Newman

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

* Tornado Warning for... Southwestern Somerset County in south central Pennsylvania... * Until 245 PM EDT. * At 212 PM EDT, a severe thunderstorm capable of producing a tornado was located near Seven Springs, moving southeast at 25 mph. HAZARD...Tornado. SOURCE...Weather spotters reported funnel cloud. IMPACT...Flying debris will be dangerous to those caught without shelter. Mobile homes will be damaged or destroyed. Damage to roofs, windows, and vehicles will occur. Tree damage is likely.

The latest 1800z Mesoanalysis basically shows almost any CIN eroded. SBCAPE up to 2000 J/kg for much of Lancaster/York/Adams and MLCAPE up to 1000 approaching ~1500 J/kg. Bulk shear has very nicely increased as expected. Low level lapse rates have been increasing as well, LCLs are low (support tornadoes). So while CAPE is certainly not incredible by any means, it should get the job down with the ample shear. Damaging winds will be the primary threat, maybe an iso tornado later

There's a tornado warning out in far western PA for a lone supercell *Reported funnel cloud with it too

Another tornado warning out in western PA for Westmoreland and Fayette counties

I don't expect the tornado threat to end up materializing, but I could definitely see a bow echo roll through the Philly area similar to last May's event, maybe not to the extreme that was. But even with all of us socked in clouds, the CAPE values should be sufficient enough to support some severe storms and the deep layer shear will help to maintain any line segments. We shall see, I think the NWS and SPC did a great job with this expressing the possible dangers of the event, while also recognizing the chance of failure as well. We might be leaning more so towards "failure" here, but that's what comes with living in this part of the country.

Latest 1630z outlook still has the enhanced risk, shifted the tornado threat furthest east to the coast.

Tornado warning for far NW PA in Erie and Crawford counties

I can't pull up any current skew-t data (which sucks, MDT should send up a weather balloon lol). But the latest 12z 3k NAM has plenty of deep layer shear and a TOR sounding for the MDT region. In layman's terms... atmosphere go spinny, just need some sun...

Latest 1500z update has MLCAPE continuing to grow. Up to 1000 J/kg across Lancaster and a pocket of 1500 J/kg across the Chesapeake Bay. Those values will continue to spread north as the low-level clouds wear thin and the warm front lifts north (hopefully).

SBCAPE and MLCAPE continue to increase in coverage and intensity across the area, favoring eastern areas as of now

Latest 3k NAM (which is among all the CAMs that have been struggling with this event) has some gnarly storms later for the area. Even a PDS TOR sounding for @CoolHandMike

SPC meso site showing pocket of MLCAPE ~ 1000 J/kg around the Chesapeake Bay area and SBCAPE between 1500-2000 J/kg for much of MD

https://weather.cod.edu/forecast/ You can choose which model to look at, then click on the map itself once selected all the parameters to create a sounding

1300z Outlook

Here is a sounding for Berks later on. Notice there is AMPLE deep layer shear and a huge amount of veering in the lower levels. 61 knots of EFF Shear is insane around here! Plenty of SRH too. The problem is the amount of SBCAPE for the storms to tap into. Lots of low level cloudiness this morning. It's still very early though, so if we're still socked in clouds by 11-12, then I'd say the storm chances dramatically diminish. However, Mount Holly mentions that even if we don't completely clear out, there will still be enough MLCAPE to tap into As described above, the forecast is for the morning showers and isolated thunderstorms to slowly translate east. As this occurs a fractured stratus deck will start to lift. The stalled front currently near the fall line will also lift north as a warm front with rich theta-e air surging northwards. This recycled moisture regime will help to destabilize the region even if the stratus doesn`t ever completely clear. Both the GFS and NAM are indicating MLCAPE values of around 1000/1500 J/kg. Still though, the amount of available instability is one of the potential failure modes today (esp. if morning showers prove to be more robust than initially forecast). Generally though, during late July it doesn`t take much to destabilize the region. Early this afternoon the MCV will be approaching from the west with showers and thunderstorms across central PA. Ascent will increase across the region as the MCV approaches. Across the warm sector, effective bulk shear values of ~45 kts will be more than sufficient to support rotating updrafts. Some upscale growth is forecast as multiple cold pools start to be deposited and merge. The primary threats with these storms will be damaging winds, large hail, and an isolated tornado (thanks to slightly back southeast flow and impressive directional shear).