Product: Weekly Highlights and Forecasts
:Issued: 2013 May 20 0139 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC web www.swpc.noaa.gov/weekly.html # # Weekly Highlights and Forecasts # Highlights of Solar and Geomagnetic Activity 13 - 19 May 2013 Solar activity reached high levels during the week, in fact the highest levels of activity since 2013 began. Between 13 and 14 May, newly-numbered Region 1748 (N11, L=296, class/area=Eki/310) produced an X2/1n flare at 13/1605Z and an X3/2b flare at 14/0111Z. Both events produced several radio emissions. Three Tenflares were observed at 14/0115Z (640 sfu), 14/0141Z (190 sfu), and 14/0203Z (370 sfu). A Type-II radio sweep was observed at 14/0107Z with an estimated velocity of 1514 km/s, in conjunction with a Type-IV radio sweep at 14/0113Z. SDO/AIA 193A showed a flare on the East limb at N12 from 14/0009-0154 and 14/0206-0224Z. A dimming and wave was observed over the east hemisphere and North Pole. Two distinct halo coronal mass ejections (CMEs) were subsequently observed on LASCO imagery. The first appeard in C2 coronagraph imagery at 14/0125Z and grew to a full HALO CME by 14/0224Z. The second event appeared at 14/0200Z with loop edge over the East and expanded to a partial HALO 280 degrees in width. Solar activity remained at high levels on 15 May. Region 1748 grew to a Dki/beta-gamma-delta and produced an X1/2n flare at 15/0148Z associated with a Type II radio sweep (estimated shock speed 501 km/s), a Type IV radio sweep, a 440 sfu Tenflare; and a fast, assymetric halo CME. The CME speed was observed in LASCO C2 coronagraph imagery at 15/0148Z and expanded to a full HALO CME by 15/0248Z. SDO/AIA 193/211/304 showed the flare at 15/0124-0212Z which produced a faint dimming in the Northeast and North direction and a wave over the East hemisphere. The CME had and earthward component and its western flank reached Earth on 18 May at 0112Z. Activity declined to moderate levels on 16 May with a single M1 flare from Region 1748 at 16/2153Z. Moderate levels continued through 17 May when Region 1748 produced an M3/2b flare at 17/0857Z. Type II (376 km/s) and Type IV radio bursts, as well as a 420 sfu Tenflare, were observed with this event. At 17/0912Z, LASCO/C2 coronagraph imagery observed a CME erupting from the east limb. It grew to a full halo CME by 17/0948Z and was estimated to be moving at approximately 1498 km/s. The CME reached Earth on 19 May at 2221Z. The remainder of the week was dominated by low levels of activity as Region 1748 shrank to less than half its largest extent. The largest flare of the latter part of the week was a C9 observed on the east limb at 19/1750Z. The other regions on the visible disk throughout the week were relatively inactive, producing only low-level C-class activity. A 10 MeV proton flux greater than 10 pfu at geosynchronous orbit event began at 15/1325Z, reached a maximum flux of 41 pfu at 17/1720Z, and ended at 18/1445Z. The 10 MeV flux remains enhanced at the time of this report. The event was attributed to the X1/2n flare at 15/0148Z. The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels all week. Geomagnetic field activity ranged from quiet to minor storm levels with the arrival of two CMEs during the week. The first CME, which was observed leaving the sun on 15 May, passed the ACE spacecraft at 18/0023Z and arrived at Earth at 18/0112Z with a 31nT sudden impulse. Activity reached minor storm levels by 18/0300Z and remained there through the end of the 0300-0600Z synoptic period. Activity then dropped to active, unsettled, then quiet levels during the subsequent periods. The following evening, active levels were observed during the 0000-0300Z synoptic period. The second CME, which left the sun on 17 May, passed the ACE spacecraft at 19/2221Z and arrived at Earth at 19/2306Z with a 29 T sudden impulse. Activity increased to active levels during the 2100-0000Z synoptic period. Forecast of Solar and Geomagnetic Activity 20 May - 15 June 2013 Solar activity is expected to be low to moderate throughout the forecast period. High levels of activity are possible through 25 May and again after 7 June associated with Region 1748. There is a chance for proton events at geosynchronous orbit, particularly through 25 May and again after 7 June associated with Region 1748. The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels from 24-31 May associated with a recurrent coronal hole high speed stream. Geomagnetic field activity is expected to reach minor to major storm levels on 20 May in response to the 17 May coronal mass ejection. In the absence of any Earth-directed coronal mass ejections, the remainder of the forecast period is expected to be characterized by quiet to unsettled levels of activity with the possible exception of 28 May, when another geoeffective coronal hole high speed stream becomes geoeffective and brings active levels.
Product: 27-day Space Weather Outlook Table 27DO.txt :Issued: 2013 May 20 0139 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC web contact www.swpc.noaa.gov/wwire.html # # 27-day Space Weather Outlook Table # Issued 2013-05-20 # # UTC Radio Flux Planetary Largest # Date 10.7 cm A Index Kp Index 2013 May 20 135 27 6 2013 May 21 130 8 3 2013 May 22 125 15 3 2013 May 23 125 12 3 2013 May 24 125 8 3 2013 May 25 120 5 2 2013 May 26 115 5 2 2013 May 27 110 5 2 2013 May 28 105 15 4 2013 May 29 105 10 3 2013 May 30 100 5 2 2013 May 31 100 5 2 2013 Jun 01 105 5 2 2013 Jun 02 110 5 2 2013 Jun 03 120 5 2 2013 Jun 04 120 5 2 2013 Jun 05 120 5 2 2013 Jun 06 125 5 2 2013 Jun 07 125 5 2 2013 Jun 08 125 5 2 2013 Jun 09 130 5 2 2013 Jun 10 135 5 2 2013 Jun 11 135 8 3 2013 Jun 12 140 12 3 2013 Jun 13 140 8 3 2013 Jun 14 135 5 2 2013 Jun 15 125 5 2
(NOAA)
