NOAA SWPC Alerts, Watches and Warnings

The National Oceanic and Atmospheric Administration Space Weather Prediction Center (NOAA SWPC) is the official space weather government agency from the United States that provides alerts, watches and warning for space weather disturbances. Below you will find the latest space weather alerts, watches and warnings issued by the NOAA SWPC.

Wednesday, 24 April 2024

15:00 UTC

Space Weather Message Code: ALTTP4
Serial Number: 630
Issue Time: 2024 Apr 24 1500 UTC

ALERT: Type IV Radio Emission
Begin Time: 2024 Apr 24 1440 UTC



Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

14:32 UTC

Space Weather Message Code: ALTTP2
Serial Number: 1287
Issue Time: 2024 Apr 24 1432 UTC

ALERT: Type II Radio Emission
Begin Time: 2024 Apr 24 1415 UTC
Estimated Velocity: 800 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

Tuesday, 23 April 2024

19:16 UTC

Space Weather Message Code: ALTTP2
Serial Number: 1286
Issue Time: 2024 Apr 23 1916 UTC

ALERT: Type II Radio Emission
Begin Time: 2024 Apr 23 1710 UTC
Estimated Velocity: 358 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

03:57 UTC

Space Weather Message Code: SUM10R
Serial Number: 789
Issue Time: 2024 Apr 23 0357 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2024 Apr 23 0313 UTC
Maximum Time: 2024 Apr 23 0314 UTC
End Time: 2024 Apr 23 0315 UTC
Duration: 2 minutes
Peak Flux: 290 sfu
Latest Penticton Noon Flux: 227 sfu



Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

Monday, 22 April 2024

22:07 UTC

Space Weather Message Code: ALTTP2
Serial Number: 1285
Issue Time: 2024 Apr 22 2207 UTC

ALERT: Type II Radio Emission
Begin Time: 2024 Apr 22 2119 UTC
Estimated Velocity: 395 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

Sunday, 21 April 2024

23:06 UTC

Space Weather Message Code: WARK04
Serial Number: 4593
Issue Time: 2024 Apr 21 2306 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4592
Valid From: 2024 Apr 21 0500 UTC
Now Valid Until: 2024 Apr 22 0900 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

22:44 UTC

Space Weather Message Code: ALTTP2
Serial Number: 1284
Issue Time: 2024 Apr 21 2244 UTC

ALERT: Type II Radio Emission
Begin Time: 2024 Apr 21 2209 UTC
Estimated Velocity: 278 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

14:57 UTC

Space Weather Message Code: WARK04
Serial Number: 4592
Issue Time: 2024 Apr 21 1457 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4591
Valid From: 2024 Apr 21 0500 UTC
Now Valid Until: 2024 Apr 21 2359 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

14:56 UTC

Space Weather Message Code: ALTK04
Serial Number: 2440
Issue Time: 2024 Apr 21 1456 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2024 Apr 21 1455 UTC
Synoptic Period: 1200-1500 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

05:00 UTC

Space Weather Message Code: WARK04
Serial Number: 4591
Issue Time: 2024 Apr 21 0500 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 21 0500 UTC
Valid To: 2024 Apr 21 1500 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Friday, 19 April 2024

19:52 UTC

Space Weather Message Code: ALTK07
Serial Number: 140
Issue Time: 2024 Apr 19 1952 UTC

ALERT: Geomagnetic K-index of 7
Threshold Reached: 2024 Apr 19 1951 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: Yes
NOAA Scale: G3 - Strong

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.

19:51 UTC

Space Weather Message Code: WARK07
Serial Number: 100
Issue Time: 2024 Apr 19 1951 UTC

WARNING: Geomagnetic K-index of 7 or greater expected
Valid From: 2024 Apr 19 1950 UTC
Valid To: 2024 Apr 19 2359 UTC
Warning Condition: Onset
NOAA Scale: G3 or greater

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.

