- **Location / Path focus**
- Site: Joensuu, Finland – high latitude, strongly affected by auroral absorption.
- Target: Transatlantic MF/AM via polar / near-polar great-circle paths.

- **Current geomagnetic / solar-wind situation (08:00 UTC)**
- Kp: **3** (unsettled; recent peaks to **5**)
- ap: **35** (elevated, lingering storm-level disturbance)
- Dst: **-65 nT** (moderate geomagnetic storm; ring current still strong)
- Bz: **-0.8 nT** (near-neutral, but has swung both north and south overnight)
- Solar wind speed: **~670 km/s** (high-speed stream; keeps auroral oval expanded)
- Proton flux (>10 MeV): **0.33 pfu** (quiet, no proton event)
- Electron flux (integrated proxy): **elevated/negative trend, |eflux| ~65–70** (enhanced high‑latitude precipitation)

- **Recent 24 h evolution relevant to the polar route**
- Kp repeatedly **4–5** from 17–05 UTC with only brief dips; ap climbed from single digits to **>30**.
- Dst has been **persistently ≤ -55 nT** since ~20 UTC, reaching **-73 nT** around 04–07 UTC.
- Solar wind rose from ~380 to **>700 km/s**, indicating a robust coronal hole / HSS influence.
- Bz has alternated between strong southward (down to **-9 nT**) and northward; enough southward intervals to pump energy into the auroral zones.
- Net effect: **auroral oval expanded and hardened**, with sustained high-latitude absorption on MF.

- **Impact on transatlantic MF/AM via polar / auroral paths**
- For Joensuu, **Kp ≥ 4 and Dst ≤ -50 nT** typically push the auroral absorption zone over or very near the polar path to eastern North America.
- The combination of:
- Elevated ap (30–35),
- High-speed solar wind (~650–700 km/s),
- Persistent moderate storm Dst (~-65 nT),
- Enhanced electron precipitation,
strongly suggests **ongoing D-layer absorption and disturbed F-layer** along the polar corridor.
- Result:
- **Severe attenuation** of MF skywave on polar routes.
- Strong fading, distortion, and flutter on any signals that do penetrate.
- Lower‑latitude, more southerly great-circle paths may fare slightly better, but Joensuu’s geometry is dominated by auroral effects.

- **Outlook for the coming local night (Joensuu)**
- With the high-speed stream still in place and no clear recovery in Dst yet, **only slow, partial geomagnetic recovery** is likely by local night.
- Expect Kp to **hover in the 3–4 range**, with possible brief spikes; even Kp 3 at this latitude, on the back of a -60 nT Dst, keeps the auroral oval **too large and too active** for clean polar MF DX.
- **Transatlantic MF/AM via polar paths:**
- Most of the night: **poor to very poor**.
- Short, marginal improvement windows may occur if Kp drops to 2 and Bz turns steadily northward, but current data do not strongly support a full recovery.
- Best chances: **pre-dawn local hours**, but still likely below typical DX quality.

- **Audio-grade reception index (1–10) for transatlantic MF tonight from Joensuu**
- **Index: 3 / 10**
- Reasoning: Sustained moderate storm conditions (Dst ~ -65, ap ~35, Kp 3–5 recent, high-speed wind, elevated electron precipitation) keep the auroral oval expanded over the polar path. This does not completely “black out” MF (which would be ~1–2/10), but it **suppresses and distorts** most transatlantic polar-route signals, limiting reception to occasional weak, noisy, and fluttery audio rather than consistent, listenable program quality.