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Tuesday, April 01, 2014

Weekly Propagation Forecast Bulletins


Product: Weekly Highlights and Forecasts
:Issued: 2014 Mar 31 0422 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 24 - 30 March 2014

An X1/2b flare (R3 radio blackout) on Saturday, at 29/1748 UTC, brought solar activity to high levels for the week. Region 2017 (N10, L=143, class/area=Dsi/160 on 27 Mar) had evolved from a simple beta to a beta-delta spot the day before. By the 29th it had grown to a beta-gamma-delta magnetic configuration. The X-flare it produced was accompanied by several radio emissions including a Castelli-U signature with 110,000 sfu on 245 MHz, a 360 sfu Tenflare at 29/1746 UTC, and a Type II sweep at 28/1753 UTC. An assymetrical halo coronal mass ejection (CME) was associated with the event and visible in LASCO/C2 coronagraph imagery beginning at 29/1812 UTC. Analysis of SOHO and STEREO coronagraph images suggested this CME was moving at 558 km/s with most ejecta directed north of the
ecliptic. 

On Friday, Region 2017 produced an M2/Sn flare at 28/1918 UTC associated with a Type II sweep at 28/1918 UTC (528 km/s). The speed obtained through analysis of coronagraph imagery was consistent with the Type II estimate. Another M2/1n flare was observed from this region at 28/2351 UTC. It was also associated wth a Type II sweep at 28/2350 UTC (857 km/s). Analysis of SOHO and STEREO coronagraph
imagery suggested the CME was moving at approximately 600 km/s. 

Finally, Region 2017 produced an M2/1n flare on Saturday at 30/1155 UTC accompanied by a Type II sweep at 30/1152 UTC (879 km/s). Analysis of SOHO and STEREO coronagraph imagery suggested the CME was moving at approximately 500 km/s. Region 2014 (S15, L=168, class/area=Ehi/290 on 27 Mar) was the largest of the 12 regions on the disk during the week, and was responsible for seven C-class
events. Region 2010 (S13, L=203, class/area=Dac/230) was the second largest region on the disk and responsible for 12 C-class events, second only to Region 2017 in productivity. 

No proton events were observed at geosynchronous orbit. However, the greater than 10 MeV proton flux at geosynchronous orbit was enhanced following the X1/2b flare on 29 March and reached a peak of 3.2 pfu at 29/2230 UTC. The flux was returning to normal levels at the time of this report. 

The greater than 2 MeV electron flux at geosynchronous orbit was at normal levels all week. 

Geomagnetic field activity remained at mostly quiet to unsettled levels during the week. The exception was a couple of active periods early on 26 March. A shock observed in ACE SWEPAM data at 25/1925 UTC announced the arrival of the 23 Mar CME. Solar wind speed increased from approximately 375 km/s to 500 km/s and the total field was enhanced from +2 nT to a maximum value of +13 nT. The Bz component turned southward following the arrival with a maximum southward deflection of -10 nT at 25/1938 UTC, and then became variable in the +9/-8 nT range. Solar wind speed reached a maximum of 554 km/s at 26/0049 UTC before decreasing to end of period values near 410 km/s. A geomagnetic sudden impulse was subsequently observed at the Hartland magnetometer (23 nT) at 25/2009 UTC. Unsettled conditions ensued from 25/1800-2400 UTC while active conditions (Below G1-Minor) occurred during the 26/0000-0300 UTC and 26/0600-0900 UTC periods. Later in the week, a rare geomagnetic crochet was observed - a minor nT deviation (17 nT at Boulder) in the H-traces of the magnetometers which were in the sunlit portion of Earth during the X-flare on 29 March described earlier. 

Forecast of Solar and Geomagnetic Activity 31 March - 26 April 2014

Solar activity is expected to be low with moderate events likely through the forecast period. 

There is a slight chance the greater than 10 MeV proton flux will exceed 10 pfu during the first week of the forecast period as Region 2017 rotates around the west limb. 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal levels through the forecast period. 

The geomagnetic field is expected to be at unsettled to active levels on 1-3 April, with minor storm periods possible on 2 April in response to the arrival of the several CMEs described above. The remainder of the forecast period should see mostly quiet to unsettled conditions in the absence of any new transient features. 

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2014 Mar 31 0423 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 2014-03-31
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2014 Mar 31     145           5          2
2014 Apr 01     145          12          4
2014 Apr 02     140          28          5
2014 Apr 03     140          10          4
2014 Apr 04     140           5          2
2014 Apr 05     140           5          2
2014 Apr 06     135           8          3
2014 Apr 07     140           8          3
2014 Apr 08     140           5          2
2014 Apr 09     140           8          3
2014 Apr 10     140           5          2
2014 Apr 11     140           5          2
2014 Apr 12     135           5          2
2014 Apr 13     135           5          2
2014 Apr 14     140           5          2
2014 Apr 15     145           5          2
2014 Apr 16     150           5          2
2014 Apr 17     150           8          3
2014 Apr 18     150           8          3
2014 Apr 19     155           8          3
2014 Apr 20     155           5          2
2014 Apr 21     155           5          2
2014 Apr 22     155           5          2
2014 Apr 23     145           8          3
2014 Apr 24     145           8          3
2014 Apr 25     145           8          3
2014 Apr 26     145           5          2
(NOAA)