6/19/06: NOW: NJ / NY / PA

[HAltschule]

Strong thunderstorms are now erupting along a line in Western/Central New York under increasing instability at the surface. Unidirectional speed shear of 40-50kts at 700-300mb favors bow echoes with this line. I also think additional lines and bows will develop ahead of this precip. shield giving much of the Northeastern states several rounds of severe thunderstorms. Interestingly, one bow echo Northwest of Syracuse, NY is showing pretty significant rotation at SRV1. A MESO has now been detected and gate to gate shear is getting kind of impressive!?! There is no SVR Warning out yet but it appears that supercells (with isolated tornado threat) may be evolving within the large scale bow echo events. Strong instability and convergence exists over Eastern NY (near Albany) and point East and South especially. I expect this line to fire into a major squall line after about 1-2 PM EDT and move quickly East-Northeastward whjile also developing southward into PA/NJ/NYC/LI. Looks like a few hours of chasing is on the offing for me this afternoon.

Severe Thunderstorm Watch now in effect until 6:00 PM.

 

[HAltschule]

Turns out the squall line was very broken. There actually a few supercells that did develop in Eastern NY. This was partly owed to more directional shear along the Hudson River Valley where a "River-Breeze" front established itself 3 miles West of the river itself. This boundary was very evident on 88D much of the afternoon. As a gust front/outflow boundary moved southeastward and collided with this river-breeze boundary, we saw supercells rapidly develop because the wind was turned more to the south/southeast in the river valley itself. The supercells did not last too long and weakened to junk pretty quickly as they moved into the Renssalaer Hills and Bershire Mountains. Organized linear convection never quite got going for some reason.

 

[Saul Trabal]

Turns out the squall line was very broken. There actually a few supercells that did develop in Eastern NY. This was partly owed to more directional shear along the Hudson River Valley where a "River-Breeze" front established itself 3 miles West of the river itself. This boundary was very evident on 88D much of the afternoon. As a gust front/outflow boundary moved southeastward and collided with this river-breeze boundary, we saw supercells rapidly develop because the wind was turned more to the south/southeast in the river valley itself. The supercells did not last too long and weakened to junk pretty quickly as they moved into the Renssalaer Hills and Bershire Mountains. Organized linear convection never quite got going for some reason.
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Yeah-the storms died out once they arrived in my area, just west of New York City. Only overcast skies-not even a raindrop, as of this writing @ 9 p.m. Whether that will change is another matter...I'm wondering if at least a shower will follow.