Message:22677 In: SPACWX.USA
From: N4SDDate: Wed, 20 May 26 12:31:00 Z
Newsgroups: SPACWX.USA
Subject: Space Weather 3-Day Forecast
Message-ID: <13720_N4SD>
Path: N2MH4|WB4WPF|KA3VSP|N4SD
R:260520/2127Z 31434@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260520/1411Z 12462@WB4WPF.#SFL.FL.USA.NOAM LinBPQ6.0.25
R:260520/1403Z 2298@KA3VSP.DE.USA.NOAM BPQ6.0.25
R:260520/1231Z 13720@N4SD.#TIDE.VA.USA.NOAM BPQ6.0.24
FXXX10 KWNP 201231
DAYTDF
:Product: 3-Day Forecast
:Issued: 2026 May 20 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 20-May 22 2026 is 3.67 (below NOAA
Scale levels).
NOAA Kp index breakdown May 20-May 22 2026
May 20 May 21 May 22
00-03UT 3.00 2.67 2.67
03-06UT 2.67 2.00 3.67
06-09UT 2.00 2.33 2.00
09-12UT 2.00 2.33 0.67
12-15UT 2.00 2.33 1.67
15-18UT 2.00 2.33 1.67
18-21UT 2.00 2.33 2.33
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-19 over the past 24 hours, was
below S-scale storm level thresholds.
Solar Radiation Storm Forecast for May 20-May 22 2026
May 20 May 21 May 22
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 20-May 22 2026
May 20 May 21 May 22
R1-R2 20% 20% 25%
R3 or greater 5% 5% 5%
Rationale: There is a slight chance for R1-R2 (Minor-Moderate) radio
blackouts through 21 May, increasing to a chance on 22 May. R3 (Strong)
or greater events are not expected.
------
73 de Sperry N4SD
N4SD@N4SD.#TIDE.VA.USA.NOAM
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