Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
641
FXXX10 KWNP 180031
DAYTDF
:Product: 3-Day Forecast
:Issued: 2025 Nov 18 0030 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# http://www.swpc.noaa.gov/wwire.html
#
# 3-Day Forecast
#
A. NOAA Geomagnetic Activity Observation and Forecast
The greatest observed 3 hr Kp over the past 24 hours was 4 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Nov 18-Nov 20 2025 is 3.67 (below NOAA
Scale levels).
NOAA Kp index breakdown Nov 18-Nov 20 2025
Nov 18 Nov 19 Nov 20
00-03UT 3.67 2.67 3.00
03-06UT 3.67 2.00 2.33
06-09UT 3.00 2.33 2.00
09-12UT 2.67 2.33 1.67
12-15UT 2.33 2.33 1.33
15-18UT 2.33 2.33 1.33
18-21UT 2.33 2.33 2.00
21-00UT 2.00 2.67 2.33
Rationale: No G1 (Minor) or greater geomagnetic storms are expected. No
significant transient or recurrent solar wind features are forecast.
B. NOAA Solar Radiation Activity Observation and Forecast
Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was
below S-scale storm level thresholds.
Solar Radiation Storm Forecast for Nov 18-Nov 20 2025
Nov 18 Nov 19 Nov 20
S1 or greater 1% 1% 1%
Rationale: No S1 (Minor) or greater solar radiation storms are expected.
No significant active region activity favorable for radiation storm
production is forecast.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for Nov 18-Nov 20 2025
Nov 18 Nov 19 Nov 20
R1-R2 15% 15% 15%
R3 or greater 1% 1% 1%
Rationale: A slight chance for R1-2 (Minor-Moderate) radio blackouts due
to isolated M-class flare activity will persit through 20 Nov due to the
flare potential presented by AR 4284.