SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Albany Perth Date: 13 April, 2026 T-index: 80 Bearings: 331 152 Distance: 386 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 7.7 4.9 2.8 ABFFF%%. 00 01 8.5 5.7 3.2 BBFFF%% .. 01 02 8.9 6.1 3.4 BBBFF%% .. 02 03 9.2 6.4 3.5 ABBFFF% %.. 03 04 9.5 6.5 3.6 ABBFFF% %.. 04 05 9.7 6.5 3.6 ABBFFF% %.. 05 06 9.4 6.3 3.5 ABBFFF% %.. 06 07 9.1 5.9 3.3 BBFFFF% %.. 07 08 8.8 5.3 3.0 ABBFFF%% %. 08 09 8.4 4.2 2.5 ABFFFF%% .. 09 10 7.1 0.9 0.0 FFFFFFF%%. . 10 11 5.6 0.9 0.0 FFFFF%%.. 11 12 4.9 0.9 0.0 FFFF%%.. 12 13 4.5 0.9 0.0 FFFF%%. 13 14 4.3 0.9 0.0 FFFF%.. 14 15 4.2 0.9 0.0 FFFF%. 15 16 4.1 0.9 0.0 FFFF%. 16 17 4.0 0.9 0.0 FFF%%. 17 18 4.0 0.9 0.0 FFF%%. 18 19 3.9 0.9 0.0 FFF%%. 19 20 3.7 0.9 0.0 FFF%.. 20 21 3.5 0.9 0.0 FFF%. 21 22 3.7 0.9 0.0 FFF%. 22 23 5.8 3.4 2.0 ABFF%%. 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-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000