SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Perth district Date: 13 March, 2026 T-index: 100 Bearings: 0 180 Distance: 0-300 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 60-90 1E 40-90 1 5 10 15 20 25 30 35 40 ** NONE ** UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 6.6 2.9 2.5 AFFF%.. 00 01 7.3 3.2 2.7 AFFFF%. 01 02 7.7 3.4 2.9 AFFFF%%. 02 03 8.2 3.6 3.0 AFFFFF%. . 03 04 8.5 3.6 3.0 AFFFFF%. . 04 05 8.7 3.6 3.0 AFFFFF%% . 05 06 8.5 3.5 2.9 AFFFFF%% . 06 07 8.3 3.3 2.8 AFFFFF%% . 07 08 8.0 3.1 2.6 AFFFF%%. . 08 09 7.8 2.6 2.3 FFFFF%%. 09 10 7.3 1.8 1.7 AFFFFF%%. 10 11 6.6 0.5 0.0 FFFFFF%%. 11 12 6.0 0.5 0.0 FFFFF%%.. 12 13 5.4 0.5 0.0 FFFFF%.. 13 14 5.0 0.5 0.0 FFFF%%. 14 15 4.8 0.5 0.0 FFFF%%. 15 16 4.7 0.5 0.0 FFFF%.. 16 17 4.5 0.5 0.0 FFFF%.. 17 18 4.3 0.5 0.0 FFFF%. 18 19 4.1 0.5 0.0 FFFF%. 19 20 3.8 0.5 0.0 FFF%. 20 21 3.7 0.5 0.0 FFF%. 21 22 4.2 0.5 0.0 FFFF%. 22 23 5.6 2.3 2.0 AFFF%. 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-Mar-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000