Sun Images for Past 72 Hours

Images copyrighted by the SDO/NASA and Helioviewer project
๐ Propagation Summary: HF propagation today is moderately challenging, with solar flux at 128 and sunspot numbers continuing a downward trend, now at 45โ72. Geomagnetic activity is elevated (K-index 4, A-index 24), likely causing some signal fading and absorption, especially on higher bands. Expect fair conditions on 20mโ15m during the day, while 80m and 40m will be best at night. 10m and 12m are open but only fair during daylight, with poor night performance. Operators should focus on the mid-bands for reliable contacts and monitor for short-lived DX windows.
๐ก Operator Tips
- Use 20m, 17m, and 15m for daytime DX and reliable regional contacts.
- 80m and 40m will perform best after sunset; try these for domestic and near-continental QSOs.
- Digital modes (FT8, PSK31) are recommended for weak-signal work, especially on higher bands.
- With increased geomagnetic activity, expect more QSB (fading) and possible auroral flutter, especially at higher latitudes.
- Vertical antennas and low-noise receiving setups will help mitigate absorption and noise.
- If chasing DX, check for brief grayline openings around sunrise and sunset.
โฐ Best Operating Times
- 80m & 40m: Best at night and early morning (local time)
- 20m: Good all day, especially late morning to afternoon
- 17m & 15m: Fair during daylight, peaking midday
- 12m & 10m: Open during late morning to early afternoon, but conditions are only fair and may close quickly after sunset
๐ DX Opportunities
- Grayline propagation is your friend todayโwatch for enhanced paths at sunrise/sunset, especially on 20m and 17m.
- Northern paths may see auroral effects; try for aurora-enhanced propagation on VHF/UHF if youโre at higher latitudes.
- East-west paths (e.g., transatlantic, transpacific) are more likely to be open on 20m and 17m during daylight.
- DXpeditions and rare entities: Focus on 20m and 17m for best shot at rare DX, especially around local dusk/dawn.
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 | ๐ก Good | ๐ Fair |
| 17m | ๐ก Good | ๐ก Good | ๐ก Good | ๐ Fair |
| 15m | ๐ก Good | ๐ก Good | ๐ก Good | ๐ Fair |
| 12m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ด Poor |
| 10m | ๐ Fair | ๐ Fair | ๐ Fair | ๐ด Poor |
Analysis:
- Best daytime bands: 20m, 17m, and 15m are your most reliable for both DX and regional contacts.
- Evening/Night: 80m and 40m improve significantly after sunset, supporting longer skip and domestic QSOs.
- 10m and 12m: Only fair during daylight, likely to close rapidly after sunsetโwatch for sporadic E or short-lived openings.
- DXers: Focus on 20m and 17m during grayline, and 15m midday for possible surprises.
๐ Current Solar Activity
Solar Activity Metrics
K-index
Solar Flux (10.7cm)
Sunspot Number
- K-index: 4 (Elevated geomagnetic activity; expect increased fading and possible absorption, especially on polar paths)
- Solar Flux: 128 (Moderate; supports fair propagation on mid and high HF bands)
- Sunspot Number: 72 (Low and declining, reducing maximum usable frequency and overall band openings)
- Space Weather: X-ray flux at B7.0 (minor activity, low risk of sudden HF blackouts)
๐ Geomagnetic Conditions
- The K-index has recently increased to 4, indicating unsettled to active geomagnetic conditions.
- Over the past 24 hours, the trend has been worsening, likely due to elevated solar wind speeds.
- Expect more QSB and absorption, especially on higher bands and polar paths. Conditions may improve if K-index drops back below 3.
๐ Space Weather Details
Space Weather Dashboard
X-ray Activity
Solar Wind Speed
Aurora Activity
- X-ray Activity: B7.0 (low-level, minimal risk of sudden HF blackouts, but keep an eye on solar flare alerts)
- Solar Wind: 748.6 km/s (very high; can increase geomagnetic disturbances, leading to absorption and auroral activity)
- Particle Environment: Electron flux at 2260 (elevated, may cause increased D-layer absorption and noise on lower HF)
- Aurora: Level 2 (minor auroral activity; VHF/UHF aurora not likely, but northern HF paths may be affected)
- Helium Line: 121.6 (stable; no significant trend change, but overall solar activity is on a slow decline)
๐ก Propagation Timeline & Technical Details
Propagation Quality Timeline (24 Hours)
- Recent months show a steady decline in both solar flux (from 138 to 108) and sunspot numbers (from 101 to 45), indicating the solar cycle is moving toward a quieter phase.
- This trend means maximum usable frequencies (MUFs) are lower, and higher bands (12m/10m) are less likely to open for long periods.
- Operators should adjust expectations and focus on mid-HF bands for consistent results.
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 forecasted.
- K-index may remain elevated for the next 24โ48 hours, so expect continued absorption and fading, especially on higher bands.
- Best bands: 20m, 17m, and 15m during the day; 80m and 40m at night.
- Watch for brief DX windows on 12m and 10m, especially during local midday and grayline.
- No major warnings at this time, but stay alert for sudden geomagnetic changes.