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The terms on the board are the real ones specialists use. Here each comes with what it means for you.

How to read the board

The badge in the header. The first answer: quiet, wind elevated or strong southward wind. It is the state of the solar wind at Earth right now. Red only when energy is entering the magnetosphere, that is with a strong southward field.

Solar wind at Earth. Four gauges from the probe at L1. Speed is usually about 400 km/s, density about 5 particles per cubic centimetre, Bz about zero. The "coupling to Earth" gauge folds everything into one number from 0 to 100: how much wind energy gets in. Usually 3, tens during a storm.

Ejection tracking. The line Sun, L1 probe, Earth. When a coronal mass ejection is heading for Earth, a red bar crawls along it with the expected arrival in your time zone and what it is based on: the NOAA model, a NOAA warning or the NASA catalog. After a hit, a "hit at" mark stays for a day and a half. Below, the 3-day Kp forecast and three days of flares.

Earth now. Greenish fill: where the NOAA model expects aurora within the hour, brighter means more likely. The dark half: night. Dots: magnetic observatories. The larger and redder the dot, the stronger the field has been changing over the last 30 minutes; a label appears on notable ones. The colour threshold depends on latitude: in the Arctic 100 nT/min is routine, at mid latitudes concern starts at 30.

Impacts. Seven rows, most important on top. The square on the left: grey quiet, green normal, orange attention, red serious, teal good news (aurora visible). Then a short tag, what is happening with numbers, what to do, and in small print what it is based on: measured live, statistics, or reported and not proven.

24-hour strip. Top strip: wind speed as a line and Bz as fill, red fill means a southward field. Middle: Kp as 3-hour bars and a minute estimate line, dashed lines at 5 and 7. Bottom: Dst as steps; the minus 50 and minus 100 thresholds appear when the scale reaches them. Time in your zone.

How fresh the data is

Wind refreshes every minute, but the NOAA feed itself lags 5-10 minutes, which the header states as "data N min ago". The strip and impacts refresh every 5 minutes, tracking and the map every 10. If a source goes silent, the panel says so: "data delayed" or "unavailable", and never shows old data as new.

Glossary

Kp

planetary index of geomagnetic activity, 0..9 per 3-hour interval, from a network of observatories. 0-3 quiet, 4 unsettled, 5 and above a storm (G1), 7 severe (G3), 9 extreme (G5). The main scale in news and forecasts.

Dst

the strength of the ring current around Earth in nanotesla, from the Kyoto observatory. The deeper the negative, the stronger the storm: minus 50 moderate, minus 100 severe, minus 250 and below extreme (May 2024 reached about minus 400).

Bz

the vertical part of the interplanetary magnetic field. Positive: pointing north, the magnetosphere is closed. Negative: south, the fields reconnect and wind energy enters. The single most important sign of a storm in the next hour.

V

solar wind speed, km/s. Usually 300-450, fast streams 500-700, ejections can carry 1000 and more. The faster, the harder the hit and the shorter the warning.

N

wind density, particles per cubic centimetre. Usually 3-8. The pile-up ahead of an ejection front compresses the magnetosphere, which gives a field jump on the ground.

Newell

the Newell formula that folds speed and field into one measure of how much energy enters the magnetosphere. On the board it is scaled to 0..100: usually about 3, tens during a storm.

dB/dt

the rate of change of the magnetic field at a station, nT per minute. This is the quantity that induces currents in long conductors: power lines, pipelines, rails. Quebec 1989 went dark at values in the hundreds.

GIC

geomagnetically induced currents, quasi-direct currents in grids and pipelines driven by field changes. They heat transformers, upset protection relays and speed up corrosion.

L1

the Lagrange point between the Sun and the Earth, 1.5 million km from us, where solar wind probes sit (currently SWFO-L1, earlier DSCOVR and ACE). The wind takes 30-60 minutes from there to Earth, which is the length of the warning.

CME

coronal mass ejection, a cloud of plasma with a magnetic field thrown off by the Sun. It takes 15 hours to 3 days to reach Earth. The main cause of severe storms. Whether it is aimed at Earth is seen in coronagraphs and models, but arrival accuracy is plus or minus 6-10 hours.

Flare

a solar flare, a burst of X-rays. Classes by strength: A, B, C, M, X, each ten times the previous. The X-rays arrive in 8 minutes and knock out HF radio on the day side; the ejection, if any, comes one to three days later.

G, R, S

NOAA scales: G geomagnetic storms (from Kp), R radio blackouts (from flare X-rays), S radiation storms (from protons). Each from 1 to 5.

OVATION

the NOAA model that draws aurora probability across the Earth 30-90 minutes ahead from the solar wind. On the map it is the fill; "oval down to N degrees" means there is almost no chance south of that latitude.

TEC

total electron content of the ionosphere. Its jumps degrade satellite navigation accuracy. TEC maps are not connected to the board yet; the navigation level is derived from Kp and Dst.

UTC

universal time, which all space data lives in. The board converts it to your zone and shows UTC alongside so you can cross-check with the sources.

Further

Where the data comes from, with what delay, and what the forecast can and cannot do: on How it works. The site change history: What is new.