Sun Images for Past 72 Hours

Images copyrighted by the SDO/NASA and Helioviewer project
๐ Propagation Summary
HF propagation today is showing moderate conditions, with solar flux at 124 and a sunspot number of 120, both slightly below recent monthly averages. The K-index is at 2, indicating quiet geomagnetic conditions, which is favorable for most HF operations. Expect good performance on 20m throughout the day and night, while higher bands (15m, 12m, 10m) may be less reliable, especially at night. Lower bands (80m, 40m) will perform best after sunset. There are no major space weather alerts, so operators can expect relatively stable conditions, but keep an eye on possible short-term changes.
๐ก Operator Tips
- For DX: Focus on 20m during the day and early evening; try 17m and 15m for shorter skip or regional contacts.
- Digital modes (FT8, FT4, PSK31) are recommended on 12m and 10m, as marginal conditions may still support weak-signal contacts.
- Use vertical antennas or directional beams to maximize your reach, especially on higher bands.
- For contesting or awards: Concentrate on 40m and 20m for consistent results, especially during local evening and night hours.
- Monitor the K-index: If it rises above 4, expect increased absorption and possible HF blackouts, especially on polar paths.
โฐ Best Operating Times
- 80m/40m: Best at night and early morning (local time)
- 20m: Good all day and into the evening
- 17m/15m: Best mid-morning to late afternoon
- 12m/10m: Try late morning to early afternoon; expect limited openings
๐ DX Opportunities
- Grayline propagation is favorable on 40m and 20m around local sunrise and sunsetโtarget long-path DX during these windows.
- 20m offers the most reliable intercontinental paths today, especially east-west.
- Aurora activity is low (Aurora index 3), so VHF/UHF auroral propagation is unlikely.
- Watch for sporadic-E on 10m and 6m, especially during daylight hours, though conditions are only fair.
๐ป Band-by-Band Analysis
| Band | Morning | Day | Evening | Night |
|---|---|---|---|---|
| 80m | ๐ Fair | ๐ Fair | ๐ก Good | ๐ก Good |
| 40m | ๐ Fair | ๐ Fair | ๐ก Good | ๐ก Good |
| 20m | ๐ก Good | ๐ก Good | ๐ก Good | ๐ก Good |
| 17m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ Fair |
| 15m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ Fair |
| 12m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ด Poor |
| 10m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ด Poor |
- Best bands: 20m is consistently good all day and night; 40m and 80m are good at night.
- Challenging bands: 12m and 10m are only fair during the day and poor at nightโuse digital modes for best results.
- 17m/15m: Usable but not optimal; expect regional rather than long-haul DX.
๐ Current Solar Activity
Solar Activity Metrics
K-index
Solar Flux (10.7cm)
Sunspot Number
- K-index: 2 (quiet geomagnetic field, minimal disturbance, good for HF)
- Solar Flux: 124 (moderate; supports reliable 20m, marginal 15m/12m/10m)
- Sunspot Number: 120 (slightly below recent averages; still enough for decent propagation)
- Space Weather: No major flares or storms reported; X-ray flux at B5.8 (quiet to low-level activity)
๐ Geomagnetic Conditions
- The K-index has fluctuated between 1 and 3.7 over the past 24 hours, but is currently stable and low.
- Recent trend: After a brief uptick (K=3.7), values have dropped back to 2, indicating improving and quiet geomagnetic conditions.
- Expect continued low absorption and minimal auroral disturbance for HF.
๐ Space Weather Details
Space Weather Dashboard
X-ray Activity
Solar Wind Speed
Aurora Activity
- X-ray Activity: B5.8 (low)โno risk of HF blackouts from solar flares.
- Solar Wind: 449 km/sโmoderate speed; not high enough to trigger geomagnetic storms.
- Electron Flux: 2720โelevated but not extreme; may cause mild absorption at high latitudes.
- Proton Flux: 8โquiet, no radiation storm risk.
- Aurora: 3โlow, so auroral propagation on VHF/UHF is unlikely.
- Helium Line: 118.9โsteady, indicating no major solar trend changes.
๐ก Propagation Timeline & Technical Details
Propagation Quality Timeline (24 Hours)
- Over the past 6 months, solar flux has trended downward from 160 to 135, and sunspot numbers have dropped from 124 to 78, reflecting a moderate decline in solar activity.
- This trend means higher bands (15m, 12m, 10m) are less likely to open for long-haul DX, but 20m remains robust.
- Quiet geomagnetic conditions in recent days have helped stabilize HF propagation.
Solar Activity Trends (6 Months)
๐ฎ 3-Day Forecast
3-Day K-index Forecast
- Expect continued moderate solar activity with solar flux and sunspot numbers holding steady.
- K-index likely to remain low (1-3), supporting stable HF conditions.
- 20m and 40m will remain the best bands for DX and general operation.
- No major space weather alerts anticipatedโwatch for any sudden K-index increases.
- VHF/UHF: No significant auroral or sporadic-E activity expected, but monitor 6m for brief openings.