KN4LF Daily HF/MF Radio Propagation Outlook #2003-21 http://www.kn4lf.com/kn4lf5.htm
Date Format is MM/DD/YY Published Tuesday 12/14/03 At 2100 UTC PAST 72 HOUR SOLAR, SPACE WEATHER AND GEOMAGNETIC INDICES- Sunspot Groups- #10520 currently contains a beta-gamma twisted magnetic field capable of producing large M class solar flares. Daily Solar Flux Readings- 89 to 84. The daily solar flux reading of 84 that occurred on the 12/12/03 was the lowest since 02/98, which was on the rising side of solar cycle 23. Daily SEC Sunspot Number- 40 to 35. Daily X-Ray Solar Flares- C-0 M-0 X-0 X-ray solar flare activity continues quiet but activity will probably increase as sunspot group #10520 now contains a beta-gamma twisted magnetic field capable of producing large M class solar flares. Daily Averaged Background X-Ray Flux- A9.7 to A7.5. Daily Energetic Protons >10 MeV (10+o)- None. Daily Geo-effective (Earth Facing) Coronal Mass Ejections- None. Recurrent Coronal Hole #071 which became geoeffective beginning on 12/5/03, should finally lose it's negative impact on Earth's magnetic field On UTC 12/15/03. I expect a to see a Kp of 5 (minor geomagnetic storm) at times today but trailing off to a Kp-4 (active) to Kp-3 (unsettled) for tomorrow. A Kp of 0-2 (quiet) will probably occur on days two and three. We should see a three day period with no geomagnetic storming, then on UTC 12/17/03 recurrent Coronal Hole #72 will rotate into geoeffective position. As CH #068 on 11/22-24/03 it produced a peak Kp of 5 (minor geomagnetic storm) and an Ap of 52 (major geomagnetic storm). The daily Ap index has been at active to major storm levels, with a range of 18 to 62. The daily Kp index has been at unsettled to minor storm levels, with a range of 3 to 5. The daily solar wind speed has ranged between 619 and 860. Here are some "general" guidelines concerning correlation of propagation indices to actual expected HF/MF propagation conditions. 1.) Dropping indices numbers are better, except solar flux for HF. 2.) For medium frequencies a solar flux under 150, under 100 better, 70 is best for E layer multi hop. 2a.) For high frequencies a solar flux of 100 is okay, 150 better, above 200 best for F 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. 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 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 (+) 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 medium and high 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 medium and high frequency transmitted signal to propagate through the Aurora Oval zone without being heavily absorbed by skirting underneath it. During 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 1250 miles at heights below the ionosphere for low take-off angles of between 10 and 25 degrees. When the geometry is just right, the medium and high 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. GLOBAL 72 HOUR PROPAGATION OUTLOOK- I expect a to see a Kp of 5 (minor geomagnetic storm) at times today but trailing off to a Kp-4 (active) to Kp-3 (unsettled) for tomorrow. A Kp of 0-2 (quiet) will probably occur on days two and three. We should see a three day period with no geomagnetic storming, then on UTC 12/17/03 recurrent Coronal Hole #72 will rotate into geoeffective position. As CH #068 on 11/22-24/03 it produced a peak Kp of 5 (minor geomagnetic storm) and an Ap of 52 (major geomagnetic storm). GLOBAL LF UNDER 300 KC PROPAGATION CONDITIONS EXPECTED- Daytime- Good Nighttime- Poor But Improving Some GLOBAL HF 3000-30000 KC PROPAGATION CONDITIONS EXPECTED- Low Latitude- Good Mid Latitude- Good High Latitude- Fair To Good GLOBAL MF 300-3000 KC PROPAGATION CONDITIONS EXPECTED- Expect fair then becoming good "Northern Hemisphere" domestic propagation conditions on east-west paths. *Expect poor then becoming fair domestic conditions on north "TO" south paths in the "Northern Hemisphere" out to approximately 1100 miles. +Expect good then becoming fair domestic conditions on south "TO" north paths in the "Northern Hemisphere" out to approximately 1100 miles. Expect poor to fair "Southern Hemisphere" domestic propagation conditions on east-west paths. +Expect good then becoming fair domestic conditions on north "TO" south paths in the "Southern Hemisphere" out to approximately 1100 miles. *Expect poor then becoming fair 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 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 poor then becoming 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 good. "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://www.lightningstorm.com/tux/jsp/gpg/lex1/mapdisplay_free.jsp;jsessionid=70301187101071113657379 During the 72 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" lightning induced QRN tied to winter season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems. Northern 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. 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 "high" lightning induced QRN, tied to summer season thunderstorms and tropical cyclones. Southern 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. 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 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. 73, Thomas F. Giella, KN4LF Plant City, FL, USA EL87WX Yaesu FT-840 & PSK31 Digital Mode E Group http://groups.yahoo.com/group/yaesu_ft840 160 Meter Amateur Radio Resources & More http://www.kn4lf.com/kn4lf.htm Daily Solar Space Weather & Geomagnetic Data Archive http://www.kn4lf.com/kn4lf5.htm HF/MF Radio Propagation Theory Notes http://www.kn4lf.com/kn4lf8.htm Florida Space & Atmospheric Weather Institute http://www.kn4lf.com/fsawi.htm Florida Daily Weather Discussion http://www.kn4lf.com/sub/fmci17.htm Friend Website Design Studio http://www.kn4lf.com --- Outgoing mail is certified Virus Free Thanks To Grisoft AVG. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.551 / Virus Database: 343 - Release Date: 12/11/2003 ---[Start Commercial]--------------------- World Radio TV Handbook 2004 is coming out! Preorder yours now! 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