TABLE 3 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 95.0% 50% 5.0% 95.0% 50% 5.0% 1998.7507 OCT 135.8 130.3 127.8 13.6 12.9 12.1 1998.8340 NOV 143.6 133.5 128.4 14.3 13.1 11.6 1998.9173 DEC 148.9 136.0 126.9 14.9 13.3 11.2 1999.0007 JAN 154.3 138.4 128.3 15.8 13.7 11.0 1999.0840 FEB 159.1 140.8 128.6 16.7 14.1 11.2 1999.1673 MAR 165.2 143.5 127.0 16.9 14.3 11.4 1999.2507 APR 173.7 146.3 124.3 17.0 14.6 11.9 1999.3340 MAY 182.9 148.7 120.1 17.1 14.9 12.4 1999.4173 JUN 190.3 151.0 115.9 17.1 15.0 12.8 1999.5007 JUL 196.1 153.1 113.9 17.1 15.0 13.1 1999.5840 AUG 201.5 154.7 113.1 17.6 15.2 13.2 1999.6673 SEP 206.4 156.2 114.3 18.3 15.2 13.0 1999.7507 OCT 210.2 157.4 114.7 19.0 15.1 12.5 1999.8340 NOV 212.7 158.2 113.3 18.9 15.2 12.3 1999.9173 DEC 213.3 159.0 111.2 18.6 15.4 12.4 2000.0007 JAN 212.5 159.4 108.5 18.8 15.6 12.4 2000.0840 FEB 210.3 159.5 107.0 19.6 16.1 12.2 2000.1673 MAR 205.6 159.8 108.9 20.5 16.4 12.1 2000.2507 APR 200.4 159.9 110.0 20.4 16.4 11.8 2000.3340 MAY 200.3 159.9 110.8 20.6 16.4 11.5 2000.4173 JUN 200.6 159.0 110.0 21.0 16.4 11.4 2000.5007 JUL 196.0 157.3 108.6 21.5 16.5 11.1 2000.5840 AUG 191.1 155.9 107.7 21.7 16.4 10.7 2000.6673 SEP 189.7 155.0 106.4 21.0 16.2 10.0 2000.7507 OCT 190.3 154.6 105.0 20.9 15.9 9.4 2000.8340 NOV 190.4 154.7 103.3 21.1 15.8 9.3 2000.9173 DEC 190.5 154.5 101.0 21.5 15.8 9.3 2001.0007 JAN 189.4 153.9 97.2 22.3 15.7 9.0 2001.0840 FEB 187.5 153.0 94.0 22.1 15.3 8.7 2001.1673 MAR 184.1 152.3 90.6 21.1 14.9 8.9 2001.2507 APR 184.3 151.9 89.0 20.4 14.6 9.2 2001.3340 MAY 187.3 151.7 87.6 20.0 14.5 9.7 2001.4173 JUN 186.5 150.8 85.8 19.5 14.4 9.9 2001.5007 JUL 183.3 149.7 84.7 19.4 14.3 10.1 2001.5840 AUG 181.7 148.1 82.9 19.2 14.4 10.1 2001.6673 SEP 180.8 146.5 81.5 18.9 14.7 10.4 2001.7507 OCT 180.2 145.0 80.0 18.6 15.1 11.1 2001.8340 NOV 180.8 143.9 79.6 18.5 15.4 11.2 2001.9173 DEC 182.3 142.5 79.7 19.0 15.5 11.0 2002.0007 JAN 182.7 140.6 80.4 19.8 15.7 11.5 2002.0840 FEB 180.7 138.5 81.5 21.4 16.2 12.0 2002.1673 MAR 178.5 136.7 82.4 22.7 16.6 12.2 2002.2507 APR 177.9 135.3 82.9 23.3 16.8 12.5 2002.3340 MAY 177.0 133.8 83.7 24.4 