SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Perth district Date: 21 May, 2026 T-index: 55 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 5.7 2.1 1.8 AFFF%. 00 01 6.5 2.7 2.2 FFFF%. 01 02 6.9 2.9 2.4 FFFF%%. 02 03 7.2 3.1 2.5 AFFFF%.. 03 04 7.1 3.2 2.5 AFFFF%.. 04 05 7.1 3.2 2.5 AFFFF%.. 05 06 7.3 3.0 2.5 AFFFF%.. 06 07 7.5 2.8 2.3 FFFFF%.. 07 08 7.2 2.5 2.1 FFFFF%. 08 09 6.5 1.7 1.5 AFFFF%. 09 10 5.0 0.4 0.0 FFFF%%. 10 11 3.9 0.4 0.0 FFF%.. 11 12 3.3 0.4 0.0 FFF%. 12 13 3.1 0.4 0.0 FFF.. 13 14 3.1 0.4 0.0 FFF.. 14 15 3.1 0.4 0.0 FFF.. 15 16 3.2 0.4 0.0 FFF.. 16 17 3.2 0.4 0.0 FFF.. 17 18 3.1 0.4 0.0 FFF%. 18 19 3.1 0.4 0.0 FFF%. 19 20 3.1 0.4 0.0 FFF%. 20 21 2.9 0.4 0.0 FF%.. 21 22 2.9 0.4 0.0 FF%. 22 23 4.2 0.4 0.0 FFFF. 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) 21-May-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000