Message:20995 In: SPACWX.USA
From: N4SDDate: Fri, 17 Apr 26 12:32:00 Z
Newsgroups: SPACWX.USA
Subject: Space Weather 3-Day Forecast
Message-ID: <11346_N4SD>
Path: N2MH4|WB4WPF|KA3VSP|N4SD
R:260417/1850Z 30335@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260417/1839Z 10441@WB4WPF.#SFL.FL.USA.NOAM LinBPQ6.0.25
R:260417/1836Z 882@KA3VSP.DE.USA.NOAM BPQ6.0.25
R:260417/1232Z 11346@N4SD.#TIDE.VA.USA.NOAM BPQ6.0.24
FXXX10 KWNP 171231
DAYTDF
:Product: 3-Day Forecast
:Issued: 2026 Apr 17 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 1 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Apr 17-Apr 19 2026 is 6.00 (NOAA Scale
G2).
NOAA Kp index breakdown Apr 17-Apr 19 2026
Apr 17 Apr 18 Apr 19
00-03UT 0.67 6.00 (G2) 5.00 (G1)
03-06UT 0.67 6.00 (G2) 4.67 (G1)
06-09UT 2.67 5.00 (G1) 4.00
09-12UT 2.00 4.00 3.33
12-15UT 1.33 3.67 3.67
15-18UT 2.67 3.33 3.00
18-21UT 4.33 3.00 3.00
21-00UT 5.67 (G2) 4.33 3.33
Rationale: G2 (Moderate) geomagnetic storms are likely on 17-18 Apr due
to the anticipated CH HSS influences. G1 (Minor) storming levels are
likely on 19 Apr as the CH HSS influences wanes.
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 Apr 17-Apr 19 2026
Apr 17 Apr 18 Apr 19
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 Apr 17-Apr 19 2026
Apr 17 Apr 18 Apr 19
R1-R2 25% 25% 25%
R3 or greater 5% 5% 5%
Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
through the 19 Apr mostly due to the flaring potential of Region 4419.
------
73 de Sperry N4SD
N4SD@N4SD.#TIDE.VA.USA.NOAM
Received via NOAA GOES-East satellite downlink
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