SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 15 May, 2026 T-index: 50 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 18-21 1E 5 1 5 10 15 20 25 30 35 40 2F 36-40 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 12.4 10.2 5.3 SSXMMMB FF%%... 8.4 6.2 3.3 00 01 14.1 12.1 6.2 ASSXMMM BBFF%%... 9.4 7.4 3.8 01 02 14.5 13.3 6.7 SSXXMM MBBF%%%... 9.7 8.2 4.1 02 03 14.5 13.9 6.9 SSXXMM MBBF%%%... 9.3 8.6 4.2 03 04 14.2 14.2 7.0 SSXXMM MBBB%%%... 9.2 8.8 4.3 04 05 13.9 14.1 7.0 SSXXMM MBBP%%... 9.0 8.7 4.3 05 06 14.1 13.7 6.8 SSXXMM MBBF%%.... 9.1 8.4 4.2 06 07 14.5 12.8 6.4 ASSXMMM MBFF%%%... 9.2 7.9 3.9 07 08 14.3 11.3 5.8 ASXMMMM MFFF%%.... 9.1 6.9 3.6 08 09 13.0 8.5 4.6 ASXMMMMM FF%%%... 8.5 5.1 2.8 09 10 9.9 1.9 0.0 XMMMMMMMF% %%... 6.8 1.1 0.0 10 11 7.6 1.9 0.0 XMMMMMF%%. ... 5.3 1.1 0.0 11 12 6.2 1.9 0.0 XMMMMF%%.. . 4.5 1.1 0.0 12 13 5.7 1.9 0.0 XMMMM%%... 4.2 1.1 0.0 13 14 5.6 1.9 0.0 XMMMM%%.. 4.2 1.1 0.0 14 15 5.5 1.9 0.0 XMMMM%%.. 4.1 1.1 0.0 15 16 5.6 1.9 0.0 XMMMM%%.. 4.1 1.1 0.0 16 17 5.5 1.9 0.0 XMMMM%%.. 4.0 1.1 0.0 17 18 5.4 1.9 0.0 XMMMM%%.. 3.9 1.1 0.0 18 19 5.2 1.9 0.0 XMMMM%%.. 3.6 1.1 0.0 19 20 5.2 1.9 0.0 XMMMM%%.. 3.5 1.1 0.0 20 21 4.8 1.9 0.0 XMMM%%... 3.3 1.1 0.0 21 22 5.1 1.9 0.0 XMMMF%.. 3.8 1.1 0.0 22 23 9.1 5.1 3.0 MMMMMFF% .. 6.2 0.0 2.1 23 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT =============================================================================== |. USABLE LESS THAN 50% OF DAYS |% USABLE 50% TO 90% OF DAYS | |B BOTH E and F MODES 90% OF DAYS |M MIXED FIRST AND SECOND F MODES | |F FIRST F MODE ONLY |E E-LAYER PROPAGATION |P 90% E and 50-90% F | |S SECOND MODES ONLY |A HIGH ABSORPTION |X COMPLEX MODES | (c) 15-May-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000