SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Geraldton Perth Date: 13 July, 2026 T-index: 65 Bearings: 162 341 Distance: 373 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 51-55 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 5.9 3.6 2.3 BFF%.. 00 01 6.9 4.6 2.8 ABFF%%. 01 02 7.3 5.1 3.0 ABBFF%.. 02 03 7.4 5.4 3.2 BBFF%.. 03 04 7.4 5.5 3.2 BBFF%.. 04 05 7.4 5.5 3.2 BBFF%.. 05 06 7.4 5.3 3.1 BBFF%.. 06 07 7.5 4.9 3.0 ABFFF%.. 07 08 7.4 4.3 2.6 ABFFF%.. 08 09 6.9 3.0 1.9 ABFFF%%. 09 10 5.3 0.7 0.0 FFFFF%.. 10 11 4.0 0.7 0.0 FFF%%.. 11 12 3.5 0.7 0.0 FFF%.. 12 13 3.2 0.7 0.0 FFF%. 13 14 3.1 0.7 0.0 FFF%. 14 15 3.2 0.7 0.0 FFF%. 15 16 3.2 0.7 0.0 FFF%. 16 17 3.2 0.7 0.0 FFF%. 17 18 3.1 0.7 0.0 FFF%. 18 19 3.1 0.7 0.0 FFF%. 19 20 3.1 0.7 0.0 FFF%. 20 21 2.9 0.7 0.0 FF%.. 21 22 2.9 0.7 0.0 FF%. 22 23 4.1 0.7 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) 13-Jul-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000