791
FXXX12 KWNP 160031
DAYDIS

:Product: Forecast Discussion
:Issued: 2024 Sep 16 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 returned to low levels with only a few C-class flares
observed. Region 3824 (S04W26, Csi/beta-gamma) was the only numbered
region to exhibit slight growth during the period. Regions 3814 (N16W70,
Cso/beta), 3822 (N14W56, Cro/beta), 3825 (S15E35, Eai/beta-gamma) and
3826 (S28W31, Dri/beta) all observed either slight decay or were stable.
Region 3825 appeared to lose its weak delta magnetic configuration, and
only produced two of the C-class events. Region 3824 added the other
C-class flares, with the other regions remaining mostly inactive. No new
CMEs were observed in available coronagraph imagery.

.Forecast...
Solar activity is likely to be moderate with a slight chance for an
X-class flare on 16 Sep, and expected to be low with a chance for
M-class flares and a slight chance for an X-class flare on 17-18 Sep.

Energetic Particles

.24 hr Summary...
The greater than 2 MeV electron flux was at moderate to high levels with
a peak flux of 1,692 pfu at 15/1605 UTC. Elevated greater than 10 MeV
proton flux levels continued through the period, reaching a peak flux of
6.18 pfu at 15/1455 UTC.

.Forecast...
The greater than 2 MeV electron flux is expected to be at moderate to
high levels through midday on 16 Sep, with values likely decreasing to
normal to moderate levels following the anticipated arrival of the 13
and 14 Sep CMEs. There is a slight chance for the 10 MeV proton flux to
reach the S1 (Minor) solar radiation storm levels on 16 Sep due to
influence from the 14 Sep X4.5 flare event. Barring additional events,
probabilities should decrease somewhat on 17 Sep, after the arrival of
the 14 Sep CME, and continue to move towards background levels on 18
Sep.

Solar Wind

.24 hr Summary...
Solar wind parameters remained slightly enhanced, likely due to positive
polarity CH HSS influences. Total field averaged around 8 nT, the Bz
component was mostly negative, fluctuating between +/-7 nT, and solar
wind speeds averaged near 480 km/s. Phi was predominantly positive.

.Forecast...
Weak, but diminishing enhancements are anticipated to continue through
the first half of 16 Sep. Stronger enhancements are then expected by
midday with the anticipated arrival of the 13 and 14 Sep CMEs. Elevated
conditions are expected to continue through 17 Sep, eventually beginning
to subside by 18 Sep.

Geospace

.24 hr Summary...
The geomagnetic field was at quiet to active levels, likely the result
of continued +CH HSS influence.

.Forecast...
By midday on 16 Sep, the 13 Sep and 14 Sep CMEs are anticipated to
arrive and combine with the +CH HSS, likely increasing conditions to G3
(Strong) storm levels. Lingering CME/CH effects are anticipated to
persist into 17 Sep, with G2 (Moderate) geomagnetic storm conditions
likely, followed by a return to mostly active conditions on 18 Sep as
CME/CH effects diminish.