W4HM's
DAILY
MF/HF/6M FREQUENCY
RADIO WAVE PROPAGATION FORECAST


"An In Depth "Daily" Radio Wave Propagation Forecast For Amateur Radio Operators And SWL's"



 

There are lot's of sources of raw solar, space and geomagnetic weather data on the internet, both via government and educational institutions. But absolutely no one on the planet takes that raw data, professionally interprets it and creates a daily comprehensive MF, HF and VHF (6 meter) radio wave propagation forecast and a daily global lightning strike noise (QRN) forecast.

The big difference between my radio wave propagation forecasts and the competition, and it is big, is that I take into account current and projected solar, space and geomagnetic weather and how they impact the ionosphere and therefore radio wave propagation conditions. I do this manually and also within my radio wave propagation forecast software mentioned below.

I do some manual calculations for medium frequencies (MF) frequencies, as well as very high frequencies (VHF) and I also use as guidance a comprehensive piece of radio wave propagation software that covers high frequencies (HF) (3000-30000 khz), that I first wrote in 1980 and continue to maintain and update. It's called NSAProp and is much more accurate than any other HF radio wave propagation software out there in the public domain. The information from both manual and software prediction sources is blended together, the MF/HF/6M radio wave propagation forecast is created and disseminated every morning UTC.

 

1.) DISCUSSION OF DAILY SOLAR SPACE AND GEOMAGNETIC WEATHER-

For Friday May 10, 2013

Note! Any data highlighted in red represents a significant event that can impact high frequency (HF) radio wave propagation conditions in a negative manner.

1.) 5 new un-numbered sunspot groups emerged. There were also 7 existing numbered sunspot groups. Sunspot group #11736 contained a beta-gamma twisted magnetic signature capable of producing M class solar flares.

2.) 7 solar flares occurred. The largest solar flare in magnitude was a small in size C2.9 which occurred at an approximate location of N15E04 and associated with sunspot group #11738.

3.) The daily solar flux index (SFI) had been at or above 100 for 41 consecutive days, at 126.9. Note! I publish the the daily maximum solar flux reading as it's frequently emphasized by government entities and education institutions. However...

The energy of 10.7 cm photons is .00001 eV, a factor of 1,000,000 too low to ionize anything in our atmosphere. So the 10.7 cm flux only tells us about the presence of active regions on the sun, not directly about the state of ionization in the ionosphere. If that was not bad enough, it has been found that the 10.7 cm flux can come from the corona above regions which are behind the east and west limbs of the sun. Those regions are much less likely to have their ionizing radiation reach the ionosphere directly. So the 10.7 cm flux has its purpose, indicating the presence of active regions, and it is a mistake to think that changes in that flux are always associated directly with the state of our ionosphere. The source of the above info was Robert Brown NM7M (SK).

The daily sunspot number (SSN) and background x-ray solar flux are much better indicators of the amount of ultraviolet light ionizing the F layer.

4.) T
he daily sunspot number (SSN) had been at or above 100 for 12 consecutive days, at 149. On Saturday May 11, 2013 the daily sunspot number (SSN) is 144.

5.) The geomagnetic field had been activated for 9 consecutive days with the Kp (planetary) index reaching a maximum of 3, which was unsettled geomagnetic conditions. As collected by NOAA SWPC Boulder, CO, USA the 3 hour Kp (planetary) intervals were 312211212. As collected by GFZ Helmholtz Potsdam, Germany the 3 hour Kp (planetary) intervals were 32222222.

6.) The Ap index ranged between 4 and 9, which was quiet to unsettled geomagnetic conditions.

7.) The Dst ranged between 0 and -17.  

8.) The maximum southward movement of the vertical component (Bz) of Earth's magnetic field was -4 nT.

9.) The 24 hour period averaged background x-ray solar flux value was B4.3.

10.) The energetic proton flux was less than 10 MeV (10+0).

11.) The energetic electron flux was greater than 2 MeV (2+0), 674 pfu.

12.) The maximum and minimum solar wind speed values were 457-579.

