SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Bunbury Perth Date: 10 December, 2025 T-index: 120 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 6.2 3.8 3.1 FFF%.. 00 01 6.6 4.2 3.3 BFF%%.. 01 02 7.0 4.4 3.5 AFF%%.. 02 03 7.3 4.5 3.6 AFFF%.. 03 04 7.5 4.6 3.6 AFFF%%. . 04 05 7.5 4.6 3.6 AFFF%%. . 05 06 7.3 4.5 3.6 AFFF%%. 06 07 7.2 4.3 3.4 BFFF%%. 07 08 7.1 4.0 3.3 BFFF%.. 08 09 7.0 3.6 3.0 AFFF%%.. 09 10 7.0 3.1 2.6 AFFF%%.. 10 11 7.0 2.0 1.8 AFFFF%%. 11 12 6.7 0.6 0.0 FFFFFF%%. 12 13 6.4 0.6 0.0 FFFFFF%.. 13 14 6.1 0.6 0.0 FFFFFF%. 14 15 5.9 0.6 0.0 FFFFF%%. 15 16 5.7 0.6 0.0 FFFFF%.. 16 17 5.4 0.6 0.0 FFFFF%. 17 18 5.1 0.6 0.0 FFFFF%. 18 19 4.6 0.6 0.0 FFFF%.. 19 20 4.4 0.6 0.0 FFFF%. 20 21 4.4 0.6 0.0 FFFF%. 21 22 5.2 2.6 2.3 FFF%.. 22 23 5.8 3.4 2.8 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) 10-Dec-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000