Message ID: 20260422-7D-001
Issue Time: 2026-04-22T14:12Z
Message Body: ## Community Coordinated Modeling Center Database Of Notifications, Knowledge, Information (CCMC DONKI)
## Message Type: Weekly Space Weather Summary Report for April 15, 2026 - April 21, 2026
##
## Message Issue Date: 2026-04-22T14:12:07Z
## Report Coverage Begin Date: 2026-04-15T00:00Z
## Report Coverage End Date: 2026-04-21T23:59Z
## Message ID: 20260422-7D-001
##
## Disclaimer: NOAA's Space Weather Prediction Center is the United States Government official source for space weather forecasts. This "Experimental Research Information" consists of preliminary NASA research products and should be interpreted and used accordingly.
## Summary:
Solar activity was at low to moderate levels during this reporting period. There were 7 C-type CMEs (see details below).
Based on preliminary analysis by the Moon to Mars Space Weather Analysis Office and heliospheric modeling carried out at NASA Community Coordinated Modeling Center, it was estimated that the following CMEs were predicted to impact missions near Earth:
CME Starting time | Predicted Impacts (plus minus 7 hours)
-----------------------------------------------------------------------------
2026-04-16T09:00Z NASA missions near Earth at at 2026-04-18T14:00Z (glancing blow), Kp index 3-5 (below minor to minor)
(see notification 20260416-AL-001).
The arrival of this CME was not detected at L1.
It was also estimated that the following CMEs were predicted to impact the listed locations:
CME Starting time | Predicted Impacts (plus minus 7 hours)
-----------------------------------------------------------------------------
2026-04-15T11:53Z Mars at 2026-04-19T02:24Z, Parker Solar Probe at 2026-04-17T03:54Z, Psyche at 2026-04-19T07:02Z, BepiColombo at 2026-04-16T11:00Z (glancing blow), Solar Orbiter at 2026-04-17T18:00Z (glancing blow) (see notification 20260415-AL-002).
2026-04-16T09:00Z Europa Clipper at 2026-04-21T06:00Z (glancing blow), OSIRIS-APEX at 2026-04-19T04:00Z (glancing blow), STEREO A at 2026-04-19T05:00Z (glancing blow) (see notification 20260416-AL-001).
Geomagnetic activity was at moderate levels with Kp index (a measure of geomagnetic activity, ranging 0-9) <= 5.67 for the reporting period. The highest value of Kp = 5.67 occurred during the nonconcurrent synoptic periods of 2026-04-18T06:00Z to 2026-04-18T09:00Z and 2026-04-19T06:00Z to 2026-04-19T09:00Z (see notifications 20260418-AL-001, 20260418-AL-002, 20260419-AL-001). This enhancement in geomagnetic activity was associated with the arrival of a coronal hole high speed stream detected at L1 by ACE on 2026-04-18.
The > 2.0 MeV energetic electron flux detected at GOES was elevated above the threshold level of 1000 pfu at the beginning of the reporting period due to a threshold crossing from a previous reporting period starting at 2026-04-10T13:55Z (see notifications 20260411-AL-001, 20260413-AL-001, 20260415-AL-001, 20260417-AL-001). This elevation of energetic electron flux levels was likely associated with the arrival of a coronal hole high speed stream detected at L1 by ACE and DSCOVR on 2026-04-10. The fluxes returned to background levels on 2026-04-18.
The >2.0 MeV energetic electron flux levels crossed the threshold of 1000 pfu again at 2026-04-19T14:00Z (see notifications 20260419-AL-002, 20260421-AL-001). This subsequent elevation of energetic electron flux levels was likely associated with the arrival of a coronal hole high speed stream detected at L1 by ACE on 2026-04-18. The energetic electron flux levels remained elevated through the end of the reporting period.
The energetic proton flux of >10 MeV protons detected at GOES and the 13-100 MeV protons at STEREO A were all at background levels for the entire reporting period.
