Amateur Radio Propagation Report

Sun Images for Past 72 Hours

Images copyrighted by the SDO/NASA and Helioviewer project

📋 Propagation Summary:
HF propagation today is showing moderate conditions, with solar flux at 142 and a sunspot number of 133—both supportive of daytime activity on the higher bands. However, a K-index of 4 and an A-index of 14 indicate unsettled geomagnetic conditions, which may cause some fading and variable signal strength, especially on polar and trans-equatorial paths. Expect fair openings on 20m–10m during daylight, but with possible short-term disruptions. Lower bands (80m/40m) will be noisy during the day but should improve after sunset. Operators should be flexible and check band conditions often for the best results.

💡 Operator Tips

• Daytime: Focus on 20m, 17m, and 15m for reliable regional and some DX contacts.
• Evening/Night: Shift to 40m and 80m for improved propagation as D-layer absorption drops.
• Modes: Use digital modes (FT8, PSK31, RTTY) for weak-signal work, especially during geomagnetic disturbances.
• Antennas: If possible, use directional antennas to maximize SNR and take advantage of fleeting DX openings.
• Contesters: Watch for short, enhanced openings on 10m and 12m—be ready to pounce!
• DXers: Monitor grayline times for best long-haul opportunities, especially on 20m and 17m.

⏰ Best Operating Times

• 80m/40m: Best after local sunset through sunrise; avoid daytime due to high absorption.
• 20m: Good from late morning through sunset; possible short evening openings.
• 17m/15m: Best from mid-morning to late afternoon.
• 12m/10m: Fair during midday; check for sporadic-E or short-lived F2 openings.
• Grayline: 30 minutes before and after sunrise/sunset for enhanced DX, especially on 40m–20m.

🌍 DX Opportunities

• Grayline paths: Enhanced propagation on 40m and 20m at sunrise/sunset—target antipodal regions.
• Daytime F2: 17m and 15m may open to Europe, Africa, and South America from North America.
• Sporadic-E: Watch 10m and 12m for short, strong openings—especially late morning and early evening.
• Aurora: With aurora at level 3, northern operators may see VHF auroral propagation; check 6m/2m for CW/SSB aurora scatter.

📻 Band-by-Band Analysis

Analysis:

• Best bands: 20m, 17m, and 15m offer the most consistent fair propagation throughout the day and into the evening.
• 80m/40m: Poor during daylight due to D-layer absorption, but fair at night for local/regional work.
• 12m/10m: Only fair during the day; expect these bands to close quickly after sunset.
• DX: Focus on 20m and 17m for the most reliable long-haul paths, especially around grayline.

📊 Current Solar Activity

• K-index: 4 (unsettled) – Indicates moderate geomagnetic activity; may cause signal fading and shortwave absorption, especially at high latitudes.
• Solar Flux: 142 – Above average, supporting F2-layer propagation on 20m–10m.
• Sunspot Number: 133 – Healthy sunspot count, generally favorable for HF propagation.
• Space Weather: X-ray flux at B8.6 (quiet), but elevated solar wind and electron flux suggest caution for sudden disturbances.

📈 Geomagnetic Conditions

• The K-index has recently risen to 4, showing a trend toward unsettled geomagnetic conditions.
• Over the past 24 hours, K-index values have fluctuated, indicating periods of increased geomagnetic activity.
• These conditions can cause signal fading, auroral absorption, and increased noise—especially on polar and trans-auroral paths.
• If the K-index drops, expect improvement; if it rises further, anticipate more severe HF disruptions.

🌟 Space Weather Details

• X-ray Activity: B8.6 – Low-level X-ray flux, so no major HF blackouts expected.
• Solar Wind: 494 km/s – Elevated speed increases the risk of geomagnetic disturbances and short-term HF absorption.
• Particle Environment: Electron flux at 2480 and proton flux at 23 – Elevated electron flux can cause minor polar absorption and increased noise on lower bands.
• Aurora Activity: Level 3 – Moderate auroral activity; northern operators may see aurora-induced propagation on VHF/UHF, especially 6m and 2m.
• Helium Line: 129.4 – Indicates moderate solar activity; watch for potential increases in solar flux if this rises.

📡 Propagation Timeline & Technical Details

• Over the past several months, solar flux and sunspot numbers have gradually declined from late 2025 highs (SF ~160, SSN ~124) to current moderate levels (SF ~120, SSN ~79).
• This trend suggests slightly less robust F2-layer propagation compared to earlier in the cycle, but conditions remain good for mid-high HF bands.
• Watch for further declines as the solar cycle progresses, which will gradually favor lower bands for DX.

🔮 3-Day Forecast

• Propagation Outlook: Expect continued fair conditions on 20m–15m, with possible short-lived enhancements or disruptions depending on geomagnetic activity.
• K-index: May remain elevated; monitor for sudden increases which could cause HF blackouts or auroral conditions.
• Best Bets: Operate during daylight on 20m–15m; switch to 40m/80m after sunset.
• Alerts: No major solar flares or storms forecast, but stay tuned for updates if geomagnetic conditions worsen.
• VHF/UHF: Northern operators should monitor for auroral propagation, especially if K-index spikes further.