SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Carnarvon Perth Date: 24 August, 2026 T-index: 75 Bearings: 165 344 Distance: 815 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 29-34 1E 10 1 5 10 15 20 25 30 35 40 2F 49-55 2E 22 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 9.3 8.1 4.1 ASMMMMF% %.. 6.9 4.8 2.8 00 01 10.3 9.5 4.6 SXMMMMF %%.. 7.6 5.6 3.2 01 02 10.6 10.4 5.0 SXXMMMB %%... 8.0 6.1 3.4 02 03 10.7 10.9 5.2 ASXMMMB %%... 8.2 6.4 3.5 03 04 10.7 11.1 5.3 ASXMMMB P%... 8.3 6.5 3.6 04 05 10.6 11.1 5.3 ASXMMMB P%... 8.3 6.5 3.6 05 06 10.3 10.8 5.2 ASXMMMB %%.. 8.1 6.3 3.5 06 07 10.0 10.2 4.9 SXMMMMP %%.. 7.9 5.9 3.4 07 08 9.8 9.2 4.5 SXMMMM% %... 7.7 5.3 3.1 08 09 9.6 7.5 3.8 AXMMMMF% %.. 7.4 4.3 2.6 09 10 8.3 1.5 0.0 MMMMMMMM%% ... 6.4 0.9 0.7 10 11 6.8 1.5 0.0 MMMMMMM%%. . 5.4 0.9 0.0 11 12 5.7 1.5 0.0 MMMMMM%... 4.6 0.9 0.0 12 13 5.1 1.5 0.0 MMMMM%... 4.2 0.9 0.0 13 14 5.0 1.5 0.0 MMMMM%.. 4.1 0.9 0.0 14 15 4.8 1.5 0.0 MMMMM%.. 4.0 0.9 0.0 15 16 4.6 1.5 0.0 MMMM%.. 3.9 0.9 0.0 16 17 4.5 1.5 0.0 MMMM%.. 3.8 0.9 0.0 17 18 4.3 1.5 0.0 MMMM%.. 3.7 0.9 0.0 18 19 4.2 1.5 0.0 MMMM%.. 3.5 0.9 0.0 19 20 4.0 1.5 0.0 MMMM%.. 3.4 0.9 0.0 20 21 3.7 1.5 0.0 MMMM%. 3.2 0.9 0.0 21 22 4.1 1.5 0.0 MMMM%. 3.5 0.9 0.0 22 23 6.8 5.0 2.7 AMMMM%%. 5.3 2.9 1.8 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) 24-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000