Joint USAF/NOAA Report of Solar and Geophysical Activity 25 Sep 2003
SDF Number 268 Issued at 2200Z on 25 Sep 2003
IA. Analysis of Solar Active Regions and Activity from 24/2100Z
to 25/2100Z: Solar activity was at low levels today. Region 464
(N04E09) produced several B and C-class flares during the period.
This region has become more complex during the past 24 hours.
Intermediate spots indicate that a gamma structure is present. The
remainder of the numbered regions were fairly quiet during the
period. No new regions were numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels. Due to the growing complexity of Region 464, there may
be a chance of an isolated M-class flare.
IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field has ranged from active to minor storm levels.
A favorably positioned high speed coronal hole stream is responsible
for the elevated conditions. The greater than 2 MeV electron flux
at geosynchronous orbit reached high levels today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly active levels due to the high speed
stream effects. The disappearing solar filament from yesterday and
the associated ejecta may further enhance the geomagnetic field,
pushing activity into minor storm levels with isolated periods of
major storming possible on day two of the period.
III. Event Probabilities 26 Sep-28 Sep
- Class M 40/40/40
- Class X 05/05/05
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 25 Sep 133
- Predicted 26 Sep-28 Sep 135/130/130
- 90 Day Mean 25 Sep 120
V. Geomagnetic A Indices
- Observed Afr/Ap 24 Sep 027/033
- Estimated Afr/Ap 25 Sep 025/030
- Predicted Afr/Ap 26 Sep-28 Sep 012/015-020/030-015/020
VI. Geomagnetic Activity Probabilities 26 Sep-28 Sep
A. Middle Latitudes
- Active 35/45/40
- Minor storm 15/25/15
- Major-severe storm 05/15/10
B. High Latitudes
- Active 40/35/50
- Minor storm 15/40/30
- Major-severe storm 10/20/10
