SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 23 March, 2026 T-index: 80 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 19-24 1E 5 1 5 10 15 20 25 30 35 40 2F 37-44 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 13.1 12.2 6.4 ASSXMMM BBF%%... 8.9 7.5 3.9 00 01 14.4 13.8 7.1 SSSXMM MBBF%%%... 9.6 8.5 4.3 01 02 14.8 14.8 7.5 ASSXXM MBBB%%%%.. 9.9 9.2 4.6 02 03 14.9 15.4 7.8 ASSXXM MMBBP%%%.. . 10.1 9.5 4.7 03 04 15.0 15.6 7.9 ASSXXM MMBBP%%%.. . 10.4 9.7 4.8 04 05 15.1 15.5 7.8 ASSXXM MMBBB%%%.. . 10.5 9.6 4.8 05 06 14.8 15.1 7.7 ASSXXM MMBBP%%%.. . 10.3 9.4 4.6 06 07 14.3 14.3 7.3 SSSXMM MMBB%%%%.. . 9.9 8.9 4.4 07 08 14.1 13.0 6.8 SSXXMM MMBF%%%%.. 9.6 8.1 4.1 08 09 14.0 11.0 5.9 ASXMMMM MFF%%%%... 9.4 6.9 3.6 09 10 12.3 6.5 3.8 SXMMMMMM FF%%%%... 8.3 4.1 2.3 10 11 10.2 2.0 0.0 XMMMMMMMMF %%%%... 7.1 1.3 0.0 11 12 8.7 2.0 0.0 XMMMMMMM%% %%... 6.3 1.3 0.0 12 13 7.8 2.0 0.0 XMMMMMM%%% ... 5.7 1.3 0.0 13 14 7.4 2.0 0.0 XMMMMMM%%% .. 5.5 1.3 0.0 14 15 7.4 2.0 0.0 XMMMMMM%%. .. 5.4 1.3 0.0 15 16 7.2 2.0 0.0 XMMMMMF%%. . 5.3 1.3 0.0 16 17 7.2 2.0 0.0 XMMMMMF%%. . 5.2 1.3 0.0 17 18 6.9 2.0 0.0 XMMMMM%%%. . 5.1 1.3 0.0 18 19 6.6 2.0 0.0 XMMMMM%%.. 4.9 1.3 0.0 19 20 5.8 2.0 0.0 XMMMM%%.. 4.3 1.3 0.0 20 21 5.3 2.0 0.0 XMMMM%%. 3.9 1.3 0.0 21 22 6.6 2.0 0.0 XMMMMM%%.. 4.9 1.3 0.0 22 23 10.7 9.5 5.2 SSMMMBF %%%.. 7.2 5.8 3.2 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) 23-Mar-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000