Sun Images for Past 72 Hours

Images copyrighted by the SDO/NASA and Helioviewer project
๐ Propagation Summary
Todayโs HF propagation is shaped by a moderate solar flux of 133 and a sunspot number near 93, with generally quiet geomagnetic conditions (K-index 2). Expect good performance on the mid-bands (20mโ15m) throughout the day and evening, while higher bands (12m, 10m) are only fair during daylight and close at night. Low bands (80m, 40m) will provide reliable nighttime operation, especially for regional contacts. With a stable geomagnetic field and no major solar disturbances, operators should enjoy relatively stable conditions, but be alert for any sudden changes due to elevated solar wind. Focus your efforts on 20mโ15m for the best DX and daytime activity!
๐ก Operator Tips
- Target 20m, 17m, and 15m during daylight and early evening for the best DX and intercontinental contacts.
- Use digital modes (FT8, PSK31) to maximize your chances on marginal bands like 12m and 10m.
- For nighttime operations, 80m and 40m will be your most reliable bandsโgreat for regional nets and ragchews.
- Monitor the K-index: If it rises above 4, expect increased absorption and fading, especially on higher bands.
- Verticals and directional antennas will help on higher bands; for low bands, use full-size dipoles or loops for best results.
- If chasing DX, check grayline times for enhanced propagation, especially on 40m and 20m.
โฐ Best Operating Times
- 80m & 40m: Best at night and early morning (regional and some DX)
- 20m: Good all day, especially late morning through early evening (DX and domestic)
- 17m & 15m: Best from late morning to late afternoon (DX focus)
- 12m & 10m: Fair only during peak daylight hours; expect these bands to close quickly after sunset
๐ DX Opportunities
- Grayline openings on 40m and 20m will offer enhanced long-haul DX, especially at sunrise and sunset.
- 20m and 17m are your best bets for trans-equatorial and east-west DX paths.
- 15m may open to South America, Africa, and the Pacific during local afternoon.
- Watch for sporadic-E on 10m and 12m during midday, but expect only brief or weak openings.
- Aurora activity is low (Aurora index 1), so VHF/UHF auroral propagation is unlikely today.
๐ป Band-by-Band Analysis
| Band | Morning | Day | Evening | Night |
|---|---|---|---|---|
| 80m | ๐ก Good | ๐ Fair | ๐ก Good | ๐ก Good |
| 40m | ๐ก Good | ๐ Fair | ๐ก Good | ๐ก Good |
| 20m | ๐ก Good | ๐ก Good | ๐ก Good | ๐ก Good |
| 17m | ๐ก Good | ๐ก Good | ๐ก Good | ๐ก Good |
| 15m | ๐ก Good | ๐ก Good | ๐ก Good | ๐ก Good |
| 12m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ด Poor |
| 10m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ด Poor |
- Best bands today: 20m, 17m, and 15m are consistently good all day and eveningโideal for DX and general contacts.
- 80m and 40m are good at night and early morning, but only fair during the day.
- 12m and 10m are fair in daylight but poor or closed at nightโuse digital modes for any chance of contacts.
๐ Current Solar Activity
Solar Activity Metrics
K-index
Solar Flux (10.7cm)
Sunspot Number
- K-index: 2 โ Low geomagnetic activity, meaning stable conditions and low absorption.
- Solar Flux (10.7cm): 133 โ Moderate, supporting decent propagation on 20mโ15m, with some potential for 12m/10m during daylight.
- Sunspot Number: 93 โ Healthy, but trending lower than earlier in the year, which slightly limits high-band openings.
- Space Weather: No major flares or disturbances reported; X-ray flux at B6.9 is quiet.
๐ Geomagnetic Conditions
- The K-index has remained low and stable over the past 24 hours, indicating quiet geomagnetic conditions.
- No recent spikes or disturbances, so HF propagation should remain steady, with minimal fading or absorption.
- If you notice a sudden rise in the K-index, expect possible short-term degradation, especially on polar and high-latitude paths.
๐ Space Weather Details
Space Weather Dashboard
X-ray Activity
Solar Wind Speed
Aurora Activity
- X-ray Activity: B6.9 โ Low-level X-ray flux, so no risk of sudden HF blackouts or D-layer absorption events.
- Solar Wind: 603 km/s โ Elevated, but not extreme; may cause minor geomagnetic fluctuations, but no major storms expected.
- Particle Environment: Electron flux at 2240 and proton flux at 12 โ Normal to slightly elevated, but not enough to impact HF significantly.
- Aurora Activity: 1 โ Very low, so no auroral propagation on VHF/UHF for northern operators.
- Helium Line: 120.5 โ Moderate, indicating stable solar activity with no major upswings or flare risk.
๐ก Propagation Timeline & Technical Details
Propagation Quality Timeline (24 Hours)
- Over the past several months, solar flux and sunspot numbers have gradually declined from spring peaks (SF ~138, SSN ~101) to current moderate levels (SF ~108, SSN ~45).
- This trend means high bands (12m, 10m) are less reliable now than earlier in the year, but mid-bands (20mโ15m) remain robust.
- No major solar events or geomagnetic storms have disrupted the trend, so expect continued stable but moderate HF conditions.
Solar Activity Trends (6 Months)
๐ฎ 3-Day Forecast
3-Day K-index Forecast
- Solar activity is expected to remain moderate, with no major flares or geomagnetic storms forecast.
- HF conditions will be stable, with 20mโ15m remaining the best bands for DX and general contacts.
- 12m and 10m may open briefly during peak daylight, especially for southern paths, but expect mostly fair to poor conditions.
- Low bands (80m, 40m) will continue to perform well at night for regional work.
- No alerts or warnings for amateur operators at this timeโenjoy the steady autumn propagation!