◉─────────────────────────────────────────────────────────────◉ AURORA NOW ////// REAL-TIME AURORA PROBABILITY & SPACE WEATHER ◉ Kp · IMF Bz · Solar Wind · Ovation Oval · Day/Night Map ◉

Aurora Now — Real-Time Aurora Probability

Live Kp index · NOAA Ovation aurora oval · ACE solar wind · IMF Bz · Day/night map · 30-min forecast · Auto-refresh every 3 min

Kp Index Now

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IMF Bz

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nT · southward = aurora-active

Solar Wind Speed

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km/s · ACE satellite

Max Kp Forecast

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next 3 hours

Aurora @ Your Lat

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click ◎ to set location

Active Alerts

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NOAA storm alerts

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Fetching data...

Aurora Oval — NOAA Ovation + Day/Night Terminator 100%

Aurora probability → Low–Med Med–High High–Max Night side Kp visibility Click map → aurora % at that point

Space Weather Alerts ◉ NOAA SWPC

Initializing space weather feed...

Source: NOAA Space Weather Prediction Center · swpc.noaa.gov · Updates every 3 min

Kp Index — Last 27 Readings (~81 hours)

Bz −25nT

Bz +25nT IMF Bz: —

📷 Aurora Photography Calculator Kp —

Visibility verdict → UNKNOWN Fetching data...

ISO

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sensor sensitivity

Aperture

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use widest available

Shutter

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avoid star trails

Focus

∞

manual, hyperfocal

White Bal.

3500K

tungsten / custom

Lens

Wide

14–24mm f/2.8

Tip: shoot in RAW, bracket exposures, disable noise reduction in-camera.

Free Aurora Probability Monitor — NOAA Ovation + ACE Solar Wind Data

Aurora Now is a free real-time aurora probability dashboard combining three NOAA data streams: the planetary Kp index (updated every 3 minutes), the NOAA Ovation Prime aurora oval (a full lat/lon probability grid updated every 5 minutes from particle precipitation models), and live ACE/DSCOVR satellite solar wind measurements including interplanetary magnetic field (IMF) Bz component and solar wind speed. This is the same data used by NOAA's own Space Weather Prediction Center — presented in a cleaner, more interactive interface.

The interactive canvas map shows the actual aurora oval drawn from the Ovation JSON data, overlaid with a day/night terminator so you can immediately see where on Earth darkness falls within the aurora zone. Click anywhere on the map to get the exact aurora probability at that point. Use the "My Location" button to see your personal aurora probability in real time.

IMF Bz — The Key Predictor Nobody Talks About

The Bz component of the Interplanetary Magnetic Field (IMF) is the single most important aurora predictor, yet most aurora apps bury it in small print. When Bz is strongly negative (southward), it means the solar wind's magnetic field is pointing opposite to Earth's magnetosphere — they connect, and solar particles stream down the field lines into the polar regions, creating aurora. A sustained Bz of −10 nT or below is typically enough for visible aurora at latitudes above 60°. Bz of −20 nT or below can push aurora visibility down to 50–55°. The Bz meter on this page shows the current value in real time from ACE satellite measurements at the L1 Lagrange point, about 1.5 million km from Earth — giving you roughly 15–45 minutes of advance warning.

Kp Index & Geomagnetic Storm Scale

The Kp index runs from 0 (quiet) to 9 (extreme storm). G-storm levels start at Kp 5 (G1 — Minor). At Kp 5, aurora is typically visible above 60° latitude. At Kp 7 (G3), aurora can reach 50°. At Kp 9 (G5 — Extreme), aurora has been seen as far south as 40°. The 3-hour sparkline lets you see whether activity is rising or falling — a rising Kp after a southward Bz onset is the optimal chase scenario.

Aurora Photography Calculator

The photography calculator gives camera settings for the current Kp level. Aurora brightness varies enormously — a faint Kp 2 display needs ISO 3200 and 25-second exposures, while a violent G5 storm can be captured at ISO 400. The 500 Rule limits shutter speed to 500÷focal_length seconds before star trailing becomes visible. Always shoot in RAW, use manual focus set to infinity, and pre-focus in daylight or on a bright star before the display begins.

Frequently Asked Questions — Aurora Now

What is the Kp index and what does it mean for aurora?

