Aurora Forecast and Prediction for Harstad, Troms, Norway

Did you mean: Härstad, Västra Götaland County, Sweden?

Aurora Visibility1Poor

Kp: 0.33 | Bz: 1.4

Prediction28Weak Activity

Current Conditions (as of 23:07 CET): Weak aurora activity in Harstad. Geomagnetic conditions are quiet. Overcast skies will likely block any aurora view.

Predicted Outlook (23:07 – 06:42 CET): Weak aurora activity currently. Faint auroras possible from high-latitude locations under dark skies.

Best Viewing Window: 23:07 – 06:42 CET (7h 35m) · peak hours typically 20:17 – 00:17

Bz 1.4 nT Aurora Weak Dark Night Overcast · 86% Prediction 28 · Weak Activity Full Moon 100% Color Key

Space Weather Now

Kp (now)

0.33

Forecast Kp (tonight)

Bz (nT)

1.4

HPI

9 Minimal · 18 GW

Dst (nT)

Density (p/cc)

3.6

Speed (km/s)

346

Sky / Darkness

Overcast Dark Night

Sunspot Number

Timing: Now

Webcam

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3-Day Forecast for Harstad, Troms, Norway

Tonight's forecast peaks at Kp 3, and Harstad needs about Kp 1 for the aurora to clear the northern horizon - so this is a promising night. It may even appear high overhead rather than just low on the northern horizon.

Oct 25

Global: Active Harstad: Likely overhead

Kp 3 is enough to bring the aurora high overhead at Harstad, not just low on the northern horizon.

Global: Moderate planetary activity expected - aurora across the high-latitude zone, and lower with a good substorm.

Best time to look up: 22:00–01:00 CET

35% chance of elevated activity · Kp 3 during viewing window

Oct 26

Global: Quiet Harstad: Likely overhead

Kp 2.3 is enough to bring the aurora high overhead at Harstad, not just low on the northern horizon.

Global: Quiet planetary conditions expected - aurora mostly confined to the far north.

Best time to look up: 22:00–01:00 CET

30% chance of elevated activity · Kp 2.33 during viewing window

Oct 27

Global: Quiet Harstad: Likely overhead

Kp 1.7 is enough to bring the aurora high overhead at Harstad, not just low on the northern horizon.

Global: Quiet planetary conditions expected - aurora mostly confined to the far north.

Best time to look up: 22:00–01:00 CET

10% chance of elevated activity · Kp 1.67 during viewing window

Aurora Oval & Satellite & Sun

Aurora Probability

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Interactive Aurora Globe

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National Weather Service

Sunspots

Current sunspot number: 22

SOHO

Coronal Mass Ejections

Space Weather Prediction Center

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Nerd Mode

Solar Wind & IMF (GSM)

Bt: 4.1 nT
Bx: 1.6 nT
By: 3.5 nT
Bz: 1.4 nT
Clock Angle θ: 20.4°
Cone Angle φ: 65.7°
Speed: 346 km/s
Density: 3.6 p/cc

Real-time solar wind and interplanetary magnetic field, in geocentric solar magnetospheric (GSM) coordinates - the values the prediction model actually runs on.

IMF Detail (GSE) & Source

Bx: 1.6 nT
By: 3.1 nT
Bz: 2.1 nT
θ Angle: 30.2°
φ Angle: 63.5°
Satellite: SOLAR-1
Data Quality: Good
Reading Time: Oct 25, 23:02 CET

The same magnetic field reading in geocentric solar ecliptic (GSE) coordinates, plus which satellite it came from and how fresh it is.

Geomagnetic Indices

Kp (now): 0.33
Dst: 10 nT
HPI: 9 GW
Sunspot Number: 22

Headline storm-activity indices - Kp (planetary), Dst (ring current), HPI (hemispheric power), and today's sunspot count.

Aurora Model

Ovation Value: 17
Ovation Label: Weak
Model Data Time: Oct 26, 00:07 CET
Ovation Data: Live

NOAA's OVATION Prime output - how far south the aurora oval is likely to extend right now.

Scores & Ratings

Aurora Visibility: 1 · Poor
Aurora Visibility (w/ Moon): 1 · Poor
Prediction Score: 28 · Weak Activity

This page's scores side by side - Aurora Visibility (activity adjusted for cloud and darkness), the same with a moonlight factor (switched off, so identical), and the Prediction score for right now.

Sky & Location

Cloud Cover: 86% · Overcast
Clouds, Next Dark Window: 80% · Mostly Cloudy · ×0.50
Aurora Visibility Tonight: 16 · Poor (Outlook Tonight 32 × cloud 0.50)
Solar Elevation: -33.3° · Dark Night
Moon Phase: Full Moon
Moon Illumination: 100%
Moon Altitude: 36.4° · Up
Latitude: 68.79833
Longitude: 16.54165
Geomagnetic Latitude: 67°
Horizon Threshold: Kp 1
Overhead Threshold: Kp 1

Local sky and moon conditions - what actually turns the raw aurora score into a real visibility score for this spot.

