Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 19 Jan 2004

By SpaceRef Editor

January 19, 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 Jan 19 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 019 Issued at 2200Z on 19 Jan 2004

IA. Analysis of Solar Active Regions and Activity from 18/2100Z
to 19/2100Z: Solar activity was moderate. Region 540 (S14W10)
produced two M1 flares this period, at 19/0532Z and again at
19/1240Z. It was also the source of several C-class events including
a C8/Sf at 19/2002Z. Some penumbral decay was noted in the trailing
spots in this group; however, considerable complexity still exists
and a weak delta configuration was identified. Region 542 (N08E15)
was spotless early on 18 January, but two new sunspot clusters
emerged quite rapidly late on the 18th and continued to develop
through this period. These spot groups may be two separate regions.
Another new spot group emerged rapidly near the trailing spots in
Region 540. This new beta-gamma group was numbered as Region 543
(S18E05) and produced a C3 flare at 19/1439Z. Portions of the very
large circular filament in the northwest quadrant became quite
active this period.

IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels. Further M-class activity is likely from Region 540.
The new emerging flux and white light developments in Region 542 and
newly numbered 543 suggest at least C-class potential.

IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z:
The geomagnetic field was quiet to active. Solar wind speed remains
elevated (560 to 660 km/s) since the onset of a high speed coronal
hole stream on 16 January. IMF Bz was predominantly northward
although there were some periods of sustained southward Bz. The
greater than 2 MeV electron flux at geosynchronous orbit was at high
levels again today

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to continue at predominantly quiet to active levels.
Isolated minor storm periods are possible on 20 – 21 January. The
coronal hole high speed stream that is currently in progress is
expected to subside by 21 January. A CME associated with the M5
flare on 17 January may have a weak impact on the geomagnetic field
on 20 January, slightly enhancing the current disturbance. Mostly
quiet to unsettled conditions are expected on 22 January.

III. Event Probabilities 20 Jan-22 Jan