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KN4LF Daily LF/MF/HF/6M Frequency Radiowave Propagation Forecast #2008-08
Date Format is MM/DD/YYYY.
Published Friday 02/22/2008 At 2000 UTC Valid Saturday-Friday 02/23-29/2008
7 contests are scheduled for the weekend of Saturday-Sunday 02/23-24, 2008. For more information check out the WA7BNM Contest website at http://www.hornucopia.com/contestcal/weeklycont.php .
The big ones are the CQ 160-Meter SSB Contest and the North American RTTY QSO Party.
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.
Northern Hemisphere Nighttime- GOOD
Southern Hemisphere Nighttime- 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-
During the CQ 160-Meter SSB Contest propagation conditions should be good in the northern hemisphere and fair in the southern hemisphere. However lightning QRN will be high in the eastern half of the U.S., as well as the western and central Caribbean. Lightning QRN will be moderately high in and near Great Britain and Japan. Lightning QRN will also be high in equatorial areas and most of the southern hemisphere.
-Expect GOOD Northern Hemisphere domestic
propagation conditions on east-west paths out to approximately 1100 miles.
*Expect 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 FAIR Southern Hemisphere domestic propagation conditions on east-west paths out to approximately 1100 miles.
+Expect POOR 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.
Equatorial region domestic propagation conditions out to approximately 1100 miles should be FAIR.
High latitude Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles should be GOOD.
High latitude Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles should be FAIR.
Mid latitude Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles should be 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 should be FAIR.
Low latitude Northern Hemisphere (TA) Trans
Atlantic, (TI) Trans Indian, (TP) Trans Pacific propagation conditions in excess
of approximately 3200 miles should be GOOD.
Low latitude Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP)
Trans Pacific propagation conditions in excess of approximately 3200 miles
should be FAIR.
Equatorial region to Northern Hemisphere mid latitude propagation conditions in excess of approximately 3200 miles should be GOOD.
Equatorial region to Southern Hemisphere mid latitude propagation conditions in excess of approximately 3200 miles should be FAIR.
Equatorial region to Northern Hemisphere high latitude propagation conditions in excess of approximately 3200 miles should be GOOD.
Equatorial region to Southern Hemisphere high latitude propagation conditions in excess of 3200 miles should be FAIR.
Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3
None- S0
GLOBAL HF 3000-30000 KC PROPAGATION CONDITIONS EXPECTED-
Lower frequency HF (80-30 meters) propagation conditions tend to be impacted in a negative manner not by 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 the lowest usable frequency (LUF) 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 tend to be impacted in a negative manner by the maximum usable frequency (MUF) along a particular propagation path and time and to a lesser extent due to geomagnetic storms that increase signal absorption via the E layer (the altitude of the Radio Aurora). D layer signal absorption due elevated proton flux at energies greater than 10 MeV (10+0) is inconsequential on 20-10 meters. However D layer signal absorption due to elevated background solar flux levels is a minor problem on 20-10 meters.
Low: 0-25 degrees N/S
Mid: 25-60 degrees N/S
High: 60-90 degrees N/S
Low Latitude- GOOD on 80-30 meters ham/90-31 meters shortwave.
Mid Latitude- GOOD on 80-30 meters ham/90-31 meters shortwave.
High Latitude- GOOD 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.
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 ARE EXPECTED-
F2- NO
Sporadic E- YES/FAIR
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 thunderstorm lightning induced QRN tied to the Winter 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 Winter 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 Winter season cold/warm/occluded
fronts and associated extra-tropical cold core low pressure systems.
Southern Hemisphere low latitude regions can
expect HIGH thunderstorm lightning induced QRN tied to the Summer season
proximity of the 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 Summer 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 Summer season cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems, as well as tropical warm core low pressure systems.
END OF FORECAST
DISCUSSION OF PAST CONDITIONS-
For 02/16-22/2008-
Per forecast #2008-07 the period was quiet to unsettled. Overall LF, MF and HF frequency propagation conditions were good.
Globally with the daily sunspot number at 0 and vaguely related solar flux level no higher than 73, 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 F layer.
The following propagation modes and strengths were observed on 6 meters.
F2- NO
Sporadic E- YES/FAIR
Auroral E- YES/POOR
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 higher MUFs, there was significant east-west F layer propagation on 17 meters. There was also intermittent to good east-west F layer propagation openings on 15 meters.
In the Southern Hemisphere due to seasonal chemical changes in the F layer of the ionosphere and therefore lower MUFs, there was little east-west F layer propagation on 10, 12 and 15, meters. There was intermittent east-west F layer propagation openings on 17 meters.
We saw 17 days consecutively without visible sunspot groups on the Earth facing side of the Sun. Sunspot groups had not been visible on the far side of the Sun via the SOHO 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. However a Plage currently located near S04 W30 could develop into new sunspot group #10983.
A recurrent northern hemisphere Coronal Hole #314 (old #309) became geo-effective (Earth facing) and the associated high velocity solar wind stream emanating from it was moderate and the impact to propagation conditions minor.
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 nil signal absorption on the MF AM broadcast band, 160 and 120 meters on high and low latitude propagation paths in the Northern Hemisphere. The nil absorption allowed propagation conditions to improve.
There was minor 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 minor absorption degraded propagation conditions.
There was nil signal absorption on the LF band on high and low latitude paths in the Northern Hemisphere. The nil absorption allowed propagation conditions to improve.
There was minor signal absorption on the LF band on high, medium and low latitude propagation paths in the Southern Hemisphere. The minor absorption degraded propagation conditions.
High lightning QRN (static) hampered receive conditions on 160/120, 80/75, 41/40 and 31/30 meters in the Northern Hemisphere.
