NZ4O Medium Frequency (300-3000 KC) Radiowave Propagation Forecast #2012-20

Thomas F. Giella <thomasfgiella@...>

For all of my amateur radio and SWL friends around the world:

A Radiowave Propagation Forecast For Hams As Well As Shortwave DXers And Listeners

Published on Friday May 11, 2012 at 0000 UTC. Valid 0000 UTC Saturday May 12, 2012 through 2359 UTC Friday May 18, 2012.

The complete MF/HF/6M forecast can be found at and .

Medium frequency (300-3000 kc) radiowave propagation conditions are impacted in a negative manner not by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic disturbances (Kp-3-4) and geomagnetic storms (Kp-5 & >) that increase signal absorption via the E layer (the general altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer signal absorption due to elevated background solar flux levels (>A0), proton flux levels at energies greater than 10 MeV (10+0) and galactic cosmic rays.

There is also the issue of magneto ionic power coupling. Antenna polarization plays a large role in the success of a long haul DX contact. As a medium frequency RF signal traverses Earth's magnetic lines of force in a perpendicular manner on high and mid latitude paths say between W3 land and SM, higher angle horizontally polarized signals are more readily absorbed than lower angle vertically polarized signals. On other propagation paths on the globe opposite results can be found, i.e., horizontally polarized signals suffer less absorption on a propagation path between VK6 and W6 or S9 and W4.

For more information on MF radiowave propagation theory check out .


Note! This forecast is based upon quiet solar, space and geomagnetic weather conditions. Geomagnetic storming Kp-5> and energetic proton storms >10 MeV (10+0) can at times render the forecast temporarily inaccurate.

Magnetic Equator-

Low 0-25 degrees

Mid 25-60 degrees

High 60-90 degrees


-East <-> West To 1100 Mi /1800 km- Fair *North <-> South To 1100 Mi /1800 km-Poor To Fair +South <-> North To 1100 Mi /1800 km- Poor To Fair

SOUTHERN -East <-> West To 1100 Mi / 1800 km- Fair To Good *South <-> North To 1100 Mi /1800 km- Fair To Good +North <-> South To 1100 Mi / 1800 km- Fair To Good

Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions in

excess of approximately 3200 mi / 5200 km

High Latitude- Poor To Fair

Mid Latitude- Fair

Low Latitude- Poor To Fair

Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions in

excess of approximately 3200 mi / 5200 km

High Latitude- Fair

Mid Latitude- Fair To Good

Low Latitude- Fair

HF Propagation Forecast Scale-
Excellent S9+1 Or Better
Good S7-S9
Fair S4-S6
Poor S1-S3
None S0

Note! I use error prone RAW public domain data from the NOAA Space Environment Center, as well as other U.S. government organizations, to produce my propagation forecasts. This data is gathered and made public by the U.S. Government using taxpayer $$$. However the propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this propagation forecast contained herein is copyrighted 1988-2012 by Thomas F. Giella, NZ4O. Reproduction of and distribution of the propagation forecast herein is allowed without advanced permission as long as proper credit is given.

Also space weather forecasting is still an inexact science. The forecasts are not official but for hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.

73 & GUD DX,
Thomas F. Giella, NZ4O
Lakeland, FL, USA

NZ4O MF/HF/6M (600-6 Meters) Radiowave Propagation Forecast:
NZ4O Solar Space Weather & Geomagnetic Data Archive:
NZ4O Solar Space Weather & Geomagnetic Data Dashboard:
NZ4O Solar Cycle 24 Forecast Discussion & Archive:
NZ4O 160 Meter (MF) Radio Propagation Theory Notes:
NZ4O Solar Space Weather & Geomagnetic Raw Forecast Data Links:

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