Aurora Outlook and Prediction for Tok, Alaska

Aurora Visibility31Fair

Kp: 2 | Bz: -9.42

Prediction38Weak Activity

Current Conditions: Little to no aurora activity in Tok. Geomagnetic conditions are quiet. Skies are clear.

Predicted Outlook: Weak aurora activity currently. Faint auroras possible from high-latitude locations under dark skies.

Best Viewing Window: 10:40 PM – 5:20 AM AKDT (6h 40m)

Bz -9.42 nT Aurora Weak Nautical Twilight Clear · 11% Prediction 38 · Weak Activity Waning Gibbous 95% Color Key

Space Weather Now

Kp (now)

Forecast Kp (today)

3.67

Bz (nT)

-9.42

HPI

7 Minimal

Dst (nT)

-35

Density (p/cc)

16.2

Speed (km/s)

419

Sky / Darkness

Clear Nautical Twilight

Sunspot Number

Timing: Now · Confidence: High

Webcam

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3-Day Forecast for Tok, Alaska

Tonight's forecast peaks at Kp 3.7, and Tok 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.

Aug 29

Active

Some activity possible - aurora may be visible at higher latitudes.

Best time to look up: 10:00 PM–1:00 AM AKDT

40% chance of elevated activity · Kp 3.67 during viewing window

Aug 30

Quiet

Low chance of aurora - geomagnetic activity is expected to stay quiet.

Best time to look up: 10:00 PM–1:00 AM AKDT

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

Aug 31

Quiet

Low chance of aurora - geomagnetic activity is expected to stay quiet.

Best time to look up: 10:00 PM–1:00 AM AKDT

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

Aurora Oval & Satellite & Sun

Aurora Probability

LowHigh

Interactive Aurora Globe

Full-size Aurora Globe

Satellite View

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National Weather Service

Sunspots

Current sunspot number: 73

SOHO

Coronal Mass Ejections

Space Weather Prediction Center

Solar Wind & IMF (GSM)

Bt: 10.8 nT
Bx: -4.8 nT
By: 2 nT
Bz: -9.42 nT
Clock Angle θ: -60.9°
Cone Angle φ: 157.8°
Speed: 419 km/s
Density: 16.2 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: -4.8 nT
By: 5.9 nT
Bz: -7.7 nT
θ Angle: -45°
φ Angle: 129.4°
Satellite: SOLAR-1
Data Quality: Good
Reading Time: Aug 29, 10:36 PM AKDT

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): 2
Dst: -35 nT
HPI: 7 GW
Sunspot Number: 73

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

Aurora Model

Ovation Value: 19
Ovation Label: Weak
Model Data Time: Aug 29, 11:31 PM AKDT
Ovation Data: Live

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

Scores & Ratings

Aurora Visibility: 31 · Fair
Aurora Visibility (w/ Moon): 31 · Fair
Prediction Score: 38 · Weak Activity

This page's three scores side by side - raw activity, moon/cloud-adjusted visibility, and the forecast.

Sky & Location

Cloud Cover: 11% · Clear
Solar Elevation: -10.7° · Nautical Twilight
Moon Phase: Waning Gibbous
Moon Illumination: 95%
Moon Altitude: 14.3° · Up
Latitude: 63.33667
Longitude: -142.98557
Geomagnetic Latitude: 65°
Horizon Threshold: Kp 1
Overhead Threshold: Kp 2

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): -3.1 nT
Newell Coupling: 15097
Dynamic Pressure: 4.8 nPa
Storm Watch (CME): —
Watch Predicted Kp: —

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

Timing & Confidence

Timing: Now
Confidence: High
L1 Delay: ~3580 min
Best Viewing Window: 10:40 PM – 5:20 AM AKDT (6h 40m)

How soon a solar wind change reaches Earth, how confident the model is right now, and today's best window to actually look up.

3-Day Kp Forecast

AKDT	Aug 30	Aug 31	Sep 01
4:00 PM–7:00 PM	2.67	1.67	1.67
7:00 PM–10:00 PM	3.67	2	1.33
10:00 PM–1:00 AM	3.67	1.67	1.67
1:00 AM–4:00 AM	2.67	1.67	1.33
4:00 AM–7:00 AM	1.67	1	1.33
7:00 AM–10:00 AM	1	1	1.33
10:00 AM–1:00 PM	1.67	0.67	1.33
1:00 PM–4:00 PM	2.67	2	1.67
Max	3.67	2	1.67
Ap Index	12	5	5

Storm Probability

Level	Aug 30	Aug 31	Sep 01
Active	40%	10%	10%
Minor storm	25%	1%	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

Aug 26

Aug 27

Aug 28

Aug 29

Now

Aug 30

Aug 31

Sep 1

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

Interplanetary Magnetic Field Bz-8.1 nT now

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

Total IMF Field Bt10.6 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.

Storm Trend40 now

Prediction score (0-100) over the last 24 hours, logged every 5 minutes. Red above 70, yellow 50-70, teal below 50 - same thresholds used everywhere else on this page. Dashed line is the overall trend.

Dst History-35 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: 406 km/s now Pressure: 3.9 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.

Related Northern Lights Pages

Aurora Outlook and Prediction for Tok, Alaska

Space Weather Now

Webcam