For my hamateur radio and SWL friends around the globe:
Feel free 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 it's entirety and give me credit for it.
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I
have decided to begin posting some of my daily solar, space and
geomagnetic
weather discussions and HF radio wave propagation forecasts in
my Twitter
account at
@GiellaW4hm https://twitter.com/?lang=en .
Of
course it will consist of little snippets of what's going on as Twitter
severely limits tweets as far as content length.
Also feel free to
leave a "LIKE" every time you access this discussion and
forecast as it's
the only method I have to gauge the usefulness of
it.
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#40
Issued on Sunday February 19, 2017 at 1330 UTC
Global HF Radio Wave
Propagation Forecast
HAMATEUR & SW BROADCAST HF
BANDS:
NORTHERN HEMISPHERE RADIO WAVE PROPAGATION-
80-60 (75-60)
meters- fair at night and poor at day,
40-30 (41-25) meters- fair at
night and fair at day,
20-17 (22-16) meters- very poor at night and fair
at day,
15 (13) meters- very poor at night and poor at day,
12-10
(11) meters- very poor at night and very poor at day.
SOUTHERN HEMISPHERE
RADIO WAVE PROPAGATION-
80-60 (75-60) meters- poor at night and very poor
at day,
40-30 (41-25) meters- fair at night and poor at day,
20-17
(22-16) meters- fair at night and fair at day,
15 (13) meters- poor at
night and fair at day,
12-10 (11) meters- very poor at night and very
poor at day.
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
Please keep in mind that this is a relatively simplified HF radio wave
propagation forecast, so as to keep it easily understandable 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 also 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
Saturday February 18,
2017-
Solar activity was low.
Earth's magnetic field was
active.
The three daily solar flux index (SFI) numbers were 75.9 76.6
76.8.
The official daily sunspot number (SSN) was 23.
Sunspot
group #12636 was located near N11E17 with a simple beta magnetic
signature.
A newly emerged but as of yet unnumbered sunspot group is
located near
S03E76 with a simple alpha class magnetic
signature.
---------------------------------------------------------------------------------------------
In
2017 there were 11 days with a daily sunspot number (SSN) of 0.
Considering
that solar minimum won't occur for approximately three more
years, +/- one
year, seeing daily SSN's of 0 occurring now is unusually
early.
In
2016 there were 32 days with a daily sunspot number (SSN) of 0.
Considering
that solar minimum won't occur for approximately three more
years, seeing
daily SSN's of 0 occurring now is unusually early.
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 fore
casted solar cycle 24 to be the weakest in the past 100 years
and that
forecast verified. I also fore casted that solar cycle 25 would be
virtually
non existent, similar to the Dalton type solar minimum that
occurred in the
early 1800's. It will probably be very difficult to
determine when solar
cycle 24 ended and solar cycle 25
began.
---------------------------------------------------------------------------------------------
No
earth directed solar flares occurred.
No earth directed coronal mass
ejections (CME) occurred.
No earth directed collapsing magnetic filament
eruptions occurred.
The twenty four hour period three hour interval
planetary K index (Kp) was
at active to quiet geomagnetic conditions of 4 4
2 2 1 2 3 3.
The Kp 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 maximum and minimum planetary A index
(Ap) ranged between 27 and 4,
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 daily averaged background x-ray flux was
B1.0, which was the highest
daily value in many months.
The daily
averaged vertical component (Bz) of earth's magnetic field
was -1.5 nT
south.
The maximum and minimum Dst ranged between +2 and -27.
No
energetic proton events greater than 10 MeV (10+0) occurred.
The maximum
and minimum solar wind speed was 540 and 454. km/s.
There was a recurrent
trans equatorial earth facing coronal hole #790
(#786). During it's previous
passage across the earth facing side of the sun
it produced minor (Kp-4)
negative impacts on HF radio wave propagation.
There was a recurrent
trans equatorial (geoeffective) directly earth facing
coronal hole #791
(#787). During it's previous passage across the earth
facing side of the sun
it produced minor (Kp-4) negative impacts on HF radio
wave
propagation.
--------------------------------------------------------------------------------------
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 organizations and
educational
institutions, to produce my comprehensive radio wave propagation
forecast.
This data is gathered and made public by the U.S. Government using
taxpayer
$$$ (including mine).
However the propagation forecast that
I produce from the RAW public domain
data is my personal intellectual
property. Therefore this radio wave
propagation forecast contained herein is
copyrighted © 1988-2017 by Thomas
F. Giella, W4HM.
Feel free to
redistribute this solar, space and geomagnetic weather
discussion and HF
radio wave propagation forecast, as long as you
redistribute it in it's
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.