17.1 12.7 2002.4173 JUN 174.1 131.9 84.9 24.9 17.3 13.0 2002.5007 JUL 170.8 129.9 85.2 24.2 17.3 13.3 2002.5840 AUG 167.6 128.5 85.6 24.1 17.2 13.4 2002.6673 SEP 164.5 127.2 86.2 23.2 17.1 13.4 2002.7507 OCT 162.7 126.0 86.3 21.4 17.0 13.2 2002.8340 NOV 161.3 124.5 85.9 21.7 17.1 13.2 2002.9173 DEC 158.0 122.6 85.9 22.5 17.1 13.1 2003.0007 JAN 152.2 120.4 86.5 22.6 17.0 12.2 2003.0840 FEB 146.6 118.3 85.3 22.1 16.8 11.8 2003.1673 MAR 144.0 116.3 84.1 21.5 16.6 11.8 2003.2507 APR 142.9 114.2 83.4 21.3 16.7 12.0 2003.3340 MAY 141.3 112.5 83.3 22.0 17.0 12.2 2003.4173 JUN 138.8 111.0 83.4 22.9 17.3 12.3 2003.5007 JUL 136.0 109.3 83.0 23.1 17.6 12.5 2003.5840 AUG 133.0 107.5 83.2 23.0 17.9 12.5 2003.6673 SEP 130.1 105.9 83.0 23.0 18.0 12.5 2003.7507 OCT 127.2 104.1 80.5 22.6 18.0 12.1 2003.8340 NOV 126.3 102.3 78.8 21.2 17.9 12.1 2003.9173 DEC 125.6 100.6 77.7 21.2 17.7 12.2 2004.0007 JAN 124.6 99.3 76.5 21.2 17.8 12.9 2004.0840 FEB 124.1 98.2 75.6 21.2 18.1 13.4 2004.1673 MAR 123.0 97.3 75.2 21.0 18.2 13.4 2004.2507 APR 120.9 96.4 75.0 21.6 18.0 13.3 2004.3340 MAY 118.6 95.4 74.5 22.5 17.7 13.2 2004.4173 JUN 117.6 94.1 73.7 22.8 17.4 13.3 2004.5007 JUL 116.4 92.8 73.0 22.7 17.2 14.0 2004.5840 AUG 114.6 91.6 72.5 22.2 17.3 13.5 2004.6673 SEP 111.8 90.4 72.4 22.0 17.4 13.1 2004.7507 OCT 108.4 89.0 72.3 21.8 17.4 12.6 2004.8340 NOV 105.3 87.9 72.4 21.8 17.2 12.3 2004.9173 DEC 102.7 87.1 72.3 22.1 17.0 12.0 2005.0007 JAN 101.1 86.2 72.1 22.3 16.6 11.6 2005.0840 FEB 99.6 85.1 71.6 22.7 16.5 10.6 2005.1673 MAR 97.8 83.9 71.0 23.2 16.3 9.8 2005.2507 APR 95.6 82.7 70.4 23.8 16.4 9.8 2005.3340 MAY 94.6 81.9 70.1 24.2 16.5 9.9 2005.4173 JUN 94.1 81.2 70.0 24.4 16.5 9.7 2005.5007 JUL 93.1 80.5 69.8 24.2 16.4 9.8 2005.5840 AUG 91.9 79.8 69.7 23.6 16.3 10.0 2005.6673 SEP 91.3 79.2 69.6 22.7 16.1 10.2 2005.7507 OCT 90.6 78.6 69.6 21.9 15.9 10.4 2005.8340 NOV 89.3 77.9 69.4 21.4 15.9 10.4 2005.9173 DEC 87.9 77.2 69.2 21.1 16.0 10.3 2006.0007 JAN 86.5 76.5 69.0 20.9 16.1 10.5 2006.0840 FEB 85.2 75.8 68.8 20.6 16.2 10.8 2006.1673 MAR 83.9 75.2 68.6 20.5 16.0 10.9 2006.2507 APR 82.7 74.5 68.4 20.7 15.7 11.0 