lunedì 28 gennaio 2019

W4HM Daily HF-MF Radio Wave Propagation Forecast #2019-28

Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world.

Welcome to my “not for profit” W4HM Daily HF-MF Radio Wave Propagation Forecast.

It’s the only accurate daily global HF-MF radio wave propagation forecast produced on the planet.

I'm a heliophysicist, terrestrial/troposphere meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all aforementioned disciplines. In terrestrial/troposphere weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years.

This is created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA © 1988-2019.

If you find this daily HF-MF 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


I enjoy hearing from likeminded fellow radio enthusiasts.

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broadening their knowledge in science.

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propagation forecast, as long as you redistribute it in its entirety and
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W4HM Solar Cycle 24 Update and Solar Cycle 25 Forecast- Short and to the point.

Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t.

On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent.

#28 issued Monday January 28, 2019 at 1745 UTC
 
Important Solar, Space & Geomagnetic Weather Indices-

Solar activity was very low.

The daily solar flux index numbers (DSFI) were

74.2 75.1 74.8.

There had been 7 consecutive days with a 2000 UTC daily solar flux index number (SFI) of 70 or above.

In general a SFI of less than 70 for an extended period of time is a signal that the solar cycle is at minimum.

The official daily sunspot number (DSSN) was 22.

There had been 6 consecutive days with an official daily sunspot number (DSSN) above 0.

In 2019 there had been 15 days with an official daily sunspot number (DSSN) of 0.

In 2018 there had been 221 days with an official daily sunspot number (DSSN) of 0.

There had been one sunspot group #12733 located near N05W49 with a relatively complex beta magnetic signature capable of releasing a very very small A and very small B class solar flare and an isolated small C class solar flare.

No small C class or stronger solar flare occurred.

The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of

2 1 2 1 1 1 1 1.

The 24 hour period planetary A index (Ap) maximum and minimum values ranged between

9 & 3,

which had been at an unsettled to quiet geomagnetic condition.

The 24 hour period maximum and minimum Disturbance Storm Time Index (Dst) ranged between

-7 & +2 nT.

The 24 hour period maximum and minimum solar wind speed was

437 & 347 km/s.

No Earth directed (geoeffective) coronal mass ejection (CME) was observed in available coronagraph imagery.

Very large coronal hole (CH) #905 (#902) became (earth facing) geoeffective. Last time around #902 created minor (Kp-5, Ap-48) geomagnetic storming.

GLOBAL (HF) HIGH FREQUENCY (3000-30000 KHZ) RADIO WAVE PROPAGATION CONDITIONS EXPECTED-

HF-MF radio wave propagation condition “trend” on Jan 28, 2019- steady.

HF-MF radio wave propagation condition “trend” on Jan 29, 2019- steady.

HF-MF radio wave propagation condition “trend” on Jan 30, 2019- minor deterioration.

Northern Hemisphere HF Radio Wave Propagation Forecast g-

We are now in the winter season northern hemisphere HF-MF radio wave propagation season.
The approximate 11000- 30000 kHz frequency range closes 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 the ions more concentrated.
The approximately 3000-10000 kHz frequency range often stays open for DX all throughout the day due to a weaker D and E layer and therefore less RF signal absorption.
Northern Hemisphere Radio Wave Propagation Forecast g-

3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day,

6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and
S4-7 at day,

13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day,

21000-21850 kHz- S0 at night and S1-2 at day,

24890-24990, 25600-26100 kHz- S0 at night and S1 at day,
28000-29700 kHz- S0 at night and S0 at day.

Southern Hemisphere HF Radio Wave Propagation Forecast g-

We are now in the summer season southern hemisphere HF-MF radio wave propagation season.

The 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer ions less concentrated.

Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-29700 kHz frequency ranges 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).

3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10 at night and S3-5 at day,

6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+15 at night and
S4-7 at day,

13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S5-8 at day,

21000-21850 kHz- S0 at night and S1-2 at day,

24890-24990, 25600-26100 kHz- S0 at night and S1 at day,

28000-29700 kHz- S0 at night and S0 at day.


GLOBAL (MF) MEDIUM FREQUENCY (300-3000 KHZ) RADIO WAVE PROPAGATION CONDITIONS EXPECTED-

FORECASTED NORTHERN HEMISPHERE SHORT PATH-
-East <-> West To 1100 Mi /1800 km
S9-+5-10
*North <-> South To 1100 Mi /1800 km
S7-8
+South <-> North To 1100 Mi /1800 km
S5-6

FORECASTED SOUTHERN HEMISPHERE SHORT PATH-
-East <-> West To 1100 Mi / 1800 km
S9
*South <-> North To 1100 Mi /1800 km
S7-8
+North <-> South To 1100 Mi / 1800 km
S5-6

FORECASTED GREAT CIRCLE LONG OR SKEWED PATH-
Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions in excess of approximately 3200 mi / 5200 km-

High Latitude
S7-8
Mid Latitude
S9+5-10
Low latitude
S9-+1

FORECASTED GREAT CIRCLE LONG OR SKEWED PATH-
Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions in excess of approximately 3200 mi / 5200 km-

High Latitude
S2-3
Mid Latitude
S6-7
Low latitude
S4-5


This HF-MF Radio wave propagation forecast is produced based on the SIGINT_CAP HF-MF radio wave propagation prediction software.
I wrote it beginning in the late 1980’s but I’m sorry to say that it still can’t be distributed to the general public. It does outperform VOA CAP and Prop Lab.
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-MF radio wave propagation conditions via remoted radio
receivers on every continent of the globe and tweak the forecast manually if
and when necessary.

