985
FXXX12 KWNP 190031
DAYDIS

:Product: Forecast Discussion
:Issued: 2024 May 19 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. Region 3679 (S08W07,
Eho/beta-gamma) developed additional intermediate spots, and was
responsible for the largest flare of the period, a C7.2/1n flare at
18/0538 UTC, as well as a few low level C-class flares. Region 3685
(S13E42, Ehi/beta-gamma) continued to show weak development in its
intermediate spots, but was far less active this period. Slight growth
was observed in Region 3674 (S12W27, Csi/beta) and Region 3683 (S23W46,
Dsi/beta). Region 3683 popped off a C3.9/Sf flare at 18/2016 UTC, while
Region 3674 remained inactive. The remaining regions were either stable
or slightly decaying.

.Forecast...
Solar activity is expected to be low with M-class flares
(R1-R2/Minor-Moderate) likely and a chance for an X-class flare
(R3/Strong or greater) on 19-21 May.

Energetic Particle

.24 hr Summary...
The greater than 10 MeV proton flux was slightly elevated, but well
below S1 (Minor) levels. The 2 MeV electron flux was at normal to
moderate levels.

.Forecast...
There is a slight chance for the greater than 10 MeV protons reaching S1
(Minor) levels on 19-21 May due to the flare potential of Region 3685.
The greater than 2 MeV electron flux is expected to remain at normal to
moderate levels, with a chance for high levels, through 21 May.

Solar Wind

.24 hr Summary...
Solar wind parameters gradually returned to near-background levels as
effects from the 14 May CME arrival relinquished. Total field decreased
from a peak of 17 nT to near 6 nT, Bz had a maximum southward deflection
to -15 nT but has since become positive, and solar wind speeds have
leveled off around 410 km/s. Phi angle was mostly negative until
approximately 18/1100 UTC when it switched to a positive orientation.

.Forecast...
Solar wind parameters are expected to continue near background levels
early on 19 May. By mid to late day, the solar wind environment is
expected to see the influences of the passing CME from 16 May.
Additional enhancements are then expected on 20 May as the CME from 17
May scrapes the Earths magnetosphere. Conditions should begin to return
to a more relaxed state on 21 May as CME influence tapers off.

Geospace

.24 hr Summary...
Geomagnetic activity was quiet to unsettled, with an isolated active
period.

.Forecast...
Quiet to unsettled levels are expected early on 19 May before increasing
to mostly active conditions, with a chance for isolated G1 levels, as
the CME from 16 May is expected to graze the Earth. By 20 May, unsettled
to active levels are expected, with G1 (Minor) storming likely, due to
glancing CME effects from the 17 May CME. Mid to late day on 21 May,
active levels are expected to decrease to mostly unsettled levels as CME
effects gradually diminish.