2008
KN4LF DAILY LF/MF/HF/6M
FREQUENCY RADIOWAVE PROPAGATION FORECAST #14

KN4LF DAILY LF/MF/HF/6M FREQUENCY RADIOWAVE PROPAGATION FORECAST #2008-14A

Date Format is MM/DD/YYYY.

Published Tuesday 04/08/2008 at 1430 UTC

As of Tuesday evening UTC 04/08/2008 it appears that we have a brand new (but as of yet unnumbered by the SWPC) sunspot group and it has the magnetic polarity and latitude of a solar cycle 24 sunspot group. At this point it is a lone small spot that will not impact the upper HF bands in a positive manner. However it is a step in the right direction for emerging solar cycle 24.

I borrowed the following information from the DXLC website at http://www.dxlc.com/solar/index.html .

.....Spotted regions not numbered by NOAA/SWPC: [S721] This region emerged on April 7 in the southeast quadrant with a single, tiny spot. Location at midnight: S28E14.....
 

KN4LF DAILY LF/MF/HF/6M FREQUENCY RADIOWAVE PROPAGATION FORECAST #2008-14

Date Format is MM/DD/YYYY.

Published Friday 04/04/2008 at 1900 UTC Valid Saturday-Friday 04/05-11/2008

CONTEST INFORMATION-

9 contests are scheduled for the weekend of Saturday-Sunday 04/05-06/2008.

The most popular ones are the EA RTTY Contest and QCWA Spring QSO Party.

For more information on contests check out the WA7BNM website at http://www.hornucopia.com/contestcal/weeklycont.php .

GLOBAL LF 30-300 KC PROPAGATION CONDITIONS EXPECTED WITH EMPHASIS ON LF AM BROADCAST BAND-

There exists a long distance “daytime” propagation medium between approximately 30-100 kc. The transmitted signal wave guides between the D layer and the surface of the Earth.

Some day time sky wave propagation does occur between approximately 100-300 kc via the E layer, especially at higher latitudes in the winter time and at the bottom of a solar cycle.

Reception is tied to the density of the D layer, as well as the E layer at radio Aurora altitude. Geomagnetic storming will suppress night time reception of signals but enhance day time reception of signals. High power broadcasters are more readily heard than low power ham radio signals.

Northern Hemisphere Night Time- POOR TO FAIR.

Southern Hemisphere Night Time- POOR TO FAIR.

Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3

None- S0

GLOBAL MF 300-3000 KC PROPAGATION CONDITIONS EXPECTED WITH AN EMPHASIS ON THE MF AM BROADCAST BAND, 160 METERS AND 120 METERS-

-Expect POOR TO FAIR Northern Hemisphere domestic propagation conditions on east-west paths out to approximately 1100 miles.
 
*Expect POOR Northern Hemisphere domestic conditions on north to south paths out to approximately 1100 miles.

+Expect GOOD TO FAIR Northern Hemisphere domestic conditions on south to north paths out to approximately 1100 miles.

 -Expect POOR TO FAIR Southern Hemisphere domestic propagation conditions on east-west paths out to approximately 1100 miles.

+Expect GOOD TO FAIR Southern Hemisphere domestic conditions on north to south paths out to approximately 1100 miles.

*Expect POOR Southern Hemisphere conditions on south to north paths out to approximately 1100 miles.

 -Expect FAIR Equatorial domestic propagation conditions on east-west paths out to approximately 1100 miles.

High latitude Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles will be POOR.

High latitude Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles will be POOR.

Mid latitude Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles will be FAIR.

Mid latitude Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles will be FAIR.

Low latitude Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific propagation conditions in excess of approximately 3200 miles will be FAIR.

Low latitude Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific propagation conditions in excess of approximately 3200 miles will be FAIR.

Equatorial region to Northern Hemisphere mid latitude propagation conditions in excess of approximately 3200 miles will be FAIR.

Equatorial region to Southern Hemisphere mid latitude propagation conditions in excess of approximately 3200 miles will be FAIR.

Equatorial region to Northern Hemisphere high latitude propagation conditions in excess of approximately 3200 miles will be POOR.

