Product: Weekly Highlights and Forecasts
:Issued: 2011 May 03 2027 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/weekly.html
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 25 April - 01 May 2011
Solar activity began the week at very low levels. An increase to low occurred with a C2 x-ray event at 0233 UTC on 27 April from Region 1201 (N16, L=116, plage region). Activity continued at low levels for the remainder of the week with the primary contributions from Region 1199 (N20, L=188, class/area Dso/210 on 01 May), Region 1203 (N18, L=061, class/area Cso/160 on 01 May), and Region 1195 (S16, L=191, class/area Ehi/400 on 25 April). The largest event of the week was a C6/Sf from Region 1199 at 2332 UTC on 01 May.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at low to moderate levels for 25-30 April, and reached high levels on 01 May.
Geomagnetic field activity was generally quiet from 25-28 April. An increase to unsettled to active levels (with occasional storm periods at high latitudes) occurred late on 29 April and persisted through 01 May in response to a favorably positioned negative polarity coronal hole. The high speed stream followed a clear solar sector boundary crossing at 1445 UTC on 28 April. Solar wind velocity began to increase at 1600 UTC on 29 April and reached peak values around 740 km/s. The north-south component of the solar wind Bz turned negative after 1600 UTC on 29 April and persisted at generally negative values for the remainder of the week. Typical values were in the range between 0 and -5 nT with peak values reaching -10 to -12 nT.
Forecast of Solar and Geomagnetic Activity 04 May - 30 May 2011
Solar activity is expected to be very low to low. There is a chance for isolated periods of moderate levels due to the possible emergence of new regions as well as the return of old Region 1195 on 15 May.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels for 04-07 May in response to the sustained high solar wind speed mentioned previously. Normal background levels should resume for 08-09 May but another increase to high levels is expected for 10-12 May in response to another high
speed stream. Normal background levels should return for the remainder of the outlook interval with the exception of 19-20 May and 28-30 May due to recurrent high speed streams.
Geomagnetic field activity is expected to be quiet to unsettled for 04 May and generally quiet for 05-08 May. An increase to unsettled levels with possible active periods is expected for 9-10 May in response to a recurrent coronal hole. Quiet levels should prevail until 17 May when another recurrent high speed stream is expected to increase activity to unsettled to active levels. Quiet levels should
return for 18-25 May, followed by an increase to unsettled to active levels with a chance for storm periods at high latitudes for 26-30 May in response to a recurrent coronal hole.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2011 May 03 2027 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC webg contact www.swpc.noaa.gov/wwire.html
#
# 27-day Space Weather Outlook Table
# Issued 2011-05-03
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2011 May 04 110 8 3
2011 May 05 110 5 2
2011 May 06 110 5 2
2011 May 07 110 5 2
2011 May 08 110 5 2
2011 May 09 110 15 3
2011 May 10 110 15 3
2011 May 11 115 7 2
2011 May 12 115 5 2
2011 May 13 115 5 2
2011 May 14 115 5 2
2011 May 15 115 5 2
2011 May 16 115 5 2
2011 May 17 115 15 3
2011 May 18 115 5 2
2011 May 19 115 5 2
2011 May 20 115 5 2
2011 May 21 115 5 2
2011 May 22 110 5 2
2011 May 23 110 5 2
2011 May 24 105 5 2
2011 May 25 105 5 2
2011 May 26 105 12 3
2011 May 27 105 22 5
2011 May 28 105 18 4
2011 May 29 110 18 4
2011 May 30 110 15 3
(NOAA)
