Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 01 Nov 2004

By SpaceRef Editor

November 1, 2004

Filed under Space Weather Prediction Center (NOAA), Space Weather Solar-Geophysical Activity, US

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2004 Nov 01 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 306 Issued at 2200Z on 01 Nov 2004

IA. Analysis of Solar Active Regions and Activity from 31/2100Z
to 01/2100Z: Solar activity was moderate. Region 691 (N13W55)
produced today’s only M-class flare: an M1/1f at 0322 UTC. The event
was associated with a type II sweep and a relatively slow CME off
the west limb (plane-of-sky speed ~ 500-550 km/s). Region 691 showed
steady decay during the past 24 hours. The most spectacular event of
the period was a bright CME from a source behind the west limb,
which was first observed in the LASCO C2 coronagraph at 0606 UTC.
The absence of disk signatures and observations in EIT 195 imagery
clearly indicate a backside source. The plane-of-sky speed of the
CME was about 800 km/s. Region 693 (S16E08) grew considerably during
the period and is the dominant region on the disk. Although the
group shows occasional brightenings it still has not produced any
flare activity. New Region 696 (N09E63) was assigned today as a
small, D-type group.

IB. Solar Activity Forecast: Solar activity is expected to be
moderate, but there is a continued slight chance for major flares or
proton producing flares from 691 or 693.

IIA. Geophysical Activity Summary 31/2100Z to 01/2100Z:
The geomagnetic field was quiet to unsettled during the past 24
hours. The arrival of transient flow from the solar events of 30
October has not yet been observed in the solar wind data. Proton
events at greater than 10 MeV and greater than 100 MeV were
observed. The 10 MeV event began at 0655 UTC, reached a maximum of
63 PFU at 0805 UTC, and appears to have ended as of 1900 UTC. The
100 MeV event began at 0635 UTC, reached a maximum of 1.5 PFU at
0645 UTC, and ended at 0755 UTC. The event was well associated with
the backside CME reported in part IA.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be predominantly active for the next 24 hours (02
November) as the impact from the solar events of 30 October is still
expected. Conditions should decline to unsettled to slightly active
for 03 November, and should be predominantly unsettled by 04
November.

III. Event Probabilities 02 Nov-04 Nov