Hail To The Sleet

Last night's thunderstorms were pretty "fun" to watch move through -- arguably less fun to drive through as the pinging of graupel, sleet, and hail hit windshields throughout the Delaware Valley during the 7:15-8:15 PM timeframe.   The National Weather Service is defining what fell last night as hail -- some places with slightly larger hail pellets than others -- but most of the reports that came in last night were classified as quarter inch hail.

One could realistically argue a case for sleet or graupel (hybrid of hail/sleet) as the precipitation type last night that fell -- the pellets that were falling were larger than traditional sleet pellets but weren't as "hard" as regular hail pellets...which makes me think a fair bit of graupel was falling in spots.  Hail certainly was do-able in many locations with these thunderstorms -- they were the remnant of severe thunderstorms that dropped a tornado across Western Pennsylvania (more on that in a bit) but given there was pretty significant instability aloft as well as cold pockets of air above a shallow mild layer in the bottom parts of the atmosphere the potential for sleet mixing in was legit, especially over the northern burbs as surface temperatures were in the 35-40 range during the event.

It can hail with temperatures in the 30's...it can sleet with temperatures in the 40's at the surface.   In this case, with temperatures around 40, it's possible we had both.




Dude...get inside the school...that's a tornado!   Yes, this tornado struck Hempfield High School in Greensburg, PA (out near Pittsburgh) yesterday afternoon with the complex of storms that hit Philadelphia later on last night.   While the caption in the linked video says he "overreacted" the best thing to do in a tornado is find shelter, even if it is in a large building (interior hall, basement if possible) as opposed to try to outrun it.  

From snow to thundersleet to hail, yesterday was a wild weather day in Pennsylvania -- especially since we had such a huge variation in weather over a short distance -- from 9-10" of snow in the Poconos to temperatures in the low 70's in Southwestern Pennsylvania.  Those types of extremes over 250 miles are "typical" of wacky early Spring storms.