Tuesday, April 13, 2010

Weekly Propagation Forecast Bulletin


Product: Weekly Highlights and Forecasts
:Issued: 2010 Apr 13 2151 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
05 - 11 April 2010


Solar activity was at very low levels with isolated low-level B-class flares. Three sunspot groups were observed on the visible disk during the period. Region 1059 (S25, L=261, class/area Hax/030 on 05 April) decayed to spotless plage on 07 April. Region 1060 (N25, L=176, class/area Cro/060 on 05 April) produced a B3 flare at 08/0325 UTC, with an associated EIT wave and an Earth-directed full halo CME. Region 1061 (N14, L=232, class/area Dso/110 on 06 April) was the largest group during the period but began to decay on 07 April.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 05 April and reached very high levels every day from 06-11 April.

Geomagnetic field activity was at quiet to severe storm levels during the period. A shock was observed at ACE at 05/0756 UTC which led to a sudden impulse at Earth at 05/0826 UTC (38 nT was observed at the Boulder magnetometer). The most likely source for the activity was the halo CME observed on 03/0954 UTC. Geomagnetic field activity was at active levels after 05/0300 UTC, with major to severe storm conditions between 05/0900-1200 UTC. Numerous high-latitude stations reported severe storm levels during this interval, as well as several mid-latitude stations in the nighttime sectors. ACE observed wind speeds between 720-800 km/s behind the shock, with Bz reaching values around -15 nT. Activity continued on 06 April with predominantly active to minor storm levels, as well as an interval of minor to major storm levels observed between 06/0000-0600 UTC. Wind speeds at ACE decreased to about 550 km/s at 06/2100 UTC. As the effects of the full halo CME waned on 07 April, a coronal hole high-speed stream moved into geoeffective position with activity levels ranging from unsettled to minor storm levels, with major storm conditions at high latitudes and a rise in the solar wind speeds at ACE from 560- 625 km/s. Quiet to active levels, with isolated minor storm conditions at high latitudes were observed on 08 April. Predominantly quiet conditions were observed on 09-10 April. Geomagnetic activity on the 11 April ranged from quiet to unsettled with some isolated storm periods at high latitudes 11/1500-1800 UTC following a weak shock observed at the ACE spacecraft at 11/1215 UTC followed by a sudden impulse at Earth at 11/1305 UTC (5 nT observed at the Boulder magnetometer). Velocity at the ACE spacecraft jumped from 380 km/s to about 450 km/s and the total magnetic field increased from 4 nT to about 10 nT. The most likely source for this activity was the full halo CME observed on 08/0325 UTC.

Forecast of Solar and Geomagnetic Activity
14 April - 10 May 2010


Solar activity is expected to be at very low levels with possible isolated periods of low levels during the forecast period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal levels through most of the period. However, moderate to high flux levels are possible during 05-08 May.

The Geomagnetic field is expected to be at mostly quiet levels from 14 April - 02 May. Activity is expected to be at quiet to active levels during 03-05 May due to a recurrent coronal hole high-speed stream. Activity is expected to return to quiet levels during the remainder of the period 06-10 May.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2010 Apr 13 2151 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 2010 Apr 13
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2010 Apr 14 75 5 2
2010 Apr 15 75 5 2
2010 Apr 16 75 5 2
2010 Apr 17 75 5 2
2010 Apr 18 78 5 2
2010 Apr 19 80 5 2
2010 Apr 20 80 5 2
2010 Apr 21 80 5 2
2010 Apr 22 80 5 2
2010 Apr 23 80 5 2
2010 Apr 24 80 5 2
2010 Apr 25 78 5 2
2010 Apr 26 75 5 2
2010 Apr 27 75 5 2
2010 Apr 28 75 5 2
2010 Apr 29 75 5 2
2010 Apr 30 75 5 2
2010 May 01 75 5 2
2010 May 02 75 5 2
2010 May 03 75 6 2
2010 May 04 75 15 3
2010 May 05 75 9 3
2010 May 06 75 5 2
2010 May 07 75 5 2
2010 May 08 75 5 2
2010 May 09 75 5 2
2010 May 10 75 5 2
(NOAA)