CTP for Monday finally barks. Buckle up.
“Model soundings indicate early low clouds should give way to brightening skies Monday, as the region breaks into the warm sector ahead of low pressure tracking across the lower Grt Lks. Heating of the moist/unstable airmass, combined with strong shear ahead of an upstream trough, will set the stage for severe weather during the PM hours.
The strongest mid level flow and best chance of severe weather appears focused over the southern tier counties. However, deep layer shear of 40kts+, combined with MLCAPE in the 1000-20000 J/kg range, will support a risk of all severe hazards over a good portion of Central PA. The latest SPC Outlook paints an Enhanced Risk of severe weather across Central Pennsylvania and a Slight Risk for the rest of the area.
Severe wind probabilities are some of the highest we get this time of year in the Lower Susquehanna Valley down into the Chesapeake Bay region. Tornadoes will also be possible with favorable 0-1km SRH values of 150 m2/s2 and STP of 1+. A mix of semi- discrete storms and some clusters will develop in the afternoon and then could congeal into a bowing MCS into the evening, especially across the south.
Flash flooding will maximize late Monday afternoon and evening as storm motions slow down and training becomes more likely. An active afternoon and evening appears increasingly likely across the mid- Atlantic with damaging winds”