Joint USAF/NOAA Report of Solar and Geophysical Activity 15 May 2005
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