For the latest solar space & geomagnetic weather data, go to the W4HM Solar Space & Geomagnetic Weather Data Dashboard at http://www.wcflunatall.com/propagation2.htm .

For an explanation of how solar space and geomagnetic weather impacts MF/HF/6M radio wave propagation, go to the W4HM 160 Meter (Medium Frequency) Radio Wave Propagation Theory Notes at http://www.wcflunatall.com/propagation5.htm  and then slide down to definition #7.

 

2.) GLOBAL MEDIUM FREQUENCY (300-3000 KHZ) RADIO WAVE PROPAGATION CONDITIONS EXPECTED, WITH AN EMPHASIS ON THE 160 METERS-

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.

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.

For more information on MF radio wave propagation theory check out http://www.wcflunatall.com/nz4o5.htm .

 

Magnetic Equator-

Low

0-25 degrees

Mid

25-60 degrees

High

60-90 degrees

 

 

FORECASTED NORTHERN HEMISPHERE GREAT CIRCLE SHORT PATH-

-East <-> West To 1100 Mi /1800 km

S7-9

*North <-> South To 1100 Mi /1800 km

S4-6

+South <-> North To 1100 Mi /1800 km

S4-6


FORECASTED SOUTHERN HEMISPHERE GREAT CIRCLE SHORT PATH-

-East <-> West To 1100 Mi / 1800 km

S7-9

*South <-> North To 1100 Mi /1800 km

S4-6

+North <-> South To 1100 Mi / 1800 km

S4-6

 

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

S4-6

Mid Latitude

S7-9

Low latitude

S4-6

 

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

S4-6

Mid Latitude

S7-9

Low latitude

S4-6

  

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

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 storms (Kp-5 & >) 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 geomagnetic storms of Kp-5 & >. Also D layer RF signal absorption due to elevated (>B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0).

 

As follows are examples of how to apply the propagation forecast to your location (QTH).

(1) If you live in Tampa, FL, USA and want to work into Salt Lake City, UT, USA which is an approximate 2000 Mi/3200 km distance, the forecast is for good propagation conditions.

(1) If you live in London, England and want to work into Moscow, Russia which is an approximate 2000 Mi/3200 km distance, the forecast is for good propagation conditions.

(2) If you live in New York City, NY and want to work into London, England which is an approximate 4000 Mi/6500 km distance, the forecast is for good propagation conditions.

(2) If you live in Moscow, Russia and want to work into Perth, Australia which is an approximate 8000 Mi/13000 km distance the forecast is for good propagation conditions.

 

As far as band openings:

Short= 100-500 miles

Medium= 501-3000 miles

Long= Greater than 3000 miles.

 

160 meters is open at day time out to short distances and medium to long distances at night time, best in winter and at the bottom of a sunspot cycle.

80 and 60 meters are open at day time out to short and medium distances and long distances at night time, best in winter and near bottom of sunspot cycle.

40 and 30 meters are open at day time out to short and medium distances and long distances at night time in summer, closed in winter close in, but open at long distances.

20, 17 and 15 meters are open at day time out to medium to long distances in winter, short to medium distances in summer, also long distances at night time during solar maximum, closed at night at solar minimum and in winter night time.

12 and 10 meters are open at day time out to short to medium distances in summer due to Es propagation, open via F2 layer at medium to long distances in winter and near sunspot maximum, also medium to long distances at night time near solar maximum, closed via F2 layer at solar minimum and in winter night time.

6 meters is open at day time out to short and medium distances in summer via Es and double Es hop propagation, medium to long distances via F2 layer propagation at the peak of "some" solar cycles (not solar cycle 24). Other propagation modes such as direct wave, Aurora E, troposphere ducting, meteor scatter, lightning plasma channel scatter and trans-equatorial propagation can occur at any time, day, season and year.

 

For a more comprehensive explanation of radio wave propagation characteristics for 160-10 meters check out  http://www.astrosurf.com/luxorion/qsl-propa4.htm .

