121
FXXX12 KWNP 171334
DAYDIS

:Product: Forecast Discussion
:Issued: 2024 May 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
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#             Forecast Discussion
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Solar Activity

.24 hr Summary...
Solar activity decreased to low levels. The largest flare was a C8.7
from Region 3679 (S10E11, Eso/beta-gamma). Region 3685 (S13E57,
Dso/beta-gamma) continued to be the largest region on the disk as it
rotates into view. This region also contributed C-class activity during
the period. Another region has rotated onto the E limb just to the NE of
3685. It has yet to be assigned a SWPC/NOAA designation. Most of the
remaining spotted regions were in decay, while the rest were stable.

An erupting filament structure was observed in GONG HA imagery beginning
at approximately 16/1500 UTC near N10W32. A subsequent CME can be seen
first in LASCO C2 coronagraph imagery just before 16/1800 UTC. There
also appears to be a wave from the far side of the disk near this time.
Analysis and modeling of this event showed a glancing blow on the 20th.
However, confidence is low. Another narrow CME is being analyzed that
was first visible in C2 at 17/0428 UTC. It appeared to originate from
the trailer area of AR3679 and propagate east in GOES SUVI 284 imagery.
No other potentially Earth-directed CMEs were observed.

.Forecast...
Solar activity is expected to continue at moderate levels with a chance
for M-class flare activity (R1-2/Minor-Moderate radio blackouts) and a
slight chance for an isolated X-class flare event (R3 Strong radio
blackouts) through 19 May.

Energetic Particles

.24 hr Summary...
The greater than 10 MeV proton flux remains elevated, decreased below S1
(Minor) solar radiation storm levels at 16/1455 UTC. The 2 MeV
electron flux was at normal to moderate levels.

.Forecast...
The greater than 10 MeV proton flux is expected to gradually return to
near background levels over the course of 17-19 May. The greater than 2
MeV electron flux is expected to remain at normal to moderate levels
through 19 May.

Solar Wind

.24 hr Summary...
Solar wind parameters were indicative of waning CME influences. Total
field reached a peak of 10 nT. Bz reached a maximum southward deflection
of -7 nT. Solar wind speeds gradually decreased from ~450 km/s to ~380
km/s. Phi was variable.


.Forecast...
An additional enhancement is likely on 17 May due to the arrival of
glancing influences of a CME from 14 May. Solar wind parameters are
expected to slowly relax over the course of 18 May before yet another
enhancement is likely on 19 May, due to glancing influences of a CME
from 15 May.

Geospace

.24 hr Summary...
The geomagnetic field reached G1 (Minor) storm levels early in the
period, then were at quiet to unsettled levels during the remainder.

.Forecast...
Unsettled to active conditions are expected on 17 May due to glancing
CME effects from the 14 May CME. Quiet to unsettled levels are expected
on 18 May as any lingering effects weaken. Unsettled to active
conditions are expected once again on 19 May, this time due to glancing
CME effects from the 15 May CME. It should be noted that there is a
chance for isolated G1 (Minor) geomagnetic storming periods on 17 and 19
May due to any stronger than anticipated CME effects.