19:42 UTC

Space Weather Message Code: WARK06
Serial Number: 515
Issue Time: 2024 Apr 19 1940 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2024 Apr 19 1939 UTC
Valid To: 2024 Apr 19 2359 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

19:40 UTC

Space Weather Message Code: ALTK06
Serial Number: 553
Issue Time: 2024 Apr 19 1940 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2024 Apr 19 1935 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: Yes
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

19:40 UTC

Space Weather Message Code: WARK06
Serial Number: 515
Issue Time: 2024 Apr 19 1940 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2024 Apr 19 1939 UTC
Valid To: 2024 Apr 19 2359 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

19:20 UTC

Space Weather Message Code: ALTK05
Serial Number: 1570
Issue Time: 2024 Apr 19 1920 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2024 Apr 19 1915 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

17:55 UTC

Space Weather Message Code: WARK04
Serial Number: 4590
Issue Time: 2024 Apr 19 1755 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4589
Valid From: 2024 Apr 19 0650 UTC
Now Valid Until: 2024 Apr 20 0600 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

15:52 UTC

Space Weather Message Code: ALTK05
Serial Number: 1569
Issue Time: 2024 Apr 19 1552 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2024 Apr 19 1550 UTC
Synoptic Period: 1500-1800 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

14:16 UTC

Space Weather Message Code: WARK05
Serial Number: 1867
Issue Time: 2024 Apr 19 1416 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1866
Valid From: 2024 Apr 19 0900 UTC
Now Valid Until: 2024 Apr 19 2359 UTC
Warning Condition: persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

14:15 UTC

Space Weather Message Code: ALTK05
Serial Number: 1568
Issue Time: 2024 Apr 19 1415 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2024 Apr 19 1414 UTC
Synoptic Period: 1200-1500 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

09:00 UTC

Space Weather Message Code: WARK05
Serial Number: 1866
Issue Time: 2024 Apr 19 0900 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2024 Apr 19 0900 UTC
Valid To: 2024 Apr 19 1500 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

07:50 UTC

Space Weather Message Code: ALTK04
Serial Number: 2439
Issue Time: 2024 Apr 19 0750 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2024 Apr 19 0745 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

06:48 UTC

Space Weather Message Code: WARK04
Serial Number: 4589
Issue Time: 2024 Apr 19 0648 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 19 0650 UTC
Valid To: 2024 Apr 19 1800 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Tuesday, 16 April 2024

23:09 UTC

Space Weather Message Code: WARK06
Serial Number: 514
Issue Time: 2024 Apr 16 2309 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2024 Apr 16 2309 UTC
Valid To: 2024 Apr 17 0300 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

22:55 UTC

Space Weather Message Code: WARK05
Serial Number: 1865
Issue Time: 2024 Apr 16 2255 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1864
Valid From: 2024 Apr 16 1909 UTC
Now Valid Until: 2024 Apr 17 0600 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

22:54 UTC

Space Weather Message Code: WARK04
Serial Number: 4588
Issue Time: 2024 Apr 16 2254 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4587
Valid From: 2024 Apr 15 2306 UTC
Now Valid Until: 2024 Apr 17 0900 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

22:45 UTC

Space Weather Message Code: ALTK05
Serial Number: 1567
Issue Time: 2024 Apr 16 2245 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2024 Apr 16 2239 UTC
Synoptic Period: 2100-2400 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

21:23 UTC

Space Weather Message Code: WATA20
Serial Number: 998
Issue Time: 2024 Apr 16 2123 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
Apr 17: None (Below G1) Apr 18: G1 (Minor) Apr 19: None (Below G1)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

19:12 UTC

Space Weather Message Code: ALTK05
Serial Number: 1566
Issue Time: 2024 Apr 16 1912 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2024 Apr 16 1910 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

19:09 UTC

Space Weather Message Code: WARK05
Serial Number: 1864
Issue Time: 2024 Apr 16 1909 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2024 Apr 16 1909 UTC
Valid To: 2024 Apr 16 2359 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

14:24 UTC

Space Weather Message Code: WARK04
Serial Number: 4587
Issue Time: 2024 Apr 16 1424 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4586
Valid From: 2024 Apr 15 2306 UTC
Now Valid Until: 2024 Apr 16 2359 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

11:08 UTC

Space Weather Message Code: WARK05
Serial Number: 1863
Issue Time: 2024 Apr 16 1108 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2024 Apr 16 1108 UTC
Valid To: 2024 Apr 16 1500 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:56 UTC

Space Weather Message Code: WARK04
Serial Number: 4586
Issue Time: 2024 Apr 16 0556 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4585
Valid From: 2024 Apr 15 2306 UTC
Now Valid Until: 2024 Apr 16 1500 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

01:00 UTC

Space Weather Message Code: ALTK04
Serial Number: 2438
Issue Time: 2024 Apr 16 0100 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2024 Apr 16 0053 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Monday, 15 April 2024

