SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Perth district Date: 28 November, 2025 T-index: 90 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 5.6 3.1 2.6 AFF%%. 00 01 5.9 3.3 2.8 AFF%%.. 01 02 6.4 3.5 2.9 AFFF%%. 02 03 6.8 3.6 3.0 AFFF%%.. 03 04 7.1 3.7 3.1 FFFF%.. 04 05 7.2 3.7 3.0 AFFFF%.. 05 06 7.0 3.6 3.0 AFFF%%.. 06 07 6.8 3.4 2.9 AFFF%%.. 07 08 6.7 3.2 2.7 AFFF%%.. 08 09 6.6 2.9 2.5 AFFF%%.. 09 10 6.4 2.4 2.2 FFFF%%. 10 11 6.2 1.4 1.4 FFFFF%.. 11 12 5.9 0.4 0.0 FFFFF%%. 12 13 5.5 0.4 0.0 FFFFF%%. 13 14 5.2 0.4 0.0 FFFFF%.. 14 15 5.1 0.4 0.0 FFFFF%. 15 16 5.0 0.4 0.0 FFFF%%. 16 17 4.7 0.4 0.0 FFFF%%. 17 18 4.5 0.4 0.0 FFFF%.. 18 19 4.3 0.4 0.0 FFFF%. 19 20 4.1 0.4 0.0 FFFF%. 20 21 4.3 0.4 0.0 FFFF%. 21 22 4.8 2.0 1.8 AFF%%. 22 23 5.2 2.7 2.3 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) 28-Nov-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000