The Alley Index

7-Day Forecast

A rule-based forecast built from NWS weather, AHPS flow predictions where available, recent storm pulse behavior, and current river scoring.

Updated Sep 12, 6:00 PM EDT

Best Window

Saturday looks like the best window so far: 78 (Good).

Sat

66 Live

95% confidence

live Alley Index snapshot

Sun

75 Projected

55% confidence

recent flow trajectory dropping

Mon

63 Projected

51% confidence

recent flow trajectory dropping

Tue

75 Projected

47% confidence - low

recent flow trajectory dropping

Wed

49 Projected

47% confidence - low

incoming rain matched to recent pulse behavior

Thu

49 Projected

44% confidence - low

incoming rain matched to recent pulse behavior

Fri

56 Projected

33% confidence - low

recent flow trajectory dropping

Saturday, Sep 12 river details 31 rivers

Cattaraugus Creek

excellent

318 CFS - 68.5 F - Clear

Confidence 95%

Conneaut Creek

excellent

33.1 CFS - 67.3 F - Clear

Confidence 95%

Oak Orchard Creek

excellent

984 CFS - 70.3 F - Clear

Confidence 95%

Genesee River

excellent

1910 CFS - 70.2 F - Clear

Confidence 95%

Ashtabula River

excellent

25.92 CFS - 54.3 F - Clear

Confidence 95%

Cuyahoga River

excellent

467 CFS - 72 F - Clear

Confidence 95%

Huron River

excellent

36.2 CFS - 71.1 F - Clear

Confidence 95%

Johnson Creek

excellent

134 CFS - 67.1 F - Stained

Confidence 95%

Walnut Creek

good

12 CFS - 66.6 F - Clear

Confidence 95%

Sandy Creek (Hamlin)

good

83.6 CFS - 70.7 F - Clear

Confidence 95%

Irondequoit Creek

good

82.4 CFS - 64.8 F - Clear

Confidence 95%

Eighteenmile Creek (Niagara)

good

119 CFS - 69.6 F - Clear

Confidence 95%

Sandy Creek (Adams)

good

58 CFS - n/a F - Clear

Confidence 95%

Rocky River

good

83.8 CFS - n/a F - Clear

Confidence 95%

Twenty Mile Creek

good

21.96 CFS - 55.6 F - Clear

Confidence 95%

Crooked Creek

good

5.56 CFS - 55.6 F - Clear

Confidence 95%

Silver Creek

good

2.34 CFS - n/a F - Clear

Confidence 95%

Vermilion River

fair

16.6 CFS - n/a F - Clear

Confidence 95%

Elk Creek

fair

11.04 CFS - 55.6 F - Clear

Confidence 95%

Euclid Creek

fair

10 CFS - n/a F - Clear

Confidence 95%

Black River (Watertown)

fair

2150 CFS - n/a F - Clear

Confidence 95%

Brandy Run

fair

1.54 CFS - n/a F - Clear

Confidence 95%

Chautauqua Creek

fair

18.3 CFS - n/a F - Clear

Confidence 95%

Eighteen Mile Creek

fair

10 CFS - n/a F - Clear

Confidence 95%

Canadaway Creek

fair

10.1 CFS - n/a F - Clear

Confidence 95%

Buffalo Creek

fair

34.3 CFS - n/a F - Clear

Confidence 95%

Cazenovia Creek

fair

22.5 CFS - n/a F - Clear

Confidence 95%

Salmon River

fair

228 CFS - n/a F - Clear

Confidence 95%

Chagrin River

fair

57.4 CFS - n/a F - Clear

Confidence 95%

Grand River

fair

81.3 CFS - n/a F - Clear

Confidence 95%

Black River

fair

56.4 CFS - n/a F - Clear

Confidence 95%

Sunday, Sep 13 river details 31 rivers

Johnson Creek

excellent

99.2 CFS - 67 F - Stained

Confidence 57.9%

Eighteenmile Creek (Niagara)

excellent

105.2 CFS - 70 F - Clear

Confidence 57.9%

Oak Orchard Creek

fair

1143.2 CFS - 70.6 F - Stained

Confidence 57.9%

Sandy Creek (Hamlin)

