SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Geraldton Perth Date: 1 May, 2025 T-index: 115 Bearings: 162 341 Distance: 373 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 52-57 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 8.9 4.2 2.7 ABFFFF%% . 00 01 10.3 5.1 3.2 BBFFFFF %.. 01 02 11.0 5.6 3.5 ABFFFFF %%.. 02 03 11.3 5.9 3.6 ABFFFFF F%.. 03 04 11.2 6.0 3.7 ABBFFFF F%.. 04 05 11.3 6.0 3.7 ABBFFFF F%.. 05 06 11.2 5.8 3.6 ABFFFFF F%.. 06 07 11.0 5.4 3.4 BBFFFFF %%.. 07 08 10.8 4.8 3.1 BFFFFFF %%.. 08 09 10.3 3.8 2.5 AFFFFFFF %.. 09 10 8.9 0.8 0.0 FFFFFFFF%% .. 10 11 7.4 0.8 0.0 FFFFFFF%.. 11 12 6.3 0.8 0.0 FFFFFF%. 12 13 5.5 0.8 0.0 FFFFF%. 13 14 5.1 0.8 0.0 FFFFF%. 14 15 4.8 0.8 0.0 FFFF%.. 15 16 4.6 0.8 0.0 FFFF%.. 16 17 4.5 0.8 0.0 FFFF%.. 17 18 4.2 0.8 0.0 FFFF%. 18 19 4.1 0.8 0.0 FFFF%. 19 20 3.9 0.8 0.0 FFF%.. 20 21 3.6 0.8 0.0 FFF%. 21 22 3.9 0.8 0.0 FFF%. 22 23 6.3 1.9 1.4 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) 1-May-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000