Joint USAF/NOAA Report of Solar and Geophysical Activity 17 Jan 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Jan 17 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 017 Issued at 2200Z on 17 Jan 2004
IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity reached high levels this period. Region
540 (S14E15), the source of several low C-class flares throughout
the period, produced an M5 flare at 17/1750Z. Moderate to strong
radio bursts accompanied this flare, including a 580 sfu Tenflare
and an extraordinary 270,000 sfu burst on 245 MHz (observed at both
Sagamore Hill and Palehua observatories). A Type II radio sweep (784
km/s) was also observed. Region 540 is a moderate size group of
approximately 350 millionths of white light areal coverage with
minor magnetic mixing. Region 537 (N04W70) continues in a slow decay
phase as it approaches the west limb. Isolated C-class activity was
observed from this region. No other significant activity was noted.
IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Isolated M-class activity is possible from Region 540.
IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was quiet to active. A coronal hole high speed
stream is responsible for the weak disturbed periods. The IMF Bz was
predominantly northward which offset the geomagnetic effects of the
high speed flow. The greater than 2 MeV electron flux at
geosynchronous orbit was at high levels today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to continue at quiet to active levels through 18 January as
the high speed stream subsides. Quiet to unsettled conditions are
expected on 19 January. A disturbance associated with today’s M5
flare, is expect to begin on 20 January. Active to minor storm
conditions are expected.
III. Event Probabilities 18 Jan-20 Jan
- Class M 20/20/20
- Class X 05/05/05
- Proton 05/05/05
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 17 Jan 123
- Predicted 18 Jan-20 Jan 125/120/110
- 90 Day Mean 17 Jan 139
V. Geomagnetic A Indices
- Observed Afr/Ap 16 Jan 021/026
- Estimated Afr/Ap 17 Jan 015/016
- Predicted Afr/Ap 18 Jan-20 Jan 015/015-010/012-020/020
VI. Geomagnetic Activity Probabilities 18 Jan-20 Jan
A. Middle Latitudes
- Active 25/20/30
- Minor storm 10/05/20
- Major-severe storm 01/01/05
B. High Latitudes
- Active 30/25/35
- Minor storm 15/10/25
- Major-severe storm 05/05/10
