SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Perth district Date: 5 July, 2025 T-index: 70 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 5.4 2.0 1.8 AFFF%. 00 01 6.3 2.6 2.2 FFFF%. 01 02 6.8 2.9 2.4 FFFF%.. 02 03 6.9 3.1 2.5 AFFF%%. 03 04 7.0 3.2 2.6 AFFF%%. 04 05 7.1 3.2 2.6 AFFFF%. 05 06 7.1 3.1 2.5 AFFFF%. 06 07 7.1 2.8 2.3 FFFFF%. 07 08 7.0 2.4 2.0 AFFFF%%. 08 09 6.4 1.5 1.4 FFFFF%. 09 10 5.0 0.4 0.0 FFFF%%. 10 11 3.8 0.4 0.0 FFF%.. 11 12 3.3 0.4 0.0 FFF%. 12 13 3.1 0.4 0.0 FFF.. 13 14 3.0 0.4 0.0 FF%.. 14 15 3.0 0.4 0.0 FF%.. 15 16 3.0 0.4 0.0 FF%.. 16 17 3.0 0.4 0.0 FF%.. 17 18 3.0 0.4 0.0 FF%.. 18 19 3.0 0.4 0.0 FF%.. 19 20 3.0 0.4 0.0 FF%.. 20 21 2.9 0.4 0.0 FF%.. 21 22 2.8 0.4 0.0 FF%. 22 23 3.9 0.4 0.0 FFF%. 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) 5-Jul-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000