KN4LF Daily HF/MF Radio Propagation Outlook #2003-10 http://www.kn4lf.com/kn4lf5.htm
Standard Disclaimer- Note! I use "RAW" public domain data from the NOAA Space Environment Center, as well as other U.S. government organizations, to produce my "not for profit" propagation forecast outlooks. 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 © 1988-2003 by Thomas F. Giella and the Florida Space And Atmospheric Weather Institute, all rights reserved. Reproduction of information herein is allowed as long as proper credit is given. Also space weather forecasting is still an inexact science. The discussions, forecasts and outlooks are not official but for educational purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied. Date Format is YY/MM/DD Published Wednesday 03/08/31 At 1800 UTC PAST 24 HOUR SOLAR, SPACE WEATHER AND GEOMAGNETIC INDICES- Sunspot Groups- No sunspot groups current contain twisted magnetic fields capable of producing very large or huge M and X class solar flares. Solar Flux Readings- 116 114 114 Sunspot Number- 120 X-Ray Solar Flares- C-2 M-0 X-0 Averaged Background X-Ray Flux- B2.8 Energetic Protons >10 MeV (10+0)- None Coronal Hole #054 which became geo-effective on 03/08/28 will begin impacting the geo-magnetic field with minor storm conditions Kp-5 by 03/09/01-02. In the past 24 hour period the Ap index has been at minor storm levels, with a peak at 37. In the past 24 hour period the Kp index has been at minor storm levels, with a peak at 5. The short lived minor storm level was due to the lopsided partially geo-effective Coronal Mass Ejection that was hurled into space on 03/08/25. Here are some general guidelines concerning correlation of propagation indices to actual expected HF/MF propagation conditions. 1.) Dropping indices numbers are better, except for solar flux on HF. 2.) For medium frequencies a solar flux under 150, under 100 better, 70 is best for E layer multi hop. Keep in mind though that the 10.7 cm (2800 mhz) solar flux index is not a "reliable" gauge of ionization in our atmosphere, as the energy of photons at this frequency is to low on the order of one million times. 2a.) For high frequencies a solar flux of 100 is okay, 150 better, above 200 best for F layer multi hop. 3.) Solar flux of at least 100 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) for 160/120 meters and no greater then (10-1) on MF broadcast band. 7.) Background x-ray flux levels less than C1 for several days consecutively for 160/120 meters and less then B9 for MF broadcast band. 8.) No current STRATWARM alert. 9.) IMF Bz with a (+) positive sign, indicates a lesser chance of high latitude path auroral absorption/unpredictable refraction or scattering of MF RF signals, when the Kp is above 3. TODAY'S PROPAGATION LESSON- 2.) Aurora Oval Blockage, Absorption And Refraction- The aurora ovals "generally" have a negative impact on high and medium-frequency propagation. If the path over which you are communicating lies along or inside one of the Aurora Ovals, you will experience degraded propagation in one of several different forms; strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multi-pathing, anomalous and rapid variations in absorption, non-great-circle propagation, horizontal or side refraction and/or scatter (skewing) due to changes in electron density and polarization changes. When the Aurora Oval zones are contracted and latitudinally-thin coinciding with low geomagnetic activity, it is possible for a high and medium-frequency transmitted signal to propagate through the Aurora Oval zone without being heavily absorbed by skirting underneath it. During long periods of very low geomagnetic activity, areas of the Aurora Oval zones may only have a latitudinal thickness of approximately 300 miles. But radio signals reflected from the E-layer can travel over distances of as much as 300 to 1100 miles at heights below the ionosphere for low take-off angles of between 10 and 25 degrees. When the geometry is just right, the high and medium-frequency transmitted signal can literally propagate underneath and through the Aurora Oval zones into the polar ionosphere which is less disturbed and from the polar ionosphere back into the middle latitude ionosphere, without ever coming in contact with the highly absorptive Aurora Ionosphere. This type of propagation is not as rare as you might think and it can provide unusually stable polar region path openings to (TA) Transatlantic and (TP) Transpacific regions. But because the Aurora Oval zone expands and contracts constantly, such conditions often do not last very long. PROPAGATION OUTLOOK- We should continue to see periods of quiet Kp-2 to unsettled Kp-3 geomagnetic conditions, with some minor storm Kp-5 to moderate storm Kp-6 conditions probable beginning on 03/09/01-02. GLOBAL HF 3000-30000 KC PROPAGATION CONDITIONS EXPECTED- Low Latitude- Good Mid Latitude- Good High Latitude- Fair Becoming Poor GLOBAL MF 300-3000 KC PROPAGATION CONDITIONS EXPECTED- Expect good but becoming fair "Northern Hemisphere" domestic propagation conditions on east-west paths. Expect fair then becoming poor domestic conditions on north "TO" south paths in the "Northern Hemisphere" out to approximately 1100 miles. Expect fair then becoming good domestic conditions on south "TO" north paths in the "Northern Hemisphere" out to approximately 1100 miles. Expect good but then becoming fair "Southern Hemisphere" domestic propagation conditions on east-west paths. Expect fair then becoming good domestic conditions on north "TO" south paths in the "Southern Hemisphere" out to approximately 1100 miles+ Expect fair then becoming poor conditions on south "TO" north paths in the "Southern Hemisphere" 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 should be fair then becoming 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 should be fair then becoming 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 should be good then becoming 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 should be good then becoming 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 good. Propagation Forecast Scales- Excellent- +1 db Over S9 Or better Good- S7-9 Fair- S4-6 Poor- S1-3 NOISE (QRN) OUTLOOK- GLOBAL SATELLITE DERIVED LIGHTNING STRIKE DATA (See Where Your QRN Is Coming From) http://aviationweather.gov/gcd/graf/expconus.gif http://aviationweather.gov/gcd/graf/exptropical.gif During the 24 hour outlook period there will be "high" lightning induced QRN levels in low latitude areas of the Northern Hemisphere due to the proximity of the Inter-Tropical Convergence Zone (ITCZ) and tropical cyclones. Northern hemisphere mid latitude regions can expect "moderate to high" lightning induced QRN tied to summer season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems and tropical cyclones. Northern hemisphere high latitude regions can expect "moderate" lightning induced QRN tied to summer season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems. During the outlook period there will be "high" lightning induced QRN levels in low latitude areas of the Southern Hemisphere due to the proximity of the Inter Tropical Convergence Zone (ITCZ) and tropical cyclones. Southern hemisphere mid latitude regions can expect "moderate" lightning induced QRN, tied to winter season thunderstorms cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems. Southern hemisphere high latitude regions can expect "low" lightning induced QRN tied to winter season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems. 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 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 73 & GUD DX, Thomas F. Giella, KN4LF Plant City, FL, USA KN4LF Daily Solar Space Weather & Geomagnetic Data Archive & Daily HF/MF Radio Propagation Outlook http://www.kn4lf.com/kn4lf5.htm KN4LF HF/MF Radio Propagation Theory Notes http://www.kn4lf.com/kn4lf8.htm KN4LF 160 Meter Amateur Radio Resources & More http://www.kn4lf.com/kn4lf.htm Florida Space & Atmospheric Weather Institute http://www.kn4lf.com/fsawi.htm --- Outgoing mail is certified Virus Free Thanks To Grisoft AVG. 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