Radar looks good southeast of us
Mesoscale Discussion 1653
NWS Storm Prediction Center Norman OK
0135 PM CDT Tue Jul 16 2024
Areas affected...Eastern Pennsylvania into Northern Maryland...New Jersey...and far Southern New York
Concerning...Severe potential...Watch possible
Valid 161835Z - 162030Z
Probability of Watch Issuance...40 percent
SUMMARY...A severe thunderstorm watch may be needed later this afternoon for storms capable of 60-70 MPH wind gusts.
DISCUSSION...Visible satellite trends and short-term WoFS guidance suggests that thunderstorm activity should increase over Central and Eastern Pennsylvania this afternoon, bringing a threat primarily for damaging straight-line winds. These storms are expected to progress eastward into New Jersey and far southern New York.
Surface observations show a hot, dry boundary-layer in place over the highlight area, with surface temperatures in the upper 90s F to low 100s F and dewpoints in the upper 60s F to low 70s F. These conditions have resulted in MLLCL heights of around 2-3 km and low-level lapse rates that are dry adiabatic beneath the LCL. Additionally, the better deep-layer wind shear supportive of organized convection is confined to northern and central PA, suggesting that the primary threat is for damaging winds from disorganized to weakly-organized multi-cell clusters. Weather watch issuance may be needed later this afternoon.