SPC MD 307

MD 0307 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF SOUTHWESTERN THROUGH THE SOUTHERN TIER OF NEW YORK STATE...NORTHWESTERN PENNSYLVANIA...AND NORTHEASTERN OHIO Mesoscale Discussion 0307 NWS Storm Prediction Center Norman OK 1249 PM CDT Tue Mar 31 2026 Areas affected...parts of southwestern through the southern tier of New York State...northwestern Pennsylvania...and northeastern Ohio Concerning...Severe potential...Watch possible Valid 311749Z - 312015Z Probability of Watch Issuance...60 percent SUMMARY...Organizing thunderstorm development accompanied by a risk of damaging wind gusts, and perhaps potential to produce a couple of tornadoes, appears increasingly probable through 4-6 PM EDT. DISCUSSION...In the wake of early day convection, substantive boundary-layer destabilization is underway in response to modest boundary-layer moistening and insolation, southeast and east of the Lake Erie vicinity. This is occurring downstream of broad mid/upper troughing progressing across the Upper Midwest into Great Lakes region, in the presence of broad lower/mid-tropospheric warm advection, south of a sharp remnant frontal zone across the Lake Ontario through southern New England vicinity. A small cluster of vigorous thunderstorm activity is already underway across Ontario, to the north of Lake Erie. This appears to have developed near/south of a remnant cyclonic vorticity center migrating toward Lake Ontario, which convection allowing guidance suggests may contribute to additional development across southwestern through the southern tier of New York by 20-22Z. The lake breeze may support additional development to the southeast of Lake Erie, as west-southwesterly low-level flow begins to strengthen across the lower Great Lakes (including to 40-50+ kt around 850 mb), downstream of a low-amplitude frontal wave migrating across Lower Michigan into southwestern Ontario. Although potential for sustained discrete thunderstorm development remains uncertain, low-level hodographs may become conducive to the evolution of low-level mesocyclones with potential to produce a couple of tornadoes, in addition to damaging wind gusts. ..Kerr/Hart.. 03/31/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BGM...BUF...CTP...PBZ...CLE... LAT...LON 42697874 43247843 43007702 43167592 42617537 42297600 41877815 41417967 41288056 41598115 42187968 42697874 Read more