 

Magnetic Equator-

Low

0-25 degrees

Mid

25-60 degrees

High

60-90 degrees

 

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE 80, 60 METERS VIA SHORT PATH-

                                                              DAY    NIGHT

East <-> West To 2000 Mi/3200 km

S3-5 -> S7-9

West <-> East To 2000 Mi/3200 km

S3-5 -> S7-9

North <-> South To 2000 Mi/3200 km

S3-5 -> S7-9

South <-> North To 2000 Mi/3200 km

S3-5 -> S7-9

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE 80, 60 METERS VIA SHORT PATH-

                                                            DAY   NIGHT

East -> West To 2000 Mi/3200 km

S3-5 -> S7-9

West -> East To 2000 Mi/3200 km

S3-5 -> S7-9

North -> South To 2000 Mi/3200 km

S3-5 -> S7-9

South -> North To 2000 Mi/3200 km

S3-5 -> S7-9

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE 40, 30 METERS VIA SHORT PATH-

                                                              DAY   NIGHT

East <-> West To 2000 Mi/3200 km

S4-6-> S9+1

West <-> East To 2000 Mi/3200 km

S4-6 -> S9+1

North <-> South To 2000 Mi/3200 km

S4-6 -> S9+1

South <-> North To 2000 Mi/3200 km

S4-6 -> S9+1

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE 40, 30 METERS VIA SHORT PATH-

                                                            DAY   NIGHT

East -> West To 2000 Mi/3200 km

S4-6 -> S9+1

West -> East To 2000 Mi/3200 km

S4-6 -> S9+1

North -> South To 2000 Mi/3200 km

S4-6 -> S9+1

South -> North To 2000 Mi/3200 km

S4-6 -> S9+1

 

FORECASTED GREAT CIRCLE  NORTHERN HEMISPHERE 20, 17 METERS VIA SHORT PATH-

                                                              DAY   NIGHT

East <-> West To 2000 Mi/3200 km

S7-9 -> S9+1

West <-> East To 2000 Mi/3200 km

S7-9 -> S9+1

North <-> South To 2000 Mi/3200 km

S7-9 -> S9+1

South <-> North To 2000 Mi/3200 km

S7-9 -> S9+1

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE 20, 17 METERS VIA SHORT PATH-

                                                            DAY    NIGHT

East -> West To 2000 Mi/3200 km

S7-9 -> S9+1

West -> East To 2000 Mi/3200 km

S7-9 -> S9+1

North -> South To 2000 Mi/3200 km

S7-9 -> S9+1

South -> North To 2000 Mi/3200 km

S7-9 -> S9+1

 

FORECASTED GREAT CIRCLE  NORTHERN HEMISPHERE 15, 12 METERS VIA SHORT PATH-

                                                              DAY   NIGHT

East <-> West To 2000 Mi/3200 km

S9+1 -> S1-3

West <-> East To 2000 Mi/3200 km

S9+1 -> S1-3

North <-> South To 2000 Mi/3200 km

S9+1 -> S1-3

South <-> North To 2000 Mi/3200 km

S9+1 -> S1-3

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE 15, 12 METERS VIA SHORT PATH-

                                                            DAY    NIGHT

East -> West To 2000 Mi/3200 km

S9+1 -> S1-3

West -> East To 2000 Mi/3200 km

S9+1 -> S1-3

North -> South To 2000 Mi/3200 km

S9+1 -> S1-3

South -> North To 2000 Mi/3200 km

S9+1 -> S1-3

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE 10 METERS VIA SHORT PATH-

                                                           DAY   NIGHT

East -> West To 2000 Mi/3200 km

S7-9 -> S0

West -> East To 2000 Mi/3200 km

S7-9 -> S0

North -> South To 2000 Mi/3200 km

S7-9 -> S0

South -> North To 2000 Mi/3200 km

S7-9 -> S0

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE 10 METERS VIA SHORT PATH-

                                                           DAY   NIGHT

East -> West To 2000 Mi/3200 km

S7-9-> S0

West -> East To 2000 Mi/3200 km

S7-9 -> S0

North -> South To 2000 Mi/3200 km

S7-9 -> S0

South -> North To 2000 Mi/3200 km

S7-9 -> S0

 

Note!!! At times radio wave propagation conditions on 10 meters can be S9 -> S9+1, via the less predictable Sporadic E (Es) and trans-equatorial (TE) propagation modes which involve the equatorial anomaly and F2 and F3 layers.

