TABLE 5 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 23 CYCLE 24 AND BEGINNING OF CYCLE 25 TIME 10.7 CM SOLAR FLUX (F10.7) GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 75.0% 50% 5.0% 75.0% 50% 5.0% 2008.1667 MAR 70.3 69.8 68.8 7.8 7.5 7.0 2008.2500 APR 70.6 70.0 67.7 8.2 7.4 6.7 2008.3333 MAY 71.0 70.2 66.5 8.7 7.5 6.5 2008.4167 JUN 71.3 70.3 65.7 9.1 7.6 6.0 2008.5000 JUL 71.7 70.5 64.9 9.4 7.8 5.8 2008.5833 AUG 72.3 70.8 64.1 10.1 7.9 5.9 2008.6667 SEP 73.0 71.3 63.4 11.3 8.3 6.3 2008.7500 OCT 73.8 71.9 62.8 13.1 8.8 6.9 2008.8333 NOV 74.3 72.5 62.1 14.3 9.2 7.5 2008.9167 DEC 75.5 73.3 61.6 15.0 9.6 7.6 2009.0000 JAN 76.9 74.3 60.9 15.8 10.2 7.7 2009.0833 FEB 78.2 75.3 60.1 16.2 10.5 7.7 2009.1667 MAR 79.8 76.5 58.9 16.4 10.7 7.7 2009.2500 APR 81.9 77.8 58.4 16.8 10.7 7.8 2009.3333 MAY 84.9 79.3 58.5 17.1 10.9 8.0 2009.4167 JUN 88.6 81.0 58.8 17.3 11.2 8.3 2009.5000 JUL 92.7 82.9 59.7 17.5 11.6 8.6 2009.5833 AUG 96.4 84.8 60.5 18.0 12.1 9.1 2009.6667 SEP 98.7 86.9 61.2 18.2 12.6 9.8 2009.7500 OCT 100.9 89.2 62.1 17.8 13.1 10.2 2009.8333 NOV 103.3 91.9 64.0 17.2 13.3 10.3 2009.9167 DEC 105.3 94.3 65.7 16.9 13.4 10.4 2010.0000 JAN 108.0 96.3 65.7 16.9 13.6 10.4 2010.0833 FEB 111.3 98.6 65.8 17.3 13.9 10.4 2010.1667 MAR 114.7 100.9 68.4 17.9 14.0 10.1 2010.2500 APR 117.0 103.1 72.1 18.4 14.1 10.0 2010.3333 MAY 119.1 105.5 75.0 18.7 14.1 9.8 2010.4167 JUN 122.5 108.2 77.7 18.8 13.7 9.0 2010.5000 JUL 127.6 112.0 79.3 19.0 13.8 9.1 2010.5833 AUG 132.6 115.7 80.9 19.2 13.9 9.3 2010.6667 SEP 137.7 119.4 82.4 19.5 14.0 9.4 2010.7500 OCT 142.6 123.0 84.0 19.7 14.0 9.5 2010.8333 NOV 147.5 126.6 85.5 19.9 14.1 9.6 2010.9167 DEC 152.2 130.1 87.0 20.1 14.2 9.8 2011.0000 JAN 156.8 133.5 88.4 20.3 14.2 9.9 2011.0833 FEB 161.3 136.8 89.8 20.5 14.3 10.0 2011.1667 MAR 165.5 139.9 91.1 20.7 14.4 10.1 2011.2500 APR 169.6 142.9 92.4 20.8 14.4 10.2 2011.3333 MAY 173.4 145.7 93.5 21.0 14.5 10.3 2011.4167 JUN 177.0 148.3 94.6 21.2 14.5 10.4 2011.5000 JUL 180.3 150.8 95.7 21.3 14.6 10.5 2011.5833 AUG 183.3 153.0 96.6 21.4 14.6 