And last but not least I look at ionsonde stations on every continent of the
globe.

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.

The MF broadcast band AM Mode RF signal levels are based on 50,000 watts (50 kw) and an omnidirectional vertical antenna.

Please keep in mind that this is a relatively simplified HF-MF radio wave
propagation forecast, so as to keep it easily understandable and applicable
by the average radio enthusiast.

THE FOLLOWING IS EDUCATIONAL MATERIAL ON SOLAR, SPACE, GEOMAGNETIC WEATHER OBSERVING AND IONOSPHERE GOINGS ON. ALSO HF AND MF RADIO WAVE PROPAGATION CONDITIONS AND FORECASTING.
Globally HF-MF 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). Also by propagation path.

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.

Lower high frequency (80-30 meters) propagation conditions are impacted in a
negative manner not so much by variations in the maximum usable frequency
(MUF) along a particular propagation path and time but rather due to
geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 &
greater) that increase signal absorption via the E layer (the altitude of
the radio aurora). Also increases in the lowest usable frequency (LUF) via D
layer RF signal absorption due to hard x-rays, galactic cosmic waves,
elevated background solar flux levels greater than B0 and energetic proton
flux levels at energies greater than 10 MeV (10+0).

Higher frequency (20-10 meters) propagation conditions are impacted in a
negative manner by variations in the maximum usable frequency (MUF) along a
particular propagation path and time due to the current sunspot number and
also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 &
greater. Also D layer RF signal absorption due to elevated (greater than B0)
background solar flux levels. Also to a lesser extent elevated proton flux
at energies greater than 10 MeV (10+0).

GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS-

NOTE!!! The propagation indices "interpretations" are my personal
intellectual property. Therefore the HF-MF radio wave propagation indices
interpretations contained herein is copyrighted © 1988-2019 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 (HF) radio wave propagation possible,
something that happens only 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.

GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL MF PROPAGATION CONDITIONS-

Medium frequency (300-3000 khz) radio wave propagation conditions are impacted in a negative manner not by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to energetic electron flux levels at energies greater than 2 MeV (2+1), geomagnetic disturbances (Kp-3-4) and geomagnetic storms (Kp-5 & >) that increase signal absorption via the E layer (the general altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer signal absorption due to elevated background solar flux levels greater than A0, proton flux levels at energies greater than 10 MeV (10+0), hard x-rays and galactic cosmic rays.
There is also the issue of magneto ionic power coupling. Antenna polarization plays a large role in the success of a long haul MF DX contact. As a MF RF signal traverses Earth's magnetic lines of force in a perpendicular manner on high and mid latitude paths say between W3 land and SM, higher angle horizontally polarized signals are more readily absorbed than lower angle vertically polarized signals. On other propagation paths on the globe opposite results can be found, i.e., horizontally polarized signals suffer less absorption on a propagation path between VK6 and W6 or S9 and W4.
Unfortunately the simplest way to look at medium frequencies with respect to radio wave propagation conditions is to accept the fact that propagation is poor the majority of the time, especially past approximately 1250 miles (one maximum distance refraction off of the E layer), with occasional short-lived good periods as far as 3200 miles.
All 13 of the following indices have to occur as described below in order to see the best global medium frequency (MF) radio wave propagation possible.
The simplest way to look at medium frequencies (MF) with respect to radio wave propagation conditions is to accept the fact that propagation is poor the majority of the time, especially past approximately 1250 miles (one refraction off of the E layer), with occasional short-lived good periods as far as 3200 miles.
1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best.
2.) A daily sunspot number under 100, under 70 best.
3.) A daily sunspot number no higher then the 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 proton flux levels no greater than 10 MeV (10+0).

7.) Background x-ray flux levels of A0 for several days consecutively.

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.) Galactic cosmic rays decrease to -3 units below zero and trending towards zero.
12.) Energetic electron flux levels no greater than 2 MeV (2+0).
13. 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 this daily HF-MF radio wave propagation
forecast. This data is gathered and made public by the U.S. Government using
taxpayer $$$ (including mine).

However this daily HF/MF propagation forecast that I produce from the RAW
public domain data is my personal intellectual property. Therefore this
daily HF-MF radio wave propagation forecast contained herein is copyrighted ©
1988-2019 by Thomas F. Giella, W4HM.

Feel free without prior permission to redistribute this daily HF/MF radio wave
propagation forecast, as long as you redistribute it in its entirety and
give me credit for it.

Also HF-MF radio wave propagation forecasting is still an inexact
science and therefore also an art. 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.