET PhD dissertation or research project in the last 30+ years.

Whose got access to PSU library that can check?


. Pro

I’m not sure of a storm like that could survive the extreme upslope shear, there is a theory in Texas that long-track tornados can’t survive the hill county due to rapid elevation gains.

Would love a met write up - or straight scientific report. 

[canderson]

If you’re interested in tornados go to the SE forum, page 18, and check out the radar images. Textbook.

I think I’ve posted this but my house growing up was hit by two. I have the best luck (this explains my wind ficus).

[Itstrainingtime]

1 hour ago, Jns2183 said:

I understand the parameters are pretty out there, but that statement feels more in line with “if you see sun before noon, say hello, you are now in Wheatland, Pennsylvania; it’s may 31st, 1985, enjoy the unique clouds on offer today”.


. Pro

That was the event that drove my fear of severe weather to a whole new level. I was 19 at the time and at the point where I, like most at 19, feel invincible. I started seeing images coming out of western PA that evening and suddenly realized that I wasn't in control. That was the day that every severe event in PA was and is measured against.

[MAG5035]

4 hours ago, Jns2183 said:

So exactly what parameters do we even need in place for their to be a legit possibility of a 70 mile long tornado rated at F4 and I believe 1-2 miles wide for the majority of its track to blaze across the mountains west to East laughing at everyone lulled into complacency at seeing countless squall line poop, puke, and decapitate themselves on the same track?

Exactly how many times have we seen parameters that at least roughly equal that days ones for our area throughout the entire period where it’s possible to compare?

Surely this had to be some PSU MET PhD dissertation or research project in the last 30+ years.

Whose got access to PSU library that can check?


. Pro

 

4 hours ago, canderson said:

I’m not sure of a storm like that could survive the extreme upslope shear, there is a theory in Texas that long-track tornados can’t survive the hill county due to rapid elevation gains.

Would love a met write up - or straight scientific report. 

If there was ever a tornado that flies in the face of that theory, that particular tornado was it. That was at the time I believe one of the widest tornadoes ever recorded and it ripped a swath in the woods of Northern Clearfield and Clinton Counties, where it is quite mountainous. I think the only reason it probably wasn't rated an F5 was because that storm miraculously tracked nearly its entire 70 mile path in the part of PA where there literally isn't anything else other than state forest, so there really wasn't anything else to rate damage-wise other than the sheared and uprooted trees. That was during the time when the original Fuguita scale was used.

That outbreak featured a setup in western PA that day more reminiscent of what you would see in major plains outbreaks, large CAPE coupled with the proper shear. Certainly the terrain in central PA is much more often than not detrimental in the aspect of having the prime setup for a classic tornadic outbreak. But if you achieve that setup and you have a long tracked supercell/tornado of that magnitude on the ground, it doesn't matter what the terrain is that it's crossing. And that's certainly the lesson to be learned there. Western PA, and especially NW PA where the absolute worst of that outbreak occurred is probably the part of the state most conducive to stuff like that. Why? Because you can achieve that low level southerly/southwesterly flow more readily. There's no mountains to the west that holds clouds in the low levels and/or maintains a stable surface/boundary layer via a cool air damming scenario. You also have to have a favorable track from the parent low pressure system for an organized severe outbreak (outside of MCS and some derecho events), and that's part of why our "tornado season" is typically in that late May-June timeframe. 

Here's the best image/loop you'll get of the 85 outbreak. You can see western PA cleared out and it's likely the severe parameters were such that it was able to maintain the supercell responsible for the Moshannon tornado. Also not mentioned much in the details of this outbreak is that this also caused several tornadoes in Ontario as well. 

 

Radar image of the Moshannon tornado from the old school radar that was on top of the Walker building at Penn State.

