Joint USAF/NOAA Report of Solar and Geophysical Activity 31 Aug 2004

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2004 Aug 31 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 244 Issued at 2200Z on 31 Aug 2004

IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 31/2100Z: Solar activity has been moderate. An M1.4 flare was
observed from Region 663 at 31/0538Z. A Type II radio sweep with a
speed of 700 km/s, as well as a CME off the west limb, were observed
in association with the M flare. No new regions were numbered
today.

IB. Solar Activity Forecast: Solar activity is expected to be at
very low to low levels. Region 663 may still produce C class
flares.

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z:
Geomagnetic activity has been at quiet to major storm levels. Bz at
ACE turned northward at 2230Z resulting in isolated major storming
early on 31 August. Unsettled to active conditions prevailed for
the rest of the period.

IIB. Geophysical Activity Forecast: Geomagnetic activity is
expected to be at quiet to unsettled levels for the next three days.
A glancing blow from the CME shock associated with today’s M flare
may cause isolated active conditions on 3 September.

III. Event Probabilities 01 Sep-03 Sep

• Class M 10/05/05
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 31 Aug 088
• Predicted 01 Sep-03 Sep 100/110/110
• 90 Day Mean 31 Aug 109

V. Geomagnetic A Indices

• Observed Afr/Ap 30 Aug 027/034
• Estimated Afr/Ap 31 Aug 024/029
• Predicted Afr/Ap 01 Sep-03 Sep 010/020-005/015-015/020

VI. Geomagnetic Activity Probabilities 01 Sep-03 Sep

A. Middle Latitudes

• Active 20/20/25
• Minor storm 15/10/15
• Major-severe storm 01/01/05

B. High Latitudes

• Active 30/25/30
• Minor storm 20/15/20
• Major-severe storm 01/01/10