852
FXXX12 KWNP 090031
DAYDIS

:Product: Forecast Discussion
:Issued: 2024 May 09 0030 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 reached very high levels. Region 3663 (N26W70,
Fkc/beta-gamma) exhibited signs of decay as it approached the western
limb, and appears to be losing its delta configuration. However, this
region continued to produce multiple M-class flares, as well as an X1.0
flare early in the period at 08/0141 UTC, and another X1 flare that
peaked at 08/2140 UTC.

Region 3664 (S19W24, Fkc/beta-gamma-delta) continued to grow and evolve,
eventually merging with Region 3668 (S15W13). This new combined spot
group will maintain the 3664 region designation, and is now over 1,760
millionths in size. This region was responsible for an X1.0 flare at
08/0509 UTC. The X flare was accompanied by Type II and IV sweeps and a
10.7 cm radio burst. A halo CME associated with this event is first
visible in C2 imagery near 08/0600 UTC. Additionally, Region 3664
produced an M8.6 flare at 08/1204 UTC, with an associated CME first
visible in C2 imagery at 08/1224 UTC. Modeling of the two CMEs indicated
that the second CME, with an estimated speed of nearly 800 km/s, will
likely overtake the first CME, which had an estimated speed 715 km/s.
The arrival time of the combined CMEs is anticipated to be late on 10
May to early on 11 May.

The remaining spotted active regions were stable or in gradual decay and
primarily inactive.

Other activity included an approximately 35 long filament that erupted,
centered near E27N18, with an associated CME, mostly moving in a
northeasterly direction. Analysis and modeling of this event is
currently underway.

.Forecast...
Solar activity is expected to persist at high to very high levels over
09-11 May, with M-class flares (R1-R2/Minor-Moderate) expected and
X-class flares (R3/Strong) likely, due to the continued flare potential
of Region 3663 and especially Region 3664.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux was at normal to moderate levels
and the greater than 10 MeV proton flux was steady at background levels.

.Forecast...
The greater than 2 MeV electron flux is expected to continue at normal
to moderate levels over 09-11 May. There is a chance for the greater
than 10 MeV proton flux to reach S1 (Minor) storm levels over 09-11 May
due to the flare potential of Regions 3663 and 3664.

Solar Wind

.24 hr Summary...
The solar wind environment reflected near-background conditions, with
the exception of slightly elevated solar wind speeds, likely attributed
to residual CH HSS influence. Total field strength was steady near 3
nT, the Bz component had no significant southward deflections, Phi
remained in a positive orientation, and solar wind speeds averaged near
470 km/s.

.Forecast...
Possible enhancements in the solar wind environment are likely on 09
May, following the anticipated glancing effects of a CME that departed
the Sun on 06 May. Late on 10 May and into 11 May, stronger enhancements
are likely as the two CMEs that departed the Sun on 08 May are
anticipated to arrive at Earth.

Geospace

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

.Forecast...
Mid to late day on 09 May, unsettled to active conditions are possible
as glancing effects from a CME that departed the Sun on 06 May are
anticipated to influence Earth. By late on 10 May, the two halo CMEs
from 8 May are anticipated to arrive at Earth, increasing the
geomagnetic response to G1 (Minor) storm levels. Early on 11 May,
conditions are likely to reach G2 (Mod) storm levels, with a chance for
G3 (Strong) levels, as the bulk of the CME moves past Earth. While
confidence in timing is fairly high, confidence in magnitude/strength of
the geomagnetic response to the CME arrival is low to moderate.