CTP's writeup on this , which is a good one with all the weather maps of the setup. 

https://www.weather.gov/ctp/TornadoOutbreak_May311985

 

[Jns2183]

If there was ever a tornado that flies in the face of that theory, that particular tornado was it. That was at the time I believe one of the widest tornadoes ever recorded and it ripped a swath in the woods of Northern Clearfield and Clinton Counties, where it is quite mountainous. I think the only reason it probably wasn't rated an F5 was because that storm miraculously tracked nearly its entire 70 mile path in the part of PA where there literally isn't anything else other than state forest, so there really wasn't anything else to rate damage-wise other than the sheared and uprooted trees. That was during the time when the original Fuguita scale was used.
That outbreak featured a setup in western PA that day more reminiscent of what you would see in major plains outbreaks, large CAPE coupled with the proper shear. Certainly the terrain in central PA is much more often than not detrimental in the aspect of having the prime setup for a classic tornadic outbreak. But if you achieve that setup and you have a long tracked supercell/tornado of that magnitude on the ground, it doesn't matter what the terrain is that it's crossing. And that's certainly the lesson to be learned there. Western PA, and especially NW PA where the absolute worst of that outbreak occurred is probably the part of the state most conducive to stuff like that. Why? Because you can achieve that low level southerly/southwesterly flow more readily. There's no mountains to the west that holds clouds in the low levels and/or maintains a stable surface/boundary layer via a cool air damming scenario. You also have to have a favorable track from the parent low pressure system for an organized severe outbreak (outside of MCS and some derecho events), and that's part of why our "tornado season" is typically in that late May-June timeframe. 
Here's the best image/loop you'll get of the 85 outbreak. You can see western PA cleared out and it's likely the severe parameters were such that it was able to maintain the supercell responsible for the Moshannon tornado. Also not mentioned much in the details of this outbreak is that this also caused several tornadoes in Ontario as well. 

 
Radar image of the Moshannon tornado from the old school radar that was on top of the Walker building at Penn State.

CTP's writeup on this , which is a good one with all the weather maps of the setup. 
https://www.weather.gov/ctp/TornadoOutbreak_May311985
 

Holy crap the meso on that thing had to be huge. Reminds me of some the more famous OKC area storms. What’s amazing is that very well might of been the strongest, largest, most violent one of the day. Out of all the other PA tornadoes, the second widest was the Kane tornado at 1000 yards. It was rated F4, on the ground for 29 miles (40 minutes) from 8:00 - 8:40 PM, injured 40, killed 4. Closely following in 3rd widest was the the Watsontown tornado at 910 yards. It too was rated F4, on the ground for 19 miles from 9:25 - 10:15 PM (50 minutes), injuring 60 and killing 6.

Our F4 friend above was 3,330 yards (1.9 miles), at its widest, and spent almost all of ifs 69 mile journey from 7:35 to 9:00 pm (85 mins) at least a mile wide. So it was bar the widest, most long tracked tornado of the day in PA.

I counted 23 tornados in CTP chart. And the intensity ratings for the group, especially being PA are about absurd as you expect.
F0 - 2
F1 - 2
F2 - 5
F3 - 6
F4 - 7
F5 - 1

It appears from about 5pm through 9 pm there was just about at all times 3-4 tornados on the ground at the same times, 2-3 of which were F3 or above.

Looks like 9 tornados tracked between 10-20 miles, 8 tornados had tracks of > 20 miles, 4 > 40 miles.

I would love if there was a data warehouse that listed all PA tornados on record. I’m sure a bunch of these would be stacked near the top in track length.

I also wonder if towns like Kane and Watsontown had in there history any tornado rated at least f3 occur within a 40 mile radius, that occurred not on that day.


. Pro

[2001kx]

6 hours ago, MAG5035 said:

 

If there was ever a tornado that flies in the face of that theory, that particular tornado was it. That was at the time I believe one of the widest tornadoes ever recorded and it ripped a swath in the woods of Northern Clearfield and Clinton Counties, where it is quite mountainous. I think the only reason it probably wasn't rated an F5 was because that storm miraculously tracked nearly its entire 70 mile path in the part of PA where there literally isn't anything else other than state forest, so there really wasn't anything else to rate damage-wise other than the sheared and uprooted trees. That was during the time when the original Fuguita scale was used.

