SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 21 July, 2026 T-index: 65 Bearings: 331 152 Distance: 386 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 50-54 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 6.0 4.1 2.4 BBF%%. 00 01 7.0 5.1 2.8 ABBF%%. 01 02 7.3 5.7 3.1 BBFF%.. 02 03 7.4 6.0 3.2 BBBF%.. 03 04 7.5 6.1 3.3 BBBF%.. 04 05 7.6 6.0 3.3 BBBF%%. 05 06 7.6 5.8 3.2 BBFF%%. 06 07 7.7 5.4 3.0 ABBFF%%. 07 08 7.6 4.6 2.6 ABFFF%.. 08 09 6.8 2.9 1.7 AFFFF%%. 09 10 5.4 0.8 0.0 FFFFF%.. 10 11 4.1 0.8 0.0 FFFF%.. 11 12 3.5 0.8 0.0 FFF%.. 12 13 3.2 0.8 0.0 FFF%. 13 14 3.1 0.8 0.0 FFF.. 14 15 3.1 0.8 0.0 FFF.. 15 16 3.1 0.8 0.0 FFF.. 16 17 3.1 0.8 0.0 FFF.. 17 18 3.0 0.8 0.0 FF%.. 18 19 3.0 0.8 0.0 FF%.. 19 20 3.0 0.8 0.0 FF%.. 20 21 2.9 0.8 0.0 FF%.. 21 22 2.9 0.8 0.0 FF%. 22 23 4.2 0.8 0.0 FFFF. 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-Jul-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000