The Kp index (planetary geomagnetic activity index) runs from 0 to 9 and measures global geomagnetic disturbance. It's updated every 3 hours by NOAA using data from 13 ground-based magnetometer stations worldwide. For aurora visibility: Kp 1–2 — aurora near Arctic/Antarctic circles only (67°+). Kp 3–4 — aurora visible from Tromsø, Iceland, northern Canada, Alaska (~62–67°). Kp 5 (G1 storm) — visible from 60°+, potentially northern Scotland, southern Alaska. Kp 7 (G3) — visible from ~50°, Belgium, Netherlands, northern US. Kp 9 (G5 extreme) — visible from ~40°, visible across much of Europe and the US.

Why is IMF Bz more important than Kp for predicting aurora?

Kp is a retrospective 3-hour average. IMF Bz is real-time and is the direct physical cause of aurora. When Bz turns southward (negative), solar wind magnetic field reconnects with Earth's magnetosphere — this is called dayside reconnection. Particles flood down the polar cusps within 15–45 minutes. A sustained Bz of −10 nT typically produces visible aurora at 60°+. Crucially, Bz can flip from +5 to −20 within minutes, so watching it live gives you advance notice that Kp is about to spike. The ACE satellite sits at the L1 Lagrange point between Earth and Sun, providing approximately 20–40 minutes of advance warning of incoming solar wind conditions.

What is the NOAA Ovation aurora oval?

The Ovation Prime model is NOAA's empirical aurora forecast model, updated every 5 minutes. It uses real-time solar wind data (from DSCOVR satellite since 2016) as input to calculate the probability of aurora at every point on Earth based on statistical relationships between solar wind conditions and auroral particle precipitation. It produces a lat/lon probability grid (0–100%) for both the northern and southern hemispheres. This dashboard draws that grid directly onto the interactive canvas map — the same data NOAA uses to generate their aurora oval images, but rendered here as an interactive heatmap you can zoom and pan.

Why does aurora need to be on the night side?

Aurora is always happening in the polar regions — particles are always precipitating. But daylight overpowers the faint aurora glow, making it invisible to the naked eye. The aurora requires a dark sky — after astronomical twilight (sun more than 18° below horizon). The day/night terminator on this map shows exactly where darkness falls. The ideal viewing scenario is being poleward of the aurora oval's equatorward boundary AND on the night side of the terminator. The map overlays both so you can identify the optimal viewing zone at a glance.

What are the best camera settings for aurora photography?

Aurora photography depends on display brightness, which scales with Kp. General rules: use your widest aperture lens (f/1.4–f/2.8), shoot in RAW not JPEG (vastly more editing latitude), and use a remote shutter release to avoid camera shake. Shutter speed is limited by the 500 Rule (500 ÷ focal length = max seconds before star trailing) — at 24mm, that's ~20 seconds. At Kp 7+, aurora moves fast and shorter exposures (5–10s) capture detail better. Focus manually to infinity — autofocus fails in low light. Set white balance to 3500–4500K (tungsten) to preserve the aurora's green colour in JPEGs; in RAW, adjust in post.

How often does this page update?

Data refreshes every 3 minutes, matching the NOAA Kp update cadence. The Ovation aurora oval updates every 5 minutes at source; the ACE solar wind plasma and IMF data are available at 1-minute resolution. Geomagnetic storm alerts from NOAA SWPC are typically issued within minutes of a storm onset. The Kp sparkline shows the last 27 readings (~81 hours) in 3-hour intervals, letting you see multi-day activity patterns.

What's the difference between a G1, G2, G3 storm?

NOAA's G-scale rates geomagnetic storms from G1 (minor, Kp 5) to G5 (extreme, Kp 9). G1: aurora at 60°+ (northern tip of Scandinavia, Alaska, Canada). Weak power grid fluctuations. G2 (Kp 6): aurora at 55°+ (southern Scandinavia, northern UK, northern US). G3 (Kp 7): aurora at 50°+ (Belgium, Netherlands, central US). Intermittent GPS degradation. G4 (Kp 8): aurora at 45°+ (central Europe, southern US). Widespread power grid problems possible. G5 (Kp 9): aurora at 40°+ (southern Europe, Mexico). The March 1989 G5 storm caused a 9-hour Quebec blackout. The May 2024 G5 storm produced aurora visible across Spain, Florida, and Hawaii.