Public Analysis: Strong to Severe T-Storm Threat Late this Afternoon

An unseasonable warm airmass continues to be over region this afternoon. Clouds will mix with some sunshine and temperatures will be rising into middle to upper 60s and some lower 70s over many inland areas through middle of this afternoon. Closer the coast, moist south-southeast winds will keep more low clouds and temperatures cooler in the mid-upper 50s or lower 60s.

But a strong cold front approaching the region will trigger a line of showers and thunderstorms over Central and Eastern parts of Pennsylvania  this afternoon. Increasing instability and strong wind shear may support some thunderstorms to be strong to severe, especially over parts of Eastern Pennsylvania, New Jersey and Upstate New York.  The main threat will for some isolated damaging wind gusts. The Storm Prediction Center has issued a slight risk for severe thunderstorms most of these areas. In fact, a severe thunderstorm watch may also be issued for these areas this afternoon, based on the latest mesocale discussion .

16zHRRRad7

HRRR model showing a line of showers and strong to possible severe t-storms moving into the region by 6pm

As these showers and thunderstorms approach more coastal areas, including New York City, Long Island and Connecticut, they will run into a cooler, more stable marine airmass. So this will likely cause showers and thunderstorms weaken or fall apart as they move into these areas. But some heavy rain, lightning and wind gusts to 40mph are still very possible.

Then any lingering showers will taper off later this evening, as the cold front moves through. It will turn colder late tonight, with northwest winds and temperatures dropping into the upper 20s to middle 30s. Sunday will be seasonably cold with mixture of sunshine and clouds, with high pressure building into the region. Highs will be in the lower to middle 40s. However, temperatures will be moderating again by Monday, as more ridging and southwest flow returns over the region.

For more technical, detailed analysis and more forecast updates, Contact us here today!