Sun Images for Past 72 Hours

Images copyrighted by the SDO/NASA and Helioviewer project
๐ Propagation Summary
Todayโs HF propagation is shaped by moderate solar activity and elevated geomagnetic conditions. The solar flux is at 127 with a sunspot number of 105, supporting fair propagation on most bands, but the K-index of 4 and A-index of 25 indicate unsettled geomagnetic conditions, which may cause some signal fading and absorptionโespecially on higher bands. Expect fair conditions on 20mโ10m during the day, with 80m and 40m performing better at night. Operators should be alert for short-lived openings and increased noise, especially on the higher bands. For best results, focus on the lower bands after sunset and watch for DX on 20m and 17m during daylight.
๐ก Operator Tips
- Use digital modes (FT8, FT4, RTTY) for improved reliability during unsettled geomagnetic conditions.
- CW and SSB will work, but expect more QSB and possible brief dropouts, especially on 12m and 10m.
- Check 20m and 17m for daytime DX, and 40m/80m at night for regional and intercontinental contacts.
- Portable and low-noise antennas will help counteract increased atmospheric noise.
- If youโre chasing DX, target grayline periods for enhanced propagation, especially on 40m and 20m.
- Monitor cluster spots and be ready to jump on short openings, as conditions may change quickly.
โฐ Best Operating Times
- 80m & 40m: Best at night and early morning (local time)
- 20m & 17m: Best from late morning through late afternoon
- 15m, 12m, 10m: Midday to early afternoon for possible short openings; less reliable but worth checking
- Grayline (sunrise/sunset): Enhanced long-path DX, especially on 40m and 20m
๐ DX Opportunities
- Grayline paths are promising for transcontinental DX on 40m and 20m, especially east-west.
- 20m and 17m may open to Europe, Africa, and South America during daylight hours.
- Short, sporadic E-skip may briefly open 10m and 12mโwatch for cluster alerts.
- Aurora activity is low, so VHF/UHF auroral propagation is unlikely.
- Contest and DXpedition activity: Focus on 20m and 17m for the best shot at rare entities.
๐ป Band-by-Band Analysis
| Band | Morning | Day | Evening | Night |
|---|---|---|---|---|
| 80m | ๐ Fair | ๐ด Poor | ๐ Fair | ๐ก Good |
| 40m | ๐ Fair | ๐ด Poor | ๐ Fair | ๐ก Good |
| 20m | ๐ก Good | ๐ก Good | ๐ Fair | ๐ Fair |
| 17m | ๐ก Good | ๐ก Good | ๐ Fair | ๐ Fair |
| 15m | ๐ Fair | ๐ก Good | ๐ Fair | ๐ Fair |
| 12m | ๐ Fair | ๐ Fair | ๐ด Poor | ๐ด Poor |
| 10m | ๐ Fair | ๐ Fair | ๐ด Poor | ๐ด Poor |
Analysis:
- 20m and 17m are the most reliable for daytime DX and general contacts.
- 15m may offer some midday openings, but conditions are variable.
- 12m and 10m are marginalโcheck for brief E-skip or solar-driven openings, but expect mostly poor conditions.
- 80m and 40m are best at night for local/regional and some DX, but daytime absorption is high due to unsettled geomagnetic conditions.
๐ Current Solar Activity
Solar Activity Metrics
K-index
Solar Flux (10.7cm)
Sunspot Number
- K-index: 4 (Unsettled geomagnetic conditions; expect increased QSB, signal fading, and possible absorption, especially on higher bands)
- Solar Flux: 127 (Moderate; supports fair propagation on 20mโ10m, but not strong enough for consistent high-band DX)
- Sunspot Number: 105 (Healthy for mid-cycle; supports decent HF activity, especially on 20m and 17m)
- Space Weather Overview: X-ray flux at B7.5 (quiet to moderate), solar wind at 394 km/s (slightly elevated), and low aurora index (1)โall suggest generally usable but unsettled HF conditions.
๐ Geomagnetic Conditions
- The K-index has recently increased to 4, indicating a period of geomagnetic unrest. This trend suggests conditions have worsened over the past 24 hours, likely due to a minor solar disturbance or coronal hole stream.
- Expect increased noise and fading, especially on polar and trans-equatorial paths.
- If the K-index drops back to 2 or below, expect a quick improvement in HF propagation.
๐ Space Weather Details
Space Weather Dashboard
X-ray Activity
Solar Wind Speed
Aurora Activity
- X-ray Activity: B7.5 (quiet to moderate; no significant HF blackouts expected, but minor absorption possible)
- Solar Wind: 394.1 km/s (slightly above average; can contribute to unsettled geomagnetic conditions)
- Particle Environment: Electron flux 3870 (moderate; may cause minor polar absorption), Proton flux 18500 (quiet, no major impact)
- Aurora Activity: 1 (very low; auroral propagation on VHF/UHF is unlikely)
- Helium Line: 120.4 (stable, indicating no major solar events in progress)
- Practical Impact: Expect some absorption and QSB, especially at higher latitudes and on higher bands; no major blackouts or auroral events anticipated.
๐ก Propagation Timeline & Technical Details
Propagation Quality Timeline (24 Hours)
- Recent months show solar flux fluctuating between 120 and 138, with sunspot numbers ranging from 77 to 105. This indicates a stable but moderate solar cycle phaseโgood for 20m/17m, but not enough for consistent 10m/12m openings.
- No major solar flares or proton events have been recorded recently.
- Geomagnetic activity has spiked in the last 24 hours, but prior conditions were quieter.
Solar Activity Trends (6 Months)
๐ฎ 3-Day Forecast
3-Day K-index Forecast
- Propagation will remain fair to good on 20m and 17m, with some improvement possible if geomagnetic activity settles.
- Watch for short 15m/12m/10m openings during midday, especially if K-index drops.
- Nighttime 40m and 80m will continue to be the most reliable for regional and some DX.
- No major space weather alerts are in effect, but monitor for sudden K-index changes.
- Best strategy: Focus on 20m/17m during the day and 40m/80m at night; use digital modes for best results during unsettled periods.