Joint USAF/NOAA Report of Solar and Geophysical Activity 25 May 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 May 25 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 145 Issued at 2200Z on 25 May 2006

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was very low. Today’s activity consisted of a few, low-level B-class events. There is also an indication in solar x-ray images of the return of old Region 882, which is just behind the east limb at about S12. Region 882 produced a few B-class events and reached a maximum area of 130 millionths on its previous transit. The region appears to be quiet and stable at this time.

IB. Solar Activity Forecast: Solar activity is expected to be very low for the next three days (26-28 May).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field was quiet during the past 24 hours. Real-time solar wind from ACE indicated the possible onset of a sector boundary, beginning at about 1800Z. As of forecast issue time there had not yet been any geomagnetic response.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled for the next 24 hours (26 May). Conditions should return to predominantly quiet levels for 27-28 May.

III. Event Probabilities 26 May-28 May

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

IV. Penticton 10.7 cm Flux

• Observed 25 May 084
• Predicted 26 May-28 May 085/085/085
• 90 Day Mean 25 May 081

V. Geomagnetic A Indices

• Observed Afr/Ap 24 May 003/004
• Estimated Afr/Ap 25 May 007/006
• Predicted Afr/Ap 26 May-28 May 007/010-005/005-005/005

VI. Geomagnetic Activity Probabilities 26 May-28 May

A. Middle Latitudes

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

B. High Latitudes

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