Prediction Model Inputs

Bz Persistence (60min): 0.4 nT
Newell Coupling: 1330
Latitude Gate: 0.73 now · 1.00 tonight (horizon Kp 0, verdict rounds to Kp 1)
Dynamic Pressure: 0.7 nPa
Storm Watch (CME): —
Watch Predicted Kp: —

The individual weighted inputs - Bz persistence, coupling, pressure, CME timing - that combine into the Prediction score.

Timing & Signal Agreement

Timing: Now
Signal Agreement: Low (2 of 7)
: Do the live inputs point the same way as the score? A score lifted by this city's own Kp can read Low while the solar wind is calm.
L1 Delay: ~72 min
Magnetic Midnight: 22:17 (peak hours 20:17 – 00:17)
Best Viewing Window: 23:07 – 06:42 CET (7h 35m)

How soon a solar wind change reaches Earth, whether the model's inputs agree with each other, and today's best window to actually look up.

3-Day Kp Forecast

UT slot (CET)	Oct 25 UT	Oct 26 UT	Oct 27 UT
00–03 UT (02:00–04:00)	2	3	1.67
03–06 UT (04:00–07:00)	3	2	1.33
06–09 UT (07:00–10:00)	3	2	1.33
09–12 UT (10:00–13:00)	3.33	2	1.33
12–15 UT (13:00–16:00)	4	2	1.33
15–18 UT (16:00–19:00)	3.33	2	1.33
18–21 UT (19:00–22:00)	4	2	1.67
21–00 UT (22:00–01:00)	3	2.33	1.67
Max	4	3	1.67
Ap Index	18	8	5

Columns are NOAA's UT days, so in CET a column's last rows run past local midnight into the next day.

Storm Probability

Level	Oct 25 UT	Oct 26 UT	Oct 27 UT
Active	35%	30%	10%
Minor storm	25%	5%	1%
Moderate storm	10%	1%	1%
Strong-Extreme storm	1%	1%	1%

NOAA SWPC's official 3-day Kp forecast and geomagnetic storm probability - an independent second opinion alongside this page's own real-time model.

Planetary K-index

Oct 22

Oct 23

Oct 24

Oct 25

Now

Oct 26

Oct 27

Quiet (Kp 0-3) Unsettled (Kp 4) Minor-Moderate Storm (Kp 5-6) Strong+ Storm (Kp 7-9) Forecast (hatched)

Interplanetary Magnetic Field Bz1.4 nT now

Southward (negative) Bz favors aurora. Observed data only, no forecast product exists for Bz.

Total IMF Field Bt4.1 nT now

Total interplanetary magnetic field strength - the ceiling on how negative Bz can go. A rising Bt alongside a still-fluctuating Bz often leads a stronger southward turn. Observed data only, no forecast product exists for Bt.

Global Storm Trend11 global now

Global (hemisphere-wide, not this city) prediction score over the last 24 hours, logged every 5 minutes - may differ from the Prediction ring above, which is specific to this location and time of night. Red from 60 (Strong), yellow from 40 (Moderate), teal below - the same cutoffs as the Prediction ring. Dashed line is the overall trend.

Dst History10 nT now

Kyoto Dst geomagnetic storm index over the last 24 hours. Negative = ring-current energy stored = an active storm, not just predicted. Red below −50nT, yellow −20 to −50nT, teal above −20nT.

Solar Wind Speed & Pressure

Speed: 346 km/s now Pressure: 0.7 nPa now

Each line is scaled independently to its own 24h range (different units) - watch the shape, not a shared axis. A rising speed line or a pressure spike can signal an incoming stream or shock before Bz/Dst move.

24-hour trend charts for the values above, so you can see whether conditions are building or fading.

Nerd Mode: See what’s really driving the score. Live solar wind, Bz, Kp, Dst, CME timing, and more. Data comes from NOAA SWPC and the Kyoto WDC, with a few metrics calculated here from the raw data. Live data refreshes every minute; trend charts every five.

Aurora Forecasts for Nearby Cities

Checking conditions somewhere else tonight? These are the closest cities with their own northern lights prediction.