excellent

77.3 CFS - 71.3 F - Clear

Confidence 57.9%

Irondequoit Creek

excellent

204 CFS - 65.8 F - Stained

Confidence 55%

Cuyahoga River

excellent

509 CFS - 74.5 F - Clear

Confidence 70%

Conneaut Creek

good

19 CFS - 68.8 F - Clear

Confidence 57.9%

Walnut Creek

good

9.2 CFS - 67.1 F - Clear

Confidence 57.9%

Cattaraugus Creek

good

305 CFS - 69.3 F - Clear

Confidence 70%

Huron River

good

38.2 CFS - 72.7 F - Clear

Confidence 57.9%

Genesee River

good

1891.8 CFS - 70.8 F - Clear

Confidence 56.3%

Black River (Watertown)

good

2731.7 CFS - n/a F - Clear

Confidence 49.9%

Ashtabula River

good

14.3 CFS - 55.4 F - Clear

Confidence 57.9%

Elk Creek

good

9 CFS - 56.8 F - Clear

Confidence 57.9%

Twenty Mile Creek

good

15.6 CFS - 55.7 F - Clear

Confidence 57.9%

Crooked Creek

good

3.9 CFS - 56.8 F - Clear

Confidence 57.9%

Black River

good

99.5 CFS - n/a F - Clear

Confidence 49.9%

Rocky River

fair

84.7 CFS - n/a F - Clear

Confidence 49.9%

Sandy Creek (Adams)

fair

44.1 CFS - n/a F - Clear

Confidence 49.9%

Chagrin River

fair

44.5 CFS - n/a F - Clear

Confidence 49.9%

Vermilion River

fair

19.5 CFS - n/a F - Clear

Confidence 49.9%

Grand River

fair

84.9 CFS - n/a F - Clear

Confidence 62%

Brandy Run

fair

1.3 CFS - n/a F - Clear

Confidence 49.9%

Chautauqua Creek

fair

16.9 CFS - n/a F - Clear

Confidence 49.9%

Eighteen Mile Creek

fair

9.6 CFS - n/a F - Clear

Confidence 49.9%

Euclid Creek

fair

10.8 CFS - n/a F - Clear

Confidence 49.9%

Canadaway Creek

fair

7.8 CFS - n/a F - Clear

Confidence 49.9%

Silver Creek

fair

1.6 CFS - n/a F - Clear

Confidence 49.9%

Buffalo Creek

fair

24.4 CFS - n/a F - Clear

Confidence 49.9%

Cazenovia Creek

fair

18 CFS - n/a F - Clear

Confidence 49.9%

Salmon River

fair

239.8 CFS - n/a F - Clear

Confidence 48.3%

Monday, Sep 14 river details 31 rivers

Johnson Creek

excellent

71.5 CFS - 64.8 F - Clear

Confidence 53.1%

Cuyahoga River

excellent

427 CFS - 71.6 F - Clear

Confidence 69%

Oak Orchard Creek

fair

1106.3 CFS - 68.1 F - Stained

Confidence 53.1%

Eighteenmile Creek (Niagara)

excellent

91.6 CFS - 67.5 F - Clear

Confidence 53.1%

Cattaraugus Creek

good

264 CFS - 66.5 F - Clear

Confidence 69%

Sandy Creek (Hamlin)

good

69.1 CFS - 68.8 F - Clear

Confidence 53.1%

Conneaut Creek

good

7.9 CFS - 65.9 F - Clear

Confidence 53.1%

Walnut Creek

good

6.3 CFS - 64.6 F - Clear

Confidence 53.1%

Huron River

good

34.3 CFS - 69.6 F - Clear

Confidence 53.1%

Genesee River

good

1464.2 CFS - 67.5 F - Clear

Confidence 53.1%

Irondequoit Creek

good

65.2 CFS - 62.5 F - Clear

Confidence 53.1%

Ashtabula River

good

5.5 CFS - 52.8 F - Clear

Confidence 53.1%

Elk Creek

good

6 CFS - 54.2 F - Clear

Confidence 53.1%

Twenty Mile Creek

good

10.6 CFS - 53.2 F - Clear

Confidence 53.1%

Crooked Creek

good

2.5 CFS - 54.2 F - Clear

Confidence 53.1%

Black River

good

244.2 CFS - n/a F - Clear

Confidence 46.1%

Black River (Watertown)

good

3661.1 CFS - n/a F - Clear

Confidence 46.1%

Rocky River

fair

82.4 CFS - n/a F - Clear

Confidence 46.1%

Euclid Creek

fair

12 CFS - n/a F - Clear

Confidence 46.1%

Salmon River

fair

219.1 CFS - n/a F - Clear

Confidence 46.1%

Sandy Creek (Adams)

