Joint USAF/NOAA Report of Solar and Geophysical Activity 24 Oct 2004

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

Updated 2004 Oct 24 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 298 Issued at 2200Z on 24 Oct 2004

IA. Analysis of Solar Active Regions and Activity from 23/2100Z
to 24/2100Z: Solar activity was moderate. A M2.3 flare occurred at
24/2028 UTC from Region 687 (N12E15). Regions 682 (S12W86) and 691
(N15E59) have produced low level C-class flares. Region 682 has
rotated off the West limb. New Region 692 (S17E30) was numbered
today.

IB. Solar Activity Forecast: Solar Activity is expected to be low
to moderate. M-class flares are possible from Region 687.

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z:
The geomagnetic field was quiet to unsettled. Solar wind speed
increased from approximately 360 km/s to 500 km/s, most likely due
to a geoeffective coronal hole. A prolonged period of the
southward Bz component was responsible for the unsettled conditions
experienced.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled with a possibility for isolated
active periods on 25 and 26 October due to a possible glancing blow
from a CME observed on 22 October.

III. Event Probabilities 25 Oct-27 Oct

• Class M 55/55/55
• Class X 05/05/05
• Proton 05/05/05
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 24 Oct 135
• Predicted 25 Oct-27 Oct 135/135/135
• 90 Day Mean 24 Oct 104

V. Geomagnetic A Indices

• Observed Afr/Ap 23 Oct 001/004
• Estimated Afr/Ap 24 Oct 005/005
• Predicted Afr/Ap 25 Oct-27 Oct 010/012-008/008-005/005

VI. Geomagnetic Activity Probabilities 25 Oct-27 Oct

A. Middle Latitudes

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

B. High Latitudes

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