23:06 UTC

Space Weather Message Code: WARK04
Serial Number: 4585
Issue Time: 2024 Apr 15 2306 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 15 2306 UTC
Valid To: 2024 Apr 16 0600 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Saturday, 13 April 2024

21:10 UTC

Space Weather Message Code: WATA20
Serial Number: 997
Issue Time: 2024 Apr 13 2110 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
Apr 14: G1 (Minor) Apr 15: G1 (Minor) Apr 16: None (Below G1)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Friday, 12 April 2024

21:12 UTC

Space Weather Message Code: WATA20
Serial Number: 996
Issue Time: 2024 Apr 12 2112 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
Apr 13: None (Below G1) Apr 14: G1 (Minor) Apr 15: None (Below G1)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Thursday, 11 April 2024

17:27 UTC

Space Weather Message Code: SUMXM5
Serial Number: 214
Issue Time: 2024 Apr 11 1727 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2024 Apr 11 1652 UTC
Maximum Time: 2024 Apr 11 1706 UTC
End Time: 2024 Apr 11 1711 UTC
X-ray Class: M5.4
Location: S15E90
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

17:14 UTC

Space Weather Message Code: ALTTP4
Serial Number: 629
Issue Time: 2024 Apr 11 1714 UTC

ALERT: Type IV Radio Emission
Begin Time: 2024 Apr 11 1659 UTC



Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

17:07 UTC

Space Weather Message Code: ALTXMF
Serial Number: 355
Issue Time: 2024 Apr 11 1707 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2024 Apr 11 1705 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

Tuesday, 9 April 2024

05:34 UTC

Space Weather Message Code: WARK04
Serial Number: 4584
Issue Time: 2024 Apr 09 0534 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 09 0533 UTC
Valid To: 2024 Apr 09 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Monday, 8 April 2024

05:21 UTC

Space Weather Message Code: WARK04
Serial Number: 4583
Issue Time: 2024 Apr 08 0521 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 08 0520 UTC
Valid To: 2024 Apr 08 1500 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Saturday, 6 April 2024

02:03 UTC

Space Weather Message Code: WARK04
Serial Number: 4582
Issue Time: 2024 Apr 06 0203 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 06 0205 UTC
Valid To: 2024 Apr 06 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Friday, 5 April 2024

18:06 UTC

Space Weather Message Code: WATA20
Serial Number: 995
Issue Time: 2024 Apr 05 1806 UTC

CANCEL WATCH: Geomagnetic Storm Category G1 Predicted
Cancel Serial Number: 994
Original Issue Time: 2024 Apr 02 1926 UTC

Comment: Conditions no longer meet watch criteria.

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:55 UTC

Space Weather Message Code: WARK04
Serial Number: 4581
Issue Time: 2024 Apr 05 0555 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4580
Valid From: 2024 Apr 04 1138 UTC
Now Valid Until: 2024 Apr 05 2359 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

00:02 UTC

Space Weather Message Code: ALTK04
Serial Number: 2437
Issue Time: 2024 Apr 05 0002 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2024 Apr 04 2359 UTC
Synoptic Period: 2100-0000 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Thursday, 4 April 2024

22:56 UTC

Space Weather Message Code: WARK04
Serial Number: 4580
Issue Time: 2024 Apr 04 2256 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4579
Valid From: 2024 Apr 04 1138 UTC
Now Valid Until: 2024 Apr 05 0600 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

11:39 UTC

Space Weather Message Code: WARK04
Serial Number: 4579
Issue Time: 2024 Apr 04 1139 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 04 1138 UTC
Valid To: 2024 Apr 04 2359 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Wednesday, 3 April 2024

02:10 UTC

Space Weather Message Code: WARK04
Serial Number: 4578
Issue Time: 2024 Apr 03 0210 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 03 0210 UTC
Valid To: 2024 Apr 03 0600 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Tuesday, 2 April 2024

19:26 UTC

Space Weather Message Code: WATA20
Serial Number: 994
Issue Time: 2024 Apr 02 1926 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
Apr 03: None (Below G1) Apr 04: G1 (Minor) Apr 05: G1 (Minor)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

11:03 UTC

Space Weather Message Code: WARK04
Serial Number: 4577
Issue Time: 2024 Apr 02 1103 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 02 1102 UTC
Valid To: 2024 Apr 02 1800 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Monday, 1 April 2024

18:08 UTC

Space Weather Message Code: WATA20
Serial Number: 993
Issue Time: 2024 Apr 01 1808 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
Apr 02: None (Below G1) Apr 03: None (Below G1) Apr 04: G1 (Minor)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