10.5 2011.6667 SEP 185.9 154.9 97.4 21.6 14.7 10.6 2011.7500 OCT 188.3 156.6 98.1 21.7 14.7 10.7 2011.8333 NOV 190.2 158.1 98.7 21.7 14.7 10.7 2011.9167 DEC 191.8 159.2 99.2 21.8 14.7 10.7 2012.0000 JAN 192.9 160.1 99.6 21.9 14.8 10.8 2012.0833 FEB 193.6 160.6 99.8 21.9 14.8 10.8 2012.1667 MAR 193.9 160.8 99.9 21.9 14.8 10.8 2012.2500 APR 192.9 159.6 98.5 20.6 14.9 11.5 2012.3333 MAY 191.7 157.8 97.8 20.2 15.0 11.8 2012.4167 JUN 188.2 156.0 96.7 19.7 15.1 11.7 2012.5000 JUL 184.1 154.7 95.4 19.4 15.3 11.9 2012.5833 AUG 180.2 153.6 93.8 19.2 15.6 12.1 2012.6667 SEP 178.7 152.7 92.6 19.0 15.7 11.6 2012.7500 OCT 177.3 151.7 91.8 19.0 15.7 10.9 2012.8333 NOV 176.9 150.4 91.2 18.9 15.7 10.8 2012.9167 DEC 175.2 148.9 90.3 19.0 15.7 10.8 2013.0000 JAN 170.9 147.2 89.3 19.2 15.8 10.8 2013.0833 FEB 167.1 145.3 88.6 19.8 15.9 10.8 2013.1667 MAR 165.8 143.4 87.7 20.4 16.1 10.9 2013.2500 APR 163.6 141.8 86.2 21.4 16.3 10.8 2013.3333 MAY 160.6 140.6 85.4 21.9 16.5 10.7 2013.4167 JUN 159.8 139.5 84.9 21.6 16.6 10.6 2013.5000 JUL 158.8 138.5 84.0 21.3 16.4 10.3 2013.5833 AUG 156.3 137.4 82.7 21.8 16.5 10.3 2013.6667 SEP 153.6 135.6 81.3 23.1 16.7 10.4 2013.7500 OCT 152.4 133.6 80.4 23.3 16.9 10.9 2013.8333 NOV 151.6 131.5 79.8 22.7 17.0 11.7 2013.9167 DEC 151.1 129.6 79.1 22.6 17.0 11.8 2014.0000 JAN 149.3 127.8 78.4 22.7 16.9 11.9 2014.0833 FEB 146.2 126.3 77.5 23.2 17.1 12.0 2014.1667 MAR 144.8 125.2 76.5 23.9 17.3 12.1 2014.2500 APR 144.9 123.7 75.5 23.9 17.2 12.5 2014.3333 MAY 143.0 121.6 74.6 23.9 17.1 13.3 2014.4167 JUN 139.7 119.5 73.6 23.3 17.0 13.7 2014.5000 JUL 135.8 117.5 72.7 21.6 16.8 13.3 2014.5833 AUG 135.2 115.9 72.3 21.8 16.6 12.8 2014.6667 SEP 134.7 114.4 72.0 21.8 16.4 12.7 2014.7500 OCT 132.8 112.9 71.6 21.5 16.4 12.5 2014.8333 NOV 130.1 111.4 71.4 21.1 16.4 12.4 2014.9167 DEC 128.2 109.9 71.5 20.5 16.4 12.2 2015.0000 JAN 126.8 108.3 71.4 19.9 16.1 11.9 2015.0833 FEB 124.8 106.7 71.2 20.1 16.0 11.9 2015.1667 MAR 122.0 104.8 70.9 21.6 15.9 11.7 2015.2500 APR 119.8 103.0 70.7 23.2 15.8 11.7 2015.3333 MAY 116.8 101.4 70.5 