Message:22467 In: SPACWX.USA
From: N4SDDate: Sat, 16 May 26 12:32:00 Z
Newsgroups: SPACWX.USA
Subject: Space Weather 3-Day Forecast
Message-ID: <13348_N4SD>
Path: N2MH4|WB4WPF|KA3VSP|N4SD
R:260518/0132Z 31277@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260516/1907Z 12169@WB4WPF.#SFL.FL.USA.NOAM LinBPQ6.0.25
R:260516/1842Z 2096@KA3VSP.DE.USA.NOAM BPQ6.0.25
R:260516/1232Z 13348@N4SD.#TIDE.VA.USA.NOAM BPQ6.0.24
FXXX10 KWNP 161231
DAYTDF
:Product: 3-Day Forecast
:Issued: 2026 May 16 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 6 (NOAA Scale
G2).
The greatest expected 3 hr Kp for May 16-May 18 2026 is 5.67 (NOAA Scale
G2).
NOAA Kp index breakdown May 16-May 18 2026
May 16 May 17 May 18
00-03UT 5.67 (G2) 3.00 3.33
03-06UT 5.33 (G1) 4.67 (G1) 3.33
06-09UT 4.67 (G1) 3.33 2.00
09-12UT 3.67 3.00 2.00
12-15UT 4.00 3.00 3.00
15-18UT 4.00 3.67 3.33
18-21UT 4.67 (G1) 3.33 3.33
21-00UT 4.33 2.67 3.00
Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are likely on 16
May due to the CIR associated with a positive polarity CH HSS. G1
(Minor) storming levels are likely on 17 May due to the CH HSS
persistence.
B. NOAA Solar Radiation Activity Observation and Forecast
Solar radiation, as observed by NOAA GOES-19 over the past 24 hours, was
below S-scale storm level thresholds.
Solar Radiation Storm Forecast for May 16-May 18 2026
May 16 May 17 May 18
S1 or greater 5% 5% 5%
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 May 16-May 18 2026
May 16 May 17 May 18
R1-R2 30% 30% 25%
R3 or greater 1% 1% 1%
Rationale: There is a decreasing chance for R1-R2 (Minor-Moderate) radio
blackouts through 18 May due to the flare potential of the regions on
the Suns visible disk.
------
73 de Sperry N4SD
N4SD@N4SD.#TIDE.VA.USA.NOAM
Received via NOAA GOES-East satellite downlink
Return To Bulletin List