Sun Images for Past 72 Hours

Images copyrighted by the SDO/NASA and Helioviewer project
๐ Propagation Summary:
HF propagation today is shaped by moderate solar activity and very quiet geomagnetic conditions. With a solar flux of 91 and sunspot number at 25, high bands (12m/10m) are mostly underperforming, while the core bands (20m, 40m, 80m) are providing the most reliable contacts. Expect stable, low-noise conditions thanks to a K-index of 0, making this a great day for regional and some DX work, especially on the lower and mid bands. Operators should focus on daytime operation for 20m and below, and use digital modes for marginal bands. No major space weather disruptions are expected.
๐ก Operator Tips
- Prioritize 20m, 40m, and 80m for both local and DX contacts; these bands are consistently open day and night.
- Digital modes (FT8, PSK31, RTTY) will outperform SSB/CW on higher bands (15m, 12m, 10m) due to weak propagation.
- Low noise levels mean even modest antennas will perform well, especially on 40m and 80m.
- For DX, target grayline periods (sunrise/sunset) on 40m and 20m.
- VHF/UHF: No auroral or enhanced propagation expected; stick to tropo and local FM/SSB.
- Check for band openings on 15m during midday, but expect only fair results.
โฐ Best Operating Times
- 80m & 40m: Best at night and early morning for both short and long-haul contacts.
- 20m: Open most of the day and evening; best for daytime DX.
- 17m & 15m: Try late morning through afternoon for possible openings.
- 12m & 10m: Limited activity; check around local noon for brief openings, but expect poor results.
- Grayline: 40m and 20m are optimal for chasing rare DX at sunrise/sunset.
๐ DX Opportunities
- Grayline paths on 40m and 20m offer the best chance for long-haul DX, especially east-west.
- 20m: Some trans-equatorial and north-south DX possible during daylight.
- 15m: Occasional short openings for DX, mostly during midday.
- No significant auroral activity; VHF/UHF DX unlikely.
- Watch for grayline enhancement at local sunrise/sunset for rare DX on lower bands.
๐ป Band-by-Band Analysis
| Band | Morning | Day | Evening | Night |
|---|---|---|---|---|
| 80m | ๐ก Good | ๐ก Good | ๐ก Good | ๐ก Good |
| 40m | ๐ก Good | ๐ก Good | 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 | ๐ด Poor | ๐ด Poor | ๐ด Poor | ๐ด Poor |
| 10m | ๐ด Poor | ๐ด Poor | ๐ด Poor | ๐ด Poor |
The best performance is on 80m, 40m, and 20m, which are consistently good throughout the day and night. 17m and 15m offer fair conditions, so check for brief openings, especially midday. 12m and 10m are largely poor and not recommended except for local contacts or sporadic E. For reliable QSOs, stick to 20m and below.
๐ Current Solar Activity
Solar Activity Metrics
K-index
Solar Flux (10.7cm)
Sunspot Number
- K-index (0): Very quiet geomagnetic fieldโminimal noise, excellent for HF.
- Solar Flux (91): Below averageโlimits high-band propagation but supports lower bands.
- Sunspot Number (25): Lowโconfirms weak high-band conditions.
- Space Weather: No major flares or disturbances; X-ray flux is at B2.8 (quiet).
๐ Geomagnetic Conditions
- The K-index has remained very low and stable over the past 24 hours, indicating calm geomagnetic conditions.
- No recent spikes or disturbancesโideal for HF operation.
- Expect low noise and minimal fading on all bands.
๐ Space Weather Details
Space Weather Dashboard
X-ray Activity
Solar Wind Speed
Aurora Activity
- X-ray Activity: B2.8 (quiet)โno risk of HF blackouts.
- Solar Wind Speed: 385 km/sโmoderate, not enough to trigger geomagnetic storms.
- Electron Flux: 3040โslightly elevated but not at levels that cause significant absorption or noise.
- Aurora: Level 1โvery low, so no auroral propagation expected on VHF/UHF.
- Helium Line: 102.1โsuggests stable solar activity with no major changes imminent.
๐ก Propagation Timeline & Technical Details
Propagation Quality Timeline (24 Hours)
- Over the past several months, solar flux and sunspot numbers have been trending downward from spring highs (SF ~138, SSN ~101) to current lower values (SF ~91, SSN ~25).
- This gradual decline means high bands are less reliable, but lower bands remain steady.
- No recent solar storms or major events have disrupted the bands.
Solar Activity Trends (6 Months)
๐ฎ 3-Day Forecast
3-Day K-index Forecast
- Expect continued quiet geomagnetic conditions (low K-index), supporting stable HF propagation.
- Solar flux and sunspot numbers are likely to remain low, so 20m, 40m, and 80m will continue to be the best bands.
- 12m and 10m will remain mostly closed except for rare, short-lived openings.
- No significant space weather warnings or alerts are forecastโenjoy the low noise and stable bands!