096
FXXX12 KWNP 101231
DAYDIS

:Product: Forecast Discussion
:Issued: 2024 May 10 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
#
Solar Activity

.24 hr Summary...
Solar activity was at high levels. The notably large Region 3664
(S17E41, Fkc/beta-gamma-delta) produced the vast majority of X-ray
activity this period. The most significant were an X1.1/2b flare
(R3/Strong) at 09/1744 UTC and an X3.9  flare (R3) at 10/0631 UTC.
Strong radio bursts, Castelli-U signatures as well as Type II and IV
radio sweeps and Tenflares were associated with both flares. Both events
produced halo CME signatures that are expected to contribute to a train
of at least five CMEs that inbound to Earth, with initial arrival likely
from late on 10 May to early on 11 May. The number of events along the
Sun-Earth line complicates the modeling process and has increased
uncertainty of arrival timing of any individual event.

The other numbered spotted regions on the visible disk were relatively
quiet and stable.

.Forecast...
Solar activity is expected to persist at high to very high levels over
10-12 May, with M-class flares (R1-R2/Minor-Moderate) to X-class flares
(R3/Strong) expected, due primarily to the flare potential of Region
3664.

Energetic Particle

.24 hr Summary...
The greater than 10 MeV proton flux remained slightly enhanced following
strong flare activity from Region 3664 but below the S1 (Minor)
threshold. The greater than 2 MeV electron flux was at normal to
moderate levels.

.Forecast...
The greater than 10 MeV proton flux is likely to reach S1 (Minor) storm
levels over 10-12 May due to the location and flare potential of Region
3664. The greater than 2 MeV electron flux is expected to be at normal
to moderate levels over 10-12 May.

Solar Wind

.24 hr Summary...
Nominal solar wind conditions prevailed throughout much of the period
with a minor perturbation observed in the magnetic field after 09/1730
UTC. Solar wind speeds decreased from initial readings near 450 km/s to
between 400-425 km/, total field strength ranged 1-7 nT, and the Bz
component varied +3/-6 nT. The phi angle transitioned from positive to
variable after 10/0300 UTC.

.Forecast...
A weakly enhanced solar wind environment associated with CME activity is
expected through most of 10 May. A stronger disturbances are expected in
over 11 May through much of 12 May due to the anticipated arrival of a
series of halo CMEs associated with activity from Region 3664 over 08-10
May.

Geospace

.24 hr Summary...
The geomagnetic field was quiet to unsettled.

.Forecast...
Periods of active conditions and G1 (Minor) storming are likely on 10
May with the possible early arrival of a series of CMEs (from 08-10
May). The bulk of the incoming CME(s) is expected to arrive early on 11
May with periods of G1-G2 (Minor-Moderate) geomagnetic storming
expected, and periods of G3-G4 (Strong-Severe) storms likely. Periods of
G1-G2 (Minor-Moderate) storms are likely on 12 May due to an enhanced
solar wind environment following the passage of the 08-10 May CMEs.