SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 4 August, 2026 T-index: 80 Bearings: 331 152 Distance: 386 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 51-55 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 6.6 4.4 2.6 ABFF%.. 00 01 7.5 5.3 3.0 ABBFF%.. 01 02 8.0 5.9 3.2 BBFF%%. . 02 03 8.3 6.2 3.4 BBBFF%. . 03 04 8.4 6.3 3.4 BBBFF%. . 04 05 8.4 6.3 3.4 BBBFF%. . 05 06 8.4 6.0 3.3 BBBFF%. . 06 07 8.3 5.6 3.1 BBFFF%. . 07 08 8.2 4.9 2.8 ABFFFF%. . 08 09 7.4 3.4 2.1 BFFFF%.. 09 10 6.2 0.9 0.0 FFFFFF%.. 10 11 4.9 0.9 0.0 FFFF%%.. 11 12 4.1 0.9 0.0 FFFF%. 12 13 3.7 0.9 0.0 FFF%.. 13 14 3.5 0.9 0.0 FFF%. 14 15 3.4 0.9 0.0 FFF%. 15 16 3.3 0.9 0.0 FFF%. 16 17 3.3 0.9 0.0 FFF%. 17 18 3.2 0.9 0.0 FFF%. 18 19 3.1 0.9 0.0 FFF%. 19 20 3.0 0.9 0.0 FF%%. 20 21 2.9 0.9 0.0 FF%.. 21 22 3.0 0.9 0.0 FF%. 22 23 4.7 0.9 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) 4-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000