SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Bunbury Perth Date: 21 December, 2025 T-index: 95 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 5.5 3.7 3.0 AFF%%. 00 01 5.9 4.1 3.2 BF%%.. 01 02 6.3 4.3 3.4 BFF%.. 02 03 6.7 4.4 3.4 BFF%%. 03 04 6.9 4.5 3.5 AFF%%.. 04 05 6.9 4.4 3.5 AFF%%.. 05 06 6.8 4.4 3.4 BFF%%.. 06 07 6.7 4.2 3.3 BFF%%.. 07 08 6.6 3.9 3.1 FFF%%.. 08 09 6.4 3.6 2.9 AFFF%%. 09 10 6.3 3.0 2.5 AFFF%%. 10 11 6.1 2.0 1.8 AFFFF%.. 11 12 5.9 0.6 0.0 FFFFF%%. 12 13 5.7 0.6 0.0 FFFFF%%. 13 14 5.5 0.6 0.0 FFFFF%.. 14 15 5.4 0.6 0.0 FFFFF%.. 15 16 5.1 0.6 0.0 FFFFF%. 16 17 4.9 0.6 0.0 FFFF%%. 17 18 4.7 0.6 0.0 FFFF%.. 18 19 4.4 0.6 0.0 FFFF%. 19 20 4.1 0.6 0.0 FFFF%. 20 21 4.2 0.6 0.0 FFFF%. 21 22 4.7 2.6 2.2 FF%.. 22 23 5.1 3.3 2.7 AFF%.. 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) 21-Dec-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000