Routine Space Environment Product Issued Weekly
Issued by NWS
FXXX06 KWNP 200327
:Product: 7-day Space Weather Highlights
:Issued: 2015 Apr 20 0248 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# 7-day Space Weather Highlights
Highlights of Solar and Geomagnetic Activity
13 - 19 April 2015
Solar activity was at very low to low levels. Numerous weak to
moderate level C-class flares were observed from Regions 2320 (S12,
L=211, class/area Dac/180 on 07 Apr), 2321 (N13, L=095, class/area
Ekc/620 on 13 Apr) and 2324 (N18, L=062, class/area Dko/410 on 15
Apr). The most significant event of the period occurred from Region
2321 on 18 April when the region produced a C5/1f flare at 18/1419
UTC. Associated with this event was a 7 degree long filament
eruption, centered near N05W16. The filament eruption resulted in an
asymmetric, faint full-halo CME, first visible in SOHO/LASCO C2
imagery at 18/1524 UTC.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at
normal levels on 13-15 April and high levels on 16-19 April.
Geomagnetic field activity began the period on 13-14 April at quiet
to active levels under the influence of a weak transient. By midday
on 15 April, field activity increased to active to minor storm
(G1-minor) levels as a co-rotating interaction region (CIR), in
advance of a negative polarity coronal hole high speed stream (CH
HSS), influenced the magnetic field of Earth. Geomagnetic activity
increased to major storm (G2-moderate) levels late on 16 April due
to CH HSS effects and continued at active to minor storm levels
through midday on 17 April. Field activity relaxed to quiet to
unsettled levels through the remainder of the summary period as CH
HSS effects waned.
During the period, ACE solar wind parameters measured a high wind
speed of 784 km/s on 17/0408 UTC with a low speed of 286 km/s on
14/0004 UTC. Total field (Bt) ranged from about 1-17 nT while the Bz
component varied between +13 to -12 nT. The phi angle was generally
in a negative (towards) orientation with intermittent periods of
rotation to a positive (away) sector.