Northern lights in Alaska tonight
The aurora reaches Alaska at about any night the sky is dark and clear in the far north of the state and Kp 6.5 at its southern edge. SWPC's highest forecast Kp over the next three days is 2, in the 03-06 UTC block on Mon, Sep 21. Worth going out. The forecast Kp of 2 is above the Kp 0 this place needs, so an aurora should be within reach low on the northern horizon.
From NOAA’s Space Weather Prediction Center, read Sep 20, 23:14 UTC.
The oval right now
NOAA’s OVATION model: the chance of aurora overhead 30 to 90 minutes from now, valid Sep 21, 00:19 UTC. Green is a low chance, red a high one.
Rain and snow mean cloud, and cloud is the last thing between a forecast aurora and the sky you are standing under. Each town page carries that town’s own sky cover forecast for the dark hours.
Open the live map with the aurora forecast
Aurora forecast from NOAA’s Space Weather Prediction Center. Original at SWPC
Tonight at Prudhoe Bay
The most poleward town in Alaska with a page, and the first place in the state an aurora reaches. Cloud cover is on each town’s own page.
Likely tonight
Worth going out. The forecast Kp of 2 is above the Kp 0 this place needs, so an aurora should be within reach low on the northern horizon.
- The aurora reaches this place at about any night the sky is dark and clear, which is 70 degrees geomagnetic latitude on NOAA's storm scales.
- SWPC forecasts a highest Kp of 2 (2.00) during tonight's dark hours: quiet.
Towns best placed in Alaska
The 24 most poleward of the 121 towns in Alaska with a page. Each page gives tonight’s chance there, the darkness, the moon and that town’s own cloud forecast.
- Prudhoe BayNorth Slope County · population 2,174 · 70.5° geomagneticany night the sky is dark and clear
- UtqiagvikNorth Slope County · population 4,384 · 70.1° geomagneticany night the sky is dark and clear
- WainwrightNorth Slope County · population 580 · 69.0° geomagneticany night the sky is dark and clear
- Fort YukonYukon-Koyukuk County · population 570 · 67.6° geomagneticany night the sky is dark and clear
- Point HopeNorth Slope County · population 701 · 66.0° geomagneticany night the sky is dark and clear
- Pleasant ValleyFairbanks North Star County · population 725 · 65.8° geomagneticany night the sky is dark and clear
- NoatakNorthwest Arctic County · population 514 · 65.8° geomagneticany night the sky is dark and clear
- Two RiversFairbanks North Star County · population 719 · 65.8° geomagneticany night the sky is dark and clear
- Farmers LoopFairbanks North Star County · population 4,853 · 65.7° geomagneticKp 0.2
- CollegeFairbanks North Star County · population 12,964 · 65.7° geomagneticKp 0.3
- FairbanksFairbanks North Star County · population 32,325 · 65.6° geomagneticKp 0.3
- BadgerFairbanks North Star County · population 19,482 · 65.6° geomagneticKp 0.3
- North PoleFairbanks North Star County · population 2,189 · 65.6° geomagneticKp 0.3
- Moose CreekFairbanks North Star County · population 747 · 65.6° geomagneticKp 0.3
- South Van HornFairbanks North Star County · population 558 · 65.6° geomagneticKp 0.3
- EsterFairbanks North Star County · population 2,422 · 65.6° geomagneticKp 0.3
- Eielson Air Force BaseFairbanks North Star County · population 2,647 · 65.6° geomagneticKp 0.3
- SalchaFairbanks North Star County · population 1,095 · 65.5° geomagneticKp 0.4
- NoorvikNorthwest Arctic County · population 694 · 65.4° geomagneticKp 0.5
- SelawikNorthwest Arctic County · population 859 · 65.4° geomagneticKp 0.5
- Big DeltaSoutheast Fairbanks County · population 591 · 65.3° geomagneticKp 0.6
- KotzebueNorthwest Arctic County · population 3,277 · 65.2° geomagneticKp 0.6
- Delta JunctionSoutheast Fairbanks County · population 929 · 65.2° geomagneticKp 0.6
- Fort GreelySoutheast Fairbanks County · population 539 · 65.2° geomagneticKp 0.7
Every town in Alaska with a page
121 towns at 48 degrees geomagnetic latitude or higher, which a strong storm reaches. The figure after each is the Kp it takes there.
