SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Geraldton Perth Date: 15 March, 2026 T-index: 85 Bearings: 162 341 Distance: 373 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 52-60 1E 24 1 5 10 15 20 25 30 35 40 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 7.1 4.8 3.0 ABFFF%. 00 01 7.8 5.4 3.3 BBFF%%. 01 02 8.1 5.8 3.5 ABFFF%. . 02 03 8.6 6.0 3.6 ABBFF%% . 03 04 8.9 6.1 3.7 ABBFF%% .. 04 05 9.0 6.1 3.7 ABBFF%% .. 05 06 8.9 5.9 3.6 ABFFF%% .. 06 07 8.5 5.7 3.5 ABFFF%% .. 07 08 8.2 5.2 3.2 BBFFF%% . 08 09 8.0 4.5 2.8 ABFFF%%% . 09 10 7.3 3.1 2.1 BFFFF%%. . 10 11 6.4 0.8 0.0 FFFFFF%%.. 11 12 5.7 0.8 0.0 FFFFF%%.. 12 13 5.1 0.8 0.0 FFFFF%.. 13 14 4.8 0.8 0.0 FFFF%%. 14 15 4.8 0.8 0.0 FFFF%%. 15 16 4.7 0.8 0.0 FFFF%%. 16 17 4.5 0.8 0.0 FFFF%.. 17 18 4.3 0.8 0.0 FFFF%.. 18 19 4.1 0.8 0.0 FFFF%. 19 20 3.7 0.8 0.0 FFF%.. 20 21 3.6 0.8 0.0 FFF%. 21 22 4.2 0.8 0.0 FFFF%. 22 23 5.8 3.7 2.4 BFF%%. 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) 15-Mar-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000