Important Disclaimer Notice

If you are looking for the official U.S. Government forecast for space weather, please go to NOAA's Space Weather Prediction Center ( This "Experimental Research Information" consists of preliminary NASA research products and should be interpreted and used accordingly.

Weekly Space Weather Report, April 18-24, 2012


## Message Type: Weekly Space Weather Summary Report for April 18, 2012 - April 24, 2012
## Message Issue Date: 2012-04-25T21:07:00Z
## Report Coverage Begin Date: 2012-04-18T00:00:00Z
## Report Coverage End Date: 2012-04-24T23:59:59Z
## Message ID: 20120425-7D-001

## Summary:

Solar activity was at moderate levels with only C and B-class flares. There were a few type C CMEs (500-1000km/s, see list below).

Geomagnetic activity was at low to moderate levels, with the Kp index (a measure of geomagnetic activity, ranging 0-9) <=6, but mostly between 2 and 3 throughout the week. The Kp index reached 6 (moderate storm, Activity ID 2012-04-24T00:00:00-GST-001, see alert 20120424-AL-001) on 2012-04-24T0:00Z to 03:00Z due to arrival of a CME (activity ID 2012-04-19T15:39:00-CME-001, see alert 20120420-AL-001). The arrival of interplanetary shock due to the CME arrival was observed by ACE at 2012-04-23T02:27Z. The flank of another CME caused Kp to increase again to 5 during 2012-04-24T21:00Z- 23:59Z.

The >0.8 MeV energetic electron flux at GEO increased remained below alert threshold levels (10^5 pfu) throughout the week.

There were no energetic proton events during the reporting period.

Space weather impact:

Spacecrafts in the path of the Earth directed CME (Activity ID 2012-04-23T18:09:00-CME-001, see alert 20120423-AL-001) could be impacted. Space weather impact is likely to have been small for the reporting week.

## Events:

Flares (M class and above):

CMEs (> 500 km/s):

Earth directed:
Starting time Speed (km/s) Direction (LON/LAT in HEE) Angular width (degrees) Detecting spacecraft (real-time)
2012-04-18T18:24Z ~ 500 25/-22 60 SOHO, STEREO B
2012-04-19T15:39Z ~ 650 -18/-28 50 STEREO A and B
2012-04-19T16:54Z ~ 535 -60/-34 64 STEREO A and B
2012-04-22T15:12 ~ 646 88/-46 78 SOHO, STEREO A and B
2012-04-23T18:09Z ~ 590 -13/-16 23 STEREO A and B
2012-04-24T08:12Z ~ 500 -60/10 30 STEREO A and B

Non-Earth directed:
Starting time Speed (km/s) Direction (LON/LAT in HEE) Angular width (degrees) Detecting spacecraft (real-time)
2012-04-18T02:48Z ~580 -147/12 48 SOHO, STEREO A, and B

2012-04-18T09:09Z ~700 -157/13 54 STEREO A and B

2012-04-18T14:54Z ~890 -158/10 44 STEREO A and B
2012-04-20T03:24Z ~600 175/13 76 SOHO, STEREO A and B

## Spacecraft Anomalies Reported to SWC:


## Space Weather Outlook:
## Outlook Coverage Begin Date: 2012-04-25T00:00:00Z
## Outlook Coverage End Date: 2012-05-01T23:59:59Z

The solar and geomagnetic activity is expected to be low to unsettled levels for the upcoming week.

## Notes:
Video versions of the weekly reports are available at

For questions, comments, requests etc. contact: GSFC-Space-Weather-Center

NASA's GSFC Space Weather Center provides information about space environment conditions using state-of-the-art observational as well as model/simulation data. Certain products are derived from combinations of existing data sets as well as the output from coupled models or model chains. Consequently, it is important to note that space weather products may be in experimental or evaluation phases of development or deemed research quality only. Space environment Information provided by the NASA GSFC Space Weather Center is “as is” and users assume all risks related to its use and interpretation. NASA, model developers, and all data resource providers disclaim any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will NASA, model developers, and any data resource provider be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this information.