SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 25 August, 2026 T-index: 80 Bearings: 331 152 Distance: 386 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 51-56 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 6.9 4.8 2.8 ABFF%%. 00 01 7.6 5.6 3.1 BBFF%%. 01 02 8.0 6.1 3.4 BBBF%%. . 02 03 8.4 6.4 3.5 ABBFF%. . 03 04 8.5 6.5 3.5 ABBFF%. . 04 05 8.5 6.4 3.5 ABBFF%% . 05 06 8.4 6.2 3.4 BBBFF%. . 06 07 8.1 5.8 3.3 BBFFF%. . 07 08 8.0 5.2 2.9 ABBFF%%. . 08 09 7.5 4.0 2.4 BBFFF%%. 09 10 6.5 0.9 0.0 FFFFFF%%.. 10 11 5.4 0.9 0.0 FFFFF%%.. 11 12 4.5 0.9 0.0 FFFF%.. 12 13 4.1 0.9 0.0 FFFF%.. 13 14 3.9 0.9 0.0 FFF%%. 14 15 3.7 0.9 0.0 FFF%.. 15 16 3.6 0.9 0.0 FFF%.. 16 17 3.5 0.9 0.0 FFF%. 17 18 3.4 0.9 0.0 FFF%. 18 19 3.3 0.9 0.0 FFF%. 19 20 3.1 0.9 0.0 FFF%. 20 21 3.0 0.9 0.0 FF%.. 21 22 3.3 0.9 0.0 FFF%. 22 23 5.3 3.1 1.9 ABFF%. 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) 25-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000