Joint USAF/NOAA Report of Solar and Geophysical Activity 11 May 2003

SDF Number 131 Issued at 2200Z on 11 May 2003

IA. Analysis of Solar Active Regions and Activity from 10/2100Z
to 11/2100Z: Solar activity has been very low. Region 357 (S16E70)
was numbered today, but poses little threat of any significant
activity.

IB. Solar Activity Forecast: Solar activity is expected to remain
very low.

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field has been at unsettled to minor storm levels due
to the continued influence of a high speed solar wind stream. The
greater than 2 MeV electron flux at geosynchronous orbit continues
to be at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled to major storm levels for the next three
days. A significant coronal hole will be in geoeffective position
at the beginning of the period, and is of great enough extent to
continue to impact the earth’s magnetic field for several days.

III. Event Probabilities 12 May-14 May

• Class M 10/10/10
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 11 May 092
• Predicted 12 May-14 May 095/100/100
• 90 Day Mean 11 May 126

V. Geomagnetic A Indices

• Observed Afr/Ap 10 May 032/043
• Estimated Afr/Ap 11 May 025/034
• Predicted Afr/Ap 12 May-14 May 025/030-030/030-030/030

VI. Geomagnetic Activity Probabilities 12 May-14 May

A. Middle Latitudes

• Active 40/40/40
• Minor storm 25/30/30
• Major-severe storm 15/15/15

B. High Latitudes

• Active 40/40/40
• Minor storm 30/30/30
• Major-severe storm 25/25/25