Greetings to
my fellow hamateur radio and SWL radio enthusiasts around the
world.
Welcome to my
“not for profit” W4HM Daily HF-MF Radio Wave Propagation
Forecast.
It’s the only
accurate daily global HF-MF radio wave propagation forecast produced on the
planet.
I'm a
heliophysicist, terrestrial/troposphere meteorologist/climatologist, physical
oceanographer and one of the few on the planet with advanced education and
forecast experience in all aforementioned disciplines. In
terrestrial/troposphere weather forecasting I have 45 years of experience and in
solar, space and geomagnetic weather forecasting 34 years.
This is
created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ©
1988-2019.
If you find
this daily HF-MF radio wave propagation forecast useful to your
hamateur and
SWL radio activities, feel free to drop me a line and let me
know that
at
I enjoy
hearing from likeminded fellow radio enthusiasts.
Hams and SWLs
that are interested in solar, space & geomagnetic weather as
well as radio
wave propagation are a special group of people interested in
broadening
their knowledge in science.
Feel free
without prior permission to redistribute this daily HF-MF radio
wave
propagation
forecast, as long as you redistribute it in its entirety and
give me credit
for it.
Supporting
images associated with this daily HF-MF radio wave propagation forecast can be
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Last but not
least here is my new HF-MF radio wave propagation web page where you can sign up
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It's a NO SPAM
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you have to
sign up by using an existing email address and creating a
password.
W4HM Solar
Cycle 24 Update and Solar Cycle 25 Forecast- Short and to the
point.
Solar minimum
may begin later this year and may last longer than any previous solar cycle in
the 20th century. When solar cycle 25 finally gets underway it could be the
weakest since the middle of the 19th century. Another Dalton type lesser grand
solar minimum may occur with a corresponding cooling of earth’s climate. This
would negate anthropogenic climate change if it were occurring which it
isn’t.
On February 1,
2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the
past 100 years. That forecast verified. I also forecasted that solar cycle 25
would be almost non nonexistent.
#6 issued
Sunday January 6, 2019 at 1745 UTC
Important
Solar, Space & Geomagnetic Weather Indices-
Solar activity
was very low.
The daily
solar flux index numbers (DSFI) were
70.9 71.1
72.0.
There had been
5 consecutive days with a 2000 UTC daily solar flux index number (SFI) above
70.
Unfortunately
daily SFI numbers in the 70’s doesn’t increase ionization via ultraviolet light
striking the F2 layer, to raise the maximum usable frequency (MUF) high enough
to activate the 15, 12 and 10 meter bands along east-west radio wave propagation
paths.
The official
daily sunspot number (DSSN) was 13.
In 2019 there
had been 5 consecutive days with an official daily sunspot number (DSSN) greater
than 0.
In 2018 there
had been 221 days with an official daily sunspot number (DSSN) of
0.
There had been
one sunspot group numbered 12732 located near N09W73 with a relatively complex
beta magnetic signature capable of releasing a very small B class solar flare
and an isolated small C class solar flare. It was in the process of setting
around the west limb of the sun.
The 24 hour
period 3 hour interval planetary K index (Kp) had been at a minor geomagnetic
storming level to a quiet geomagnetic condition of
5 4 2 3 1 2 2
3.
The 24 hour
period planetary A index (Ap) maximum and minimum values ranged between
48 & 5,
which had been
at a minor geomagnetic storming level to a quiet geomagnetic
condition.
The 24 hour
period maximum and minimum Disturbance Storm Time Index (Dst) ranged between
-21 & -7
nT.
The 24 hour
period maximum and minimum solar wind speed was
544 & 382
km/s.
GLOBAL (HF)
HIGH FREQUENCY (3000-30000 KHZ) RADIO WAVE PROPAGATION CONDITIONS
EXPECTED-
HF-MF radio
wave propagation condition “trend” on Jan 6, 2019- steady.
HF-MF radio
wave propagation condition “trend” on Jan 7, 2019- improving
HF-MF radio
wave propagation condition “trend” on Jan 8, 2019- improving.
