:Product: Weekly Highlights and Forecasts :Issued: 2004 Feb 10 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 02 - 08 February 2004 Solar activity ranged from very low to moderate levels. The period began at low levels with occasional C-class flares from Region 547 (S09, L=116, class/area Dai/150 on 03 February) and Region 551 (S06, L=024, class/area Eko/370 on 08 February). Region 549 (N14, L=049, class/area Eai/240 on 02 February) produced a C9/1f flare on 4 February with an associated 350 sfu Tenflare. A small CME was observed with this event, but it did not appear to be Earth directed. Low C-class activity continued through 05 February from Regions 547 and 549. Activity levels dropped to very low on 06 February. Low C-class activity from the SE limb on 07 February indicated that a new active region was rotating onto the visible disk. The new region was numbered 554 (S08, L=308, class/area Dkc/170 on 08 February) and was responsible for elevating activity levels to moderate on 08 February. This region was responsible for several C-class flares on the 8th, and produced an M1/Sf flare at 08/2051UTC. Solar wind data were available from the NASA Advanced Composition Explorer (ACE) spacecraft during most of the summary period. The period began quietly with solar wind speed at around 500 km/s, but quickly began an upward trend as a coronal hole rotated into a geoeffective position. Solar wind speed increased to over 650 km/s on 03 February and IMF Bz experienced occasional sustained southward periods. Solar wind speed was in gradual decline through 5 February before the onset of another high speed coronal hole stream. Solar wind speed increased to just over 600 km/s on 06 February, but began a slow decline late on the 6th to under 400 km/s by 08 February. The IMF Bz was mostly southward during this high speed stream. There were no greater than 10 MeV proton events at geosynchronous orbit during the summary period. There was a slight enhancement in the greater than 10 MeV protons following the C9 flare on 04 February. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels every day this period. The geomagnetic field ranged from quiet to major storm levels. Quiet to unsettled conditions early on 02 February quickly gave way to active to major storm periods following the onset of a high speed coronal hole stream. The storming was short-lived as quiet to unsettled levels with isolated active periods persisted from 03 February through 06 February. The disturbed periods were in response to moderately high speed solar wind and periods of sustained southward Bz. The geomagnetic field was predominantly quiet to unsettled on the 7th and 8th, as the high speed solar wind subsided. Forecast of Solar and Geomagnetic Activity 11 February - 08 March 2004 Solar activity is expected to range from very low to moderate levels. Regions 551 and 554 contain moderate complexity and size and have potential for low M-class activity during the first week of the period. Predominantly very low to low activity levels are expected from late February through early March as the active longitudes rotate out of view. No greater than 10 MeV proton event are expected during the period. The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 13 - 16 February, and again on 24 February – 05 March, due to recurrent coronal holes. Geomagnetic activity is expected to range from quiet to minor storm levels with a chance of isolated major storm levels. A coronal hole high speed stream will become geoeffective on 13 – 16 February and produce occasional active to minor storm conditions. Recurrent coronal hole high speed streams are expected by late February through early March and will likely produce occasional active to minor storm periods with isolated major storm periods possible.