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

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

Updated 2004 Aug 26 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 239 Issued at 2200Z on 26 Aug 2004

IA. Analysis of Solar Active Regions and Activity from 25/2100Z
to 26/2100Z: Solar activity remained at low levels today. Region
663 (N10W14) produced the largest flare during the period, a C1
x-ray flare that occurred at 26/0219Z. No significant changes were
observed in the two visible spotted Regions 663 and 664 (S11W42) in
magnetic complexity or spot area during the period. Spray was
observed at N01W90 from 26/0034Z to 26/0103Z and is believed to be
from Region 661 (N06, L=348) which rotated off the solar west limb
today. No new regions were numbered today.

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

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field was at quiet to unsettled levels today. The
greater than 2 MeV electron flux at geosynchronous orbit reached
high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels throughout the period.

III. Event Probabilities 27 Aug-29 Aug
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF Green

IV. Penticton 10.7 cm Flux
Observed 26 Aug 098
Predicted 27 Aug-29 Aug 095/095/090
90 Day Mean 26 Aug 110

V. Geomagnetic A Indices
Observed Afr/Ap 25 Aug 003/007
Estimated Afr/Ap 26 Aug 004/007
Predicted Afr/Ap 27 Aug-29 Aug 006/008-006/008-004/005

VI. Geomagnetic Activity Probabilities 27 Aug-29 Aug
A. Middle Latitudes
Active 15/15/10
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 05/05/01
Major-severe storm 01/01/01

COMMENTS: The ACE spacecraft orbit will
bring ACE to its closest approach with the Sun
on August 30, 2004. During that time possible
solar radio noise may interfere with spacecraft
telemetry resulting in the loss of real time
solar wind plasma, magnetic field, and particle
data.