Northwestern Pennsylvania - PA10

Included Counties: Erie, Warren, McKean, Potter, Crawford, Mercer, Venango, Forest, Clarion, Jefferson

Watersheds:

Ashtabula-Chagrin, Chautauqua-Conneaut, Clarion, Conewango, Connoquenessing, French, Lake Erie, Middle Allegheny-Redbank, Middle Allegheny-Tionesta, Middle West Branch Susquehanna, Pine, Shenango, Sinnemahoning, Tioga, Upper Allegheny, Upper Genesee, Upper West Branch Susquehanna

Geography Immediately adjacent to Lake Erie is the Lake Erie Plain, a narrow strip of flat, rich land 3 to 4 miles wide. Fine alluvial soils and a favorable climate sustain substantial vegetable and fruit cultivation typical of the area surrounding Lake Erie. The division extends irregularly inland and east, including much of Allegheny National Forest and the cities of Erie, Brookville, and Coudersport. Overview Although the northwestern areas of Pennsylvania’s Northwest Climate Division experience a strong lake effect, the climate is primarily continental, characterized by larger temperature ranges than in areas at the same latitude near the Great Lakes which have moderated temperatures. The northwestern sections of the division do, however, reside in the “snowbelt” of northern Pennsylvania and can experience significant lake-effect snow. Because the day-to-day weather is controlled by the movement of pressure systems across the nation, this area seldom experiences prolonged periods of extreme heat or cold, though hot and humid days are more frequent than in more northerly locations. Precipitation is well-distributed throughout the year with slightly more rain falling during the late spring and early summer. Summer precipitation comes mainly in the form of afternoon thunderstorms.