SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 18 October, 2026 T-index: 60 Bearings: 331 152 Distance: 386 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 51-60 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 6.0 5.4 3.1 BB%%. 00 01 6.4 6.0 3.3 BBB%.. 01 02 6.8 6.4 3.5 ABB%%. 02 03 7.1 6.6 3.6 ABBF%.. 03 04 7.5 6.7 3.6 ABBF%%. 04 05 7.6 6.7 3.6 ABBF%%. . 05 06 7.5 6.5 3.5 ABBF%%. . 06 07 7.1 6.2 3.4 BBBF%%. 07 08 6.8 5.7 3.2 BBF%%.. 08 09 6.7 5.0 2.8 ABBF%%. 09 10 6.3 3.8 2.2 BFFF%%.. 10 11 5.6 0.8 0.0 FFFFF%%.. 11 12 5.0 0.8 0.0 FFFF%%.. 12 13 4.4 0.8 0.0 FFFF%%. 13 14 4.2 0.8 0.0 FFFF%.. 14 15 4.2 0.8 0.0 FFFF%. 15 16 4.0 0.8 0.0 FFF%%. 16 17 3.9 0.8 0.0 FFF%%. 17 18 3.7 0.8 0.0 FFF%.. 18 19 3.6 0.8 0.0 FFF%. 19 20 3.4 0.8 0.0 FFF%. 20 21 3.5 0.8 0.0 FFF%. 21 22 4.6 2.7 1.7 AFF%.. 22 23 5.5 4.6 2.6 ABF%.. 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) 18-Oct-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000