Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 May 15 2230 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 135 Issued at 2200Z on 15 May 2005
IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity was low. Several low level C-flares
were produced by Regions 758 (S10 on the west limb) and 763
(S15E16). Region 759 (N11W20) has decayed slightly over the past 24
hours. A CME off the west limb with a speed of approximately 580
km/s was seen on LASCO imagery at 14/2122 UTC associated with a long
duration C2.8 which occurred at 14/2058 UTC from Region 758. At the
time of issue, the greater than 10 MeV proton flux at geosynchronous
orbit was at 3.4 PFU as of 15/2135 UTC.
IB. Solar Activity Forecast: Solar activity is expected to be at
low to moderate levels. Region 759 is still capable of producing an
M-class event.
IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
The geomagnetic field was at quiet to severe storm levels. The
arrival of a CME from 13 May initiated the disturbance which caused
severe storming conditions between 15/0600 UTC and 0900 UTC. Solar
wind speed at ACE increased from approximately 200 km/s to 950 km/s.
Solar wind speed has declined to approximately 750 km/s by the end
of the period. The greater than 2 MeV electron flux at
geosynchronous orbit reached high levels again today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled to minor storm levels on 16 May. On 17
May, a possible glancing blow from the 14 May CME along with a
recurrent coronal hole high speed stream are expected to become
geoeffective causing unsettled to active conditions. Quiet to
unsettled conditions are expected on 18 May.
III. Event Probabilities 16 May-18 May
- Class M 40/35/30
- Class X 05/05/05
- Proton 40/10/05
- PCAF yellow
IV. Penticton 10.7 cm Flux
- Observed 15 May 103
- Predicted 16 May-18 May 100/100/100
- 90 Day Mean 15 May 093
V. Geomagnetic A Indices
- Observed Afr/Ap 14 May 004/008
- Estimated Afr/Ap 15 May 075/100
- Predicted Afr/Ap 16 May-18 May 020/040-012/015-008/010
VI. Geomagnetic Activity Probabilities 16 May-18 May
A. Middle Latitudes
- Active 30/25/20
- Minor storm 25/10/10
- Major-severe storm 15/01/01
B. High Latitudes
- Active 25/25/20
- Minor storm 30/15/10
- Major-severe storm 25/05/01