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.

   ..Mosier/Guyer.. 04/21/2021

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...GYX...BOX...OKX...ALY...PHI...BGM...

   LAT...LON   42007464 42827370 42997248 42527173 40567305 40117347
               39677459 39897543 40937512 42007464