Ausgestellt: 2018 May 23 0030 UTC
Erstellt von NOAA, Space Weather Prediction Center und verarbeitet SpaceWeatherLive.com
Solar activity remained at very low levels. Region 2710 (N17E52,
Bxo/beta) has been stable since rotating onto the disk. A long duration
B2 flare, followed by a B8 flare, were observed at 22/0507 UTC and
22/1459 UTC, respectively. Both of these events occurred from an area of
enhanced brightening beyond the E limb at about N13. This new region is
expected to rotate onto the visible disk on or about 25 May. No
Earth-directed CMEs were observed in available satellite imagery.
Solar activity is expected to remain very low with a chance for C-class
activity all three days (23-25 May). The chance for C-class activity is
due to potential flare activity from an unnumbered region beyond the NE
The greater than 2 MeV electron flux was at normal to moderate levels
with a peak flux of 954 pfu observed at 22/2025 UTC. The greater than 10
MeV proton flux remained at background levels.
The greater than 2 MeV electron flux is expected to be at expected to
increase to moderate to high levels all three days (23-25 May) due to an
enhanced solar wind environment associated with CH HSS effects. The
greater than 10 MeV proton flux is expected to continue at background
Solar wind parameters, as measured by the DSCOVR spacecraft, indicated a
nominal solar wind environment through 22/1110 UTC. Wind speeds averaged
about 300 km/s, total field ranged between 2-4 nT, the Bz component
varied between +1 nT to -4 nT and phi remained in a mostly negative
After 22/1110 UTC, a weak CIR in advance of the anticipated positive
polarity CH HSS, was observed. Wind speeds indicated a slight uptick to
about 325 km/s through about 22/1630 UTC and further increased to near
400 km/s through periods end. Total field ranged between 4-9 nT while
Bz varied between +/-7 nT. A SSBC from a negative to positive
orientation was observed at about 22/1640 UTC.
Solar wind parameters are expected to become further enhanced on day one
(23 May) as a positive polarity extension off the northern crown CH HSS
becomes geoeffective. Based on STEREO-A PLASTIC data, wind speeds are
anticipated to increase to near 500 km/s through day two (24 May). By
day three (25 May), wind parameters are expected to slowly weaken as the
CH HSS moves out of a geoeffective position.
The geomagnetic field was at quiet levels.
The geomagnetic field is expected to be at predominately quiet to
unsettled conditions, with isolated active intervals, on days one and
two (23-24 May) under positive polarity CH HSS influence. By day three
(25 May), geomagnetic conditions are expected to taper off to
predominately quiet levels with isolated unsettled conditions early.