SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Bunbury Perth Date: 21 April, 2026 T-index: 78 Bearings: 8 188 Distance: 155 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F/1E: Near 90 1 5 10 15 20 25 30 35 40 ** NONE ** UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 6.9 2.9 2.4 FFFF%%. 00 01 7.8 3.5 2.7 AFFFF%%. 01 02 8.2 3.8 2.9 AFFFFF%. . 02 03 8.5 4.0 3.1 BFFFF%% . 03 04 8.7 4.1 3.1 BFFFF%% .. 04 05 8.9 4.0 3.1 BFFFF%% .. 05 06 8.7 3.9 3.0 AFFFFF%% .. 06 07 8.4 3.7 2.9 AFFFFF%% .. 07 08 8.2 3.3 2.6 AFFFFF%% . 08 09 7.7 2.6 2.1 FFFFF%%. . 09 10 6.4 0.5 0.0 FFFFFF%%.. 10 11 5.1 0.5 0.0 FFFFF%.. 11 12 4.5 0.5 0.0 FFFF%%. 12 13 4.1 0.5 0.0 FFFF%. 13 14 3.9 0.5 0.0 FFF%%. 14 15 3.9 0.5 0.0 FFF%.. 15 16 3.8 0.5 0.0 FFF%.. 16 17 3.8 0.5 0.0 FFF%.. 17 18 3.7 0.5 0.0 FFF%.. 18 19 3.6 0.5 0.0 FFF%. 19 20 3.4 0.5 0.0 FFF%. 20 21 3.2 0.5 0.0 FFF%. 21 22 3.4 0.5 0.0 FFF%. 22 23 5.1 1.7 1.5 AFFF%. 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-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000