Equatorial region to Southern Hemisphere high latitude propagation conditions in excess of 3200 miles will be POOR.

Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3

None- S0

GLOBAL F/F2 LAYER HF 3000-30000 KC PROPAGATION CONDITIONS EXPECTED-

Lower frequency HF (80-30 meters) 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 geomagnetic storms 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 signal absorption due to elevated background solar flux levels and 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. D layer signal absorption due to elevated proton flux at energies greater than 10 MeV (10+0) and elevated background solar flux levels, is usually but not always inconsequential on 20-10 meters.

Low Latitude- POOR TO FAIR between 04/05-08/2008, FAIR TO GOOD between 04/09-11/2008 on 80-30 meters ham/90-31 meters shortwave.

Mid Latitude- FAIR between 04/05-08/2008, GOOD between 04/09-11/2008    on 80-30 meters ham/90-31 meters shortwave.

High Latitude- POOR between 04/05-08/2008, FAIR between 04/09-11/2008 on 80-30 meters ham/90-31 meters shortwave.

Low Latitude- FAIR on 20-17 meters ham/25-17 meters shortwave.

Mid Latitude- FAIR on 20-17 meters ham/25-17 meters shortwave.

High Latitude- FAIR on 20-17 meters ham/25-17 meters shortwave.

Low Latitude- POOR TO FAIR on 15 meters ham/13 meters shortwave.

Mid Latitude- POOR TO FAIR on 15 meters ham/13 meters shortwave.

High Latitude- POOR TO FAIR on 15 meters ham/13 meters shortwave.

Low Latitude- POOR on 12-10 meters ham/11 meters shortwave.

Mid Latitude- POOR on 12-10 meters ham/11 meters shortwave.

High Latitude- POOR on 12-10 meters ham/11 meters shortwave.

Note!!! At times propagation conditions on 12-10 meters ham/11 meters shortwave will be FAIR to GOOD, via the less predictable Sporadic E (Es) and Trans Equatorial (TEP) propagation modes.

Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3

None- S0

GLOBAL HF 50-54 MC (6 METER) PROPAGATION MODES AND STRENGTHS EXPECTED-

F2- NO

Sporadic E- YES/GOOD

Auroral E- YES/FAIR

Tropospheric Ducting- YES/GOOD

Meteor Scatter- YES/FAIR

Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3

None-S0

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

http://www.vhfdx.net/spots/map.php?Frec=MUF

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

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

GLOBAL 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 hemisphere low latitude regions can expect MODERATE thunderstorm lightning induced QRN tied to the Spring season proximity of cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems, as well as the Inter Tropical Convergence Zone (ITCZ).

Northern Hemisphere mid latitude regions can expect MODERATE to HIGH thunderstorm lightning induced QRN tied to Spring season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.
 
Northern Hemisphere high latitude regions can expect LOW to MODERATE thunderstorm lightning induced QRN tied to Spring season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

Southern Hemisphere low latitude regions can expect MODERATE thunderstorm lightning induced QRN tied to the Fall season proximity of cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems, Inter Tropical Convergence Zone (ITCZ) and tropical warm core low pressure systems.

Southern Hemisphere mid latitude regions can expect MODERATE to HIGH 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 Hemisphere high latitude regions can expect LOW to MODERATE thunderstorm lightning induced QRN tied to Fall season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.

The lightning QRN will hamper receive conditions on 160/120, 80/75, 40/41 and 30/31 meters in the Northern Hemisphere.

The lightning QRN will hamper receive conditions on 160/120, 80/75, 40/41 and 30/31 meters in the Southern Hemisphere.

END OF FORECAST

SOLAR, SPACE WEATHER AND GEOMAGNETIC CONDITIONS EXPECTED-

For 04/05-11/2008-

Recurrent transequatorial Coronal Hole #319 (old #316) will become geo-effective (Earth facing) and the associated high velocity solar wind stream emanating from it will be strong (>700 m/s) and the impact to propagation conditions major.

Globally with the daily sunspot number at ~00 and vaguely related solar flux level at ~70, decreased F layer MUFs will negatively impact 6, 10, 12, 15, 17 and 20 meters.

There will be a few Sporadic E (Es) propagation openings on 6-160 meters.

