Newman

The 18z GFS is trying to have that weak trough/Upper low on the East Coast pull Henri back in like the ICON did, not quite as successful but 100% trended that way. Stronger ridge over the top and everything. This run might possibly be a hit.

18z 3k NAM not backing down, in fact it increased the already impressive bulk shear values and storm relative helicity values from it's previous run. And my God, SCP of 20.2 and STP of 6.2. I know the NAM is notorious for overhyping these types of things, but look no further than what we're seeing in the SE today for what could be instore for us tomorrow

If these CAMs come to fruition for tomorrow, there's a legit tornado threat for much of the Lehigh Valley towards the evening. Sounding below is for Berks county, there's some PDS TOR soundings coming out of Harrisburg on the 3k NAM. With ample daytime heating, along with a remnant tropical system moving to our west putting us in the warm sector with increased Storm Relative Helicity and Effective Shear... yeah it could mean lots of rotating cells like what we're seeing in Georgia and South Carolina today

Latest 12z EPS spaghetti plots for Henri, continues to trend a bit further west. Some members are even trying to hook back west. At the minimum, lots of rough surf along the Mid-Atlantic and New England coasts. The Euro camp seems to be on the weaker side of most guidance as of now, compared to the other global models and the hurricane models.

All depends on this large cyclonic flow and deep trough in the North Atlantic which is ultimately creating the weakness for it to escape. You would need it to not only be weaker for an even more conducive environment, but also move east. That would allow for the ridge to build over the top and to the east, possibly blocking it from moving out east. This past 12z run was not as favorable if you want a hit, with a deeper and stronger Upper low feature and a weaker eastern Canada ridge. Not to mention that low barely moves and sits/spins in place.

Thank you all! As a met student, I try my best to learn on my own and equally try to convey the information to the public in a detailed and scientific, yet clear and understanding way. I'm just here to help everyone stay informed, plus I love sharing info as well. Just as another note, there have been some tornado warnings down in the south this morning with "radar confirmed" tornado messages. Plus some confirmed tornados and damage across Georgia yesterday with Fred. We'll see if that all can or will make it's way up here tomorrow. Now to play devils advocate, its also very possible the primary low tracks too far east and many end up with 1. Just some moderate rains or 2. A brief period of rain and nothing after. In a time of the year when the weather seems to slow down and eyes turn towards the tropics, it's nice having something to watch.

As of now, just a slight conditional 2% risk from the SPC, which I would agree with. It won't be a widespread event and is highly dependent on track among other factors too. But absolutely worth keeping an eye on, any time you have a tropical system (even a remnant one) track to your west, you have a shot of tornados.

As I said above, the HRRR is not too dissimilar from the NAM. The difference is timing, where the HRRR brings storms in around ~5pm compared to ~10pm on the NAM. Still very curvy hodographs with lots and lots of veering up the column in the low levels, plenty of effective bulk shear (over 50kts!). LCLs are low, which help to favor tornado formation as well, and MLCAPE is solidly in the 1000 J/kg to 1500 J/kg range (although it wouldn't hurt if it was a bit higher).

Lets not sleep on tomorrow (literally). With the remnants of Fred moving in, lots of shear will be in place. And unfortunately, in the evening and towards the overnight hours when some might be sleeping. The 3k NAM has some impressive hodographs showing up in the area, the one below for Harrisburg with a PDS TOR sounding. The HRRR is in the same boat as well with discrete cells ahead of the primary low pressure system. Surface warming during the daytime may allow for sufficient CAPE for a sneaky tornado or two, although it'll ultimately depend on the hourly track of Fred and where it decides to go. Not often, if ever, you see a nocturnal tornado threat in this part of the country. We shall see...

Slight conditional tornado risk tomorrow evening and night with Fred coming through

@MacChump Thank you for the Mt. Jo recommendation! Went at 7am yesterday and was one of the best views I've ever seen! On a weather related note, current temp is 86F. Very excited for tomorrow's lower temps and lower dew points too. Tired of the heat and can't wait until Autumn. Also, the tropics seem to be heating up. Maybe we'll get a storm to move up this way later towards fall?

Just looked up the Mt. Jo trail, definitely what I'm gonna do! I just got surgery on Monday, so I have to be very careful with how strenuous these hikes are. I'm up here to begin with because my brother is getting married up here and I was hoping to do some hiking. The Cobble Lookout was a very simple 2 mile out and back with virtually no elevation gain. If the Mt. Jo loop ends up being too much, I'll turn around. And obviously hiking up Whiteface isn't gonna happen, but 100% will drive up. Thanks for the recommendations!

I'm in Lake Placid NY until Saturday. First time up here, and wow it's beautiful! Got up at 4:45am to go watch the sunrise at Cobble Overlook (around 2350' elevation). Hoping to either drive or hike to the peak of Whiteface Mountain tomorrow (around 4850' elevation). Wish I could live up here year round, plus they average 100+ inches of snow. Side note, some severe storms forecasted for up here today.

That bow echo was very underwhelming. Just some rain.

Some record low, or nearing record low, temps tonight for July 31st.

Record low temps possible tonight. Philadelphia forecast is to get down to 57F which would tie the record low for July 31st. Reading and Allentown forecast to get down to 52-54 which would be close as well.

Video of an apparent tornado in Lebanon earlier today https://www.facebook.com/100009682356689/videos/2668568046777171/

What an insane day it turned out to be. My post about this being more so a "damaging wind" threat did not age well. This ended up being a localized tornado outbreak for SE PA and Southern Jersey. I actually went to chase the two tornado warned storms in northern MD and ended up missing them, started to drive back and was getting phone calls from my friend in Levittown who was chasing that New Hope storm. He then backtracked and tried to intercept the Bensalem storm but missed that one. Overall, just an incredible day. Low level shear for the win, sun/CAPE for the loss. I hope everyone here on the board and across the area is okay.

Video of a Lebanon County tornado earlier https://www.facebook.com/100009682356689/videos/2668568046777171/

Yeah the hook on that storm is something you don't see often around here.

Those storms in Bedford county, entering Fulton, look to have that discrete/curvy look to them. No warnings on them though