KN4LF 2008 AGE 51
PROPAGATION FORECASTER

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KN4LF DAILY LF/MF/HF/6M FREQUENCY RADIOWAVE PROPAGATION FORECAST #2008-18

Date Format is MM/DD/YYYY.

Published Friday 05/09/2008 at 1600 UTC.

Valid 0000 UTC Saturday 05/10/2008 through 2359 UTC Friday 05/16/2008.

CONTEST INFORMATION-

9 contests are scheduled for the weekend of Saturday-Sunday 05/10-11/2008.

The most popular ones are the Volta WW RTTY 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- GOOD TO FAIR 05/10-12/2008, FAIR TO POOR 05/13-16/2008.

Southern Hemisphere Night Time- GOOD 05/10-12/2008, FAIR 05/13-16/2008.

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 600 METERS, THE MF AM BROADCAST BAND, 160 METERS AND 120 METERS-

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

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

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

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

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

 -Expect Equatorial GOOD TO FAIR 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 FAIR 05/10-12/2008, POOR 05/13-16/2008.

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 GOOD 05/10-12/2008, FAIR 05/13-16/2008.

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 GOOD 05/10-12/2008, FAIR 05/13-16/2008.

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 05/10-12/2008, FAIR 05/13-16/2008.

Low latitude Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific propagation conditions in excess of approximately 3200 miles will be GOOD TO FAIR 05/10-12/2008, FAIR TO POOR 05/13-16/2008.

Low latitude Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific propagation conditions in excess of approximately 3200 miles Will be GOOD 05/10-12/2008, FAIR 05/13-16/2008.

Equatorial region to Northern Hemisphere high latitude propagation conditions in excess of approximately 3200 miles will be FAIR 05/10-12/2008, POOR 05/13-16/2008.

Equatorial region to Southern Hemisphere high latitude propagation conditions in excess of 3200 miles will be GOOD 05/10-12/2008, FAIR 05/13-16/2008.

Equatorial region to Northern Hemisphere mid latitude propagation conditions in excess of approximately 3200 miles will be GOOD 05/10-12/2008, FAIR 05/13-16/2008.

Equatorial region to Southern Hemisphere mid latitude propagation conditions in excess of approximately 3200 miles will be GOOD 05/10-12/2008, FAIR 05/13-16/2008.

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: 0-25 degrees

Mid: 25-60 degrees

High: 60-90 degrees

Low Latitude- GOOD 05/10-13/2008, FAIR 05/14-16/2008 on 80-30 meters ham/90-31 meters shortwave.

Mid Latitude- GOOD 05/10-13/2008, FAIR 05/14-16/2008 on 80-30 meters ham/90-31 meters shortwave.

High Latitude- GOOD TO FAIR 05/10-13/2008, FAIR TO POOR 05/14-16/2008 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 POOR on 20-17 meters ham/25-17 meters shortwave.

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

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

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

Low Latitude- POOR TO NONE on 12-10 meters ham/11 meters shortwave.

Mid Latitude- POOR TO NONE on 12-10 meters ham/11 meters shortwave.

High Latitude- NONE 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/FAIR

Auroral E- YES/FAIR

Tropospheric Ducting- YES/GOOD

Meteor Scatter- NO, excluding occasional random meteors.

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.

SOLAR, SPACE WEATHER AND GEOMAGNETIC CONDITIONS EXPECTED-

For 05/10-16/2008-

Recurrent northern hemisphere Coronal Hole #326 (old #320) will become geo-effective (Earth facing) and the associated high velocity solar wind stream emanating from it will be moderate (>650 m/s) and the impact to propagation conditions minor (Kp-4-5).

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 and 17 meters.

There will be Sporadic E (Es) propagation openings on 6-160 meters. We are still awaiting the beginning of the northern hemisphere summer time Sporadic E (Es) season. It seems to be a ramping up a little slower than normal this year?!

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- solar cycle 23 #10991 with an alpha magnetic field on 05/12/2008.

Some new solar cycle 23/24 sunspot groups may form but it is nearly impossible to forecast. A tip off is a rising background solar flux level.

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 degrade propagation 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 for improved propagation conditions.

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

The following planetary geomagnetic conditions will occur:

05/10-12/2008- Kp 2-0. 05/13-16/2008 Kp 4-2, isolated Kp 5.

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 MAY 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 maximum/minimum solar flux index levels (SFI) should range between 68 and 65.

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) to be POSITIVE.

PROPAGATION LESSON-

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

9.) Electron Gyro Frequency Absorption-

Unfortunately medium frequencies fall within or very near the electron gyro-frequency which is in the approximate range of 630 to 1630 kHz and of course the AM broadcast band and 160 meter band is very close to these electron gyro frequencies. There is a direct correlation between the strength of Earth's magnetic field lines and electron gyro frequencies.

Basically, the electron gyro frequency is a measure of the interaction between an electron in the Earth's atmosphere and the Earth's magnetic field. The closer a transmitted medium frequency carrier or sideband wave frequency is to the electron gyro frequency, the more energy that is absorbed by the gyro (spinning) electrons from that carrier wave frequency. This is especially true for medium frequency signals traveling perpendicular to the Earth's magnetic field, meaning high latitude NW and NE propagation paths. Unfortunately this form of medium frequency signal absorption is ALWAYS present.

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.

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.

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& God Bless,

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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