Message:20939 In: SPACWX.USA
From: N4SDDate: Thu, 16 Apr 26 12:31:00 Z
Newsgroups: SPACWX.USA
Subject: Space Weather 3-Day Forecast
Message-ID: <11269_N4SD>
Path: N2MH4|N3MEL|KA3VSP|N4SD
R:260416/1538Z 30300@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260416/1538Z 15800@N3MEL.#EPA.PA.USA.NOAM LinBPQ6.0.25
R:260416/1533Z 839@KA3VSP.DE.USA.NOAM BPQ6.0.25
R:260416/1231Z 11269@N4SD.#TIDE.VA.USA.NOAM BPQ6.0.24
FXXX10 KWNP 161231
DAYTDF
:Product: 3-Day Forecast
:Issued: 2026 Apr 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 2 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Apr 16-Apr 18 2026 is 6.00 (NOAA Scale
G2).
NOAA Kp index breakdown Apr 16-Apr 18 2026
Apr 16 Apr 17 Apr 18
00-03UT 0.67 2.33 6.00 (G2)
03-06UT 1.00 2.67 6.00 (G2)
06-09UT 1.00 2.67 5.00 (G1)
09-12UT 0.67 2.00 4.00
12-15UT 1.67 1.33 3.67
15-18UT 1.67 2.67 3.33
18-21UT 1.67 4.33 3.00
21-00UT 2.33 5.67 (G2) 4.33
Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are likely on 17-18
Apr due to the anticipated arrival of a negative polarity CH HSS CIR.
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 16-Apr 18 2026
Apr 16 Apr 17 Apr 18
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 16-Apr 18 2026
Apr 16 Apr 17 Apr 18
R1-R2 30% 30% 30%
R3 or greater 5% 5% 5%
Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
through 18 Apr, mostly due to the flare potential of Region 4419.
------
73 de Sperry N4SD
N4SD@N4SD.#TIDE.VA.USA.NOAM
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