Narvik 54 km
Svolvær 102 km
Abisko 105 km
Tromsø 134 km
Kiruna 184 km
Bodø 191 km
Alta 294 km
Hammerfest 344 km

Debug / Test Data

UTC: 2026-10-25 22:07:36

Variable	Value
Geo
locale (GET)	harstad
pred_city	Harstad
pred_region	Troms
pred_lat	68.79833 68.79833° N
pred_lon	16.54165 16.54165° E
pred_tz	Europe/Oslo
Cloud Cover (Open-Meteo)
cloud_pct	86%
cloud_cover	overcast
cloud_mult	0.05 (5%)
Sky Darkness
dark_elev	-33.33°
dark_label	Dark Night
dark_mult	1.00 (100%)
Space Weather
cKp (current)	0.33
bz (nT)	1.4
speed (km/s)	346
day1_max Kp	4
day2_max Kp	3
day3_max Kp	1.67
Aurora Score 0–4 None · 5–19 Weak · 20–49 Nearby · 50–100 Overhead
ovation_val	17 (Weak)
ovation_time	2026-10-25T23:07:00Z
space_score	17
Space Weather
bz_score	0%
bz_bar	43% (visual)
kp_score	4.7%
fcst_score	57.1%
Visibility Score 0.15×Ovation + 0.55×Bz + 0.30×Kp
activity_score	24
Aurora Visibility Visibility Score × cloud × darkness
× cloud_mult	0.05 (Overcast)
× dark_mult	1.00 (Dark Night)
aurora_score	1 (Poor)
Aurora Visibility Tonight Outlook Tonight × cloud (dark window) × 1.0
pred_score_tonight	32 (Weak Activity)
× cloud_mult_tonight	0.50 (Mostly Cloudy 80%)
aurora_score_tonight	16 (Poor)
Cache Freshness * = per-request, no cron
Kp Index _kps/	fresh 34s / 60s
Bz / RTSW outlook/	fresh 20s / 60s
Solar Wind outlook/	fresh 19s / 60s
Sunspots _kps/	fresh 19.4h / 24h
Ovation Aurora outlook/	stale 6m / 5m
3-Day Geomag ^* outlook/	fresh 6m / 1h
GeoIP DB geoip/	fresh 14.5h / 168h
geo (newest) ^* outlook/geo/	fresh 16s / 24h
wx (newest) ^* outlook/wx/	fresh 0s / 20m
Image Cache /_files/_dynamic/_images/ · cron every 15m
Ovation North	fresh 34s / 15m
Ovation South	fresh 34s / 15m
Sat - Alaska	fresh 34s / 15m
Sat - N. America	fresh 33s / 15m
Sat - N. Atlantic	fresh 33s / 15m
Sat - Europe	fresh 31s / 15m
Sat - Australia	stale 4.1h / 15m
Sat - S. America	fresh 33s / 15m

Legend

Visibility Rating (aurora_score /100)
Poor	0–29	Little chance of seeing aurora
Fair	30–49	Possible under ideal conditions
Good	50–69	Good chance if skies clear
Excellent	70–100	Strong aurora likely visible

Ovation Label (0–100 scale)
None	0–4	No aurora activity at location
Weak	5–19	Faint aurora, auroral oval nearby
Nearby	20–49	Aurora active, oval edge overhead
Overhead	50–100	Aurora directly overhead

Cloud Cover Multiplier (cloud_pct %)
Clear	0–25%	× 1.00
Partly Cloudy	26–50%	× 0.85
Mostly Cloudy	51–85%	× 0.50
Overcast	86–100%	× 0.05
Unknown	—	× 0.60

Label	Elev.	Mult	Setting	Rising
Daytime	≥ 3°	× 0.00	Sun above horizon. Check back after sunset.	Sun well above horizon. Aurora viewing is over.
Appr. Civil	0–3°	× 0.00	Sunset imminent. Watch for aurora soon.	Approaching sunrise. Aurora window closing.
Civil Twilight	−4–0°	× 0.10	Too bright yet. Darkness improving.	Brightening. Last chance to catch aurora.
Appr. Nautical	−6–−4°	× 0.10	Sky darkening. Faint aurora may be visible.	Sky brightening. Window narrowing.
Nautical Twilight	−12–−6°	× 0.50	Sky darkening. Bright aurora may be visible.
Astronomical Twilight	−18–−12°	× 0.85	Near-dark sky. Good aurora viewing conditions.
Dark Night	< −18°	× 1.00	Full darkness. Optimal aurora viewing.

Debug output - remove before production

Related Northern Lights Pages

Aurora Forecast and Prediction for Harstad, Troms, Norway

Space Weather Now

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3-Day Forecast for Harstad, Troms, Norway

Oct 25

Oct 26

Oct 27

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Sunspots

Coronal Mass Ejections

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Nerd Mode

Solar Wind & IMF (GSM)

IMF Detail (GSE) & Source

Geomagnetic Indices

Aurora Model

Scores & Ratings

Sky & Location

Prediction Model Inputs

Timing & Signal Agreement

3-Day Kp Forecast

Storm Probability

Planetary K-index

Interplanetary Magnetic Field Bz1.4 nT now

Total IMF Field Bt4.1 nT now

Global Storm Trend11 global now

Dst History10 nT now

Solar Wind Speed & Pressure

Aurora Forecasts for Nearby Cities

Debug Panel ▾

Debug / Test Data

Legend

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