Joint USAF/NOAA Report of Solar and Geophysical Activity 12 Apr 2003

SDF Number 102 Issued at 2200Z on 12 Apr 2003

IA. Analysis of Solar Active Regions and Activity from 11/2100Z
to 12/2100Z: Solar activity was very low. None of the three spotted
regions currently visible produced anything of significance.

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

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z:
The geomagnetic field was quiet to unsettled. The solar wind speed
remains elevated — 550 km/s — but the IMF has been steady and
weak. The greater than 2 MeV electrons at geosynchronous orbit were
again at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels for the remainder of the
forecast period.

III. Event Probabilities 13 Apr-15 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 12 Apr 102
• Predicted 13 Apr-15 Apr 100/100/095
• 90 Day Mean 12 Apr 130

V. Geomagnetic A Indices

• Observed Afr/Ap 11 Apr 014/014
• Estimated Afr/Ap 12 Apr 008/012
• Predicted Afr/Ap 13 Apr-15 Apr 015/015-015/015-010/015

VI. Geomagnetic Activity Probabilities 13 Apr-15 Apr

A. Middle Latitudes

• Active 30/30/25
• Minor storm 20/20/10
• Major-severe storm 10/10/05

B. High Latitudes

• Active 40/40/30
• Minor storm 20/20/15
• Major-severe storm 10/10/10