SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Bunbury Perth Date: 17 September, 2025 T-index: 100 Bearings: 8 188 Distance: 155 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F/1E: Near 90 1 5 10 15 20 25 30 35 40 ** NONE ** UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 7.4 3.3 2.7 AFFFF%. 00 01 8.0 3.8 3.0 AFFFF%%. 01 02 8.4 4.1 3.2 BFFFF%. . 02 03 8.7 4.2 3.3 BFFFF%% . 03 04 8.8 4.3 3.3 BFFFF%% . 04 05 8.8 4.3 3.3 BFFFF%% . 05 06 8.4 4.2 3.3 BFFFF%% . 06 07 8.2 3.9 3.1 FFFFF%. . 07 08 8.0 3.6 2.9 AFFFF%%. . 08 09 7.9 3.0 2.5 AFFFF%%. 09 10 7.3 1.7 1.6 AFFFFF%.. 10 11 6.4 0.6 0.0 FFFFFF%%. 11 12 5.6 0.6 0.0 FFFFF%%. 12 13 5.1 0.6 0.0 FFFFF%. 13 14 4.8 0.6 0.0 FFFF%.. 14 15 4.6 0.6 0.0 FFFF%.. 15 16 4.3 0.6 0.0 FFFF%. 16 17 4.2 0.6 0.0 FFFF%. 17 18 4.0 0.6 0.0 FFF%%. 18 19 3.9 0.6 0.0 FFF%. 19 20 3.7 0.6 0.0 FFF%. 20 21 3.6 0.6 0.0 FFF%. 21 22 4.2 0.6 0.0 FFFF%. 22 23 6.1 2.5 2.1 FFFF%. 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-Sep-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000