Message:22801 In: SPACWX.USA
From: N4SDDate: Thu, 21 May 26 00:32:00 Z
Newsgroups: SPACWX.USA
Subject: Space Weather 3-Day Forecast
Message-ID: <13777_N4SD>
Path: N2MH4|N3MEL|KA3VSP|N4SD
R:260521/0243Z 31505@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260521/0243Z 17578@N3MEL.#EPA.PA.USA.NOAM LinBPQ6.0.25
R:260521/0225Z 2321@KA3VSP.DE.USA.NOAM BPQ6.0.25
R:260521/0032Z 13777@N4SD.#TIDE.VA.USA.NOAM BPQ6.0.24
FXXX10 KWNP 210031
DAYTDF
:Product: 3-Day Forecast
:Issued: 2026 May 21 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 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for May 21-May 23 2026 is 3.67 (below NOAA
Scale levels).
NOAA Kp index breakdown May 21-May 23 2026
May 21 May 22 May 23
00-03UT 2.67 2.67 2.33
03-06UT 3.67 3.00 2.67
06-09UT 2.33 2.00 2.33
09-12UT 2.00 1.67 1.67
12-15UT 1.67 0.67 1.67
15-18UT 2.33 1.67 2.00
18-21UT 2.33 2.33 2.33
21-00UT 3.00 2.67 2.33
Rationale: No G1 (Minor) or greater geomagnetic storms are expected.
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 21-May 23 2026
May 21 May 22 May 23
S1 or greater 5% 5% 5%
Rationale: No S1 (Minor) or greater solar radiation storms are expected.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for May 21-May 23 2026
May 21 May 22 May 23
R1-R2 20% 25% 25%
R3 or greater 5% 5% 5%
Rationale: There is a slight chance for R1-R2 (Minor-Moderate) radio
blackouts on 21 May, increasing to a chance on 22-23 May due to regions
anticipated to rotate onto the visible disk in that interval.
------
73 de Sperry N4SD
N4SD@N4SD.#TIDE.VA.USA.NOAM
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