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Solar
SFI 148
SN 124
A 6
K 5 Storm
X-Ray B9.8
Wind 627.2 km/s
Aurora 6
Updated 16:30 UTC HamQSL · N0NBH
Day 80/40m Poor 30/20m Poor 17/15m Fair 12/10m Fair
Night 80/40m Poor 30/20m Poor 17/15m Fair 12/10m Poor

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Solar flux trending down from 160 to 135 - impact on contest season?

Been tracking the solar data and noticed SFI has dropped from around 160 in December to 135 this month, with sunspot numbers also declining from 124 to around 80. Still decent numbers, but the trend has me wondering about contest season.

For those with more cycles under their belt - how much impact does a 25-point SFI drop typically have on the higher bands during major contests? Should we be adjusting our band plans for CQWW CW later this year?

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  • Michael Peterson
    Michael Peterson

    Good observation! That SFI drop will definitely affect 15M and 10M reliability, especially for European paths during contests. 20M will become even more important - make sure your antennas are optimiz

  • Emily Wilson23
    Emily Wilson23

    Thanks for posting this - I hadn't been watching the trend closely. Are you using any particular sites for tracking these long-term patterns? I'd like to start paying more attention to the solar cycle

  • David Chen
    David Chen

    SFI of 135 is still workable, but you're right to be concerned about contest planning. The key is that geomagnetic activity matters more than absolute SFI - even SFI 120 with K=1-2 can produce great c

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Good observation! That SFI drop will definitely affect 15M and 10M reliability, especially for European paths during contests. 20M will become even more important - make sure your antennas are optimized there. I've seen similar drops kill 10M completely during winter contests.

Thanks for posting this - I hadn't been watching the trend closely. Are you using any particular sites for tracking these long-term patterns? I'd like to start paying more attention to the solar cycle progression.

SFI of 135 is still workable, but you're right to be concerned about contest planning. The key is that geomagnetic activity matters more than absolute SFI - even SFI 120 with K=1-2 can produce great contest conditions. Watch the A-index trends too, not just solar flux.

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