Space Weather Impact:
Space weather impacts on NASA spacecraft are expected to have been moderate this reporting period due to the elevated energetic electron flux in the Earth's outer radiation belt described above.
##Events:
Flares (M-class and above)
Date Start Stop Peak Class Location
None Observed
CMEs (>500 km/s):
Earth directed:
Starting time Speed (km/s) Type Direction (LON/LAT in HEEQ) Half-Angle width (degrees) Detecting spacecraft (real-time)
2026-04-16T09:00Z ~677 C 22/-9 16 SOHO, STEREO A, GOES
Non-Earth directed (POS = Plane Of Sky):
Starting time Speed (km/s) Type Direction (LON/LAT in HEEQ) Half-Angle width (degrees) Detecting spacecraft (real-time)
2026-04-15T01:26Z ~602 C 86/-39 10 SOHO, STEREO A, GOES
2026-04-15T11:53Z ~880 C 143/12 32 STEREO A, SOHO, GOES
2026-04-19T16:38Z ~709 C -35/13 16 STEREO A
2026-04-20T02:36Z ~674 C NONE(POS)/9 10 SOHO
2026-04-21T02:12Z ~751 C 112/-51 10 SOHO, STEREO A, GOES
2026-04-21T10:23Z ~596 C -24/60 18 STEREO A, GOES
## Space Weather Outlook:
## Outlook Coverage Begin Date: 2026-04-22T00:00Z
## Outlook Coverage End Date: 2026-04-28T23:59Z
Solar activity is expected to vary between low to moderate levels during the outlook period. There are currently four numbered Active Regions on the Earth-facing disk.
Geomagnetic activity is expected to vary between low to moderate levels during the outlook period. Two coronal holes centered around S18W10 and N23E05 (as seen in available EUV imagery from SDO/AIA 193) may become geoeffective on or around 2026-04-24 and 2026-04-27 respectively. The energetic electron flux levels at GOES mentioned above exceeded the threshold of 1000 pfu at 2026-04-19T14:00Z and may continue to be elevated during the outlook period.
## Notes:
SCORE CME typification system:
S-type: CMEs with speeds less than 500 km/s
C-type: Common 500-999 km/s+
O-type: Occasional 1000-1999 km/s
R-type: Rare 2000-2999 km/s
ER-type: Extremely Rare >3000 km/s
URL: View Details
Message ID: 20260421-AL-001
Issue Time: 2026-04-21T15:32Z
Message Body: ## Community Coordinated Modeling Center Database Of Notifications, Knowledge, Information ( CCMC DONKI )
## Message Type: Space Weather Notification - Continued Radiation Belt Enhancement
##
## Message Issue Date: 2026-04-21T15:32:54Z
## Message ID: 20260421-AL-001
##
## Disclaimer: NOAA's Space Weather Prediction Center is the United States Government official source for space weather forecasts. This "Experimental Research Information" consists of preliminary NASA research products and should be interpreted and used accordingly.
## Summary:
Significantly elevated energetic electron fluxes in the Earth's outer radiation belt. GOES "greater than 2.0 MeV" integral electron flux remains elevated, recently crossing the threshold of 1000 pfu at 2026-04-21T13:15Z.
The elevated energetic electron flux levels observed since 2026-04-19T14:00Z are caused by a coronal hole high speed stream starting on 2026-04-18, reaching maximum sustained speeds of approximately 570 km/s. The solar wind speed observed at L1 is currently around 517 km/s.
NASA spacecraft at GEO, MEO and other orbits passing through or in the vicinity of the Earth's outer radiation belt can be impacted.
Activity ID: 2026-04-19T14:00:00-RBE-001.
## Notes:
This coronal hole high speed stream is also associated with the moderate geomagnetic storm with ID 2026-04-18T06:00:00-GST-001 (see notifications 20260418-AL-001, 20260418-AL-002, 20260419-AL-001).
URL: View Details