Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Feb 2003

SDF Number 051 Issued at 2200Z on 20 Feb 2003

IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity was low. Only a few C-class events
occurred during the day. Region 290 (N17E18) grew in both white
light and H-alpha as it produced occasional subflares. Little else
of significance occurred.

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

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was at quiet to active levels. The solar wind
is currently hovering near 700 km/s, emanating from a coronal hole
in the western hemisphere.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled to active levels for the next 24 hours.
Conditions should calm to strictly unsettled levels by the end of
the period.

III. Event Probabilities 21 Feb-23 Feb

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

IV. Penticton 10.7 cm Flux
Observed 20 Feb 118
Predicted 21 Feb-23 Feb 120/120/125
90 Day Mean 20 Feb 145

V. Geomagnetic A Indices

• Observed Afr/Ap 19 Feb 010/012
• Estimated Afr/Ap 20 Feb 015/020
• Predicted Afr/Ap 21 Feb-23 Feb 015/020-010/012-010/012

VI. Geomagnetic Activity Probabilities 21 Feb-23 Feb

A. Middle Latitudes

• Active 40/20/20
• Minor storm 15/10/10
• Major-severe storm 05/05/05

B. High Latitudes

• Active 50/30/30
• Minor storm 20/15/15
• Major-severe storm 05/05/05