fair

30.9 CFS - n/a F - Clear

Confidence 46.1%

Chagrin River

fair

30.9 CFS - n/a F - Clear

Confidence 46.1%

Vermilion River

fair

24.4 CFS - n/a F - Clear

Confidence 46.1%

Grand River

fair

154 CFS - n/a F - Clear

Confidence 62%

Brandy Run

fair

1.1 CFS - n/a F - Clear

Confidence 46.1%

Chautauqua Creek

fair

14.5 CFS - n/a F - Clear

Confidence 46.1%

Eighteen Mile Creek

fair

8 CFS - n/a F - Clear

Confidence 46.1%

Canadaway Creek

fair

5.1 CFS - n/a F - Clear

Confidence 46.1%

Silver Creek

fair

0.8 CFS - n/a F - Clear

Confidence 46.1%

Buffalo Creek

fair

15.9 CFS - n/a F - Clear

Confidence 46.1%

Cazenovia Creek

fair

13 CFS - n/a F - Clear

Confidence 46.1%

Tuesday, Sep 15 river details 31 rivers

Oak Orchard Creek

excellent

1095.8 CFS - 70.4 F - Stained

Confidence 48.2%

Johnson Creek

excellent

65 CFS - 67 F - Clear

Confidence 48.2%

Eighteenmile Creek (Niagara)

excellent

87.9 CFS - 69.7 F - Clear

Confidence 48.2%

Cuyahoga River

excellent

387 CFS - 74.3 F - Clear

Confidence 68%

Sandy Creek (Hamlin)

excellent

66.9 CFS - 71 F - Clear

Confidence 48.2%

Conneaut Creek

good

6 CFS - 68.5 F - Clear

Confidence 48.2%

Walnut Creek

good

5.6 CFS - 67.3 F - Clear

Confidence 48.2%

Cattaraugus Creek

good

226 CFS - 68.8 F - Clear

Confidence 68%

Huron River

good

33.2 CFS - 72.7 F - Clear

Confidence 48.2%

Genesee River

good

1439.1 CFS - 69.8 F - Clear

Confidence 48.2%

Irondequoit Creek

good

62.7 CFS - 64.8 F - Clear

Confidence 48.2%

Black River

good

317.1 CFS - n/a F - Clear

Confidence 42.2%

Black River (Watertown)

good

3987.5 CFS - n/a F - Clear

Confidence 42.2%

Ashtabula River

good

4.1 CFS - 55.4 F - Clear

Confidence 48.2%

Elk Creek

good

5.3 CFS - 56.5 F - Clear

Confidence 48.2%

Twenty Mile Creek

good

9.4 CFS - 55.7 F - Clear

Confidence 48.2%

Crooked Creek

good

2.2 CFS - 56.8 F - Clear

Confidence 48.2%

Rocky River

fair

81.7 CFS - n/a F - Clear

Confidence 42.2%

Euclid Creek

fair

12.4 CFS - n/a F - Clear

Confidence 42.2%

Salmon River

fair

217.7 CFS - n/a F - Clear

Confidence 42.2%

Sandy Creek (Adams)

fair

27.9 CFS - n/a F - Clear

Confidence 42.2%

Chagrin River

fair

27.8 CFS - n/a F - Clear

Confidence 42.2%

Vermilion River

fair

26.1 CFS - n/a F - Clear

Confidence 42.2%

Grand River

fair

128 CFS - n/a F - Clear

Confidence 62%

Brandy Run

fair

1 CFS - n/a F - Clear

Confidence 42.2%

Chautauqua Creek

fair

13.9 CFS - n/a F - Clear

Confidence 42.2%

Eighteen Mile Creek

fair

7.6 CFS - n/a F - Clear

Confidence 42.2%

Canadaway Creek

fair

4.5 CFS - n/a F - Clear

Confidence 42.2%

Silver Creek

fair

0.7 CFS - n/a F - Clear

Confidence 42.2%

Buffalo Creek

fair

14 CFS - n/a F - Clear

Confidence 42.2%

Cazenovia Creek

fair

11.9 CFS - n/a F - Clear

Confidence 42.2%

Wednesday, Sep 16 river details 31 rivers

Oak Orchard Creek

good

1095.8 CFS - 70.6 F - Stained

Confidence 43.4%

Ashtabula River

good

78 CFS - 55.3 F - Stained

Confidence 52%

Johnson Creek

good

65 CFS - 66.8 F - Clear

Confidence 43.4%

Black River (Watertown)

good

3987.5 CFS - n/a F - Clear

Confidence 38.4%

Twenty Mile Creek

good

9.4 CFS - 55.9 F - Clear

Confidence 43.4%

Eighteenmile Creek (Niagara)

