Overview

The UV Emerging Thunder is a small, slim emerger pattern from Montana Fly Company, tied for the stage of a hatch when midges and small mayflies are rising through the water and struggling to break the surface.

Emergers are often the easiest food for a trout to catch, so fish key on them during a hatch. This fly keeps a natural, slender outline and adds UV-reactive materials that show up to trout under the low, flat light of overcast days, when many small-fly hatches happen. In sizes 18 to 22 it fits the tailwaters and spring creeks where small bugs make up much of a trout's diet.

How to Fish It

• In or just under the film: fish it on 6X tippet as a dropper 12 to 18 inches behind a small dry during a hatch.
• Trailing nymph: run it as the second fly behind a heavier nymph under an indicator as fish start moving up for emergers.
• Swing at the end: let the fly rise at the end of a drift; that lift imitates an emerging insect and draws strikes.
• Cold-season hatches: midges and blue-winged olives hatch through winter and spring on many tailwaters, so this fly works much of the year.

Choosing Color and Size

Chocolate is a natural brown that matches many midges and darker mayfly emergers. Huckleberry is a darker, purple-toned option that holds contrast in low light and on pressured water where trout have seen plenty of natural colors.

Use size 18 for larger midges and small mayflies, size 20 as the everyday size, and size 22 for the smallest midges and the most selective fish.