2008
KN4LF DAILY LF/MF/HF/6M
FREQUENCY RADIOWAVE PROPAGATION FORECAST #15

KN4LF DAILY LF/MF/HF/6M FREQUENCY RADIOWAVE PROPAGATION FORECAST #2008-15A

Date Format is MM/DD/YYYY.

Published Monday 04/14/2008 at 1330 UTC

As of Sunday 04/13/2008 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. Hopefully unlike last weeks (S721 on April 8th) unnumbered sunspot, this one will be numbered by NOAA/SWPC.

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 continued 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 .

.....At midnight there was 1 spotted region on the visible solar disk. The solar flare activity level was very low. Spotted regions not numbered by NOAA/SWPC: [S722] This cycle 24 region developed small spots on April 13. Location at midnight: N27E30.....

Added 04/14/2008 at 2200 UTC:

We finally have a second solar cycle #24 sunspot group! It was numbered today by NOAA/SWPC as 10990 at N26E20. I never thought that I would see a day when such a tiny sunspot could be such a big deal!
 

KN4LF DAILY LF/MF/HF/6M FREQUENCY RADIOWAVE PROPAGATION FORECAST #2008-15

Date Format is MM/DD/YYYY.

Published Friday 04/11/2008 at 1700 UTC Valid Saturday-Friday 04/12-18/2008

CONTEST INFORMATION-

9 contests are scheduled for the weekend of Saturday-Sunday 04/12-13/2008.

The most popular ones are the PODXS 070 Club PSK 31 Flavors Contest and the SKCC Weekend CW Sprintathon.

For more information on contests worldwide 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 04/12-13/2008, FAIR TO GOOD 04/14-18/2008.

Southern Hemisphere Night Time- FAIR 04/12-13/2008, GOOD 04/14-18/2008.

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

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

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

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

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

 -Expect GOOD 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 TO FAIR 04/12-13/2008, FAIR TO GOOD 04/14-18/2008.

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 TO FAIR 04/12-13/2008, FAIR TO GOOD 04/14-18/2008.

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 TO GOOD.

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 GOOD.

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

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

Equatorial region to Northern Hemisphere high latitude propagation conditions in excess of approximately 3200 miles will be POOR TO FAIR 04/12-13/2008, FAIR TO GOOD 04/14-18/2008.

Equatorial region to Southern Hemisphere high latitude propagation conditions in excess of 3200 miles will be POOR TO FAIR 04/12-13/2008, FAIR TO GOOD 04/14-18/2008.

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

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

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- FAIR 04/12-13/2008, GOOD 04/14-18/2008 on 80-30 meters ham/90-31 meters shortwave.

Mid Latitude- GOOD on 80-30 meters ham/90-31 meters shortwave.

High Latitude- POOR TO FAIR 04/12-13/2008, FAIR TO GOOD 04/14-18/2008 on 80-30 meters ham/90-31 meters shortwave.

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

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

High Latitude- FAIR TO GOOD 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- NO

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 TO HIGH 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 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 HIGH TO 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 HIGH TO MODERATE 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 MODERATE TO LOW 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 and 40/41 in the Southern Hemisphere.

END OF FORECAST

SOLAR, SPACE WEATHER AND GEOMAGNETIC CONDITIONS EXPECTED-

For 04/12-18/2008-

No significant Coronal Holes will become geo-effective (Earth facing) during the forecast period.

Globally with the daily sunspot number at ~00 and vaguely related solar flux level at ~68, 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 groups may rotate around the east limb of the Sun during the forecast period if they survived the back side transit-

10987 Alpha 04/16/2008.

10988 Alpha 04/18/2008.

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 minor 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 minor absorption will allow propagation conditions to improve compared to recent conditions.

There will be nil signal absorption on the MF AM broadcast band, 160 and 120 meters on high and low latitude propagation paths in the Southern Hemisphere. The nil absorption will allow propagation conditions to improve to the best in a good while.

There will be minor signal absorption on the LF band on high, mid and low latitude paths in the Northern Hemisphere. The minor absorption will allow propagation conditions to improve compared to recent conditions.

There will be nil signal absorption on the LF band on high and low latitude propagation paths in the Southern Hemisphere. The nil absorption will allow propagation conditions to improve to the best in a good while.

The following planetary geomagnetic conditions will occur:

04/12/2008- Kp 3-1, isolated 4. 04/13-18/2008 Kp 2-0, isolated 3.

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 NOT OCCUR.

During the period minor (Kp- 5) geomagnetic storming conditions WILL NOT OCCUR.

During the period moderate (Kp- 6) geomagnetic storming conditions WILL NOT 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 MODERATE.

Daily maximum/minimum solar flux index levels (SFI) should range between 69 and 66.

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 04/05-11/2008-

Per forecast #2008-14 the period saw propagation conditions ranging from poor to fair on LF, MF and HF frequencies.

Globally with the daily sunspot number at 0 and vaguely related solar flux level as low as 67, the Maximum Usable Frequency (MUF) did not rise high enough to give 6, 10, 12, 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/GOOD

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 15, 12 and 10 meters. There were 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 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 8 days consecutively without visible sunspot groups on the Earth facing side of the Sun. A sunspot group had been visible on the far side of the Sun via the SOHO GONG holographic image.

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

On early Monday 04/07/2008 a Plage located at S28E14 developed into the second sunspot (S721) group of solar cycle 24. Unfortunately by late Tuesday 04/08/2008 the new solar cycle 24 sunspot degenerated back into a spotless Plage, before NOAA/SWPC could get around to numbering it. Either way it is a step in the right direction for emerging solar cycle 24.

As seems to happen so often within the NOAA umbrella organization, the SWPC could not move fast enough within its own bureaucratic inertia to number the new sunspot before it weakened. As a retired Meteorologist I see the same type of thing happen quite regularly within the NWS.

Recurrent southern hemisphere Coronal Hole #319 (old #316) became geo-effective (Earth facing) during the forecast period and the associated high velocity solar wind stream emanating from it was strong (743 m/s) and the impact to propagation conditions moderate (Kp-6).

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- 71.6 to 67.1.

Max/Min Background Solar Flux Readings- A0.0 to A0.0.

Max/Min SWPC Sunspot Number- 00 to 00.

Max/Min Solar Wind Speed- 743 to 467.

Max/Min DST via Kyoto- -32 to +4.

Max/Min DST via G3YNK- -25 to -16.

Solar Flares- C-0 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 major geomagnetic storming levels, with a range of 02-67.

The Kp index had been at quiet geomagnetic levels to moderate geomagnetic storming levels, with a range of 0 to 6.

The Boulder CO mid latitude K index had been at quiet geomagnetic levels to minor geomagnetic storming levels, with a range of 0 to 5.

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 strong geomagnetic storming levels, with a range of 0 to 7. 

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 active geomagnetic levels, with a range of 1 to 4. 

PROPAGATION LESSON-

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

6.) Solar Filament-

A relatively cool and dense ribbon of gas held together by solar magnetic fields. From Earth they usually appear as relatively dark lines across the face of the Sun. At times the magnetic lines holding the filament open up creating a tremendous eruption similar in size and impact of a Coronal Mass Ejection (CME). (See definition #4. Coronal Mass Ejection). (See definition #11. Geomagnetic/Ionospheric Storm).

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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