SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 16 December, 2025 T-index: 105 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 6.1 6.1 3.5 ABB%.. 00 01 6.5 6.5 3.7 ABB%%.. 01 02 6.9 6.9 3.9 ABB%%.. 02 03 7.3 7.1 4.0 ABBB%%. . 03 04 7.5 7.2 4.0 ABBB%%. . 04 05 7.5 7.1 4.0 ABBB%%. . 05 06 7.4 7.0 3.9 ABBB%%. . 06 07 7.2 6.7 3.8 ABBF%%. . 07 08 7.2 6.3 3.6 ABBF%%. . 08 09 7.1 5.7 3.3 BBFF%%. 09 10 7.0 4.8 2.9 ABFF%%.. 10 11 6.9 3.1 2.0 ABFFF%%.. 11 12 6.5 0.9 0.0 FFFFFF%%. 12 13 6.3 0.9 0.0 FFFFFF%%. 13 14 6.1 0.9 0.0 FFFFFF%.. 14 15 5.9 0.9 0.0 FFFFF%%. 15 16 5.6 0.9 0.0 FFFFF%%. 16 17 5.3 0.9 0.0 FFFFF%.. 17 18 5.1 0.9 0.0 FFFFF%. 18 19 4.7 0.9 0.0 FFFF%.. 19 20 4.4 0.9 0.0 FFFF%.. 20 21 4.6 0.9 0.0 FFFF%.. 21 22 5.3 4.3 2.6 ABF%.. 22 23 5.7 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) 16-Dec-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000