Hello to my fellow hamateur radio and SWL radio enthusiasts around the world.
Welcome to my “not for profit” daily HF radio wave propagation forecast
and solar, space and geomagnetic weather discussion.
If you find this
"not for profit" daily HF radio wave propagation forecast and solar, space and
geomagnetic weather discussion 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 "not for profit"
daily HF radio wave propagation forecast
and solar, space and geomagnetic weather discussion, as long as you redistribute
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give me credit for it.
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.
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#237
Issued on Friday August 25, 2017 at 1630 UTC
Global Daily HF Radio Wave
Propagation Forecast-
HF radio wave propagation condition trend-
improving.
NORTHERN HEMISPHERE RADIO WAVE PROPAGATION-
80-60
(75-60) meters- poor to fair at night and very poor at day,
40-30 (41-25)
meters- fair to good at night and poor at day,
20-17 (22-15) meters- fair to
good at night and poor to fair at day,
15 (13) meters- very poor at night
and poor to fair at day,
12(11) meters- very poor at night and poor at
day.
10 (11) meters- very poor at night and very poor at day.
Keep in
mind that almost daily during the northern 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 can open up on
east-west paths. And last but not least equidistant north-south propagation
paths occur across the equator via trans equatorial propagation
(TEP).
SOUTHERN HEMISPHERE RADIO WAVE PROPAGATION-
80-60
(75-60) meters- good at night and poor at day,
40-30 (41-25) meters- good at
night and fair at day,
20-17 (22-15) meters- very poor at night and good at
day,
15 (13) meters- very poor at night and fair to good at day,
12 (11)
meters- very poor at night and fair at day.
10 (11) meters- very poor at
night and poor at day.
During the southern 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 northern hemisphere. But the
maximum useable frequency (MUF) is higher than in the northern hemisphere as the
F layer of the ionosphere is more dense.
Received RF signal strength
scale-
Very Good- +1 over S9 Or Greater
Good- S7-9
Fair- S4-6
Poor-
S1-3
Very Poor- S0
Meter Band Equivalents
Ham &
SWL
160-> 90
80-> 75
60-> 60
40-> 49,
41
30-> 31, 25
20-> 22, 19
17-> 16,
15
15-> 13
12,10-> 11
We are now firmly in summer/winter
solstice type of HF radio wave propagation conditions.
This means
generally poor HF radio wave propagation conditions in the northern hemisphere
especially at day and generally good HF radio wave propagation conditions in the
southern hemisphere especially at day.
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
solstice.
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).
---------------------------------------------------------------------------------------------------------------------
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 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.
---------------------------------------------------------------------------------------------
Solar,
Space & Geomagnetic Weather Conditions On
Thursday August 24,
2017-
Solar activity was low.
Earth's geomagnetic field was at an
unsettled level.
The three daily solar flux index (SFI) numbers were 80.8
78.8 80.0.
The official daily sunspot number (SSN)
was 43.
In 2017 officially there were 56 days with a daily sunspot number
(SSN) of
0.
Considering that solar minimum won't occur for
approximately 2 more years,
+/- 1 year, daily SSN's of 0 are occurring
unusually early.
In 2016 officially there were 32 days with a daily
sunspot number (SSN) of
0.
As we move forward towards the next solar
minimum between solar cycle #24
and #25 the number of days with a 0 daily
SSN will steadily increase.
Eventually every day for many, many, many months
will see a 0, the big goose
egg.
In 2008 I forecasted solar cycle 24
to be the weakest in the past 100 years
and that forecast verified. I also
forecasted that solar cycle 25 would be
virtually nonexistent, similar to
the Dalton type solar minimum that
occurred in the early 1800's.
Other than sunspot magnetic polarity it will probably be very difficult
to determine when solar cycle 24 ended and solar cycle 25
began.
---------------------------------------------------------------------------------------------------------------------
Officially
there were 2 earth facing sun spot groups (SSG).
Sunspot group (SSG)
#12671 was located near N11W63 with a complex beta-gamma magnetic
signature.
It was capable of producing a small in size C class solar
flare, and an isolated moderate in size M class solar flare.
Sunspot
group (SSG) #12672 was located near N07E21 with a complex beta magnetic
signature.
It was capable of producing a small in size C class solar
flare.
There was 1 unofficial and as of yet unnumbered earth facing
sunspot group (SSG) located near
N13E56.
There were 2 small in
size C class solar flares,
C3.0,
C1.6.
There was no earth aimed
(geoeffective) coronal mass ejection (CME).
No directly earth aimed
(geoeffective) coronal mass ejection (CME) related high and mid latitude
energetic proton storm occurred (polar cap absorption).
No directly earth
aimed (geoeffective) solar flare related x-ray day side solar fade out (SFO)
occurred.
No directly earth aimed (geoeffective) collapsing magnetic
filament eruption occurred.
The 24 hour period 3 hour interval planetary
K index (Kp) was at unsettled to quiet geomagnetic conditions of
2 3 3 2
2 1 0 1.
The 24 hour period 3 hour interval Boulder, CO K index was at
active to quiet geomagnetic conditions of
4 4 4 3 4 2 1 1.
The
K(p) geomagnetic indices are-
0-2- quiet
3- unsettled
4- active
5-
minor geomagnetic storming
6- moderate
7- strong
8- severe
9-
extreme
10- our atmosphere just got cooked off like on Mars and we are all
dead.
The 24 hour period maximum and minimum planetary A index (Ap)
ranged between
18 and 2,
which was at active to quiet geomagnetic
conditions.
The Ap geomagnetic indices are-
0-7- quiet
8-15
unsettled
16-29- active
30-49- minor geomagnetic storm
50-99-
major
100-400- severe
>401- our atmosphere just got cooked off like on
Mars and we are all dead.
The 24 hour period averaged energetic proton flux
was at a background level below 10 MeV.
The 24 hour period averaged
background x-ray flux was at C5.59.
The 24 hour period averaged vertical
component (Bz) of earth's geomagnetic magnetic field was at
-2.37 nT
south.
The 24 hour period maximum and minimum disturbance storm time
index (Dst) ranged between
-29 and -6 nT.
The 24 hour period
maximum and minimum solar wind speed ranged between
469 and 350
km/s.
There was a very small in size directly (geoeffective) earth aimed
southern hemisphere coronal hole (CH) #821.
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 © 1988-2017 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.
11.) Rising positive T index number. The T Index tracks with the F2
layer
critical frequency (foF2) and sunspot number (SSN) and indicates the
capability of the F2 layer to refract RF signals.
12.) Galactic
cosmic rays decrease to -3 units below zero and trending
towards
zero.
13.) Energetic electron flux levels no greater than 2 MeV
(2+0).
14. 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 my comprehensive HF radio wave propagation
forecast. This data is gathered and made public by the U.S. Government using
taxpayer $$$ (including mine).
However the solar, space and
geomagnetic discussions as well as the HF propagation forecast that I produce
from the RAW public domain
data is my personal intellectual property.
Therefore the solar, space and geomagnetic weather discussions and HF radio wave
propagation forecast contained herein is copyrighted © 1988-2017 by Thomas
F. Giella, W4HM.
Feel free without advanced permission to
redistribute this "not for profit"
solar, space and geomagnetic weather
discussion and HF radio wave propagation forecast, as long as you redistribute
it in its entirety and
give me credit for it.
Also solar, space and
geomagnetic weather 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.
