Message:22420 In: SPACWX.USA
From: N4SDDate: Fri, 15 May 26 12:31:00 Z
Newsgroups: SPACWX.USA
Subject: Space Weather Forecast Discussion
Message-ID: <13268_N4SD>
Path: N2MH4|N3MEL|KA3VSP|N4SD
R:260515/1315Z 31238@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260515/1315Z 17131@N3MEL.#EPA.PA.USA.NOAM LinBPQ6.0.25
R:260515/1307Z 2041@KA3VSP.DE.USA.NOAM BPQ6.0.25
R:260515/1231Z 13268@N4SD.#TIDE.VA.USA.NOAM BPQ6.0.24
FXXX12 KWNP 151231
DAYDIS
:Product: Forecast Discussion
:Issued: 2026 May 15 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
#
# Forecast Discussion
#
Solar Activity
.24 hr Summary...
Solar activity remained at low levels, with C-class flares coming from
all three active regions on disk and also from the west limb. Region
4436 (N19W06, Cao/beta) was the source of the largest flare of the day:
a long duration C5.1/Sf peaking at 14/1821 UTC (that represented the
second peak of a complex flare initiated with emissions from the west
limb). Region 4438 (N20W50, Dao/beta) showed significant growth during
the period and was responsible for most part of the B- and C-class
flares observed. The X-ray background level decreased during the period,
as the contribution of the region beyond the west limb diminished as the
Sun rotates.
Multiple CMEs were observed in the coronagraph imagery during the past
24h. At least three of them had their sources identified in the visible
solar disk and their propagation path is currently under analysis: a
filament centered near N40W50 lifted off around 14/1230 UTC, another
filament with one of its feet anchored near S50W50 lifted off around
15/0100 UTC, and a filament disappearance followed a C3.3 flare at
15/0309 UTC from Region 4436 (also associated with type-III radio
sweeps).
.Forecast...
Solar activity is expected to remain predominately at low levels with a
chance for M-class (R1-R2/Minor-Moderate) flares through 17 May.
Energetic Particle
.24 hr Summary...
The greater than 2 MeV electron flux was at normal to moderate levels.
The greater than 10 MeV proton flux was at background levels.
.Forecast...
The greater than 2 MeV electron flux is expected to remain at moderate
levels through 16 May, potentially reaching high levels on 17 May. The
greater than 10 MeV proton flux is expected to stay at background levels
through 17 May.
Solar Wind
.24 hr Summary...
The solar wind parameters indicated the end of the positive polarity CH
HSS influences near Earth, with Phi angle sharply transitioning from
positive to predominately negative sector values after 14/1950 UTC.
Around 15/0530 UTC, the first signs of the anticipated CIR associated
with a negative polarity CH HSS were observed: speeds increased from 400
km/s up to about 600 km/s by the end of the period and the total
interplanetary magnetic field strength increased to above 10 nT levels.
The north-south Bz component reached as south as -10 nT around 15/1010
UTC.
.Forecast...
Solar wind parameters are expected to continued to be disturbed through
17 May due to the onset and persistence of the negative polarity CH HSS
influences.
Geospace
.24 hr Summary...
The geomagnetic field was quiet to unsettled during the period.
.Forecast...
G2 (Moderate) storming conditions are likely on 15 May due to the
ongoing impact of a CIR associated with a negative polarity CH HSS.
Active to G1 (Minor) storm levels are likely to prevail on 16-17 May due
to lingering CH HSS influences.
------
73 de Sperry N4SD
N4SD@N4SD.#TIDE.VA.USA.NOAM
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