* AFFECTED AREA...White Mountains and High Terrain South of the Yukon River, Fortymile Country, Upper Chena River Valley, Tanana Flats, Eielson AFB and Salcha, Goldstream Valley and Nenana Hills, Chatanika River Valley, Two Rivers, Fairbanks Metro Area, Nenana and Central Interior.

* TIMING...Until 10 PM AKDT this evening.

* LIGHTNING ACTIVITY LEVEL...4.

* WINDS...Southeast 5 to 10 mph.

* HUMIDITY...As low as 29 percent.

* TEMPERATURES...Highs in the upper 80s.

* IMPACTS...Frequent lightning can promote new fire starts. Hot and dry conditions may lead to rapid spread of fires.

* WHAT...Visibility less than one mile in dense smoke.

* WHERE...Tanana Flats, Eielson AFB and Salcha and Fairbanks Metro Area. Also in the White Mountains and High Terrain South of the Yukon River along the Elliott Highway between mileposts 38 through 48 and the Steese Highway near Central.

* WHEN...Until 6 AM AKDT Friday.

* IMPACTS...Hazardous driving conditions due to low visibility.