The Sun Had a Weekend. The Bands Are Waking Up

by Greyline Performance

The Signal Lab — Monday, April 20, 2026

The Sun Had a Weekend.
The Bands Are Waking Up.

By Jon KL2A — Greyline Performance, Sun Valley, Idaho

If you were on the air this weekend and wondered why the West Coast sounded like a quiet library while East Coast operators were working the world — you’re not imagining things. Here’s what happened, why, and what this week looks like from your shack.

What happened this weekend

A coronal hole opened up on the Sun and sent a high-speed solar wind stream straight at Earth. By Friday night into Saturday morning, NOAA registered a G2 moderate geomagnetic storm — Kp climbing to 6. Auroras showed up as far south as the mid-latitudes. Space weather folks were posting pictures. Ham radio operators on the West Coast, sitting closer to the polar path where the disruption hits hardest, had a rougher time.

As of this morning, Kp is settling back around 3 to 3.7 — active but not storming. The forecast clears further toward quiet by Tuesday or Wednesday. The bands are coming back. Watch them.

Plain English for the new operator

What is a geomagnetic storm? The Sun periodically opens up large holes in its outer atmosphere called coronal holes. These fire a river of charged particles at Earth. When that stream hits our magnetic field and the geometry is right, it shakes the ionosphere — the reflective layer that bounces your HF signal around the globe — like a snow globe. Reception gets noisy. Signals fade. The higher HF bands (10M, 15M) can go quiet entirely. 10M and 6M take the biggest hit because they depend on a calm, reflective ionosphere.

One nuance worth knowing: a strong X-class solar flare can actually blank HF briefly before it improves — the ionizing radiation arrives first and causes a Radio Blackout (R-scale event) on the dayside. Once that passes, the enhanced F-layer can briefly improve conditions. So if the band goes dead right after a flare alert, give it 30 minutes before concluding it’s a lost session.

What is the K-index? Think of it as a weather forecast for your antenna. K=0–1 is flat calm — DX is easy. K=3 is partly cloudy. K=5 is a geomagnetic storm beginning. K=6 (where we were Saturday) is moderate storm. Right now K≈3 and falling. Partly cloudy, improving.

Why did East Coast have more fun? Geography. Geomagnetic disruption is worst near the poles and along polar paths. East Coast transatlantic paths on 20M and 15M were on a more favorable geometry. West Coast Pacific paths clip higher latitudes. East Coast also had a head start, catching good conditions before the storm fully developed Friday afternoon.

What This Week Looks Like

Coronal hole storms follow a predictable shape: they ramp up fast, peak for a day or so, then ease off over 24–48 hours. The second half of this week should offer some of the best conditions since the storm started — a classic post-storm recovery that DXers have learned to love. Watch solar flux as conditions settle — SFI above 120 means 10M is worth a listen. Above 150, look at 12M and 15M seriously.

We’re also deep into prime spring 6M F2 season — late April through May is the best window for North American operators to catch Equatorial Ionization Anomaly openings. When K drops back to 1 or 2 and solar flux is above 150, point the radio at 50 MHz. You might be surprised. For a deeper look at where Cycle 25 stands right now and what the descending phase means for your operating, read the full Cycle 25 update on the Signal Lab →

Three tools to bookmark right now

CT1BOH’s Propagation Dashboard — José Carlos Nunes, operating from Portugal at the crossroads of Europe, Africa, and the Atlantic, runs one of the cleanest live space weather dashboards on the web. K-index, geospace timeline, aurora maps, solar wind — all on one page. This is what serious contesters actually check. qsl.net/ct1boh/propagation.htm

PSKreporter — Type in your callsign and watch a live world map of who’s hearing you. Empty map means the band is actually closed — not your antenna. Spots across the Atlantic mean you’re getting out. pskreporter.info

DXMaps — Live spots on every band, mapped. Particularly useful for 6M — when that map starts lighting up with transatlantic paths, the opening is real. dxmaps.com

Standing on the Shoulders of Gurus

None of this is new knowledge — the ham radio community has been reading the Sun for a century. Two voices worth knowing:

Frank Donovan W3LPL — Maryland, one of the most thoughtful HF propagation observers in the country, publishing daily in The Daily DX . Back in March 2023 when the Cycle 25 story was just getting exciting, Frank wrote about unusual 6M activity and predicted exactly what’s been happening. He was right. Good physics doesn’t expire.

“Give 6 meters a try — almost every modern HF transceiver covers 6 meters. A simple indoor or outdoor dipole only 25 feet high or a tuner driving your existing HF antenna will give you a taste of enhanced 6-meter F2 propagation as we approach solar maximum.”

— Frank Donovan, W3LPL — Maryland (March 2023)

José Carlos Nunes CT1BOH — Portugal, world-class contester and DXer whose propagation dashboard we referenced above. His geographic position at the southwestern tip of Europe, facing the Atlantic and Africa, makes him one of the best natural observation points on the planet for transatlantic propagation. When CT1BOH’s dashboard shows clear conditions, the opening is real.

New to HF? Just got back into radio?

Here’s the single best piece of advice for your first months on HF: check conditions before you conclude your antenna is broken. We hear this constantly — someone fires up the rig, the band sounds dead, and they wonder if they assembled something wrong. Sometimes the band actually is dead. The Sun decides that, not your hardware.

Open PSKreporter while you operate. If you call CQ on 20M FT8 and the map shows spots from Europe and South America, your antenna is working. If the map is empty, wait an hour and try again. The ionosphere has a schedule. Learn it and you’ll have ten times more fun.

And if you just got back on the air after years away — welcome back. You picked a good time. Even on the way down from the Cycle 25 peak, these are historically good conditions.

Your Antenna & This Week’s Conditions

Every Greyline covers 10M, 12M, 15M, and 6M — plus 30M, 60M, and the full WARC allocation. As K-index drops this week, the high bands are where to watch first. The 5/8λ sweet spot on the 12-footer is 6M — the one model in the lineup that has a natural resonance advantage on the magic band. The 20-footer hits 5/8λ on 10M. The 28-footer hits 5/8λ on 15M, right where this week’s recovery shows up first. Not sure which height is right for your operating goals? Use the selection guide →

If you have the 9-foot DX Whip : the 20+9 combination (29 feet total) hits 5/8λ on 15M, matching the bare 28-footer on that band. This week’s recovery window on 15M is a good reason to have it on.

Put it up. Get on the air. Call CQ and watch PSKreporter. The bands are coming back.

Ham Radio is fun again. Pass it on… 73, Jon KL2A & the Greyline Performance Team — greylineperformance.com — 435-200-4902

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