It’s here! Extreme instability, thanks to nearly dry adiabatic lapse rates in the 500-700 mb layer, is spreading east across the northeast. The evening sounding from Buffalo is Great Plains-like with more than 4,000 j/kg of CAPE rooted above the boundary layer!
Tomorrow that instability will be over us. Dew points and low level moisture will remain oppressively high as a stout “cap” will effectively prevent drier air from mixing down. The question is – will that cap break or will it hold?
At this point odds are the cap will hold here in Connecticut. Models show a fair amount of convective inhibition thanks to that cap. Odds favor that cap holding with 700mb temperatures near over over 10C through most of the day here in Connecticut. Additionally there is only very weak/subtle forcing with a weak shortwave moving east through Pennsylvania and modest height falls.
That said, I do expect convection will fire across parts of Pennsylvania and upstate New York and likely slide into central and northern New England. Storms are possible in western Connecticut but not as likely.
Here’s one solution from our WSI WRF model at 4km resolution. While it’s unlikely this exact solution will verify this seems reasonable given the synoptic setup tomorrow.
We’ll have to babysit the radar all afternoon and evening tomorrow. While the threat for severe weather is low anything that manages to develop has the potential to grow explosively. One other note – it’s possible that storms may consolidate to the west and move toward southern New England well after dark as a complex of strong storms.
I’ll keep you posted!