Greetings to my fellow hamateur radio and SWL radio enthusiasts around the
world.
Welcome to my “not for profit” daily W4HM Daily HF Radio Wave
Propagation
Forecast.
It’s the only daily global HF radio wave
propagation forecast produced on
the planet.
I'm a retired space and
terrestrial meteorologist and one of the few on the
planet with advanced
education & 44 years of forecasting experience in both
disciplines.
Created and disseminated by Thomas F. Giella, W4HM in
Lakeland, FL, USA ©
1988-2018.
If you find this daily HF 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
thomasfgiella@gmail.com
Feel
free without prior permission to redistribute this daily HF 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 radio wave propagation
forecast can be found in my Facebook account
at
https://www.facebook.com/thomasfranklingiellaw4hm
and
at
http://lists.contesting.com/mailman/listinfo/spaceweather
but
without supporting images.
It's a NO SPAM voluntary "opt" in email type
group hosted by contesting on
line (COL), so you have to sign up by using an
existing email address and
creating a password.
And last but not
least I also post solar, space and geomagnetic weather
goings on and some
images in my Twitter account at
https://twitter.com/GiellaW4hm
.
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#54
Issued Friday February 23, 2018 at 1430 UTC
Important Solar, Space &
Geomagnetic Weather Indices-
The daily solar flux index numbers (DSFI)
were 69.7 68.2 70.6
There had been 4 days in a row with a 2000 UTC daily
solar flux index number
(DSFI) below 70.
The official daily sunspot
number (DSSN) was 0.
There had been 6 days in a row with a daily sunspot
number (DSSN) of 0.
In 2018 there had been 24 days with a daily sunspot
number (DSSN) of 0.
The 24 hour period 3 hour interval planetary K index
(Kp) had been at an
active to quiet geomagnetic condition of
2 1 1 2
2 3 4
3.
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Global
Daily HF Radio Wave Propagation Forecast-
At 0900 UTC on February 23,
2018 the Kp index is 5 which is minor
geomagnetic storming
condition.
HF radio wave propagation condition trend February 24, 2018-
deteriorating
HF radio wave propagation condition trend February 25,
2018- deteriorating
Northern Hemisphere Radio Wave Propagation Forecast
b-
3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- fair to good at night
and
poor at day,
6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz-
fair at night and fair
at day,
13570-13850, 14000-14350, 15005-15900,
17450-17950, 18068-18168 kHz- poor at
night and fair at
day,
21000-21850 kHz- very poor at night and fair at
day,
24890-24990, 25600-26100 kHz- very poor at night and poor at
day,
28000-29700 kHz- very poor at night and very poor at
day.
Excellent- S9+10 or >
Very Good- S9 +1-9
Good-
S8-9
Fair- S4-7
Poor- S1-3
Very Poor- S0
During the northern
hemisphere winter season the higher HF bands of 10-20
meters (11-19 meters)
close 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 more dense.
Southern Hemisphere Radio Wave Propagation
Forecast b-
3150-3400, 3500-4100, 4750-5050, 5700-6300- poor at night and
poor at day,
6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- poor at
night and fair
at day,
13570-13850, 14000-14350, 15005-15900,
17450-17950, 18068-18168, kHz-
fair at night and poor to fair at
day,
21000-21850 kHz- poor at night and poor at day,
24890-24990,
25600-26100 kHz- very poor at night and poor at day,
28000-29700 kHz-
very poor at night and very poor at day.
Excellent- S9+10 or >
Very
Good- S9 +1-9
Good- S8-9
Fair- S4-7
Poor- S1-3
Very Poor-
S0
Keep in mind that almost daily during the southern hemisphere summer
season
you will find that the 10 (11) meter bands 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).
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
This
HF Radio wave propagation forecast is produced based on the SIGINT_CAP
HF
radio wave propagation prediction software. I wrote it beginning in the
late
1980’s but I’m sorry to say that it can’t be distributed to the general
public.
And though this HF radio wave propagation forecast is
produced based on the
SIGINT_CAP, 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 radio wave propagation conditions via
remoted radio receivers
around on every continent of the globe and tweak the
forecast manually if
and when necessary.
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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Please
keep in mind that this is a relatively simplified HF radio wave
propagation
forecast, so as to keep it easily understandable and applicable
by the
average radio enthusiast.
Globally HF 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).
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
wave propagation
conditions in a negative
manner.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
GENERAL
GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL
HF
PROPAGATION CONDITIONS-
NOTE!!! The propagation indices "interpretations"
are my personal
intellectual property. Therefore the radio wave propagation
indices
interpretations contained herein is copyrighted © 1988-2018 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 radio wave propagation
possible,
something that happens 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.
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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 radio wave
propagation
forecast. This data is gathered and made public by the U.S.
Government using
taxpayer $$$ (including mine).
However this daily HF
propagation forecast that I produce from the RAW
public domain data is my
personal intellectual property. Therefore this
daily HF radio wave
propagation forecast contained herein is copyrighted ©
1988-2018 by Thomas
F. Giella, W4HM.
Feel free without prior permission to redistribute this
daily HF radio wave
propagation forecast, as long as you redistribute it in
its entirety and
give me credit for it.
Also HF radio wave propagation
forecasting is still an inexact
science. 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.