24.0 15.8 11.5 2015.4167 JUN 115.1 99.9 70.7 25.1 15.7 11.3 2015.5000 JUL 113.4 98.7 71.1 25.8 15.7 11.3 2015.5833 AUG 111.9 97.7 71.2 25.0 15.6 10.8 2015.6667 SEP 111.3 96.7 71.4 25.0 15.6 10.3 2015.7500 OCT 110.5 95.6 71.2 24.1 15.7 10.7 2015.8333 NOV 109.2 94.3 70.7 22.2 15.7 10.8 2015.9167 DEC 107.4 93.0 70.3 21.4 15.6 10.8 2016.0000 JAN 106.7 91.9 69.9 21.7 15.8 11.0 2016.0833 FEB 106.3 91.1 69.6 22.4 16.0 11.2 2016.1667 MAR 103.9 90.2 69.2 22.6 16.0 11.2 2016.2500 APR 100.8 89.2 69.0 22.5 16.1 11.0 2016.3333 MAY 98.4 88.2 68.7 22.7 16.3 11.0 2016.4167 JUN 98.2 87.1 68.2 22.9 16.6 11.3 2016.5000 JUL 97.5 86.1 68.0 23.4 16.8 11.2 2016.5833 AUG 96.1 85.1 67.8 24.1 16.9 11.2 2016.6667 SEP 93.2 84.2 67.7 24.8 17.0 11.8 2016.7500 OCT 91.8 83.2 67.6 25.4 16.9 12.2 2016.8333 NOV 90.3 82.3 67.6 25.6 16.7 12.1 2016.9167 DEC 89.3 81.3 67.5 25.4 16.4 12.0 2017.0000 JAN 88.5 80.6 67.3 24.7 16.0 12.2 2017.0833 FEB 88.7 80.0 67.2 23.6 15.6 12.3 2017.1667 MAR 88.6 79.4 67.2 22.8 15.2 12.2 2017.2500 APR 87.2 78.8 67.2 22.4 14.9 11.8 2017.3333 MAY 85.8 78.2 67.2 21.9 14.6 11.2 2017.4167 JUN 85.0 77.8 67.1 21.6 14.2 10.7 2017.5000 JUL 84.0 77.2 67.1 20.9 13.8 10.0 2017.5833 AUG 83.1 76.6 67.0 20.0 13.4 9.4 2017.6667 SEP 81.7 76.0 67.0 18.7 13.1 9.0 2017.7500 OCT 80.4 75.6 67.0 18.2 12.8 8.5 2017.8333 NOV 79.2 75.1 67.0 18.7 12.6 8.0 2017.9167 DEC 78.5 74.7 67.1 18.7 12.5 7.8 2018.0000 JAN 78.1 74.4 67.3 18.4 12.4 7.4 2018.0833 FEB 77.5 74.0 67.4 18.4 12.2 7.0 2018.1667 MAR 76.7 73.7 67.5 18.8 12.1 6.6 2018.2500 APR 76.0 73.2 67.6 18.9 12.0 6.5 2018.3333 MAY 75.2 72.7 67.7 18.8 12.0 6.4 2018.4167 JUN 74.3 72.3 67.7 18.4 11.9 6.6 2018.5000 JUL 73.8 71.9 68.0 17.5 11.8 6.9 2018.5833 AUG 73.6 71.7 68.0 16.5 11.7 7.2 2018.6667 SEP 73.6 71.5 68.0 16.3 11.6 7.4 2018.7500 OCT 73.0 71.4 68.0 16.6 11.6 7.5 2018.8333 NOV 73.2 71.3 67.9 16.9 11.6 7.5 2018.9167 DEC 73.4 71.2 67.9 17.2 11.6 7.7 2019.0000 JAN 73.4 71.2 67.7 17.3 11.6 7.7 2019.0833 FEB 73.2 71.3 67.6 17.7 11.5 7.6 2019.1667 MAR 73.6 71.5 67.7 18.0 11.4 7.6 2019.2500 APR 74.0 71.9 67.6 18.2 