In the Northern Hemisphere due to seasonal chemical changes in the F layer of the ionosphere and therefore lower MUFs, there will be little east-west F layer propagation on 10, 12 and 15, meters. However there will be intermittent east-west propagation openings on 17 meters.

In the Southern Hemisphere due to seasonal chemical changes in the F layer of the ionosphere and therefore higher MUFs, there will be east-west F layer propagation on 17, 15 and 12 meters. There will be intermittent east-west propagation openings on 10 meters.

No sunspot groups will contain a twisted magnetic field capable of producing small sized C class, medium sized M class and large sized X class solar flares.

The following old sunspot group may rotate around the east limb of the Sun during the forecast period if it survived the back side transit- None

Trans Equatorial (TEP) HF propagation between North and South America will occur, as well between southern Africa to Europe/West Asia and also Australia to Eastern Asia/Oceania.

There will be moderate signal absorption on the MF AM broadcast band, 160 and 120 meters on high, mid and low latitude propagation paths in the Northern Hemisphere. The moderate absorption will degrade propagation conditions.

There will be moderate signal absorption on the MF AM broadcast band, 160 and 120 meters on high and low latitude propagation paths in the Southern Hemisphere. The moderate absorption will degrade propagation conditions.

There will be moderate signal absorption on the LF band on high, mid and low latitude paths in the Northern Hemisphere. The moderate absorption will degrade propagation conditions.

There will be moderate signal absorption on the LF band on high and low latitude propagation paths in the Southern Hemisphere. The moderate absorption will degrade propagation conditions.

The following planetary geomagnetic conditions will occur:

04/05-08/2008- Kp 3-5 isolated 6. 04/09-11/2008 Kp 4-0.

During the period quiet (Kp 0-2) geomagnetic conditions WILL OCCUR.

During the period unsettled (Kp- 3) geomagnetic conditions WILL OCCUR.

During the period active (Kp- 4) geomagnetic conditions WILL OCCUR.

During the period minor (Kp- 5) geomagnetic storming conditions WILL OCCUR.

During the period moderate (Kp- 6) geomagnetic storming conditions MAY OCCUR.

During the period strong (Kp- 7) geomagnetic storming conditions WILL NOT OCCUR.

During the period severe (Kp- 8) geomagnetic storming conditions WILL NOT OCCUR.

During the period extreme (Kp- 9) geomagnetic storming conditions WILL NOT OCCUR.

The chance of polar cap absorption on high latitude propagation paths due to excessive energetic protons >10 Mev (10+0) is LOW.

The chance of daylight side Sudden Ionospheric Disturbances (SID) radio blackouts from solar flares is LOW.

The chance of a geoeffective (Earth facing) Coronal Mass Ejection (CME) is LOW.

The chance of a partially geoeffective (Earth facing) Coronal Mass Ejection (CME) is LOW.

The chance of a geoeffective (Earth facing) Coronal Hole is HIGH.

Daily maximum/minimum solar flux index levels (SFI) should range between 72 and 68.

The probability of a small C class solar flare is LOW.

The probability of a large M class solar flare is LOW.

The probability of a huge X class solar flare is LOW.

When the Interplanetary Magnetic Field (IMF) polarity is negative the probability of geomagnetic storming on Earth increases. The NOAA/SWPC Wang-Sheeley-Arge model forecasts the Interplanetary Magnetic Field (IMF) polarity to be POSITIVE.

PAST SOLAR, SPACE WEATHER AND GEOMAGNETIC CONDITIONS-

For 03/29-04/04//2008-

Per forecast #2008-13 the period saw propagation conditions ranging from poor early then to fair on LF, MF and HF frequencies.

Globally with the daily sunspot number as high as 50 and vaguely related solar flux level as high as 83, the Maximum Usable Frequency (MUF) rose high enough to give 15, 17 and 20 meters a boost in propagation conditions via the F2 layer.

The following propagation modes and strengths were observed on 6 meters.

F2- NO

Sporadic E- YES/FAIR

Auroral E- YES/FAIR

Tropospheric Ducting- YES/GOOD

Meteor Scatter- YES/FAIR

Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3

None-S0

There were some Sporadic E (Es) propagation openings on 6-160 meters.

