SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 21 December, 2025 T-index: 95 Bearings: 331 152 Distance: 386 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 52-64 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 5.9 6.0 3.4 BBP%.. 00 01 6.3 6.5 3.7 ABB%%.. 01 02 6.7 6.8 3.8 ABB%%.. 02 03 7.1 7.0 3.9 ABBB%.. 03 04 7.3 7.1 3.9 ABBB%%. . 04 05 7.3 7.1 3.9 ABBB%%. . 05 06 7.2 6.9 3.9 ABBF%%. 06 07 7.1 6.6 3.7 ABBF%%. 07 08 7.0 6.2 3.5 ABB%%.. 08 09 6.8 5.6 3.3 BBF%%.. 09 10 6.7 4.7 2.8 ABFF%%.. 10 11 6.5 3.1 2.0 ABFFF%%. 11 12 6.2 0.9 0.0 FFFFFF%%. 12 13 6.0 0.9 0.0 FFFFF%%.. 13 14 5.8 0.9 0.0 FFFFF%%. 14 15 5.7 0.9 0.0 FFFFF%%. 15 16 5.4 0.9 0.0 FFFFF%.. 16 17 5.1 0.9 0.0 FFFFF%. 17 18 4.9 0.9 0.0 FFFF%%. 18 19 4.5 0.9 0.0 FFFF%.. 19 20 4.3 0.9 0.0 FFFF%. 20 21 4.4 0.9 0.0 FFFF%.. 21 22 5.1 4.2 2.6 ABF%.. 22 23 5.4 5.3 3.1 BB%.. 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