 

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

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE VIA LONG OR SKEWED PATH-

80, 60 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                          DAY    NIGHT

Low Latitude

S3-5 -> S7-9

Mid Latitude

S3-5 -> S7-9

High Latitude

S3-5 -> S7-9

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE VIA LONG OR SKEWED PATH-

80, 60 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.        

                          DAY    NIGHT

Low Latitude

S3-5 -> S7-9

Mid Latitude

S3-5 -> S7-9

High Latitude

S3-5 -> S7-9

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE VIA LONG/LONGER PATH-

40, 30 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                           DAY   NIGHT

Low Latitude

S4-6 -> S9+1

Mid Latitude

S4-6 -> S9+1

High Latitude

S4-6 -> S9+1

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE VIA LONG/LONGER PATH-

40, 30 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                           DAY   NIGHT

Low Latitude

S4-6 -> S9+1

Mid Latitude

S4-6 -> S9+1

High Latitude

S4-6 -> S9+1

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE VIA LONG/LONGER PATH-

20, 17 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                             DAY  NIGHT

Low Latitude

S7-9-> S9+1

Mid Latitude

S7-9 -> S9+1

High Latitude

S7-9 -> S9+1

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE VIA LONG/LONGER PATH-

20, 17 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                             DAY  NIGHT

Low Latitude

S7-9 -> S9+1

Mid Latitude

S7-9 -> S9+1

High Latitude

S7-9 -> S9+1

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE VIA LONG/LONGER PATH-

15, 12 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                           DAY  NIGHT

Low Latitude

S9+1 -> S1-3

Mid Latitude

S9+1 -> S1-3

High Latitude

S9+1 -> S1-3

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE VIA LONG/LONGER PATH-

15, 12 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                           DAY  NIGHT

Low Latitude

S9+1 -> S1-3

Mid Latitude

S9+1 -> S1-3

High Latitude

S9+1 -> S1-3

 

FORECASTED GREAT CIRCLE NORTHERN HEMISPHERE VIA LONG/LONGER PATH-

10 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                           DAY  NIGHT

Low Latitude

S7-9 -> S0

Mid Latitude

S7-9 -> S0

High Latitude

S7-9 -> S0

 

FORECASTED GREAT CIRCLE SOUTHERN HEMISPHERE VIA LONG/LONGER PATH-

10 meters (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross Equatorial propagation conditions greater than 2000 mi/3200 km.

                          DAY   NIGHT

Low Latitude

S7-9 -> S0

Mid Latitude

S7-9 -> S0

High Latitude

S7-9 -> S0

 

Note!!! At times radio wave propagation conditions on 10 meters can be S7-9 -> S9+1, via the less predictable Sporadic E (Es) and trans-equatorial (TE) propagation modes which involve the equatorial anomaly and F2 and F3 layers.

 

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

 

Magnetic Equator-

Low

0-25 degrees

Mid

25-60 degrees

High

60-90 degrees

 

 

4.) GLOBAL 50000-54000 KC (6 METER) RADIO WAVE PROPAGATION FORECAST-

F2

NO

Sporadic E (Es)

YES

Aurora E High Latitude

NO

Aurora E Mid Latitude

NO

Troposphere Ducting

YES, ducting is always present in the vicinity of large deeply stacked high pressure systems mainly along coastal areas

Trans Equatorial (TE) F2/F3

YES, ir-regardless of what you may read in a book or magazine, TE radio wave propagation occurs every day of the year though signal strength can vary significantly

Meteor Scatter

NO, excluding random meteors, lightning bolt plasma channels, space junk and alien spacecraft

 

For more information about meteor shower events check out http://stardate.org/nightsky/meteors .