good

125.9 CFS - 69.7 F - Clear

Confidence 53.3%

Elk Creek

fair

11.9 CFS - 56.6 F - Clear

Confidence 53.3%

Crooked Creek

fair

5.2 CFS - 56.9 F - Clear

Confidence 53.3%

Salmon River

fair

217.7 CFS - n/a F - Clear

Confidence 38.4%

Sandy Creek (Hamlin)

fair

66.9 CFS - 71.4 F - Clear

Confidence 43.4%

Sandy Creek (Adams)

fair

27.9 CFS - n/a F - Clear

Confidence 38.4%

Rocky River

fair

86.4 CFS - n/a F - Clear

Confidence 48.3%

Cuyahoga River

fair

349 CFS - 74.5 F - Clear

Confidence 67%

Cattaraugus Creek

fair

237 CFS - 69.4 F - Clear

Confidence 43.4%

Eighteen Mile Creek

fair

7.6 CFS - n/a F - Clear

Confidence 38.4%

Black River

fair

52.4 CFS - n/a F - Clear

Confidence 48.3%

Canadaway Creek

fair

4.5 CFS - n/a F - Clear

Confidence 38.4%

Buffalo Creek

fair

14 CFS - n/a F - Clear

Confidence 38.4%

Cazenovia Creek

fair

11.9 CFS - n/a F - Clear

Confidence 38.4%

Genesee River

fair

1439.1 CFS - 70.5 F - Clear

Confidence 43.4%

Irondequoit Creek

fair

62.7 CFS - 65.4 F - Clear

Confidence 43.4%

Conneaut Creek

fair

34.7 CFS - 68.4 F - Clear

Confidence 53.3%

Chagrin River

fair

57.6 CFS - n/a F - Clear

Confidence 48.3%

Vermilion River

fair

18.3 CFS - n/a F - Clear

Confidence 48.3%

Grand River

fair

104 CFS - n/a F - Clear

Confidence 62%

Brandy Run

fair

1.5 CFS - n/a F - Clear

Confidence 48.3%

Walnut Creek

fair

12.5 CFS - 67.5 F - Clear

Confidence 53.3%

Chautauqua Creek

fair

18.9 CFS - n/a F - Clear

Confidence 48.3%

Huron River

fair

41.3 CFS - 72.7 F - Clear

Confidence 53.3%

Euclid Creek

fair

10 CFS - n/a F - Clear

Confidence 48.3%

Silver Creek

fair

2.8 CFS - n/a F - Clear

Confidence 48.3%

Thursday, Sep 17 river details 31 rivers

Oak Orchard Creek

good

1095.8 CFS - 70.6 F - Stained

Confidence 38.5%

Johnson Creek

good

65 CFS - 67 F - Clear

Confidence 38.5%

Black River (Watertown)

good

3987.5 CFS - n/a F - Clear

Confidence 34.5%

Ashtabula River

good

49.8 CFS - 55.2 F - Stained

Confidence 51%

Elk Creek

good

5.3 CFS - 56.7 F - Clear

Confidence 38.5%

Twenty Mile Creek

good

9.4 CFS - 56 F - Clear

Confidence 38.5%

Eighteenmile Creek (Niagara)

good

87.9 CFS - 69.9 F - Clear

Confidence 38.5%

Crooked Creek

fair

5.2 CFS - 56.7 F - Clear

Confidence 52.3%

Sandy Creek (Hamlin)

fair

66.9 CFS - 71.4 F - Clear

Confidence 38.5%

Sandy Creek (Adams)

