Greetings to my hamateur radio and SWL friends
around the globe:
If you find this "not for profit" daily solar,
space and geomagnetic weather discussion and HF radio wave propagation forecast
useful to your hamateur and SWL radio activities feel free to drop me a line and
letting me know that at
Feel free without advanced permission to
redistribute this "not for profit"
daily 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.
Supporting images associated with my "not for
profit" daily solar, space and geomagnetic weather discussion and HF radio wave
propagation forecast can be found in my Facebook account at https://www.facebook.com/thomasfranklingiellaw4hm
My “not for profit” daily solar, space &
geomagnetic weather discussions as well as my daily HF radio wave propagation
forecasts can also be found at
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.
---------------------------------------------------------------------------------------------------------------------
#146 Issued on Friday May 26, 2017 at 1400
UTC
We are now into the 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
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).
Global Daily HF Radio Wave Propagation
Forecast-
HAMATEUR & SW BROADCAST HF
BANDS-
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.
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.
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
This HF Radio wave propagation forecast is based
on the W4HM_Cap HF radio wave propagation prediction
software.
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 May 25, 2017-
Solar activity was very
low.
Earth's geomagnetic field was at a quiet
level.
The three daily solar flux index (SFI) numbers
were 78.7 76.1 77.1.
The official daily sunspot number (SSN) was 19.
In the next few days we may be headed for yet another period of time with no
daily sunspot numbers (SSN).
In 2017 officially there were 37 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 now
unusually early.
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 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.
---------------------------------------------------------------------------------------------------------------------
There was 1 newly risen or emerged official
sunspot group.
Sunspot group #12659 was located near N13W32 with
a magnetically simple beta magnetic signature.
There were 2 unofficial and as of yet unnumbered
earth facing sunspot groups located near
N12E11,
N15W82.
No earth facing C class or larger solar flares
occurred.
No day side high latitude solar fade outs (SFO)
occurred.
The solar fade out (SFO) events are related to
polar cap absorption (PCA) events mostly caused by energetic protons striking
earth’s geomagnetic field and increasing RF signal absorption in the D layer at
high latitudes.
No earth facing coronal mass ejections (CME)
occurred.
No earth facing collapsing magnetic filament
eruptions occurred.
The twenty four hour period 3 hour interval
planetary K index (Kp) was at quiet geomagnetic conditions of
0 0 0 0 1 1 0
1.
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
5 and 0,
which was at 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 B5.01.
The 24 hour period averaged vertical component
(Bz) of earth's geomagnetic magnetic field was at
+1.64 nT North.
The 24 hour period maximum and minimum
disturbance storm time index (Dst) ranged between
-9 and +9
nT.
The 24 hour period maximum and minimum solar wind
speed ranged between
365 and 309 km/s.
There was a new earth facing northern hemisphere coronal hole #805.
--------------------------------------------------------------------------------------
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.