SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Geraldton Perth Date: 4 July, 2025 T-index: 70 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 6.1 3.6 2.3 BFFF%. 00 01 7.2 4.5 2.8 ABFFF%. 01 02 7.7 5.1 3.0 ABBFF%%. 02 03 7.8 5.4 3.2 BBFF%%. 03 04 7.8 5.5 3.3 BBFF%%. 04 05 7.8 5.5 3.2 BBFF%%. 05 06 7.8 5.3 3.2 BBFF%%. . 06 07 7.8 4.9 3.0 ABFFF%%. . 07 08 7.7 4.3 2.6 ABFFF%%. 08 09 7.2 2.9 1.9 AFFFFF%.. 09 10 5.5 0.8 0.0 FFFFF%.. 10 11 4.1 0.8 0.0 FFFF%.. 11 12 3.5 0.8 0.0 FFF%.. 12 13 3.3 0.8 0.0 FFF%. 13 14 3.2 0.8 0.0 FFF%. 14 15 3.1 0.8 0.0 FFF%. 15 16 3.2 0.8 0.0 FFF%. 16 17 3.2 0.8 0.0 FFF%. 17 18 3.2 0.8 0.0 FFF%. 18 19 3.2 0.8 0.0 FFF%. 19 20 3.2 0.8 0.0 FFF%. 20 21 3.0 0.8 0.0 FF%.. 21 22 2.9 0.8 0.0 FF%. 22 23 4.2 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) 4-Jul-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000