2006.3340 MAY 81.5 73.9 68.2 20.7 15.5 11.4 2006.4173 JUN 80.3 73.4 68.0 20.7 15.2 11.9 2006.5007 JUL 79.2 72.8 67.9 20.3 15.0 11.6 2006.5840 AUG 78.2 72.3 67.7 19.6 14.7 11.5 2006.6673 SEP 77.2 71.8 67.6 18.8 14.5 11.2 2006.7507 OCT 76.3 71.4 67.5 17.9 14.4 10.7 2006.8340 NOV 75.6 71.0 67.3 17.5 14.2 10.0 2006.9173 DEC 74.9 70.6 67.2 17.4 14.0 9.8 2007.0007 JAN 74.3 70.3 67.2 17.3 13.9 9.7 2007.0840 FEB 73.9 70.1 67.1 16.9 13.8 9.6 2007.1673 MAR 73.5 69.9 67.0 16.4 13.7 9.7 2007.2507 APR 73.3 69.8 67.0 16.4 13.5 9.7 2007.3340 MAY 73.2 69.8 67.0 16.2 13.3 9.6 2007.4173 JUN 73.4 69.9 67.0 15.9 13.0 9.5 2007.5007 JUL 74.0 70.2 67.0 15.4 12.6 9.3 2007.5840 AUG 74.8 70.6 67.1 14.9 12.2 9.0 2007.6673 SEP 75.7 71.0 67.2 14.4 11.7 8.7 2007.7507 OCT 76.7 71.4 67.3 13.9 11.3 8.4 2007.8340 NOV 78.3 72.0 67.4 13.5 11.0 8.2 2007.9173 DEC 79.6 72.6 67.5 13.0 10.6 8.0 2008.0007 JAN 81.1 73.2 67.7 12.6 10.3 7.7 2008.0840 FEB 83.4 74.0 67.8 12.2 9.9 7.5 2008.1673 MAR 86.5 75.0 67.9 11.9 9.7 7.4 2008.2507 APR 91.3 76.1 68.2 11.6 9.4 7.2 2008.3340 MAY 95.8 77.5 68.3 11.4 9.2 7.1 2008.4173 JUN 99.3 79.0 68.3 11.2 9.1 7.0 2008.5007 JUL 104.6 80.7 68.3 11.1 9.0 6.9 2008.5840 AUG 110.7 82.7 68.3 11.1 9.0 6.9 2008.6673 SEP 116.6 84.7 68.2 11.3 9.1 6.9 2008.7507 OCT 124.0 87.0 68.5 11.6 9.3 7.1 2008.8340 NOV 132.5 89.4 68.6 11.7 9.4 7.4 2008.9173 DEC 139.0 92.0 68.8 11.9 9.5 7.5 2009.0007 JAN 143.6 94.8 69.1 12.0 9.6 7.5 2009.0840 FEB 147.9 97.6 69.1 12.1 9.6 7.3 2009.1673 MAR 152.2 100.3 69.3 12.2 9.7 7.2 2009.2507 APR 157.0 103.1 69.8 12.6 9.8 7.0 2009.3340 MAY 162.1 106.2 70.4 12.9 10.1 6.9 2009.4173 JUN 167.2 109.3 70.7 13.3 10.5 7.1 2009.5007 JUL 171.5 112.5 71.1 13.8 10.8 7.5 2009.5840 AUG 177.3 115.7 71.3 14.6 11.1 7.8 2009.6673 SEP 185.2 118.8 71.9 15.8 11.4 7.6 2009.7507 OCT 190.2 122.0 72.8 16.2 11.6 7.6 2009.8340 NOV 192.8 124.9 73.2 16.4 11.7 7.5 2009.9173 DEC 195.4 127.3 74.0 16.9 11.9 7.5 2010.0007 JAN 198.3 129.5 74.5 18.1 12.2 7.5 2010.0840 FEB 202.9 131.7 74.8 19.0 12.6 7.6 2010.1673 MAR 209.1 134.2 75.3 19.2 12.8 7.6 2010.2507 APR 213.2 136.7 75.5 19.3 13.0 7.7 2010.3340 MAY 215.9 139.0 75.7 