National Weather Service United States Department of Commerce

Areas of Severe Thunderstorms and Excessive Rainfall through This Weekend

Severe thunderstorms are expected across portions of the central into southern Plains into Sunday, with large hail and severe gusts the main threats. The threat for heavy to excessive rainfall and possible flash flooding will return to the south-central U.S. Friday into this weekend. Read More >

Plaese go to the Space Weather Prediction Center for more information.
Items in grey italics apparently are older than 24 hours


471
WOXX13 KWNP 210141
WARK04

Space Weather Message Code: WARK04
Serial Number: 4972
Issue Time: 2025 May 21 0138 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 21 0138 UTC
Valid To: 2025 May 21 1200 UTC
Warning Condition: Onset
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.

# Issued by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Recent messages, data, and help at http://swpc.noaa.gov/alerts/
# Send questions to SWPC.Webmaster@noaa.gov



840
WOXX11 KWNP 172101
WARK05

Space Weather Message Code: WARK05
Serial Number: 2045
Issue Time: 2025 May 17 2055 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2044
Valid From: 2025 May 17 0050 UTC
Now Valid Until: 2025 May 18 1200 UTC
Warning Condition: Persistence
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.

# Issued by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Recent messages, data, and help at http://swpc.noaa.gov/alerts/
# Send questions to SWPC.Webmaster@noaa.gov



741
WOXX12 KWNP 171156
WARK06

Space Weather Message Code: WARK06
Serial Number: 581
Issue Time: 2025 May 17 1152 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 580
Valid From: 2025 May 17 0052 UTC
Now Valid Until: 2025 May 17 1800 UTC
Warning Condition: Persistence
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.

# Issued by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Recent messages, data, and help at http://swpc.noaa.gov/alerts/
# Send questions to SWPC.Webmaster@noaa.gov