SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 24 December, 2025 T-index: 80 Bearings: 331 152 Distance: 386 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 51-64 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 5.5 5.9 3.3 BB%%.. 00 01 5.9 6.4 3.6 ABP%.. 01 02 6.3 6.7 3.7 ABB%%.. 02 03 6.7 6.9 3.8 ABB%%.. 03 04 7.0 7.0 3.8 ABBP%.. 04 05 7.0 6.9 3.8 ABB%%.. 05 06 6.9 6.8 3.8 ABB%%.. 06 07 6.8 6.5 3.6 ABB%%.. 07 08 6.6 6.1 3.4 BBB%%.. 08 09 6.5 5.5 3.2 BBF%%.. 09 10 6.2 4.7 2.7 ABFF%%. 10 11 6.0 3.0 1.9 ABFF%%%. 11 12 5.8 0.9 0.0 FFFFF%%.. 12 13 5.5 0.9 0.0 FFFFF%%. 13 14 5.4 0.9 0.0 FFFFF%%. 14 15 5.3 0.9 0.0 FFFFF%.. 15 16 5.0 0.9 0.0 FFFF%%. 16 17 4.7 0.9 0.0 FFFF%%. 17 18 4.6 0.9 0.0 FFFF%.. 18 19 4.4 0.9 0.0 FFFF%.. 19 20 4.1 0.9 0.0 FFFF%. 20 21 4.3 0.9 0.0 FFFF%. 21 22 4.8 4.2 2.5 AB%%. 22 23 5.1 5.2 3.0 ABB%.. 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) 24-Dec-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000