**Severe Thunderstorm Watch may be issued**
Mesoscale Discussion 0402 NWS Storm Prediction Center Norman OK 1049 AM CDT Wed Apr 21 2021
Areas affected...Western MA...NY Hudson Valley...Western/Central Long Island...Western CT...NJ
Concerning...Severe potential...Watch possible
Valid 211549Z - 211815Z
Probability of Watch Issuance...60 percent
SUMMARY...Thunderstorm development is anticipated over the next hour or two along a cold front progressing through the Northeast. Damaging wind gusts are possible with these storms and trends are being monitored for possible Severe Thunderstorm Watch issuance.
DISCUSSION...Recent surface analysis places a low near the NY/NJ/PA border intersection. A warm front extends eastward/northeastward from this low across southern NY through western MA and off the far southern ME coast. This low is embedded within a broad area of low pressure preceding a strong frontal surge attendant to a shortwave moving into western PA/NY. This low is expected to deepen over the next few hours ahead of the front while the warm front lifts northward. As a result, temperatures in the low to mid 60s will likely be in place ahead of the front from western MA through central NJ. Low-level moisture will be modest (i.e. in upper 40s/low 50s) but the steep low and mid-level lapse rates will foster modest buoyancy.
Expectation is that deeper convection will begin developing along the front during the next hour or two before then moving quickly eastward across the region. Previously mentioned steep low-level lapse rates coupled with deep convection and strengthening low to mid-level flow will result in the potential for damaging wind gusts as the storms move through. Storm coverage may be high enough to merit watch issuance and convective trends are being monitored closely.