South Fork Bull Run River Near Bull Run
South Fork Bull Run River · Pacific NW · USGS gage 14139800
Coldwater (summer mean 13.4°C — prime coldwater).
Water
54°F
Flow
9 cfs
Air
55°F
Sky
0%
Pressure
30.01 in
Wind
3 mph
Predicted hatches · 2026-09-15
PredictedMidgeChironomidae0.31
water 12.3°C (54°F) is cooling past the prime band (1-10°C); shoulder of the season; 8 days sustained ≥0°C; watch midday, especially cold months.
flies: Zebra Midge #18-22, Griffith's Gnat, Disco Midge
PredictedBlue-Winged OliveBaetis spp.0.28
water 12.3°C (54°F) is cooling past the prime band (6-11°C); shoulder of the season; 8 days sustained ≥4°C; watch midday, especially overcast afternoons.
flies: BWO Sparkle Dun #18-22, RS2, Pheasant Tail #18
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.