Joint USAF/NOAA Report of Solar and Geophysical Activity 18 May 2005
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 May 18 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 138 Issued at 2200Z on 18 May 2005
IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity was low. Region 763 (S16W24) was
responsible for three low level C-flares. This region continues to
decay. A CME off the SW limb was observed today on LASCO imagery at
18/0206 UTC, but does not appear to be Earth directed.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low with a chance for an isolated M-flare.
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was quiet to active. Solar wind speed at ACE
has been variable between 450 km/s and 550 km/s. The greater than 2
MeV electron flux at geosynchronous orbit was high again today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to active on 19 May as a faint full halo CME,
from 17 May, may arrive late in the day. Unsettled conditions are
expected on 20 May. Quiet to unsettled conditions are expected on
21 May.
III. Event Probabilities 19 May-21 May
- Class M 35/20/10
- Class X 05/01/01
- Proton 05/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 18 May 084
- Predicted 19 May-21 May 085/085/085
- 90 Day Mean 18 May 092
V. Geomagnetic A Indices
- Observed Afr/Ap 17 May 010/019
- Estimated Afr/Ap 18 May 010/018
- Predicted Afr/Ap 19 May-21 May 012/015-010/015-005/010
VI. Geomagnetic Activity Probabilities 19 May-21 May
A. Middle Latitudes
- Active 25/20/15
- Minor storm 10/10/05
- Major-severe storm 01/01/01
B. High Latitudes
- Active 25/25/20
- Minor storm 15/15/10
- Major-severe storm 05/05/01
