SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Bunbury Perth Date: 18 December, 2025 T-index: 60 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 4.9 3.6 2.8 AF%%. 00 01 5.3 3.9 3.0 AFF%.. 01 02 5.6 4.1 3.2 BF%%. 02 03 6.1 4.2 3.2 BFF%.. 03 04 6.3 4.3 3.3 BFF%.. 04 05 6.4 4.3 3.3 BFF%%. 05 06 6.3 4.2 3.2 BFF%%. 06 07 6.2 4.0 3.1 BFF%.. 07 08 6.1 3.8 2.9 AFFF%.. 08 09 6.1 3.4 2.7 AFFF%.. 09 10 5.8 2.9 2.4 FFF%%.. 10 11 5.6 1.9 1.7 AFFF%%. 11 12 5.4 0.5 0.0 FFFFF%%. 12 13 5.0 0.5 0.0 FFFF%%. 13 14 4.8 0.5 0.0 FFFF%%. 14 15 4.7 0.5 0.0 FFFF%%. 15 16 4.5 0.5 0.0 FFFF%. 16 17 4.3 0.5 0.0 FFFF%. 17 18 4.2 0.5 0.0 FFFF%. 18 19 4.0 0.5 0.0 FFF%.. 19 20 3.8 0.5 0.0 FFF%.. 20 21 3.9 0.5 0.0 FFF%.. 21 22 4.4 2.4 2.0 AFF%. 22 23 4.6 3.1 2.5 AF%%. 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) 18-Dec-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000