Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
089
FXXX10 KWNP 151231
DAYTDF
:Product: 3-Day Forecast
:Issued: 2025 May 15 1230 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 May 15-May 17 2025 is 4.00 (below NOAA
Scale levels).
NOAA Kp index breakdown May 15-May 17 2025
May 15 May 16 May 17
00-03UT 3.00 2.33 3.33
03-06UT 4.00 2.33 2.00
06-09UT 2.67 2.33 2.00
09-12UT 2.00 1.67 3.00
12-15UT 2.00 2.33 3.00
15-18UT 2.67 2.33 3.67
18-21UT 3.67 2.00 3.33
21-00UT 3.00 2.33 3.33
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 May 15-May 17 2025
May 15 May 16 May 17
S1 or greater 10% 5% 5%
Rationale: There remains a slight chance for an S1 (Minor) solar
radiation storm on 15 May.
C. NOAA Radio Blackout Activity and Forecast
Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at May 14 2025 1811 UTC.
Radio Blackout Forecast for May 15-May 17 2025
May 15 May 16 May 17
R1-R2 65% 65% 65%
R3 or greater 30% 30% 30%
Rationale: Given the magnetic complexity of Region 4087, theres a 65%
chance that M-Class (R1-R2, Minor-Moderate) level flare activity will
occur through 17 May with a 30% chance for X-Class (R3-Strong) levels
during the same time.