Viewing archive of Wednesday, 18 May 2005
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2005 May 18 2210 UTC# Prepared jointly by the U.S. Dept. of Commerce, NOAA, #Space Environment Center and the U.S. Air Force. #
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 138 Issued at 2200Z on 18 May 2005IA. 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 to 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 to 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% |
All times in UTC
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