Joint USAF/NOAA Report of Solar and Geophysical Activity 01 Aug 2003

SDF Number 213 Issued at 2200Z on 01 Aug 2003

IA. Analysis of Solar Active Regions and Activity from 31/2100Z
to 01/2100Z: Solar activity has been low. A new Region 424 (S18E77)
has been single-handedly responsible for a long series of C-class
x-ray flares since it first appeared as a prominence on the
East-limb on July 31st at approximately 2200 UTC.

IB. Solar Activity Forecast: Solar activity is expected to be low.
There’s a slight chance for an M-class flare from Region 424
(S18E77), but overall the disk will be relatively inactive.

IIA. Geophysical Activity Summary 31/2100Z to 01/2100Z:
The geomagnetic field has been at active to minor storm levels. A
large polar-connected coronal hole which has maintained a high-speed
solar wind stream, combined with a series of periods where the
interplanetary magnetic field has been oriented Southward,
maintaining elevated activity. The greater than 2 MeV electron flux
at geosynchronous orbit reached high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at active to minor storm levels for the next 24
hours. The coronal hole which has generated the current activity
will pass beyond geoeffective range by the end of tomorrow, and the
geomagnetic field should settle to quiet to unsettled levels for
days two and three.

III. Event Probabilities 02 Aug-04 Aug

• Class M 20/20/20
• Class X 05/05/05
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 01 Aug 107
• Predicted 02 Aug-04 Aug 110/115/115
• 90 Day Mean 01 Aug 123

V. Geomagnetic A Indices

• Observed Afr/Ap 31 Jul 022/032
• Estimated Afr/Ap 01 Aug 025/034
• Predicted Afr/Ap 02 Aug-04 Aug 020/025-012/015-010/010

VI. Geomagnetic Activity Probabilities 02 Aug-04 Aug

A. Middle Latitudes

• Active 35/25/25
• Minor storm 20/10/10
• Major-severe storm 05/05/05

B. High Latitudes

• Active 35/25/25
• Minor storm 20/10/10
• Major-severe storm 10/05/05