A
B
- Badger Kp 0.3
- Bear Creek Kp 4.2
- Bethel Kp 5.1
- Big Delta Kp 0.6
- Big Lake Kp 3.2
- Buffalo Soapstone Kp 2.9
- Butte Kp 3
C
D
- Delta Junction Kp 0.6
- Deltana Kp 0.7
- Diamond Ridge Kp 4.8
- Dillingham Kp 5.3
- Dutch Harbor Kp 6.5
E
- Eagle River Kp 3.3
- Eielson Air Force Base Kp 0.3
- Elmendorf Air Force Base Kp 3.3
- Emmonak Kp 4.1
- Ester Kp 0.3
F
- Fairbanks Kp 0.3
- Farm Loop Kp 3
- Farmers Loop Kp 0.2
- Fishhook Kp 2.9
- Fort Greely Kp 0.7
- Fort Yukon any night the sky is dark and clear
- Fox River Kp 4.6
- Fritz Creek Kp 4.8
- Funny River Kp 4.1
G
H
- Haines Kp 3.1
- Happy Valley Kp 4.7
- Healy Kp 1.2
- Homer Kp 4.9
- Hoonah Kp 3.9
- Hooper Bay Kp 5.1
- Houston Kp 3.1
J
- Juneau Kp 3.7
K
- Kake Kp 4.7
- Kalifornsky Kp 4.2
- Kasigluk Kp 5.1
- Kasilof Kp 4.3
- Kenai Kp 4.1
- Ketchikan Kp 5.2
- King Cove Kp 6.2
- Kipnuk Kp 5.3
- Klawock Kp 5.2
- Knik River Kp 3.1
- Knik-Fairview Kp 3.1
- Kodiak Kp 5.3
- Kodiak Station Kp 5.4
- Kotlik Kp 3.8
- Kotzebue Kp 0.6
- Kwethluk Kp 5.1
L
- Lakes Kp 3
- Lazy Mountain Kp 3
M
- Meadow Lakes Kp 3
- Metlakatla Kp 5.2
- Moose Creek Kp 0.3
- Mountain Village Kp 4.5
N
- Naknek Kp 5.3
- New Stuyahok Kp 5.2
- Nikiski Kp 4
- Ninilchik Kp 4.6
- Noatak any night the sky is dark and clear
- Nome Kp 2.8
- Noorvik Kp 0.5
- North Pole Kp 0.3
- Nunapitchuk Kp 5.1
P
- Palmer Kp 3
- Petersburg Kp 4.7
- Pilot Station Kp 4.5
- Pleasant Valley any night the sky is dark and clear
- Point Hope any night the sky is dark and clear
- Point MacKenzie Kp 3.3
- Prudhoe Bay any night the sky is dark and clear
Q
- Quinhagak Kp 5.3
R
- Ridgeway Kp 4.1
S
- Salamatof Kp 4.1
- Salcha Kp 0.4
- Sand Point Kp 6.1
- Savoonga Kp 4.1
- Scammon Bay Kp 5
- Selawik Kp 0.5
- Seward Kp 4.2
- Shishmaref Kp 1.6
- Sitka Kp 4.8
- Skagway Kp 2.9
- Soldotna Kp 4.1
- South Van Horn Kp 0.3
- St. Mary's Kp 4.5
- Stebbins Kp 3.2
- Sterling Kp 4.1
- Susitna North Kp 2.7
- Sutton-Alpine Kp 2.9
T
- Talkeetna Kp 2.6
- Tanaina Kp 3
- Togiak Kp 5.4
- Tok Kp 0.8
- Toksook Bay Kp 5.2
- Two Rivers any night the sky is dark and clear
U
- Unalakleet Kp 2.7
- Unalaska Kp 6.5
- Utqiagvik any night the sky is dark and clear
V
- Valdez Kp 3
W
- Wainwright any night the sky is dark and clear
- Wasilla Kp 3.1
- Willow Kp 3
- Womens Bay Kp 5.4
- Wrangell Kp 4.9
Y
- Yakutat Kp 3.4
How far south each storm level reaches
NOAA’s space weather scales state the geomagnetic latitude each level of geomagnetic storm reaches, and the places its aurora has been seen from. The geographic latitudes are those lines converted with the geomagnetic dipole; the aurora sits low on the northern horizon there, and overhead far poleward of it.
