Historical and modeled monthly values for Lake Superior for the 64 months prior to the forecast outlooks starting 03May2018 Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Basin Runoff to Lake (mm) 2013 31.74 23.92 25.33 49.40 101.62 57.22 37.37 34.08 32.36 39.24 46.59 33.61 2014 25.33 21.11 24.08 65.66 105.84 65.51 37.99 33.61 45.34 53.94 40.81 42.21 2015 34.71 26.27 42.84 82.24 98.18 61.76 43.62 38.46 32.83 35.96 56.28 56.44 2016 42.68 34.71 62.69 65.51 53.94 55.35 38.93 31.58 31.74 40.65 35.02 48.00 2017 38.46 43.15 52.22 85.21 112.88 70.82 47.84 48.00 43.78 53.78 53.31 52.22 2018 40.81 31.89 34.55 48.78 - - - - - - - - Total Over-Lake Precipitation (mm) 2013 39.90 28.63 36.52 68.08 99.11 73.83 116.88 81.57 70.16 71.45 65.55 46.78 2014 41.21 36.71 33.34 66.43 71.22 113.80 80.13 66.67 103.53 83.52 66.78 47.99 2015 36.11 44.55 63.48 43.15 88.06 79.43 60.65 86.34 73.58 68.96 70.70 78.58 2016 36.61 34.25 45.37 29.55 60.32 119.72 76.24 80.24 94.31 67.92 63.08 99.28 2017 128.02 75.03 51.81 79.94 93.60 93.63 52.78 96.76 97.54 82.61 81.76 146.63 2018 97.85 26.62 9.92 56.43 - - - - - - - - Total Lake Evaporation (mm) 2013 132.65 85.10 66.11 34.20 5.61 -1.89 8.63 15.26 54.33 82.43 122.95 150.32 2014 117.50 49.78 31.14 13.67 -1.11 -3.87 -4.58 0.71 39.99 58.57 123.60 86.11 2015 101.00 72.41 29.24 11.75 -0.50 -3.07 -3.58 10.59 28.40 76.29 70.34 87.84 2016 111.53 78.84 35.81 32.80 3.37 2.85 11.20 28.86 46.65 79.18 72.67 161.54 2017 109.79 81.58 70.92 15.99 5.56 5.52 14.95 41.06 40.83 87.03 130.00 145.75 2018 110.69 79.05 56.32 48.64 - - - - - - - - Total Net Basin Supply to Lake (mm) 2013 -61.00 -32.55 -4.26 83.29 195.12 132.94 145.61 100.39 48.20 28.26 -10.81 -69.93 2014 -50.96 8.03 26.28 118.43 178.17 183.18 122.71 99.58 108.88 78.89 -16.01 4.09 2015 -30.19 -1.59 77.08 113.63 186.75 144.26 107.85 114.21 78.01 28.63 56.64 47.17 2016 -32.24 -9.88 72.26 62.26 110.88 172.21 103.97 82.96 79.40 29.39 25.44 -14.26 2017 56.70 36.60 33.11 149.15 200.92 158.93 85.67 103.71 100.49 49.37 5.07 53.10 2018 27.96 -20.54 -11.85 56.57 - - - - - - - - Average Over-Land Air Temperature (C) 2013 -11.66 -11.75 -6.69 -0.48 8.45 14.51 17.24 17.68 13.35 6.44 -2.23 -15.66 2014 -17.10 -15.74 -10.20 0.31 9.31 14.94 16.13 16.65 12.10 5.81 -5.64 -6.96 2015 -13.10 -18.00 -4.77 2.80 9.82 14.21 17.78 17.23 15.66 6.36 2.16 -3.07 2016 -9.94 -9.16 -2.02 1.46 10.42 14.94 18.47 18.86 15.02 7.90 3.25 -8.41 2017 -8.49 -6.87 -5.10 3.99 8.56 15.00 17.62 15.86 14.08 8.03 -3.03 -12.09 2018 -11.91 -12.23 -5.64 -1.17 - - - - - - - - Average Lake Surface Temperature (C) 2013 4.24 1.77 1.04 1.62 2.80 5.11 12.31 15.64 15.29 11.49 7.34 4.44 2014 1.03 0.00 0.00 0.00 0.79 2.61 4.79 11.38 12.51 9.18 6.00 3.62 2015 0.92 0.01 0.00 0.22 1.81 3.17 7.35 13.59 14.68 10.82 7.73 5.70 2016 3.72 1.81 1.72 2.47 3.77 9.32 15.47 18.43 16.84 12.44 9.06 6.34 2017 4.26 2.42 