:Product: Weekly Highlights and Forecasts :Issued: 2004 Mar 09 2212 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Environment Center # Product description and SEC contact on the Web # http://www.sec.noaa.gov/weekly.html # # Weekly Highlights and Forecasts # Highlights of Solar and Geomagnetic Activity 01 - 07 March 2004 Solar activity levels ranged from very low to moderate with all of this period’s activity confined to just two regions. Region 567 (S12, L=070, class/area, Eac/160 on 04 March) produced six weak, impulsive C-class flares, the largest a C2.7/Sf on 06/0701 UTC. New Region 570 (S14, L=302, class/area, Ekc/570 on 07 March) rotated onto the disk on 05 March as a large, single Alpha spot and produced three low to moderate level C-class flares. Activity levels increased from low to moderate on 06 March as Region 570 produced four low-level C-class flares and one M-class flare, an M1.3 at 06/1217 UTC. This region has shown significant areal growth since first appearing on 05 March. Solar wind data were available from the NASA Advanced Composition Explorer (ACE) spacecraft during most of the summary period. The period began with solar wind velocities elevated at speeds between 625 – 725 km/s and speeds remained at these levels through 03 March. By 04 March, wind speeds began a gradual decline and decreased to just over 300 km/s by the end of the period. The elevated solar wind speeds at the beginning of the period were driven by a favorably positioned, recurrent coronal hole. The Bz component of the interplanetary magnetic field did not vary beyond +/- 5 nT for the entire period. There were no greater than 10 MeV proton events at geosynchronous orbit during the summary period. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels every day of the summary period. The geomagnetic field ranged from quiet to minor storm levels. Mostly quiet to active levels, with one isolated period of minor storming mid-day on 03 March, were observed during the period 01 - 03 March. This activity was due to a coronal hole driven high-speed solar wind stream. Quiet to unsettled levels occurred during the remainder of the summary period. Forecast of Solar and Geomagnetic Activity 10 March - 05 April 2004 Solar activity is expected to be at low to moderate levels through 18 March. From 19 – 31 March, predominantly very low to low levels are expected due to Region 570 rotating off the west limb. By 01 April, old Region 570 is due to return and as a result, low to moderate level activity is expected through the end of the forecast period. Greater than 10 MeV proton events are possible with significant flare activity from Region 570. The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 10 – 17 March, 22 – 23 March and again on 29 – 31 March due to recurrent coronal holes. Geomagnetic activity is expected to range from quiet to minor storm levels. A large, recurrent coronal hole high-speed stream is due to return on 09 – 14 March and is expected to produce active to minor storm conditions. A weak coronal hole high-speed stream is due to return on 19 – 20 March and is expected to produce quiet to active conditions. From 26 – 27 March, activity levels are expected to increase to active to minor storm levels as another small coronal hole high-speed stream rotates into geoeffective position.