 

For global real time information concerning 6 meter band openings check out the VHFDX website at:

http://www.vhfdx.info/spots/map.php 

A good source of information concerning 6 meter band openings via troposphere ducting in the U.S. is at:

http://www.dxinfocentre.com/tropo.html

 

 

5.) GLOBAL LIGHTNING NOISE (QRN) OUTLOOK-

U.S. near real time lightning strike data:

http://thunderstorm.vaisala.com/explorer.html

A global view of near real time lightning strike data:

http://webflash.ess.washington.edu  

 

 

 

Northern and western hemisphere low latitude regions can expect S9+10 thunderstorm lightning induced QRN tied to spring season proximity

to the Inter-Tropical Convergence Zone (ITCZ) as well as cold/warm/occluded fronts and associated extra-tropical cold core low

pressure systems.

 

Northern and western hemisphere mid latitude regions can expect S9+10 thunderstorm lightning induced QRN tied to spring

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

 

Northern and western hemisphere high latitude regions can expect S3-5 thunderstorm lightning induced QRN tied to spring

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

 

-----

 

Northern and eastern hemisphere low latitude regions can expect S9+10 thunderstorm lightning induced QRN tied to spring season proximity

to the Inter-Tropical Convergence Zone (ITCZ) as well as cold/warm/occluded fronts and associated extra-tropical cold core low

pressure systems.

 

Northern and eastern hemisphere mid latitude regions can expect S9+10 thunderstorm lightning induced QRN tied to spring

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

 

Northern and eastern hemisphere high latitude regions can expect S3-5 thunderstorm lightning induced QRN tied to spring

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

 

-----

 

Southern and western hemisphere low latitude regions can expect S9+10 thunderstorm lightning induced QRN tied to fall season

proximity to the Inter-Tropical Convergence Zone (ITCZ) and tropical warm core low pressure systems.

 

Southern and western hemisphere mid latitude regions can expect S7-9 thunderstorm lightning induced QRN tied to fall

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems, as well as tropical warm core low pressure systems.
 
 

Southern and western hemisphere high latitude regions can expect S3-5 thunderstorm lightning induced QRN tied to fall

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

 

-----

 

Southern and eastern hemisphere low latitude regions can expect S9+20 thunderstorm lightning induced QRN tied to fall season

proximity to the Inter-Tropical Convergence Zone (ITCZ) and tropical warm core low pressure systems.

 

Southern and eastern hemisphere mid latitude regions can expect S7-9 thunderstorm lightning induced QRN tied to fall

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems, as well as tropical warm core low pressure systems.
 
 

Southern and eastern hemisphere high latitude regions can expect S3-5 thunderstorm lightning induced QRN tied to fall

season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

 

6A.) GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL MF PROPAGATION CONDITIONS-

NOTE!!!  The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted
1988-2014 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 13 of the following indices have to occur as described below in order to see the best global medium frequency radio wave propagation possible.

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 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.
 

6B.) 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
1988-2014 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.

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 1988-2014 by Thomas F. Giella, W4HM.

As this MF/HF/6M radio wave propagation forecast is created for paid subscribers only reproduction and retransmission of this MF/HF/6M radio wave propagation forecast is expressly forbidden under any and all circumstances.

Also solar, space and geomagnetic weather forecasting is still an inexact science. The forecasts are not official but for hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied. 

 

W4HM's DAILY SOLAR CYCLE 24 DISCUSSION AND ARCHIVE

W4HM's DAILY SOLAR SPACE & GEOMAGNETIC WEATHER DATA ARCHIVE

W4HM's SOLAR SPACE & GEOMAGNETIC WX DATA RAW FORECAST LINKS

W4HM's 160 METER (300-3000 KHZ) RADIO WAVE PROPAGATION THEORY NOTES

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You can contact me
Thomas F. Giella, W4HM
Lakeland, FL, USA at


thomasfgiella at gmail dot com


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