In the Northern Hemisphere due to seasonal chemical changes in the F layer of the ionosphere and therefore lower MUFs, there was little significant east-west F layer propagation on 17, 15, 12 and 10 meters.

In the Southern Hemisphere due to seasonal chemical changes in the F layer of the ionosphere and therefore higher MUFs, there was significant east-west F layer propagation on 17 and 15 meters. There were intermittent east-west openings on 12 and 10 meters.

There were 12 days consecutively with visible sunspot groups on the Earth facing side of the Sun. No sunspot groups had been visible on the far side of the Sun via the SOHO GONG holographic image.

Sunspot group #10989 contained a Beta twisted magnetic field capable of producing small sized C class and medium sized M class solar flares.

On Thursday 04/03/2008 sunspot group #10989 produced two C1.2 class solar flares. The first one occurred at 0112 UTC and the second one at 0218 UTC. No dayside SID radio blackouts occurred with these solar flares.

Recurrent transequatorial Coronal Hole #318 (old #315) became geo-effective (Earth facing) during the forecast period and the associated high velocity solar wind stream emanating from them was strong (>719 m/s) and the impact to propagation conditions major.

Trans Equatorial (TEP) HF propagation between North and South America occurred, as well as between southern Africa to Europe/West Asia and also Australia to Eastern Asia/Oceania.

There was moderate signal absorption on the MF AM broadcast band, 160 and 120 meters on high and low latitude propagation paths in the Northern Hemisphere. The moderate absorption degraded propagation conditions.

There was moderate signal absorption on the MF AM broadcast band, 160 and 120 meters on high, medium and low latitude propagation paths in the Southern Hemisphere. The moderate absorption degraded propagation conditions.

There was moderate signal absorption on the LF band on high and low latitude paths in the Northern Hemisphere. The moderate absorption degraded propagation conditions.

There was moderate signal absorption on the LF band on high, medium and low latitude propagation paths in the Southern Hemisphere. The moderate absorption degraded propagation conditions.

High lightning QRN (static) hampered receive conditions on 160/120, 80/75, 40/41 and 30/31 meters in the Northern Hemisphere.

High lightning QRN (static) hampered receive conditions on 160/120, 80/75, 40/41 and 30/31meters in the Southern Hemisphere.

Max/Min Solar Flux Readings- 82.9 to 72.8.

Max/Min Background Solar Flux Readings- A4.1 to A1.4.

Max/Min SWPC Sunspot Number- 50 to 14.

Max/Min Solar Wind Speed- 603 to 313.

Max/Min DST via Kyoto- -32 to +19.

Max/Min DST via G3YNK- -40 to -19.

Solar Flares- C-2 M-0 X-0

Elevated Energetic Protons >10 MeV (10+0)- None.

Geoeffective (Earth Facing) Coronal Mass Ejections- None.

Partially geoeffective (Earth Facing) Coronal Mass Ejections- None

Polar cap absorption on high latitude propagation paths due to excessive energetic protons >10 Mev (10+0)- None.

The Ap index had been at quiet geomagnetic levels to minor geomagnetic storming levels, with a range of 00-39.

The Kp index had been at quiet geomagnetic levels to minor geomagnetic storming levels, with a range of 0 to 5.

The Boulder CO mid latitude K index had been at quiet to active geomagnetic levels, with a range of 0 to 4.

The Fredericksburg, MD mid latitude K index had been at quiet to active geomagnetic levels, with a range of 0 to 4.

The College, AK high latitude K index had been at quiet geomagnetic levels to minor geomagnetic storming levels, with a range of 0 to 5. 

The Troms, Norway high latitude K index had been at quiet geomagnetic levels to moderate geomagnetic storming levels, with a range of 0 to 6. 

The Australia Region K index had been at quiet to unsettled geomagnetic levels, with a range of 0 to 3. 

