SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Carnarvon Perth Date: 17 August, 2026 T-index: 60 Bearings: 165 344 Distance: 815 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 29-33 1E 10 1 5 10 15 20 25 30 35 40 2F 49-54 2E 22 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 8.7 7.7 3.8 AXMMMF%% .. 6.4 4.5 2.6 00 01 9.7 9.2 4.4 ASXMMMB% %.. 7.2 5.4 3.0 01 02 9.9 10.1 4.8 SXMMMBP %... 7.4 5.9 3.3 02 03 10.1 10.6 5.0 SXXMMMB %%.. 7.6 6.2 3.4 03 04 10.0 10.8 5.1 ASXMMMP %... 7.7 6.3 3.5 04 05 9.9 10.8 5.1 ASXMMMP %... 7.6 6.3 3.5 05 06 9.8 10.5 5.0 SXXMMMP %.. 7.7 6.1 3.4 06 07 9.8 9.8 4.7 SXMMMB% %.. 7.6 5.8 3.2 07 08 9.4 8.8 4.3 ASXMMMF% %.. 7.4 5.1 3.0 08 09 9.2 7.1 3.6 AMMMMMF% .. 7.0 4.0 2.5 09 10 7.8 1.4 0.0 MMMMMMM%%. .. 6.0 0.8 0.0 10 11 6.2 1.4 0.0 MMMMMM%%.. 4.9 0.8 0.0 11 12 5.2 1.4 0.0 MMMMM%... 4.1 0.8 0.0 12 13 4.6 1.4 0.0 MMMM%%.. 3.8 0.8 0.0 13 14 4.5 1.4 0.0 MMMM%.. 3.7 0.8 0.0 14 15 4.3 1.4 0.0 MMMM%.. 3.6 0.8 0.0 15 16 4.2 1.4 0.0 MMMM%.. 3.6 0.8 0.0 16 17 4.2 1.4 0.0 MMMM%.. 3.5 0.8 0.0 17 18 4.0 1.4 0.0 MMMM%.. 3.4 0.8 0.0 18 19 3.9 1.4 0.0 MMMM%.. 3.3 0.8 0.0 19 20 3.8 1.4 0.0 MMMM%.. 3.2 0.8 0.0 20 21 3.5 1.4 0.0 MMMM.. 3.0 0.8 0.0 21 22 3.6 1.4 0.0 MMM%. 3.1 0.8 0.0 22 23 6.2 4.1 2.2 AMMMF%. 4.9 2.4 1.5 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) 17-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000