Northern
Hemisphere HF Radio Wave Propagation Forecast g-
We
are now in the winter season northern hemisphere HF-MF radio wave propagation
season.
The
approximate 11000- 30000 kHz frequency range closes sooner due to less sun light
illuminating
the ionosphere than in the southern
hemisphere. But the maximum usable frequency (MUF) is higher than in the
southern hemisphere as the F layer of the ionosphere is lower in height and the
ions more concentrated.
The
approximately 3000-10000 kHz frequency range often stays open for DX all
throughout the day due to a weaker D and E layer and therefore less RF signal
absorption.
Northern
Hemisphere Radio Wave Propagation Forecast g-
3150-3400,
3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at
day,
6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at
night and
S4-7 at day,
13570-13850, 14000-14350, 15005-15900,
17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day,
21000-21850
kHz- S0 at night and S1-2 at day,
24890-24990, 25600-26100 kHz- S0 at
night and S1 at day,
28000-29700
kHz- S0 at night and S0 at day.
Southern
Hemisphere HF Radio Wave Propagation Forecast g-
We are now in
the summer season southern hemisphere HF-MF radio wave propagation
season.
The 14000-
30000 kHz frequency range closes later due to more sun light illuminating the
ionosphere than in the southern hemisphere. But the maximum usable frequency
(MUF) is lower than in the southern hemisphere as heating in the F2 layer of the
ionosphere is higher and the layer ions less concentrated.
Almost
daily during
the northern hemisphere summer season you will find that the 25600- 26100 kHz
and 28000-29700 kHz frequency ranges will open via short north-south and
east-west propagation paths via sporadic E (Es). Also when multiple sporadic E
(Es) clouds form and line up favorably much longer propagation paths open up on
east-west paths. And last but not least north-south propagation paths occur
across the equator via trans equatorial propagation
(TEP).
3150-3400,
3500-4100, 4750-5050, 5700-6300 kHz- S9+10 at night and S3-5 at
day,
6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+15 at night
and
S4-7 at day,
13570-13850, 14000-14350, 15005-15900, 17450-17950,
18068-18168 kHz- S1-3 at night and S5-8 at day,
21000-21850 kHz- S0 at
night and S1-2 at day,
24890-24990, 25600-26100 kHz- S0 at night and S1
at day,
28000-29700 kHz- S0 at night and S0 at day.
GLOBAL (MF)
MEDIUM FREQUENCY (300-3000 KHZ) RADIO WAVE PROPAGATION CONDITIONS
EXPECTED-
FORECASTED NORTHERN HEMISPHERE SHORT
PATH-
|
-East <-> West To 1100 Mi /1800 km
|
S9-+1
|
|
*North <-> South To 1100 Mi /1800
km
|
S6-8
|
|
+South <-> North To 1100 Mi /1800
km
|
S9+5
|
FORECASTED SOUTHERN HEMISPHERE SHORT
PATH-
|
-East <-> West To 1100 Mi / 1800
km
|
S9+1
|
|
*South <-> North To 1100 Mi /1800
km
|
S6-7
|
|
+North <-> South To 1100 Mi / 1800
km
|
S9
|
FORECASTED GREAT CIRCLE LONG OR SKEWED
PATH-
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
|
S4-6
|
|
Mid Latitude
|
S9+10
|
|
Low latitude
|
S7-8
|
FORECASTED GREAT CIRCLE LONG OR SKEWED
PATH-
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
|
S2-4
|
|
Mid Latitude
|
S6-7
|
|
Low latitude
|
S3-5
|
This HF-MF
Radio wave propagation forecast is produced based on the SIGINT_CAP HF-MF radio
wave propagation prediction software.
I wrote it
beginning in the late 1980’s but I’m sorry to say that it still can’t be
distributed to the general public. It does outperform VOA CAP and Prop
Lab.
I do check the
actual band conditions at my location in the USA and tweak the forecast manually
where and when necessary.
I also check
global HF-MF radio wave propagation conditions via remoted radio
receivers on
every continent of the globe and tweak the forecast manually if
and when
necessary.