fair

27.9 CFS - n/a F - Clear

Confidence 34.5%

Rocky River

fair

86.4 CFS - n/a F - Clear

Confidence 48.3%

Cuyahoga River

fair

349 CFS - 74.2 F - Clear

Confidence 66%

Brandy Run

fair

1 CFS - n/a F - Clear

Confidence 34.5%

Walnut Creek

fair

5.6 CFS - 67.8 F - Clear

Confidence 38.5%

Cattaraugus Creek

fair

309 CFS - 69.7 F - Clear

Confidence 52.3%

Chautauqua Creek

fair

13.9 CFS - n/a F - Clear

Confidence 34.5%

Eighteen Mile Creek

fair

7.6 CFS - n/a F - Clear

Confidence 34.5%

Black River

fair

52.4 CFS - n/a F - Clear

Confidence 48.3%

Silver Creek

fair

0.7 CFS - n/a F - Clear

Confidence 34.5%

Buffalo Creek

fair

14 CFS - n/a F - Clear

Confidence 34.5%

Cazenovia Creek

fair

11.9 CFS - n/a F - Clear

Confidence 34.5%

Salmon River

fair

228 CFS - n/a F - Clear

Confidence 48.3%

Irondequoit Creek

fair

81.6 CFS - 65.5 F - Clear

Confidence 52.3%

Conneaut Creek

fair

34.7 CFS - 68.5 F - Clear

Confidence 52.3%

Chagrin River

fair

57.6 CFS - n/a F - Clear

Confidence 48.3%

Vermilion River

fair

16.6 CFS - n/a F - Clear

Confidence 48.3%

Grand River

fair

104 CFS - n/a F - Clear

Confidence 62%

Huron River

fair

41.3 CFS - 72.6 F - Clear

Confidence 52.3%

Euclid Creek

fair

10 CFS - n/a F - Clear

Confidence 48.3%

Canadaway Creek

fair

10.5 CFS - n/a F - Clear

Confidence 48.3%

Genesee River

fair

1819.7 CFS - 70.6 F - Clear

Confidence 52.3%

Friday, Sep 18 river details 31 rivers

Oak Orchard Creek

good

1095.8 CFS - 69.5 F - Stained

Confidence 34.8%

Ashtabula River

good

4.1 CFS - 54.1 F - Clear

Confidence 34.8%

Black River

good

317.1 CFS - n/a F - Clear

Confidence 31.8%

Johnson Creek

good

65 CFS - 66.1 F - Clear

Confidence 34.8%

Black River (Watertown)

good

3987.5 CFS - n/a F - Clear

Confidence 31.8%

Cuyahoga River

good

490.3 CFS - 72.8 F - Clear

Confidence 34.8%

Elk Creek

good

5.3 CFS - 55.5 F - Clear

Confidence 34.8%

Twenty Mile Creek

good

9.4 CFS - 55.1 F - Clear

Confidence 34.8%

Crooked Creek

good

2.2 CFS - 55.7 F - Clear

Confidence 34.8%

Eighteenmile Creek (Niagara)

good

87.9 CFS - 68.9 F - Clear

Confidence 34.8%

Rocky River

fair

81.7 CFS - n/a F - Clear

Confidence 31.8%

Euclid Creek

fair

12.4 CFS - n/a F - Clear

Confidence 31.8%

Salmon River

fair

217.7 CFS - n/a F - Clear

Confidence 31.8%

Sandy Creek (Hamlin)

fair

66.9 CFS - 70.2 F - Clear

Confidence 34.8%

Sandy Creek (Adams)

fair

27.9 CFS - n/a F - Clear

Confidence 31.8%

Conneaut Creek

fair

6 CFS - 67.4 F - Clear

Confidence 34.8%

Chagrin River

fair

27.8 CFS - n/a F - Clear

Confidence 31.8%

Vermilion River

fair

26.1 CFS - n/a F - Clear

Confidence 31.8%

Grand River

fair

70.9 CFS - n/a F - Clear

Confidence 31.8%

Brandy Run

fair

1 CFS - n/a F - Clear

Confidence 31.8%

Walnut Creek

fair

5.6 CFS - 66.6 F - Clear

Confidence 34.8%

Cattaraugus Creek

fair

237 CFS - 68.5 F - Clear

Confidence 34.8%

Chautauqua Creek

fair

13.9 CFS - n/a F - Clear

Confidence 31.8%

Eighteen Mile Creek

fair

7.6 CFS - n/a F - Clear

Confidence 31.8%

Huron River

fair

33.2 CFS - 71.3 F - Clear

Confidence 34.8%

Canadaway Creek

fair

4.5 CFS - n/a F - Clear

Confidence 31.8%

Silver Creek

fair

0.7 CFS - n/a F - Clear

Confidence 31.8%

Buffalo Creek

fair

14 CFS - n/a F - Clear

Confidence 31.8%

Cazenovia Creek

fair

11.9 CFS - n/a F - Clear

Confidence 31.8%

Genesee River

fair

1439.1 CFS - 69.2 F - Clear

Confidence 34.8%

Irondequoit Creek

fair

62.7 CFS - 64.1 F - Clear

Confidence 34.8%

Methodology

This is a deterministic forecast, not an AI prediction. Flow uses AHPS when available, then storm pulse signatures, then recent log-linear flow trajectory, then a flat baseline fallback. Temperature and clarity are conservative heuristics. Confidence drops as the horizon gets farther out, especially on days 5-7.