SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 22 August, 2026 T-index: 80 Bearings: 201 24 Distance: 1680 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 12-16 1E 2 1 5 10 15 20 25 30 35 40 2F 28-34 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 16.5 13.5 7.9 ASSXMM MMBFFF%%%. ... 10.4 8.7 4.7 00 01 18.2 15.4 8.8 SSSXM MMMBBFFF%% %.... 11.3 10.0 5.2 01 02 18.2 16.5 9.3 ASSSX MMMBBBFF%% %..... 11.5 10.9 5.5 02 03 18.2 17.1 9.6 ASSSX XMMBBBBF%% %..... 11.5 11.3 5.7 03 04 17.5 17.4 9.7 ASSSX XMMBBBB%%% ..... 11.4 11.5 5.7 04 05 17.1 17.2 9.7 ASSSX XMMBBBB%%% ..... 11.1 11.4 5.6 05 06 16.4 16.6 9.4 ASSSX MMBBBB%%%. .... 10.7 11.0 5.5 06 07 16.1 15.5 8.9 SSSXX MMBBBF%%%. .... 10.6 10.3 5.2 07 08 15.9 13.7 8.0 ASSXXM MMBFF%%%%. .... 10.4 9.2 4.6 08 09 15.9 10.6 6.4 ASSMMMM MMFFF%%%%. .... 10.4 7.0 3.8 09 10 13.4 2.3 0.0 XMMMMMMMMM MFF%%%%... .. 9.0 1.5 0.0 10 11 10.4 2.3 0.0 XMMMMMMMMF %%%%..... 7.3 1.5 0.0 11 12 9.0 2.3 0.0 XMMMMMMM%% %%..... 6.4 1.5 0.0 12 13 8.2 2.3 0.0 XMMMMMMF%% %.... 5.8 1.5 0.0 13 14 7.9 2.3 0.0 XMMMMMM%%% ..... 5.6 1.5 0.0 14 15 7.6 2.3 0.0 XMMMMMF%%% .... 5.3 1.5 0.0 15 16 7.3 2.3 0.0 XMMMMMF%%% ... 5.2 1.5 0.0 16 17 7.1 2.3 0.0 XMMMMMF%%. ... 5.1 1.5 0.0 17 18 6.6 2.3 0.0 XMMMMM%%%. ... 4.9 1.5 0.0 18 19 6.1 2.3 0.0 XMMMMM%%%. .. 4.5 1.5 0.0 19 20 5.5 2.3 0.0 XMMMM%%%.. . 4.0 1.5 0.0 20 21 5.1 2.3 0.0 XMMMM%%... 3.9 1.5 0.0 21 22 6.5 2.3 0.0 XMMMMF%%.. . 4.8 1.5 0.0 22 23 13.3 10.1 6.2 ASSMMMB FFF%%... 8.3 6.0 3.8 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) 22-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000