SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 10 December, 2025 T-index: 120 Bearings: 331 152 Distance: 386 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 52-65 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 6.6 6.1 3.6 ABB%%.. 00 01 7.0 6.6 3.8 ABB%%.. . 01 02 7.4 7.0 4.0 ABBB%%. . 02 03 7.7 7.2 4.1 BBB%%. . 03 04 7.9 7.3 4.1 BBB%%. . 04 05 7.9 7.2 4.1 BBB%%. . 05 06 7.7 7.1 4.0 ABBB%%. . 06 07 7.6 6.8 3.9 ABBF%%. . 07 08 7.5 6.4 3.7 ABBF%%. . 08 09 7.4 5.8 3.4 BBFF%%. . 09 10 7.4 4.8 2.9 ABFFF%%. 10 11 7.4 3.1 2.0 ABFFFF%%. 11 12 7.1 1.0 0.0 BFFFFFF%.. 12 13 6.8 1.0 0.0 BFFFFF%%. 13 14 6.5 1.0 0.0 BFFFFF%.. 14 15 6.2 1.0 0.0 BFFFFF%.. 15 16 5.9 1.0 0.0 BFFFF%%. 16 17 5.6 1.0 0.0 BFFFF%.. 17 18 5.3 1.0 0.0 BFFFF%. 18 19 4.8 1.0 0.0 BFFF%%. 19 20 4.5 1.0 0.0 BFFF%.. 20 21 4.7 1.0 0.0 BFFF%%. 21 22 5.6 4.3 2.6 ABF%%. 22 23 6.1 5.4 3.2 BBF%.. 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