SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Geraldton Perth Date: 17 May, 2025 T-index: 90 Bearings: 162 341 Distance: 373 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 52-56 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 7.6 3.9 2.5 AFFFF%.. 00 01 9.0 4.8 3.0 ABFFFF%% .. 01 02 9.7 5.3 3.2 BBFFFF% %.. 02 03 10.0 5.6 3.4 BBFFFF% %.. 03 04 9.8 5.7 3.5 ABFFFF% %.. 04 05 9.7 5.7 3.4 BBFFFF% %. 05 06 9.7 5.5 3.3 BBFFFF% %.. 06 07 9.8 5.2 3.2 BBFFFF% %.. 07 08 9.6 4.5 2.8 ABFFFFF% %.. 08 09 8.9 3.4 2.2 BFFFFF%% .. 09 10 7.3 0.8 0.0 FFFFFFF%.. 10 11 5.7 0.8 0.0 FFFFF%%.. 11 12 4.7 0.8 0.0 FFFF%.. 12 13 4.1 0.8 0.0 FFFF%. 13 14 4.0 0.8 0.0 FFF%.. 14 15 3.9 0.8 0.0 FFF%.. 15 16 3.8 0.8 0.0 FFF%.. 16 17 3.8 0.8 0.0 FFF%.. 17 18 3.6 0.8 0.0 FFF%.. 18 19 3.5 0.8 0.0 FFF%.. 19 20 3.4 0.8 0.0 FFF%.. 20 21 3.2 0.8 0.0 FFF%. 21 22 3.3 0.8 0.0 FFF%. 22 23 5.3 0.8 0.0 FFFFF%. 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) 17-May-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000