National Weather Service United States Department of Commerce

Heat Wave Expands to the East Coast; Flash Flooding Likely in the Central Plains into the Midwest; Severe Thunderstorms in the Northeast

Dangerous, prolonged heat is ongoing in the Mid-South to Mid-Mississippi Valley and heat expands into the Northeast for a brief period today. Widely scattered instances of flash flooding due to heavy rains are forecast from northeast Kansas to much of Indiana. Scattered strong to severe thunderstorms are possible across parts of New England, northern Mid-Atlantic, and North Dakota. Read More >

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


464
WOXX13 KWNP 261745
WARK04

Space Weather Message Code: WARK04
Serial Number: 5048
Issue Time: 2025 Jul 26 1730 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Jul 26 1730 UTC
Valid To: 2025 Jul 27 0300 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



364
WOXX11 KWNP 231141
WARK05

Space Weather Message Code: WARK05
Serial Number: 2084
Issue Time: 2025 Jul 23 1136 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2083
Valid From: 2025 Jul 22 2051 UTC
Now Valid Until: 2025 Jul 23 1800 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



826
WOXX12 KWNP 222256
WARK06

Space Weather Message Code: WARK06
Serial Number: 598
Issue Time: 2025 Jul 22 2252 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2025 Jul 22 2252 UTC
Valid To: 2025 Jul 23 0600 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate
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