SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Perth district Date: 10 September, 2026 T-index: 55 Bearings: 0 180 Distance: 0-300 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 60-90 1E 40-90 1 5 10 15 20 25 30 35 40 ** NONE ** UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 5.7 2.6 2.2 FFF%.. 00 01 6.1 2.9 2.4 FFFF%. 01 02 6.4 3.2 2.6 AFFF%.. 02 03 6.6 3.3 2.7 AFFF%%. 03 04 6.7 3.4 2.7 AFFF%%. 04 05 6.8 3.4 2.7 AFFF%%. 05 06 6.5 3.3 2.6 AFFF%%. 06 07 6.4 3.1 2.5 AFFF%.. 07 08 6.2 2.8 2.3 FFFF%. 08 09 5.9 2.3 2.0 AFFF%%. 09 10 5.2 1.0 1.0 AFFFF%.. 10 11 4.4 0.4 0.0 FFFF%.. 11 12 3.9 0.4 0.0 FFF%%. 12 13 3.6 0.4 0.0 FFF%.. 13 14 3.5 0.4 0.0 FFF%. 14 15 3.5 0.4 0.0 FFF%. 15 16 3.4 0.4 0.0 FFF%. 16 17 3.3 0.4 0.0 FFF%. 17 18 3.2 0.4 0.0 FFF%. 18 19 3.1 0.4 0.0 FFF%. 19 20 3.0 0.4 0.0 FF%. 20 21 2.9 0.4 0.0 FF%. 21 22 3.3 0.4 0.0 FFF%. 22 23 4.7 1.9 1.7 AFF%. 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) 10-Sep-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000