And last but
not least I look at ionsonde stations on every continent of the
globe.
The hamateur
radio JT65A mode RF signal levels received are based on 5 watts
and ½ wave
dipole up at 40 feet.
The hamateur
radio PSK31 mode RF signal levels received are based on 25
watts and ½
wave dipole up at 40 feet.
The hamateur
radio CW mode RF signal levels received are based on 50 watts
and ½ wave
dipole up at 40 feet.
The hamateur
radio SSB RF mode signal levels received are based on 100 watts
and ½ wave
dipole up at 40 feet.
The HF
shortwave broadcast band AM Mode RF signal levels are based on
100,000 watts
(100 kw) and a typical high gain VOA type curtain array
antenna.
The MF
broadcast band AM Mode RF signal levels are based on 50,000 watts (50 kw) and an
omnidirectional vertical antenna.
Please keep in
mind that this is a relatively simplified HF-MF radio wave
propagation
forecast, so as to keep it easily understandable and applicable
by the average
radio enthusiast.
THE FOLLOWING
IS EDUCATIONAL MATERIAL ON SOLAR, SPACE, GEOMAGNETIC WEATHER OBSERVING AND
IONOSPHERE GOINGS ON. ALSO HF AND MF RADIO WAVE PROPAGATION CONDITIONS AND
FORECASTING.
Globally HF-MF
radio wave propagation conditions are most evenly balanced
during the
fall and spring equinoxes and most diametrically opposed during
the summer and
winter solstices.
Conditions
change daily, weekly, monthly, yearly and by decade, as the
sun rises and
sets at different times and at different angles from the
ecliptic, as
well as by radio wave frequency. This is due to changes in the
maximum usable
frequency (MUF), lowest usable frequency (LUF) and F layer
critical
frequency (FoF2). Also by propagation path.
The D and E
layers also come into play through RF radio wave signal
absorption and
refraction. And then there is sporadic E (Es) radio wave
propagation
that can really throw a wrench into the gears so to speak.
Things like
sporadic E (Es) radio wave propagation and lightning storm
static can
impact HF radio wave propagation in an unpredictable manner and
mostly
bad.
Ongoing solar,
space and geomagnetic weather goings on also impact HF radio.
Lower high
frequency (80-30 meters) propagation conditions are impacted in a
negative
manner not so much by variations in the maximum usable frequency
(MUF) along a
particular propagation path and time but rather due to
geomagnetic
elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 &
greater) that
increase signal absorption via the E layer (the altitude of
the radio
aurora). Also increases in the lowest usable frequency (LUF) via
D
layer RF
signal absorption due to hard x-rays, galactic cosmic waves,
elevated
background solar flux levels greater than B0 and energetic proton
flux levels at
energies greater than 10 MeV (10+0).
Higher
frequency (20-10 meters) propagation conditions are impacted in a
negative
manner by variations in the maximum usable frequency (MUF) along
a
particular
propagation path and time due to the current sunspot number and
also due to
elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 &
greater. Also
D layer RF signal absorption due to elevated (greater than B0)
background
solar flux levels. Also to a lesser extent elevated proton flux
at energies
greater than 10 MeV (10+0).
GENERAL
GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF
PROPAGATION CONDITIONS-
NOTE!!! The
propagation indices "interpretations" are my personal
intellectual
property. Therefore the HF-MF radio wave propagation indices
interpretations
contained herein is copyrighted © 1988-2019 by Thomas F.
Giella, W4HM,
all rights reserved. Reproduction of information herein is
allowed
without permission in advance as long as proper credit is given.
All 14 of the
following indices have to occur as described below in order to
see the best
global high frequency (HF) radio wave propagation possible,
something that
happens only rarely.
1.) Dropping
geomagnetic field indices numbers are better, Kp of 0 best.
2.) A daily
sunspot number of 150 or higher, 200 or higher best.
3.) A daily
sunspot number of greater than 100 for routine stable formation
of the E
Valley/F Layer ducting mechanism.