That outbreak featured a setup in western PA that day more reminiscent of what you would see in major plains outbreaks, large CAPE coupled with the proper shear. Certainly the terrain in central PA is much more often than not detrimental in the aspect of having the prime setup for a classic tornadic outbreak. But if you achieve that setup and you have a long tracked supercell/tornado of that magnitude on the ground, it doesn't matter what the terrain is that it's crossing. And that's certainly the lesson to be learned there. Western PA, and especially NW PA where the absolute worst of that outbreak occurred is probably the part of the state most conducive to stuff like that. Why? Because you can achieve that low level southerly/southwesterly flow more readily. There's no mountains to the west that holds clouds in the low levels and/or maintains a stable surface/boundary layer via a cool air damming scenario. You also have to have a favorable track from the parent low pressure system for an organized severe outbreak (outside of MCS and some derecho events), and that's part of why our "tornado season" is typically in that late May-June timeframe. 

Here's the best image/loop you'll get of the 85 outbreak. You can see western PA cleared out and it's likely the severe parameters were such that it was able to maintain the supercell responsible for the Moshannon tornado. Also not mentioned much in the details of this outbreak is that this also caused several tornadoes in Ontario as well. 

 

Radar image of the Moshannon tornado from the old school radar that was on top of the Walker building at Penn State.

CTP's writeup on this , which is a good one with all the weather maps of the setup. 

https://www.weather.gov/ctp/TornadoOutbreak_May311985

 

I remember that day...was very scared as a kid (would be now as well)

Was hiding in the basement listening to the radio...They were calling for a hit to my area (leconted mills) but it went just north of us luckily.

[canderson]

Right on time, winds starting o crank up. 
 

Never did get any storm to fire overnight. 

[sauss06]

5 minutes ago, canderson said:

Right on time, winds starting o crank up. 
 

Never did get any storm to fire overnight. 

Had a couple brief downpours that woke me up. 

[Voyager]

Quite a bit of rain overnight, tipping the gauge at 1.14" as I type. Wind so far is not an issue, but will likely change later. As for storms, what is everyone's best take on who sees the best potential for severe storms and excessive wind gusts? South central? True central? The eastern locations? I suppose some consideration has to be given to if anyone sees any sun today, but I just wonder what's going to take place today, and where the worst might be.

[sauss06]

1 minute ago, Voyager said:

Quite a bit of rain overnight, tipping the gauge at 1.14" as I type. Wind so far is not an issue, but will likely change later. As for storms, what is everyone's best take on who sees the best potential for severe storms and excessive wind gusts? South central? True central? The eastern locations? I suppose some consideration has to be given to if anyone sees any sun today, but I just wonder what's going to take place today, and where the worst might be.

i doubt we see sun today down here i the Harrisburg region.

[anotherman]

The wind here is scary.

[canderson]

38 minutes ago, sauss06 said:

Had a couple brief downpours that woke me up. 

Yup, lots o rain. 

[sauss06]

21 minutes ago, canderson said:

Yup, lots o rain. 

Strictly a guess, but i think we'll have wind later, but i don't think we will see severe. 

[Jns2183]

i doubt we see sun today down here i the Harrisburg region.

Take a look a WV and W. PA on GOES. clearing already in dry slot. Biggest issue maybe eastern component to wind. Warm front seems to be progressing rapidly through Virginia with mid 60 dew points south of DC. Warm front passage along with dry slot should scour out boundary layer and allow for at least some broken sun during prime heating


. Pro

[Cashtown_Coop]

1.35” of rain over this way.  Only had a gust to 26 mph so far

Current dew of 58

Charleston WV radar already showing a large area of rain with embedded line segments.    Looks active for this early in the day.  Hrrr also looks impressive later

 

[Itstrainingtime]

1 hour ago, canderson said:

Right on time, winds starting o crank up. 
 

Never did get any storm to fire overnight. 

Pretty good lightning and thunder here around 4:45am.

[pawatch]

Some good reading with the tornado posts...Thanks

Only 0.10" of rain overnight here.

[Voyager]

No wind here as of yet, but 1.39" in the gauge so far.