1.73 2.70 4.04 9.98 14.96 16.81 15.30 12.22 7.65 5.33 2018 2.52 0.53 0.68 1.26 - - - - - - - - Average Over-Lake Air Temperature (C) 2013 -3.65 -5.01 -2.92 1.00 5.22 8.41 13.85 16.50 14.75 9.42 2.59 -5.69 2014 -8.95 -11.08 -6.92 0.45 4.54 7.05 8.80 13.30 12.50 8.03 0.20 -1.41 2015 -6.22 -11.50 -3.10 1.63 5.07 7.05 10.92 14.96 15.24 9.35 5.16 1.53 2016 -3.31 -3.51 0.22 2.14 6.43 11.31 16.54 18.80 16.53 10.73 6.72 -1.33 2017 -2.37 -2.29 -1.68 3.50 6.08 11.57 15.69 16.58 15.19 10.60 2.41 -3.46 2018 -4.76 -6.24 -2.50 0.04 - - - - - - - - Average Over-Lake Vapor Pressure (mb) 2013 3.49 3.21 3.57 5.09 7.15 9.49 13.66 15.92 13.68 9.08 5.40 2.86 2014 2.34 1.98 2.80 4.87 6.90 8.66 10.02 13.63 12.06 8.54 4.50 4.42 2015 2.88 1.81 3.67 5.15 7.20 8.75 11.52 14.72 14.51 8.92 7.09 5.51 2016 3.64 3.59 4.82 5.24 7.76 11.31 16.03 18.32 15.64 10.17 7.81 4.12 2017 4.07 3.91 4.04 6.08 7.57 11.52 14.98 15.66 14.40 9.88 5.19 3.60 2018 3.26 2.78 3.42 4.14 - - - - - - - - Average Over-Lake Wind Speed (m/s) 2013 8.34 7.81 7.19 6.41 4.86 3.94 4.20 4.05 5.39 6.32 8.08 8.06 2014 8.31 6.94 5.94 5.24 4.16 4.15 4.13 3.83 5.37 6.44 8.14 7.36 2015 8.17 7.65 5.99 5.18 4.48 3.95 4.08 4.43 4.68 6.61 6.84 7.62 2016 7.78 7.79 5.87 5.85 4.45 4.34 4.16 4.49 5.39 6.42 6.64 8.83 2017 7.54 7.91 7.17 5.32 4.58 4.32 4.10 4.92 5.17 6.73 8.05 8.17 2018 8.09 7.56 6.58 6.43 - - - - - - - - Average Over-Lake Cloud Cover (%) 2013 84.19 83.21 77.55 78.43 54.26 53.33 49.06 43.32 48.20 65.10 76.00 74.13 2014 71.19 64.89 55.19 60.50 57.55 51.57 50.77 53.84 55.97 70.87 74.33 77.29 2015 76.19 62.86 51.10 51.00 54.16 49.50 41.32 57.97 43.57 58.81 67.03 87.06 2016 82.52 77.41 61.45 58.60 50.90 51.80 41.94 50.29 56.73 67.55 63.53 81.68 2017 78.10 68.54 57.48 62.00 60.65 55.20 42.16 53.87 51.80 57.48 81.70 76.32 2018 72.87 59.07 51.81 46.20 - - - - - - - - Average Lake Surface Incident SW Radiation (w/m2) 2013 45.81 74.87 121.14 155.51 245.05 255.84 258.38 235.71 173.46 103.11 52.87 41.45 2014 54.78 95.02 156.56 193.17 237.54 260.38 253.45 215.11 160.95 94.38 54.80 39.99 2015 51.14 99.07 164.46 213.93 244.53 265.69 276.88 204.95 182.14 110.97 59.47 34.75 2016 47.10 82.64 146.96 198.64 252.47 259.81 275.06 221.52 160.81 100.51 63.33 37.28 2017 49.50 91.54 153.65 189.35 228.24 250.97 274.33 213.06 168.32 111.96 48.58 40.47 2018 53.21 101.39 163.47 225.18 - - - - - - - - Average Lake Surface Reflection (w/m2) 2013 -4.58 -7.49 -12.11 -15.55 -24.50 -25.58 -25.84 -23.57 -17.35 -10.31 -5.29 -4.14 2014 -6.21 -25.43 -50.04 -48.17 -25.19 -26.04 -25.34 -21.51 -16.09 -9.44 -5.48 -4.00 2015 -5.11 -21.58 -45.45 -31.40 -24.45 -26.57 -27.69 -20.49 -18.21 -11.10 -5.95 -3.48 2016 -4.71 -8.26 -14.70 -19.86 -25.25 -25.98 -27.51 -22.15 -16.08 -10.05 -6.33 -3.73 2017 -4.95 -9.15 -15.37 -18.93 -22.82 -25.10 -27.43 -21.31 -16.83 -11.20 -4.86 -4.05 2018 -5.32 -10.14 -16.35 -22.52 - - - - - - - - Average Lake Surface Net Long Wave Radiation (w/m2) 2013 -83.09 -78.80 -69.14 -47.37 -41.58 -28.91 -26.20 -27.81 -38.68 -50.16 -68.10 -100.71 2014 -100.25 -102.10 -89.52 -54.24 -34.29 -28.10 -25.38 -19.90 -35.35 -42.14 -77.09 -69.93 2015 -84.99 -107.05 -77.38 -55.72 -37.32 -31.86 -29.62 -16.06 -34.02 -52.33 -56.94 -56.89 2016 -79.53 -74.33 -62.63 -59.08 -40.48 -30.39 -27.31 -16.16 -23.32 -42.26 -56.49 -82.01 2017 -78.46 -76.69 -76.08 -47.99 -36.93 -28.23 -32.63 -25.08 -30.90 -50.84 -67.98 -91.02 2018 -86.88 -93.25 -81.57 -75.19 - - - - - - - - Average Lake Surface Latent Heat Flux (w/m2) 2013 -123.36 -87.83 -61.67 -32.95 -5.23 1.82 -7.95 -14.04 -51.66 -76.17 -117.82 -139.76 2014 -109.63 -51.92 -29.85 -13.78 1.03 3.73 4.26 -0.65 -38.13 -54.21 -118.59 -80.13 2015 -94.20 -75.07 -28.09 -11.54 0.47 2.96 3.32 -9.75 -27.03 -70.49 -67.40 -81.60 2016 -103.76 -78.55 -33.38 -31.58 -3.14 -2.72 -10.31 -26.48 -44.30 -73.08 -69.53 -149.94 2017 -102.09 -84.13 -66.12 -15.39 -5.17 -5.27 -13.76 -37.73 -38.83 -80.36 -124.53 -135.42 2018 -103.08 -81.67 -52.55 -46.89 - - - - - - - - Average Lake Surface Sensible Heat Flux (w/m2) 2013 -122.38 -95.70 -50.57 -12.81 6.99 6.00 3.27 2.36 -6.22 -23.79 -71.48 -152.15 2014 -153.40 -70.52 -28.68 0.26 7.32 7.62 7.24 4.38 -5.95 -14.23 -87.11 -72.38 2015 -113.01 -106.51 -16.79 3.87 8.07 6.41 6.94 3.35 0.12 -16.83 -32.21 -57.99 2016 -101.75 -77.04 -17.96 -10.43 6.74 6.54 3.58 0.83 -3.42 -18.70 -29.87 -127.31 2017 -98.98 -75.68 -54.05 1.78 6.36 4.95 2.28 -2.43 -3.37 -22.56 -73.87 -133.94 2018 -111.38 -95.24 -34.30 -23.82 - - - - - - - - Average Lake Surface Net Surface Flux (w/m2) 2013 -288.48 -195.23 -72.46 46.73 180.70 209.19 201.47 172.29 58.20 -58.75 -211.27 -356.39 2014 -314.89 -154.92 -41.48 77.25 186.42 217.60 214.25 177.40 64.61 -26.49 -234.65 -186.94 2015 -246.37 -211.12 -3.23 119.14 191.29 216.65 229.88 161.75 102.33 -41.09 -103.87 -165.96 2016 -243.33 -155.79 18.21 77.57 190.33 207.20 213.24 156.73 72.42 -45.11 -99.94 -327.32 2017 -235.74 -154.48 -58.16 108.74 169.64 197.22 202.43 125.43 77.37 -54.61 -224.28 -325.16 2018 -253.94 -179.00 -21.36 56.69 - - - - - - - - Average Lake-Ice Surface Temperature (C) 2013 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2014 -2.46 -12.96 -7.74 -0.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2015 0.00 -12.61 -3.90 -0.38 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2016 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2017 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2018 0.00 0.00 0.00 0.00 - - - - - - - - Average Lake Ice Cover (%) 2013 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2014 3.41 47.68 62.96 42.24 2.