Joint USAF/NOAA Report of Solar and Geophysical Activity 26 Oct 2004

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Oct 26 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 300 Issued at 2200Z on 26 Oct 2004

IA. Analysis of Solar Active Regions and Activity from 25/2100Z
to 26/2100Z: Solar activity was low. Region 687 (N12W11) produced
a C2.2 flare at 26/1506 UTC. This Region exhibited some decay in
both white light area coverage and magnetic complexity. Region 691
(N15E32), still shows a beta-gamma-delta configuration and produced
a C1.3 flare at 26/1839 UTC.

IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Regions 687 and 691 have potential for M-class
activity.

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field was quiet. Solar wind speed at ACE declined
from approximately 470 km/s to 420 km/s during the reporting period.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled.

III. Event Probabilities 27 Oct-29 Oct

• Class M 50/50/50
• Class X 05/05/05
• Proton 05/05/05
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 26 Oct 137
• Predicted 27 Oct-29 Oct 135/135/130
• 90 Day Mean 26 Oct 104

V. Geomagnetic A Indices

• Observed Afr/Ap 25 Oct 009/013
• Estimated Afr/Ap 26 Oct 005/005
• Predicted Afr/Ap 27 Oct-29 Oct 005/005-005/005-008/010

VI. Geomagnetic Activity Probabilities 27 Oct-29 Oct

A. Middle Latitudes

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

B. High Latitudes

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