| Storm | Geomagnetic | Central US | Eastern US | Northern Europe | NOAA says the aurora |
|---|---|---|---|---|---|
| G1 MinorKp 5 | 60° | 52°N | 51°N | 61°N | commonly visible at high latitudes: northern Michigan and Maine |
| G2 ModerateKp 6 | 55° | 47°N | 46°N | 56°N | has been seen as low as New York and Idaho |
| G3 StrongKp 7 | 50° | 42°N | 41°N | 51°N | has been seen as low as Illinois and Oregon |
| G4 SevereKp 8 | 45° | 37°N | 36°N | 45°N | has been seen as low as Alabama and northern California |
| G5 ExtremeKp 9 | 40° | 32°N | 31°N | 40°N | has been seen as low as Florida and southern Texas |
Source: NOAA space weather scales, swpc.noaa.gov/noaa-scales-explanation. Below Kp 5 the oval contracts more slowly; this section runs the line from 66 degrees geomagnetic at Kp 0 to the scale’s 60 degrees at Kp 5.
Kp by 3-hour block
SWPC’s planetary K index forecast, three days ahead. Kp is a single number for the whole planet, from magnetometers around the world, on a scale of 0 to 9 in thirds.
| Block (UTC) | Kp | Level | Seen from | Central US |
|---|---|---|---|---|
| 0.67 | Quiet | 65° geomag. | 57°N | |
| 1.67 | Quiet | 64° geomag. | 56°N | |
| 2.00 | Quiet | 64° geomag. | 55°N | |
| 1.67 | Quiet | 64° geomag. | 56°N | |
| 1.33 | Quiet | 64° geomag. | 56°N | |
| 0.67 | Quiet | 65° geomag. | 57°N | |
| 1.33 | Quiet | 64° geomag. | 56°N | |
| 1.33 | Quiet | 64° geomag. | 56°N | |
| 1.67 | Quiet | 64° geomag. | 56°N | |
| 1.67 | Quiet | 64° geomag. | 56°N | |
| 2.00 | Quiet | 64° geomag. | 55°N | |
| 1.67 | Quiet | 64° geomag. | 56°N | |
| 1.33 | Quiet | 64° geomag. | 56°N | |
| 0.67 | Quiet | 65° geomag. | 57°N | |
| 0.67 | Quiet | 65° geomag. | 57°N | |
| 1.67 | Quiet | 64° geomag. | 56°N | |
| 1.67 | Quiet | 64° geomag. | 56°N | |
| 1.67 | Quiet | 64° geomag. | 56°N |
The forecast is for the planet, not for your sky. A block at Kp 5 means the field is disturbed enough for the aurora to reach 60 degrees geomagnetic somewhere along the night side; whether you see it depends on being on the night side, on darkness, and on the clouds.
Other states with aurora pages
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New York
- North Dakota
- Ohio
- Oregon
- Pennsylvania
- Rhode Island
- South Dakota
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
What this means
Each place is placed by its geomagnetic latitude, measured from the geomagnetic dipole pole, and compared with the reach NOAA states for each storm level on its space weather scales: G1 (Kp 5) about 60 degrees geomagnetic, G2 55, G3 50, G4 45, G5 (Kp 9) 40. Reading that backwards gives the Kp a place needs. Below Kp 5 the oval contracts more slowly and the line runs from 66 degrees at Kp 0 to 60 at Kp 5.
The forecasts have different horizons and the pages keep them apart: OVATION is the only thing that knows whether an aurora is out now, and it reaches 30 to 90 minutes ahead; the planetary Kp forecast runs three days; the 27-day outlook names likely active days and is not a forecast of any one night. None of them knows the clouds, which is why a town page reads its own forecast for those.
Sources
From NOAA’s Space Weather Prediction Center: the OVATION aurora forecast, the planetary K index forecast, the 3-day forecast, the 27-day outlook, its watches, warnings and alerts, and the real-time solar wind. Read Sep 20, 23:14 UTC.