Best sulphur patterns I've used in central PA have been the dark sulphur nymph and dark sulphur emerger patterns from FFP. Background info and recipe for their nymph is below (taken from their site) - for the emerger I just eliminate the wingcase and tie in a tuft of muskrat in it's place:
The Sulphur hatch is actually a multiplicity of insects, consisting of at least three species: Ephemerella rotunda, E. invaria, and E. dorothea. For those not inclined to speak in dead languages, think of the first two as large Sulphurs and the final species as the little Sulphur. For years at the store we sold a fairly pale Sulphur nymph, the body of which was a blend of cinnamon mink and chopped gold sparkle yarn. This nymph was (and is) deadly during the dorothea activity but is not nearly as effective during the earlier emergence of the large Sulphurs.
To meet this need, Dan Shields, partner in Flyfisher's Paradise, created the Dark Sulphur Nymph. Dan's original tie consisted of a Charles Brooks' style nymph in the round. The body was a blend of dark brown rabbit and chopped up gold Berber wool. The thorax was palmered with a furnace hen hackle, and furnace hen hackle fibers were the tail. The Dark Sulphur Nymph is extremely effective during the hatches of large, early Sulphurs.
Not content with Dan's original tie, I tweaked the pattern a bit. Because the Berber wool was hard to pick apart and blend, I opted for orange sparkle yarn, since its color was close to the wool and it added a touch of translucence that the trout seemed to like. In place of the furnace hen, I employed speckled brown hen saddle, because of the barring, and a wingcase seemed in order.
A bonus to carrying the Dark Sulphur Nymph is that it looks like many other nymphs. To me, it is more realistic that a Hare's Ear Nymph and fishes better, especially during the mid-April to mid-June burst of mayfly emergences.
Tying Instructions
* Hook: TMC #5262, #12-16
* Thread: 6/0 black unweighted, 6/0 brown weighted
* Weight: Fine lead wire, if desired
* Tail: Brown partridge or brown speckled hen fibers
* Body: Blend of 50% dyed brown Australian opossum and 50% orange sparkle yarn
* Wingcase: Doubled thickness of turkey tail quil
* Legs: Brown partridge or brown speckled hen fibers, tied in front of and to either side of the thorax