19.1 13.2 7.6 2010.4173 JUN 220.4 141.0 75.7 18.7 13.3 7.6 2010.5007 JUL 225.0 143.0 75.5 18.6 13.3 7.7 2010.5840 AUG 227.3 144.7 75.5 19.0 13.5 7.9 2010.6673 SEP 228.4 146.3 75.8 18.9 13.6 8.1 2010.7507 OCT 230.3 147.6 76.1 17.9 13.6 8.5 2010.8340 NOV 232.4 148.5 76.8 18.0 13.8 8.6 2010.9173 DEC 235.4 149.4 78.0 18.6 14.1 8.6 2011.0007 JAN 238.7 149.9 78.7 19.2 14.3 8.9 2011.0840 FEB 240.3 150.2 79.7 19.7 14.8 9.3 2011.1673 MAR 238.7 150.6 81.3 20.4 15.1 9.5 2011.2507 APR 236.9 150.9 83.0 20.4 15.2 9.5 2011.3340 MAY 238.1 151.1 84.9 20.4 15.2 9.7 2011.4173 JUN 238.7 150.4 85.9 20.6 15.2 9.9 2011.5007 JUL 236.3 148.9 87.3 20.9 15.4 10.4 2011.5840 AUG 232.9 147.8 89.2 21.3 15.4 11.0 2011.6673 SEP 229.2 147.2 90.5 21.3 15.3 11.6 2011.7507 OCT 227.4 147.2 92.9 21.5 15.1 11.2 2011.8340 NOV 227.8 147.3 94.0 21.7 15.1 11.1 2011.9173 DEC 227.9 147.2 95.3 22.1 15.1 10.6 2012.0007 JAN 226.5 146.7 95.6 22.9 15.0 10.1 2012.0840 FEB 224.8 146.1 95.2 22.6 14.7 9.8 2012.1673 MAR 224.3 145.4 95.3 21.4 14.4 10.0 2012.2507 APR 224.2 145.1 96.8 20.7 14.3 10.0 2012.3340 MAY 223.6 144.9 97.6 20.1 14.2 10.2 2012.4173 JUN 222.6 144.1 97.1 19.7 14.1 10.5 2012.5007 JUL 220.3 143.0 96.3 19.6 14.1 10.5 2012.5840 AUG 216.8 141.5 96.2 19.4 14.1 10.4 2012.6673 SEP 213.9 140.0 96.7 19.2 14.4 10.4 2012.7507 OCT 211.1 138.6 96.3 19.0 14.7 10.4 2012.8340 NOV 207.6 137.6 95.4 19.0 14.9 10.2 2012.9173 DEC 206.6 136.3 95.9 19.5 14.8 9.8 2013.0007 JAN 204.5 134.7 97.0 20.5 14.9 10.1 2013.0840 FEB 201.1 132.9 96.2 22.1 15.3 10.6 2013.1673 MAR 197.5 131.5 94.4 23.5 15.6 10.6 2013.2507 APR 195.2 130.3 93.7 24.1 15.8 10.8 2013.3340 MAY 193.4 129.2 93.5 25.3 16.1 10.9 2013.4173 JUN 189.6 127.5 91.6 25.8 16.3 11.1 2013.5007 JUL 185.1 125.7 88.1 25.0 16.3 11.4 2013.5840 AUG 180.7 124.4 87.7 24.9 16.2 11.6 2013.6673 SEP 176.8 123.4 88.7 24.1 16.2 11.7 2013.7507 OCT 174.6 122.3 87.2 22.2 16.1 11.7 2013.8340 NOV 172.7 121.0 86.3 22.5 16.2 11.9 2013.9173 DEC 168.6 119.3 85.7 23.2 16.3 11.7 2014.0007 JAN 162.0 117.4 84.8 23.3 16.3 10.9 2014.0840 FEB 156.1 115.5 83.5 22.8 16.1 10.6 2014.1673 MAR 152.5 113.6 82.4 22.1 15.9 10.7 2014.2507 