Joint USAF/NOAA Report of Solar and Geophysical Activity 12 May 2004

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

Updated 2004 May 12 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 133 Issued at 2200Z on 12 May 2004

IA. Analysis of Solar Active Regions and Activity from 11/2100Z
to 12/2100Z: Solar activity has been mostly very low to low. Region
609 (S04E41) generated a single C1.3 x-ray event on 12 May at 1543
UTC. Two new regions 610 (S02E19) and 611 (S12W14) were numbered
today.

IB. Solar Activity Forecast: Solar activity is expected to remain
very low to low. There’s a chance for isolated C-class x-ray
activity.

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z:
The geomagnetic field has been at mostly quiet to unsettled levels
with a period of active levels from 12 May at 0300 through 0600 UTC.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels with isolated periods of
active for 13 May. From 14 through 15 May, the activity should
increase to mostly unsettled with periods of active to minor
storming due to the influence of a high-speed solar wind stream, and
the possible effects of an interplanetary transient.

III. Event Probabilities 13 May-15 May

• Class M 10/10/10
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 12 May 099
• Predicted 13 May-15 May 095/100/100
• 90 Day Mean 12 May 105

V. Geomagnetic A Indices

• Observed Afr/Ap 11 May 008/010
• Estimated Afr/Ap 12 May 012/012
• Predicted Afr/Ap 13 May-15 May 010/010-012/015-012/015

VI. Geomagnetic Activity Probabilities 13 May-15 May

A. Middle Latitudes

• Active 25/30/30
• Minor storm 10/15/15
• Major-severe storm 01/01/01

B. High Latitudes

• Active 30/35/35
• Minor storm 15/20/20
• Major-severe storm 01/05/05