Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 30 Oct 2004

By SpaceRef Editor

October 31, 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 Oct 30 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 304 Issued at 2200Z on 30 Oct 2004

IA. Analysis of Solar Active Regions and Activity from 29/2100Z
to 30/2100Z: Solar activity was high. Region 691 (N14W25) grew
quickly at the end of yesterday, and emerging flux near the leader
spot fueled an instability that resulted in major flares.
Chronologically, Region 691 produced: a C9/Sf with type II sweep at
0049UTC, an M3/Sf with type II at 0333UTC, an M4/Sf TENFLARE with
types II and IV sweep at 0618UTC, an M3/1n with type II at 0928UTC,
an X1/Sf (partially obscured by clouds) TENFLARE with types II and
IV sweep at 1146UTC, and most recently an M5/Sn TENFLARE with type
II sweep at 1633UTC. Numerous large (i.e., 9500 sfu at 245 MHz at
1413UTC) radio bursts occurred throughout the period. A paucity of
LASCO observations made it difficult to discern if associated CMEs
occurred, but there seems to be an indication that at least some CME
activity did occur in conjunction with the latter flares. The region
seems to still retain an amount of potency making additional
significant activity likely. Elsewhere, Region 687 (N12W66) and
Region 693 (S16E34) each had an occasional small C-class flare as
both regions seemed to decay. New Region 695 (S16E68) was numbered.

IB. Solar Activity Forecast: Solar activity is expected to be
moderate to high. Region 691 is still capable of producing M and X
class flares.

IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z:
The geomagnetic field was quiet to mildly active. Alfven waves in the
solar wind coupled with a slow increase in the radial speed caused
intervals of active conditions. The greater than 10 MeV proton flux
at geosynchronous orbit became enhanced around 0700UTC, in response
to earlier activity in Region 691. The flux has hovered near 1 pfu
for the past 16 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be generally unsettled for the next 36 hours. Activity
is expected to increase near midday on 01 November when effects of
shocks and CMEs are due, bringing active to periodic major storming
over the final 36 hours of the period. The greater than 10 MeV
proton flux may exceed event level if Region 691 produces more M and
X level activity. The region is in a well-connected location so this
proton increase would be abrupt should it occur.

III. Event Probabilities 31 Oct-02 Nov