APR 150.3 111.7 82.0 22.0 15.9 10.7 2014.3340 MAY 148.0 110.1 82.0 22.9 16.1 10.6 2014.4173 JUN 145.1 108.7 82.0 23.8 16.4 10.7 2014.5007 JUL 142.0 107.1 80.9 24.0 16.6 10.7 2014.5840 AUG 138.4 105.5 80.4 24.0 16.8 10.6 2014.6673 SEP 134.5 104.1 80.5 24.0 16.9 10.5 2014.7507 OCT 130.1 102.5 79.9 23.6 16.9 10.2 2014.8340 NOV 124.0 100.9 79.0 22.7 16.9 10.3 2014.9173 DEC 119.5 99.4 77.7 22.9 16.8 10.5 2015.0007 JAN 118.6 98.2 75.5 23.1 16.9 11.3 2015.0840 FEB 118.7 97.2 74.5 23.2 17.2 11.8 2015.1673 MAR 119.3 96.2 73.9 22.6 17.3 11.9 2015.2507 APR 119.7 95.3 73.5 21.6 17.2 12.1 2015.3340 MAY 118.8 94.3 73.4 21.3 17.1 12.2 2015.4173 JUN 117.4 93.1 73.0 21.8 16.9 12.4 2015.5007 JUL 116.0 91.9 72.7 21.8 16.7 13.2 2015.5840 AUG 113.9 90.9 71.9 22.2 16.8 13.0 2015.6673 SEP 110.3 89.8 71.3 22.6 16.9 12.7 2015.7507 OCT 105.9 88.5 71.0 22.4 16.9 13.0 2015.8340 NOV 103.2 87.5 70.6 22.4 16.7 12.7 2015.9173 DEC 101.7 86.7 70.3 22.8 16.5 12.4 2016.0007 JAN 100.2 85.8 70.3 23.0 16.1 12.0 2016.0840 FEB 98.2 84.9 70.2 23.6 15.8 11.1 2016.1673 MAR 96.6 83.7 69.8 24.2 15.6 10.4 2016.2507 APR 94.6 82.6 69.6 25.0 15.5 10.5 2016.3340 MAY 93.6 81.8 69.5 25.5 15.5 10.6 2016.4173 JUN 93.3 81.0 69.4 25.7 15.5 10.5 2016.5007 JUL 92.3 80.4 69.2 25.6 15.4 10.6 2016.5840 AUG 91.4 79.6 69.0 25.0 15.3 10.9 2016.6673 SEP 90.7 79.0 68.7 24.1 15.1 11.0 2016.7507 OCT 89.9 78.3 68.5 23.1 14.9 11.2 2016.8340 NOV 88.9 77.6 68.3 22.6 15.0 11.1 2016.9173 DEC 88.0 77.1 68.3 22.2 15.2 11.0 2017.0007 JAN 87.2 76.6 68.4 21.9 15.4 11.1 2017.0840 FEB 85.8 76.1 68.4 21.5 15.5 11.3 2017.1673 MAR 84.4 75.6 68.4 20.8 15.5 11.4 2017.2507 APR 82.3 75.0 68.4 20.0 15.3 11.4 2017.3340 MAY 79.9 74.3 68.3 20.1 15.1 11.7 2017.4173 JUN 78.4 73.6 68.0 20.2 14.9 11.9 2017.5007 JUL 77.5 72.9 67.7 19.9 14.7 11.6 2017.5840 AUG 77.0 72.4 67.6 19.5 14.6 11.5 2017.6673 SEP 76.9 72.1 67.5 19.0 14.6 11.1 2017.7507 OCT 76.7 71.7 67.4 18.2 14.6 10.6 2017.8340 NOV 76.5 71.3 67.2 17.3 14.5 9.8 2017.9173 DEC 76.2 71.0 67.1 17.4 14.4 9.4 2018.0007 JAN 75.2 70.7 67.0 17.5 14.3 9.3 2018.0840 FEB 74.2 70.4 67.0 17.6 14.2 9.3 2018.1673 MAR 74.0 70.1 67.0 17.6 14.1 9.3