For my hamateur radio and SWL friends around the globe:
Feel free without
advanced permission to redistribute this "not for profit"
solar, space and
geomagnetic weather observation, discussion and HF radio
wave propagation
forecast, as long as you redistribute it in its entirety
and
give me
credit for it.
Supporting images associated with my daily solar, space
& geomagnetic
weather observations and discussions can be found in my
Twitter account at
https://twitter.com/GiellaW4hm and in
my Facebook account at
https://www.facebook.com/thomasfranklingiellaw4hm
My
daily solar, space & geomagnetic weather observations and discussions as
well as my daily HF radio wave propagation forecasts can also be found
at
http://lists.contesting.com/mailman/listinfo/spaceweather
and in my Facebook
account at https://www.facebook.com/thomasfranklingiellaw4hm
It's
a NO SPAM "opt" in email type group, so you have to sign up by using an
existing email address and creating a password.
I'm also posting
excerpts some of my daily solar, space and geomagnetic
weather observations,
discussions and HF radio wave propagation forecasts in
my Twitter account at
https://twitter.com/GiellaW4hm
.
---------------------------------------------------------------------------------------------------------------------
#96
Issued on Friday April 21, 2017 at 1400 UTC
Global Daily HF Radio Wave
Propagation Forecast-
HAMATEUR & SW BROADCAST HF BANDS:
Global
generalized HF radio wave propagation conditions are
very poor to fair on
10-80 (11-75) meters
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- 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.
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
Thursday April 20,
2017-
Solar activity was moderate.
Earth's geomagnetic field was
at storming level.
The three daily solar flux index (SFI) numbers were
80.5 80.7 82.6.
The official daily sunspot number (SSN) was 26.
In
2017 officially there were 30 days with a daily sunspot number (SSN)
of
0.
Considering that solar minimum won't occur for approximately 2
more years,
+/- 1 year, observations daily SSN's of 0 occurring now is
unusually early.
Recurrent sunspot group #12651 (#12644) was located near
N11E45 with a
complex beta-gamma twisted magnetic signature capable of
producing small C
and medium size M class solar flares.
Newly emerged
sunspot group #12652 was located near N12E58 with a
magnetically simple
alpha magnetic signature.
Unofficially there were 4 earth facing but
as of yet unnumbered sunspot
groups. They were located
near
N24E33,
N17E46,
S10E87,
S07W11.
No earth facing
C class or larger solar flares
occurred.
---------------------------------------------------------------------------------------------
In
2016 officially 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 nonexistent, 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 facing coronal mass ejections (CME) occurred.
One earth directed
collapsing magnetic filament eruptions occurred. At that
time it was
unknown as to whether a directly (geoeffective) earth facing
coronal mass
ejection (CME) was released.
No earth directed day side radio black outs
occurred.
The twenty four hour period 3 hour interval planetary K index
(Kp) was at
moderate (Kp-6) geomagnetic storming conditions to unsettled
(Kp-3)
geomagnetic conditions of
4 6 4 4 3 3 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 24 hour period maximum and minimum planetary A index (Ap)
ranged between
67 and 12,
which was at major geomagnetic storming
conditions to unsettled 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 at B6.2.
The daily averaged vertical component
(Bz) of earth's magnetic field was at
-2.39 nT south.
The 24 hour
period maximum and minimum disturbance storm time index (Dst)
ranged
between
-1 and -55 nT.
The 24 hour period maximum and minimum
solar wind speed ranged between
609 and 492 km/s
and was directly
attached by a high speed solar wind stream to recurrent
(CH) coronal hole
#801 (#797).
There was a recurrent southern hemisphere earth facing (CH)
coronal hole
#801 (#797). It produced minor (Kp-5) geomagnetic storming
during its last
trip across the earth facing side of the sun. So far this
trip around it has
produced moderate (Kp-6) storming.
There was a
recurrent southern hemisphere (geoeffective) directly earth
facing (CH)
coronal hole #802 (#798). It produced moderate (Kp-6)
geomagnetic storming
during its last trip across the earth facing side of
the sun and is expected
to do the same this time
around.
--------------------------------------------------------------------------------------
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
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.