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2015 0.00 30.69 50.90 13.84 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2016 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2017 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2018 0.00 0.00 0.00 0.00 - - - - - - - - End-of-Month Lake Heat Storage (cal/10e17) 2013 441.92 349.32 311.28 335.06 429.95 536.27 642.08 732.55 762.01 731.02 623.63 436.47 2014 286.78 261.02 245.30 228.26 306.56 417.15 529.67 622.84 655.57 641.52 522.26 424.08 2015 294.70 248.11 229.79 248.63 349.09 459.20 579.92 664.79 716.69 694.85 642.03 554.87 2016 427.09 350.56 360.15 399.58 499.54 604.84 716.82 799.07 835.73 811.95 761.09 589.20 2017 465.39 392.12 361.60 416.86 505.95 606.18 712.49 778.34 817.48 788.66 674.68 503.91 2018 370.56 285.67 274.48 303.30 - - - - - - - - End-of-Month Basin Soil Moisture (cm) 2013 3.52 2.73 3.31 7.84 9.01 1.66 2.03 0.85 1.22 3.25 4.04 2.85 2014 2.16 1.74 2.26 8.20 7.42 1.64 1.37 0.89 2.81 4.80 4.35 4.13 2015 3.01 2.35 3.87 9.93 9.78 4.88 1.03 0.60 0.90 4.06 4.85 5.02 2016 3.94 3.67 6.73 7.75 5.40 2.17 0.57 0.68 2.16 3.52 5.43 3.70 2017 4.30 5.17 5.81 9.18 10.93 6.82 1.39 1.70 1.55 3.28 4.16 3.47 2018 2.76 2.29 2.63 7.61 - - - - - - - - End-of-Month Basin Groundwater Moisture (cm) 2013 11.95 11.47 11.15 11.92 14.69 15.64 14.81 13.81 13.24 13.39 13.80 13.10 2014 12.34 11.72 11.29 12.37 15.15 17.14 15.74 14.50 14.56 15.39 15.34 14.91 2015 14.03 13.25 13.03 14.40 17.41 17.55 16.45 15.53 14.56 14.43 15.48 15.55 2016 14.62 13.99 14.37 14.90 15.89 15.79 14.56 13.48 12.88 13.27 13.45 13.68 2017 13.63 13.92 14.19 15.86 18.91 21.79 20.97 19.25 18.39 17.76 17.11 16.51 2018 15.42 14.47 13.70 13.81 - - - - - - - - End-of-Month Basin Surface Moisture (cm) 2013 4.26 4.00 3.99 5.52 4.88 4.54 4.78 4.72 4.64 4.86 4.98 4.72 2014 4.51 4.30 4.26 5.62 5.08 5.29 5.32 5.43 5.84 6.11 6.24 6.17 2015 5.89 5.63 5.97 7.13 6.85 6.46 6.17 6.27 6.12 6.33 6.35 6.27 2016 5.95 5.75 6.15 6.11 5.95 5.98 5.50 5.38 5.46 5.33 5.96 5.19 2017 5.22 5.44 5.41 6.23 7.18 7.22 7.47 7.95 8.24 8.54 8.41 8.18 2018 7.83 7.47 7.12 8.39 - - - - - - - - End-of-Month Basin Snow Pack (cm) 2013 5.13 7.97 9.60 5.29 0.00 0.00 0.00 0.00 0.00 0.00 1.60 6.20 2014 10.31 13.93 15.51 8.58 0.86 0.00 0.00 0.00 0.00 0.13 4.21 6.66 2015 10.22 14.68 16.27 5.36 0.00 0.00 0.00 0.00 0.00 0.00 0.35 3.89 2016 6.98 9.12 5.16 1.40 0.00 0.00 0.00 0.00 0.00 0.00 0.57 9.48 2017 19.00 21.99 22.52 17.75 10.20 4.15 0.00 0.00 0.00 0.55 4.70 17.31 2018 26.51 28.81 28.23 23.69 - - - - - - - - End-of-Month Basin Total Moisture (cm) 2013 24.86 26.17 28.05 30.57 28.58 21.84 21.62 19.38 19.10 21.50 24.42 26.87 2014 29.32 31.69 33.32 34.77 28.51 24.07 22.43 20.82 23.21 26.43 30.14 31.87 2015 33.15 35.91 39.14 36.82 34.04 28.89 23.65 22.40 21.58 24.82 27.03 30.73 2016 31.49 32.53 32.41 30.16 27.24 23.94 20.63 19.54 20.50 22.12 25.41 32.05 2017 42.15 46.52 47.93 49.02 47.22 39.98 29.83 28.90 28.18 30.13 34.38 45.47 2018 52.52 53.04 51.68 53.50 - 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