Joint USAF/NOAA Report of Solar and Geophysical Activity 25 Jun 2003
SDF Number 176 Issued at 2200Z on 25 Jun 2003
IA. Analysis of Solar Active Regions and Activity from 24/2100Z
to 25/2100Z: Solar activity was low. The period was highlighted by a
very long duration C3.7 X-ray flare and CME that appears to have
originated from behind the NE limb. The likely source region of this
event is old Region 375 (N12, L=026) which was very large and
complex during its last transit of the visible disk. It is due to
make its return on the visible disk late on day two. Region 391
(N14W09) continues to grow, but after the burst of minor C-class
flares yesterday, it could only yield minor plage fluctuations this
period. No other noteworthy activity was observed.
IB. Solar Activity Forecast: Solar activity is expected to continue
at low levels. Increased activity is possible on days two and three
with the return of old Region 375.
IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field was quiet to active. A high speed coronal hole
stream continues with solar wind speed ranging from 520 to 620 km/s.
The greater than 2 MeV electrons at geosynchronous orbit reached
high levels today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to continue at quiet to active levels through day two. A
large southern coronal hole with a transequatorial extension will
move into a geoeffective position by day three; consequently,
occasional minor storm conditions are expected by the end of the
period.
III. Event Probabilities 26 Jun-28 Jun
- Class M 20/30/35
- Class X 01/05/05
- Proton 01/01/05
- PCAF Green
IV. Penticton 10.7 cm Flux
- Observed 25 Jun 116
- Predicted 26 Jun-28 Jun 115/120/130
- 90 Day Mean 25 Jun 125
V. Geomagnetic A Indices
- Observed Afr/Ap 24 Jun 020/031
- Estimated Afr/Ap 25 Jun 015/015
- Predicted Afr/Ap 26 Jun-28 Jun 012/015-012/015-020/020
VI. Geomagnetic Activity Probabilities 26 Jun-28 Jun
A. Middle Latitudes
- Active 35/30/35
- Minor storm 15/10/15
- Major-severe storm 05/01/05
B. High Latitudes
- Active 45/35/45
- Minor storm 25/20/25
- Major-severe storm 10/05/10