SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 1 May, 2025 T-index: 115 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 18-23 1E 5 1 5 10 15 20 25 30 35 40 2F 37-43 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 16.4 11.4 6.2 ASSMMMM MMFFFF%%.. . 10.9 6.9 3.8 00 01 18.7 13.4 7.1 SSSXMM MMMMFFFF%% %... 12.3 8.2 4.3 01 02 19.3 14.6 7.6 ASSXMM MMMMFFFFF% %%.. 12.8 9.0 4.6 02 03 19.3 15.2 7.9 ASSXXM MMMMBFFFF% %... 13.0 9.4 4.8 03 04 19.0 15.5 8.0 ASSXXM MMMMBFFF%% %... 12.9 9.6 4.9 04 05 18.7 15.4 8.0 ASSXXM MMMMBFFF%% %.. 12.9 9.5 4.9 05 06 18.2 14.9 7.8 ASSXXM MMMMFFFF%% %.. 12.8 9.2 4.7 06 07 18.2 14.0 7.4 ASSXMM MMMMFFFF%% %... 12.6 8.7 4.5 07 08 18.1 12.5 6.7 SSXMMM MMMMFFFF%% %.. 12.4 7.7 4.1 08 09 17.6 9.7 5.4 SSMMMMM MMMFFFF%%% ... 11.9 5.9 3.3 09 10 15.5 2.2 0.0 XMMMMMMMMM MMFFF%%%.. . 10.4 1.4 0.0 10 11 12.7 2.2 0.0 XMMMMMMMMM FF%%%... 8.7 1.4 0.0 11 12 10.7 2.2 0.0 XMMMMMMMFF %%... 7.4 1.4 0.0 12 13 9.2 2.2 0.0 XMMMMMMFF% %.. 6.5 1.4 0.0 13 14 8.2 2.2 0.0 XMMMMMMF%% .. 6.0 1.4 0.0 14 15 7.6 2.2 0.0 XMMMMMF%%. .. 5.6 1.4 0.0 15 16 7.4 2.2 0.0 XMMMMMF%%. . 5.4 1.4 0.0 16 17 7.1 2.2 0.0 XMMMMMF%.. . 5.3 1.4 0.0 17 18 6.7 2.2 0.0 XMMMMM%%.. 5.1 1.4 0.0 18 19 6.3 2.2 0.0 XMMMMM%%.. 4.6 1.4 0.0 19 20 6.0 2.2 0.0 XMMMM%%.. 4.3 1.4 0.0 20 21 5.5 2.2 0.0 XMMMM%%.. 4.0 1.4 0.0 21 22 6.3 2.2 0.0 XMMMMF%.. 4.8 1.4 0.0 22 23 11.9 7.1 4.1 ASMMMMMF F%%.. 7.9 3.9 2.7 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) 1-May-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000