11.4 7.6 2019.3333 MAY 74.8 72.3 67.6 18.1 11.3 7.6 2019.4167 JUN 75.5 72.6 67.7 17.8 11.2 7.5 2019.5000 JUL 76.4 73.2 67.9 17.3 11.1 7.5 2019.5833 AUG 77.5 74.0 68.1 16.3 11.0 7.5 2019.6667 SEP 78.8 74.9 68.5 15.5 10.9 7.5 2019.7500 OCT 80.1 75.8 68.6 16.1 10.8 7.7 2019.8333 NOV 81.4 76.9 68.8 16.3 10.8 7.7 2019.9167 DEC 82.8 78.4 69.1 16.6 10.9 7.8 2020.0000 JAN 84.6 80.0 69.3 16.7 11.0 7.7 2020.0833 FEB 87.1 81.8 69.6 16.8 11.1 7.7 2020.1667 MAR 89.6 83.6 70.2 17.1 11.1 7.8 2020.2500 APR 91.9 85.6 71.1 17.3 11.1 8.0 2020.3333 MAY 95.1 87.7 71.8 17.3 11.2 8.3 2020.4167 JUN 97.7 89.8 72.5 17.4 11.5 8.6 2020.5000 JUL 101.0 92.1 73.7 17.6 11.7 9.0 2020.5833 AUG 106.6 94.4 74.2 17.5 12.0 8.8 2020.6667 SEP 109.0 96.7 74.5 16.9 12.2 8.7 2020.7500 OCT 111.9 99.5 74.8 16.2 12.4 8.9 2020.8333 NOV 116.4 102.3 75.1 16.0 12.5 9.0 2020.9167 DEC 121.0 104.8 75.3 16.0 12.7 9.0 2021.0000 JAN 125.4 107.3 75.2 16.1 12.9 8.8 2021.0833 FEB 129.9 109.6 75.2 16.7 13.0 8.4 2021.1667 MAR 134.5 111.9 75.3 17.1 13.0 8.2 2021.2500 APR 139.7 114.5 75.7 17.5 13.1 8.2 2021.3333 MAY 144.5 117.4 76.1 18.2 13.2 8.1 2021.4167 JUN 147.3 120.5 76.6 18.5 13.2 7.9 2021.5000 JUL 149.3 123.1 77.5 18.5 13.1 7.8 2021.5833 AUG 150.4 125.3 78.3 18.7 13.1 7.9 2021.6667 SEP 151.2 127.4 78.6 19.0 13.2 8.1 2021.7500 OCT 151.5 129.3 79.6 18.6 13.3 8.6 2021.8333 NOV 153.9 131.0 80.8 17.8 13.3 9.2 2021.9167 DEC 156.4 132.7 82.2 18.1 13.4 9.6 2022.0000 JAN 160.0 134.8 84.1 18.9 13.5 10.1 2022.0833 FEB 163.9 137.2 85.4 19.1 13.6 10.1 2022.1667 MAR 167.9 139.6 86.3 19.5 13.9 10.3 2022.2500 APR 171.2 142.2 88.1 20.5 14.1 10.4 2022.3333 MAY 174.1 144.8 90.0 20.2 14.1 10.6 2022.4167 JUN 176.5 146.9 91.1 20.4 14.1 10.2 2022.5000 JUL 178.1 148.9 93.3 20.7 14.1 10.2 2022.5833 AUG 178.7 150.9 95.7 21.1 14.2 9.9 2022.6667 SEP 181.8 152.8 97.5 21.4 14.2 9.8 2022.7500 OCT 184.2 154.7 98.7 21.4 14.4 10.5 2022.8333 NOV 187.0 156.3 98.8 21.6 14.5 10.9 2022.9167 DEC 189.7 157.5 98.2 21.9 14.7 10.9 2023.0000 JAN 191.8 158.9 97.8 22.4 14.9 11.0 2023.0833 FEB 192.7 160.7 99.1 22.9 15.1 11.2