Newman

Central PA, I'm well out of this. I'm tracking this and rooting for you guys

Clear trend west. Some members even take this into Jersey now

Probability of Watch Issuance...80 percent SUMMARY...The tornado threat is expected to gradually increase into this afternoon. Tornado Watch issuance is likely by 16Z. DISCUSSION...At 1445Z, T.D. Fred is still moving northeastward near the OH/WV border northeast of Parkersburg, WV. A warm front extends east-northeast from the cyclone across southern PA, while a surface confluence axis is noted extending from southwest PA into central VA. Rich low-level moisture will continue to stream northward across PA in conjunction with the warm front this afternoon, with some breaks in the clouds allowing for some modest destabilization from central PA southward into MD/northern VA. Convection will likely increase in coverage with time near/north of the warm front, with more scattered convection possible along/east of the surface confluence axis into MD/northern VA. This afternoon, 0-1 km SRH will likely be maximized over central PA (potentially in excess of 200 m2/s2), though somewhat enhanced SRH will also extend southward into MD/VA where surface winds remain backed to a southeasterly direction. Scattered supercells are likely to evolve with time as convection matures, with an attendant threat of a few tornadoes and isolated/scattered damaging wind gusts. Tornado Watch issuance is likely by 16Z in response to these threats.

Probability of Watch Issuance...80 percent SUMMARY...The tornado threat is expected to gradually increase into this afternoon. Tornado Watch issuance is likely by 16Z. DISCUSSION...At 1445Z, T.D. Fred is still moving northeastward near the OH/WV border northeast of Parkersburg, WV. A warm front extends east-northeast from the cyclone across southern PA, while a surface confluence axis is noted extending from southwest PA into central VA. Rich low-level moisture will continue to stream northward across PA in conjunction with the warm front this afternoon, with some breaks in the clouds allowing for some modest destabilization from central PA southward into MD/northern VA. Convection will likely increase in coverage with time near/north of the warm front, with more scattered convection possible along/east of the surface confluence axis into MD/northern VA. This afternoon, 0-1 km SRH will likely be maximized over central PA (potentially in excess of 200 m2/s2), though somewhat enhanced SRH will also extend southward into MD/VA where surface winds remain backed to a southeasterly direction. Scattered supercells are likely to evolve with time as convection matures, with an attendant threat of a few tornadoes and isolated/scattered damaging wind gusts. Tornado Watch issuance is likely by 16Z in response to these threats.

LOL this might be a bit too much, taken from Mid-Atlantic forum

Latest 11am NHC cone continues to nudge further west

The sun continues to peak in and out here. CAPE on the increase

Latest 12z Hurricane tracks

Yeah for Central PA, it would take a miracle and a half to get any impacts (other than maybe some breezy conditions?) from Henri. But very fun to watch evolve regardless, SNE and perhaps even as far west as NYC are still very much in play as of now. More hurricane spaghetti models continue to show that capture and tug back west. GFS and UKMET are on board.

Posting this not because I believe it, but because it's funny and deep down we're all weenies... HMON captures future Hurricane Henri into the coast. The GFS is similar, only it captures it into SNE. Same with the UKMET. Whether or not the Philly region gets any impact is up in the air (leaning hard no as of now), but fun to watch it evolve

I think much of South Central PA has a chance at something significant later today, but Harrisburg is probably the bullseye spot to be.

Where the most shear and CAPE overlap... Leads to parameters like this: And ultimately the chance for something like this: I would never call for tornados, that's something you simply can't do. Look at that severe event a few weeks ago that looked great for tornados: it ended up missing our area but smacked the Jersey and Philly area. Simply put, every CAM is pointing towards lots of shear and helicity with the remnants of Fred tomorrow. In the warm sector, discrete rotating cells are a real possibility. There were 13 tornado reports out of the SE today -> That's heading this way tomorrow (does it remain as potent or weaken?). Each NAM and HRRR run today kept to the idea of potential tornados tomorrow, the scariest part being the timing leaning towards dusk and overnight. In 24 hours we'll see if they had the right idea or not.

Mount Holly on tomorrow: With impressive curved hodographs and low-level helicity values from 200 to 300 m2/s2, there easily could be a quick spin up tornado or two. Again, this depends on the exact track of the low and how much surface heating we can realize tomorrow. Shear and helicity may be enough to overcome the low CAPE values generally less than 2000 J/kg across the region.

For you New England tropical chasers, a great trend on this GFS run. Stronger ridge sprawling further east and that weak trough on the EC trying to pull it back to the coast is similar to what Yakkov said in his tweet regarding the 1938 Great New England Hurricane. Slowly stepping towards putting an even bigger eye on Henri...

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.