08:03 UTC

Space Weather Message Code: ALTK04
Serial Number: 2436
Issue Time: 2024 Apr 01 0803 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2024 Apr 01 0803 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

07:39 UTC

Space Weather Message Code: WARK04
Serial Number: 4576
Issue Time: 2024 Apr 01 0739 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Apr 01 0740 UTC
Valid To: 2024 Apr 01 1500 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Sunday, 31 March 2024

02:00 UTC

Space Weather Message Code: ALTK04
Serial Number: 2435
Issue Time: 2024 Mar 31 0200 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2024 Mar 31 0158 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

01:48 UTC

Space Weather Message Code: WARK04
Serial Number: 4575
Issue Time: 2024 Mar 31 0148 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2024 Mar 31 0147 UTC
Valid To: 2024 Mar 31 1800 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Saturday, 30 March 2024

22:24 UTC

Space Weather Message Code: SUMXM5
Serial Number: 213
Issue Time: 2024 Mar 30 2224 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2024 Mar 30 2101 UTC
Maximum Time: 2024 Mar 30 2116 UTC
End Time: 2024 Mar 30 2215 UTC
X-ray Class: M9.4
Location: S13W88
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

21:16 UTC

Space Weather Message Code: ALTXMF
Serial Number: 354
Issue Time: 2024 Mar 30 2116 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2024 Mar 30 2114 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

Thursday, 28 March 2024

23:37 UTC

Space Weather Message Code: SUMXM5
Serial Number: 212
Issue Time: 2024 Mar 28 2112 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2024 Mar 28 2029 UTC
Maximum Time: 2024 Mar 28 2056 UTC
End Time: 2024 Mar 28 2101 UTC
X-ray Class: X1.1
Optical Class: 3b
Location: S14W61
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

21:12 UTC

Space Weather Message Code: SUMXM5
Serial Number: 212
Issue Time: 2024 Mar 28 2112 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2024 Mar 28 2029 UTC
Maximum Time: 2024 Mar 28 2056 UTC
End Time: 2024 Mar 28 2101 UTC
X-ray Class: X1.1
Optical Class: 3b
Location: S14W61
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

20:45 UTC

Space Weather Message Code: ALTXMF
Serial Number: 353
Issue Time: 2024 Mar 28 2045 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2024 Mar 28 2041 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

16:33 UTC

Space Weather Message Code: SUMXM5
Serial Number: 211
Issue Time: 2024 Mar 28 1633 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2024 Mar 28 1540 UTC
Maximum Time: 2024 Mar 28 1556 UTC
End Time: 2024 Mar 28 1603 UTC
X-ray Class: M6.1
Optical Class: 1n
Location: S13W56
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

16:00 UTC

Space Weather Message Code: ALTXMF
Serial Number: 352
Issue Time: 2024 Mar 28 1600 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2024 Mar 28 1556 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

06:45 UTC

Space Weather Message Code: SUMXM5
Serial Number: 210
Issue Time: 2024 Mar 28 0645 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2024 Mar 28 0616 UTC
Maximum Time: 2024 Mar 28 0629 UTC
End Time: 2024 Mar 28 0636 UTC
X-ray Class: M7.0
Location: S13W52
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

06:29 UTC

Space Weather Message Code: ALTXMF
Serial Number: 351
Issue Time: 2024 Mar 28 0629 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2024 Mar 28 0627 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

Tuesday, 26 March 2024

02:51 UTC

Space Weather Message Code: WARK04
Serial Number: 4574
Issue Time: 2024 Mar 26 0251 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4573
Valid From: 2024 Mar 23 0415 UTC
Now Valid Until: 2024 Mar 26 0900 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

01:30 UTC

Space Weather Message Code: SUMPX1
Serial Number: 110
Issue Time: 2024 Mar 26 0130 UTC

SUMMARY: Proton Event 10MeV Integral Flux exceeded 10pfu
Begin Time: 2024 Mar 23 0815 UTC
Maximum Time: 2024 Mar 23 1820 UTC
End Time: 2024 Mar 25 1515 UTC
Maximum 10MeV Flux: 956 pfu
NOAA Scale: S2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Monday, 25 March 2024

19:12 UTC

Space Weather Message Code: WARK04
Serial Number: 4573
Issue Time: 2024 Mar 25 1912 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4572
Valid From: 2024 Mar 23 0415 UTC
Now Valid Until: 2024 Mar 26 0300 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.