Joint USAF/NOAA Report of Solar and Geophysical Activity 27 May 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 May 27 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 148 Issued at 2200Z on 27 May 2004
IA. Analysis of Solar Active Regions and Activity from 26/2100Z
to 27/2100Z: Solar activity was at low levels today. Region 618
(S10W27) produced a C1/Sf flare that occurred at 27/0027Z. This
region continued to show decay in magnetic complexity and sunspot
area during the period. The delta structure near region center
remains intact. Region 619 (S09W89) managed to produce a C1 flare
just before the sunspots vanished in white light. No new regions
were numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels. Region 618 continues to exhibit the potential for
producing isolated M-class flares.
IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field was at quiet to unsettled levels.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels. NOTE: The ACE
spacecraft orbit will bring ACE nearly in line with the Sun from
about May 30 to June 2, 2004. During that time solar radio noise is
expected to interfere with spacecraft telemetry resulting in the
loss of solar wind plasma, magnetic field, and particle data.
III. Event Probabilities 28 May-30 May
- Class M 40/40/40
- Class X 05/05/05
- Proton 05/05/05
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 27 May 102
- Predicted 28 May-30 May 100/100/105
- 90 Day Mean 27 May 105
V. Geomagnetic A Indices
- Observed Afr/Ap 26 May 003/006
- Estimated Afr/Ap 27 May 004/008
- Predicted Afr/Ap 28 May-30 May 004/010-004/010-008/012
VI. Geomagnetic Activity Probabilities 28 May-30 May
A. Middle Latitudes
- Active 10/10/15
- Minor storm 05/05/05
- Major-severe storm 05/01/05
B. High Latitudes
- Active 20/20/25
- Minor storm 10/10/15
- Major-severe storm 05/05/05
