SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Geraldton Perth Date: 1 June, 2026 T-index: 90 Bearings: 162 341 Distance: 373 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 52-55 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 7.1 3.7 2.4 BFFFF%. 00 01 8.5 4.7 2.9 ABFFFF%. . 01 02 9.2 5.2 3.2 BBFFFF% .. 02 03 9.4 5.5 3.3 BBFFFF% .. 03 04 9.3 5.7 3.4 BBFFFF% .. 04 05 9.3 5.6 3.4 BBFFFF% .. 05 06 9.3 5.4 3.3 BBFFFF% .. 06 07 9.4 5.1 3.1 BBFFFF% .. 07 08 9.2 4.4 2.8 ABFFFFF% .. 08 09 8.5 3.1 2.0 ABFFFFF%. . 09 10 6.8 0.8 0.0 FFFFFF%%.. 10 11 5.2 0.8 0.0 FFFFF%.. 11 12 4.2 0.8 0.0 FFFF%. 12 13 3.9 0.8 0.0 FFF%.. 13 14 3.7 0.8 0.0 FFF%.. 14 15 3.6 0.8 0.0 FFF%. 15 16 3.6 0.8 0.0 FFF%. 16 17 3.6 0.8 0.0 FFF%. 17 18 3.5 0.8 0.0 FFF%. 18 19 3.4 0.8 0.0 FFF%.. 19 20 3.5 0.8 0.0 FFF%.. 20 21 3.2 0.8 0.0 FFF%. 21 22 3.2 0.8 0.0 FFF%. 22 23 4.9 0.8 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) 1-Jun-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000