:Product: Weekly Highlights and Forecasts :Issued: 2002 Feb 19 2212 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Environment Center # For a descriptive text, or to contact SEC, refer to the Web page # http://www.sec.noaa.gov/weekly.html # # Weekly Highlights and Forecasts # Highlights of Solar and Geomagnetic Activity 11 - 17 February 2002 Solar activity was low through the period with isolated to occasional C-class flares. Sunspot groups of interest included Regions 9825 (N13, L = 206, Fkc/500 on 14 February) and 9830 (S20, L = 135, Fai/360 on 17 February). Region 9825 produced isolated C-class flares as it gradually developed during the first half of the period, then gradually decayed during the second half of the period (for flare details, please refer to the Optical Flares list) . Region 9830 produced C-class flares as it gradually increased in size and complexity during the latter half of the period. By the close of the period, Region 9830 had become large and magnetically complex as multiple delta magnetic configurations developed within its leader spots. One event of note was a partial-halo CME from the southwest quadrant early on 14 February. Solar wind data were available from the NASA Advanced Compositions Explorer (ACE) spacecraft for most of the period. A high-speed stream associated with a coronal hole was observed during 11 – 13 February. Wind speeds increased to as high as 620 km/sec during 11 – 12 February. This stream subsided by midday on 13 February. A weak CME passage occurred on 17 February. The passage began at approximately 17/0210 UTC followed by increased velocities (peaks to 460 km/sec), densities, and a few brief intervals of southward IMF Bz (maximum deflections to minus 11 nT (GSM)). CME effects began to subside during the latter half of 17 February. There were no proton events at geosynchronous orbit during the period. The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels. Geomagnetic field activity was at quiet to unsettled levels during most of the period. However, isolated active conditions occurred on 11 and 17 February. The 11 February activity was due to a high-speed stream associated with a coronal hole. The 17 February activity was preceded by a sudden impulse at 17/0257 UTC (13 nT, as measured by the Boulder USGS magnetometer) and was due to a weak CME passage, likely associated with the partial-halo observed early on 14 February. Forecast of Solar and Geomagnetic Activity 20 February - 18 March 2002 Solar activity is expected to be at low to moderate levels. Isolated low-level M-class flares are likely during the period. Region 9830 could produce a major flare before it crosses the west limb on 27 February. There is a slight chance for a proton event through the end of February. The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels during most of the period. However, high flux levels are possible during 06 – 08 March. Geomagnetic field activity is expected to increase to unsettled to active levels during 04 – 06 March due to recurrent coronal hole effects. Quiet to unsettled levels are expected for the rest of the period. .