High lightning QRN (static) hampered receive conditions on 160/120, 80/75, 41/40, 31/30 and 22/20 meters in the Southern Hemisphere.
DISCUSSION OF FUTURE CONDITIONS-
For 02/23-29/2008-
Recurrent transequatorial Coronal Hole #315 (old #311) will become geo-effective (Earth facing) and it's associated high velocity solar wind stream could negatively impact propagation conditions by 02/28/2008.
Globally with the daily sunspot number at ~0 and vaguely related solar flux level at low levels (~73), 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 higher MUFs, there will be east-west F layer propagation on 17 meters. There will be intermittent east-west propagation openings on 15 meters.
In the Southern 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.
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- #10982.
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 nil signal absorption on the MF AM broadcast band, 160 and 120 meters on high and low latitude propagation paths in the Northern Hemisphere. The nil absorption will allow propagation conditions to be the best in a good while.
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 Southern Hemisphere. The minor absorption will degrade propagation conditions.
There will be nil signal absorption on the LF band on high and low latitude paths in the Northern Hemisphere. The nil absorption will allow propagation conditions to be the best in a good while.
There will be minor signal absorption on the LF band on high, mid and low latitude propagation paths in the Southern Hemisphere. The minor absorption will degrade propagation conditions.
High lightning QRN will hamper receive conditions on 160/120, 80/75, 41/40 and 31/30 meters in the Northern Hemisphere.
High lightning QRN will hamper receive conditions on 160/120, 80/75, 41/40, 31/30 and 22/20 meters in the Southern Hemisphere.
SOLAR, SPACE WEATHER AND GEOMAGNETIC CONDITIONS EXPECTED-
For 02/23-29/2008-
Kp 0-3, isolated 4.
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 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 HIGH.
Daily solar flux index levels (SFI) should range between 69-73.
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.
The NOAA/SEC Wang-Sheeley-Arge model forecasts the interplanetary magnetic field (IMF) polarity to be POSITIVE between 02/23-26/2008 and NEGATIVE between 02/27-29/2008.
PAST SOLAR, SPACE WEATHER AND GEOMAGNETIC INDICES-
For 02/16-22/2008-
Sunspot Groups- 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.
Max/Min Solar Flux Readings- 71.9 to 70.3.
Max/Min SWPC Sunspot Number- 00 to 00.
Max/Min Solar Wind Speed- 675 to 450.
Max/Min DST via Kyoto- -20 to +20.
Max/Min DST via G3YNK- -32 to -15.
Solar Flares- C-0 M-0 X-0
Elevated Energetic Protons >10 MeV (10+0)- None.
A recurrent northern hemisphere Coronal Hole #314 (old #309) became geo-effective (Earth facing) and the associated high velocity solar wind stream emanating from it was moderate and the impact to propagation conditions minor.
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 to active geomagnetic levels, with a range of 00-27.
The Kp index had been at quiet to unsettled geomagnetic levels, with a range of 0 to 3.
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 unsettled geomagnetic levels, with a range of 0 to 3.
The College, AK high latitude K index had been at quiet geomagnetic levels to moderate geomagnetic storming levels, with a range of 0 to 6.
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.
PROPAGATION LESSON-
From http://www.kn4lf.com/kn4lf8.htm
23.) The Greyline/Greyline Propagation-
A general east-west transition between daytime and nighttime (twilight) where enhanced propagation conditions "may" occur. Near local sunrise the absorptive D layer has yet to become illuminated by the Sun, though the higher in altitude F/F2 layer has. Inversely near local sunset the absorptive D layer is losing illumination by the Sun, though the higher in altitude F/F2 layer still is. There is also a strengthening and weakening process in the E layer, as well as angle tilts and altitude changes in the D, E and F layers.
This process can allow for enhanced propagation conditions within the general north-south greyline corridor. It is most pronounced on 30, 40 and 60 meters and less so on 80 and 160 meters. Actually most greyline propagation on 160 meters and to a lesser extent on 80 meters is perpendicular (right angles) to the corridor. In my professional observation the greyline propagation enhancement process is still not totally understood and its benefit exaggerated to almost mythical proportion. (See definition #8.) E Valley/F Layer Propagation Ducting Mechanism/Chordal Hop Propagation).
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 -50 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 $$$. However the forecast outlooks that I produce from the RAW public domain data, is my personal intellectual property. Therefore the propagation outlooks contained herein is copyrighted © 1988-2008 by Thomas F. Giella, KN4LF. Reproduction of and distribution of information herein is allowed without advanced permission as long as proper credit is given.
Also space weather forecasting is still an inexact science. The forecasts are not official but for hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
73,
Thomas F. Giella, KN4LF
Lakeland, FL, USA
kn4lf@arrl.net
KN4LF Daily Solar Space Weather & Geomagnetic Data Archive: http://www.kn4lf.com/kn4lf5.htm
KN4LF Daily LF/MF/HF/6M Frequency Radiowave Propagation Forecast & Archive: http://www.kn4lf.com/kn4lf6.htm
KN4LF 160 Meter Radio Propagation Theory Notes: http://www.kn4lf.com/kn4lf8.htm
LF/MF/HF/VHF Frequency Radiowave Propagation
Email Reflector:
http://montreal.kotalampi.com/mailman/listinfo/kn4lf
Standard Disclaimer-
Note! I use error prone RAW public domain data from the NOAA Space Environment Center, as well as other U.S. government organizations, to produce my propagation forecasts. This data is gathered and made public by the U.S. Government using taxpayer $$$. However the forecast outlooks 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.