PROPAGATION LESSON-

From http://www.kn4lf.com/kn4lf8.htm

5.) Coronal Hole-

The Corona is not part of the Sun's surface. It is instead part of the Sun's atmosphere, much like Earth's troposphere. Coronal Holes are low density areas associated with open magnetic field lines and are found near the Sun's poles at the bottom of a sunspot cycle and everywhere during a cycle maximum. A Coronal Hole is a dark region where a breakdown in the magnetic field structure in the solar corona has occurred. From these regions stream the high velocity solar wind that is a source of geomagnetic storming on Earth.

Coronal Holes occur most often on the downside of a solar cycle and their absence at the bottom of a solar cycle and at the beginning of the next, allow for the best medium frequency radio propagation conditions. Many think it's the lower solar flux values seen at the bottom of a solar cycle that accounts for improved propagation conditions but it's actually pretty much a lack of Coronal Holes and geomagnetic storming. (See definition #11. Geomagnetic/Ionospheric Storm).

One thing to keep in mind is that the high velocity solar wind stream emanating from a Coronal Hole is a neutral phenomenon with respect to the Bz (magnetic component) of the Interplanetary Magnetic Field (IMF). If the Bz component is negative (southward) prior to arrival of the solar stream, there will exist a tendency to see a larger swing negative after the disturbance arrives. If the Bz component is positive (northward) prior to arrival of the solar stream, there will exist a tendency to see a larger swing positive after the disturbance arrives.

SPACE WEATHER SCALES-
 
Kp Indices-
 
G5 = Extreme Storm - Kp = 9
G4 = Severe Storm - Kp = 8
G3 = Strong Storm - Kp = 7
G2 = Moderate Storm - Kp = 6
G1 = Minor Storm - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3

Ap Indices--
 
Ap 100-400 Severe Storm
Ap 50-99 Major Storm
Ap 30-49 Minor Storm
Ap 16-29 Active
Ap 8-15 Unsettled
Ap 0-7 Quiet
 
Correlation Of Kp To Ap Indices-
 
K- 0= A- 0
K- 1= A- 3
K- 2= A- 7
K- 3= A- 15
K- 4= A- 27
K- 5= A- 48
K- 6= A- 80
K- 7= A- 140
K- 8= A- 240
K- 9= A- 400

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

NOTE!!!  The propagation indices "interpretations" are my personal intellectual property. Therefore the propagation indices interpretations contained herein is copyrighted © 1988-2008 by Thomas F. Giella, KN4LF, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given.

1.) Dropping indices numbers are better.

2.) A solar flux of 150 or higher, 200+ best, for medium frequencies under 100, under 70 best.

Keep in mind though that the 10.7 cm (2800 mhz) solar flux index is not a "reliable" gauge of ionization in our atmosphere for F layer medium frequency refractions, as the energy of photons at this frequency is to low on the order of one million times. However most are used to solar flux and sunspot number and it's a hard habit to break. A better indicator is the background X-Ray Flux. See #7 below.

3.) Solar flux of at least 150 for E Valley/F Layer ducting mechanism.

4.) Previous 24 hour Ap index under 10, under 7 for several days consecutively is best.

5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for high latitude paths, 0-1 for several days consecutively is best.

6.) Energetic protons no greater then 10 MeV (10+0).

7.) Background X-Ray flux levels less than A1 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 Auroral absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3.

10.) A -20 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.

Standard Disclaimer-

Note! I use error prone RAW public domain data from the NOAA Space Environment Center, as well as other U.S. government organizations, to produce my propagation forecasts. This data is gathered and made public by the U.S. Government using taxpayer $$$. However the forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore the propagation outlooks contained herein is copyrighted © 1988-2008 by Thomas F. Giella, KN4LF. Reproduction of and distribution of information herein is allowed without advanced permission as long as proper credit is given.

Also space 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.

73,

Thomas F. Giella, KN4LF

Lakeland, FL, USA

kn4lf@arrl.net

KN4LF Daily Solar Space Weather & Geomagnetic Data Archive: http://www.kn4lf.com/kn4lf5.htm  

KN4LF Daily LF/MF/HF/6M Frequency Radiowave Propagation Forecast & Archive: http://www.kn4lf.com/kn4lf6.htm  

KN4LF 160 Meter Radio Propagation Theory Notes: http://www.kn4lf.com/kn4lf8.htm  

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