Updated Mar 07 2200 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 067 Issued at 2200Z on 07 Mar 2012
IA. Analysis of Solar Active Regions and Activity from 06/2100Z
to 07/2100Z: Solar activity was high. Region 1429 (N17E15) produced
an X5/3B long-duration flare with maximum at 07/0024Z. The event was
associated with type II and type IV radio sweeps and a full halo,
though slightly asymmetric coronal mass ejection (CME). The CME had
an estimated plane of sky speed of about 2200 km/s. During the decay
of the X5 x-ray event, Region 1430 (N21W00) produced an X1/Sf at
0114Z. Region 1429 dominates the disk with an area of about 1300
millionths. Observations show slight separation of the central spots
but the region continues to be large and magnetically complex;
multiple deltas are clearly evident as well as a dominant east-west
polarity inversion line. Region 1430 showed steady growth during the
past 24 hours. Region 1428 (S17W05) also showed growth during the
period but was relatively quiet and stable.
IB. Solar Activity Forecast: Solar activity is expected to be
moderate to high. M-class level activity is expected to continue and
there continues to be a good chance for an additional major flare
and/or proton producing event from Region 1429. In addition, the
growth trend in 1430 suggests that it may also contribute to the
M-flare activity during the next three days.
IIA. Geophysical Activity Summary 06/2100Z to 07/2100Z:
The geomagnetic field ranged from quiet to major storm levels during
the past 24 hours. Activity levels were initially quiet to unsettled
until an interplanetary shock arrived. The shock was seen at ACE at
07/0334Z and was followed by a sudden storm commencement (SSC) at
Earth at 07/0421Z. Although solar wind speeds did not increase
greatly, the interplanetary magnetic field (IMF) and density did
increase markedly and the Bz component had numerous intervals of
fairly strong southward orientation (with the strongest negative
intervals at about -15 to -20 nT). Geomagnetic activity increased to
minor to major storm levels following the SSC with some periods of
severe storm levels at high latitudes. The disturbance most likely
originated from the X1/halo CME that occurred on 05 March. A greater
than 10 MeV proton event began at 07/0500Z and has reached a peak so
far of 1630 PFU at 1540Z. A greater than 100 MeV proton event also
occurred, beginning at 07/0405Z and reaching an apparent maximum of
69 PFU at 07/1525Z. Both of these events continue in progress and
are clearly associated with todays X5/Full halo CME event.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be active initially on day 1 (08 March) but is expected
to increase to major storm levels with a likelihood for isolated
severe storm levels after the arrival of the CME from todays
X5/full halo event. The arrival time is estimated to be sometime
between 0600-1000Z. Minor to major storm levels are expected to
continue partway (6-12 hours) into the second day (09 March), but a
decline to predominantly active levels is expected for the remainder
of the day. Predominantly unsettled levels are expected for the
third day (10 March). The greater than 10 MeV proton event is
expected to continue through the first day and is also likely to
continue partway through the second day. The greater than 100 Mev
proton event is expected to slowly decline over the next 24 hours.
III. Event Probabilities 08 Mar-10 Mar
Class M 85/85/85
Class X 40/40/40
Proton 99/80/50
PCAF red