Joint USAF/NOAA Report of Solar and Geophysical Activity 23 May 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 May 23 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 143 Issued at 2200Z on 23 May 2005

IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was at very low levels. Region 766
(N15E49) was limited to minor B-class flare production and underwent
decay in sunspot coverage today. Region 767 (S07E54) underwent
little change during the period. No new regions were numbered
during the period.

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

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was at quiet to unsettled levels. 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 predominantly quiet to unsettled levels throughout
the period. Isolated active periods may be possible in conjunction
with sustained periods of southward Bz, more likely at higher
latitudes.

III. Event Probabilities 24 May-26 May

• Class M 05/05/05
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 23 May 083
• Predicted 24 May-26 May 085/085/085
• 90 Day Mean 23 May 091

V. Geomagnetic A Indices

• Observed Afr/Ap 22 May 010/014
• Estimated Afr/Ap 23 May 004/010
• Predicted Afr/Ap 24 May-26 May 006/008-004/008-008/012

VI. Geomagnetic Activity Probabilities 24 May-26 May

A. Middle Latitudes

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

B. High Latitudes

• Active 20/20/25
• Minor storm 05/05/10
• Major-severe storm 01/01/05