4.) Previous
24 hour Ap index under 10, fewer than 7 for several days
consecutively
are best.
5.) Previous 3
hours Kp index fewer than 3 for mid latitude paths, fewer
than 2 for
high latitude paths, 0 for several days consecutively is best.
6.) Energetic
protons no greater than 10 MeV (10+0).
7.) Background
x-ray flux levels greater than B1 for several days
consecutively,
greater than C1 best.
8.) No current
STRATWARM alert.
9.)
Interplanetary magnetic field (IMF) Bz with a (positive number)
sign,
indicates a
lesser chance of high latitude path aurora
absorption/unpredictable
refraction or scattering of medium frequency RF
signals, when
the Kp is above 3.
10.) A -10 or
better towards a positive number Dst index during the recovery
time after a
geomagnetic storm, as related to the equatorial ring current. A
positive
number is best.
GENERAL
GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL MF
PROPAGATION CONDITIONS-
Medium
frequency (300-3000 khz) radio wave 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 energetic electron flux
levels at energies greater than 2 MeV (2+1), 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 greater than A0, proton flux levels at energies greater than
10 MeV (10+0), hard x-rays 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 MF DX contact. As a MF 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.
Unfortunately
the simplest way to look at medium frequencies with respect to radio wave
propagation conditions is to accept the fact that propagation is poor the
majority of the time, especially past approximately 1250 miles (one maximum
distance refraction off of the E layer), with occasional short-lived good
periods as far as 3200 miles.
All 13 of the
following indices have to occur as described below in order to see the best
global medium frequency (MF) radio wave propagation possible.
The simplest
way to look at medium frequencies (MF) with respect to radio wave propagation
conditions is to accept the fact that propagation is poor the majority of the
time, especially past approximately 1250 miles (one refraction off of the E
layer), with occasional short-lived good periods as far as 3200 miles.
1.) Dropping
geomagnetic field indices numbers are better, Kp of 0 best.
2.) A daily
sunspot number under 100, under 70 best.
3.) A daily
sunspot number no higher then the 100 for routine stable formation of the E
Valley/F Layer ducting mechanism.
4.) Previous 24 hour Ap index under
10, fewer than 7 for several days consecutively are best.
5.) Previous 3
hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high
latitude paths, 0 for several days consecutively is best.
6.) Energetic
proton flux levels no greater than 10 MeV (10+0).
7.) Background x-ray
flux levels of A0 for several days consecutively.
8.) No current
STRATWARM alert.
9.) Interplanetary magnetic field (IMF) Bz with a
(positive number) sign, indicates a lesser chance of high latitude path aurora
absorption/unpredictable refraction or scattering of medium frequency RF
signals, when the Kp is above 3.
10.) A -10 or better towards a positive
number Dst index during the recovery time after a geomagnetic storm, as related
to the equatorial ring current. A positive number is best.
11.) Galactic
cosmic rays decrease to -3 units below zero and trending towards
zero.
12.) Energetic
electron flux levels no greater than 2 MeV (2+0).
13. A solar
wind speed of less than 300 km/s for several days consecutively.
Standard
Disclaimer-
Note! I use
error prone RAW public domain data from the NOAA Space
Environment
Center, other U.S. government entities and educational
institutions,
to produce this daily HF-MF radio wave propagation
forecast. This
data is gathered and made public by the U.S. Government using
taxpayer $$$
(including mine).
However this
daily HF/MF propagation forecast that I produce from the RAW
public domain
data is my personal intellectual property. Therefore this
daily HF-MF
radio wave propagation forecast contained herein is copyrighted ©
1988-2019 by
Thomas F. Giella, W4HM.
Feel free
without prior permission to redistribute this daily HF/MF radio
wave
propagation
forecast, as long as you redistribute it in its entirety and
give me credit
for it.
Also HF-MF
radio wave propagation forecasting is still an inexact
science and
therefore also an art. The forecasts are not official but for
educational
and hobby related purposes only and are subject to human error
and acts of
God, therefore no guarantee or warranty implied.
