Storms today will mean business! We’re expecting a fairly sizable severe weather event in the northeast this afternoon and while we can never say with certainty that the severe will strike our backyard – odds are pretty good we’ll get some nasty weather in Connecticut. Any storm that develops today has the potential to produce winds strong enough to take down trees and power lines and could produce a tornado or two. We’re expecting a “high impact” day of weather across the state.
A deep and anomalous closed low over the Great Lakes has allowed copious amounts of moisture to come north under a strengthening mid level flow on the eastern seaboard. Dew points in the low to mid 70s are common across the region. This is a climatologically favored pattern for severe weather in Connecticut – even down to the beaches.
The morning weather balloon launch on Long Island shows a fairly unstable environment that’s loaded with moisture. There is a bit of a cap this morning for surface based convection that models show eroding by early afternoon. High resolution models develop some nasty storms in western Connecticut that move in later today. In addition, models show a spike in storm relative helicity (a way to measure the shear or turning of winds in the lower atmosphere) as the storms approach.
With strengthening wind fields just above the surface any storms will have to be watched closely today. Below is the 12 hour NAM forecast valid at 18z today. Note the >30 knot low level jet at 850mb that has developed from NYC to central Massachusetts. Any time the 850mb flow increases above 30 knots in a setup like this it’s worth watching closely – especially on a day like today with lifted condensation levels as low at 500 meters.
Damaging winds at the ground, lots of lightning, flooding rains, and tornadoes are all possible today. Keep an eye to the sky – or to Twitter!