Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Mar 2005
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Mar 20 2200 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 079 Issued at 2200Z on 20 Mar 2005
IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity remained at low levels today. Old
Region 742 (S06 L=160) which rotated off the west solar limb 19
March produced the largest flare of the period, a C4 x-ray event
that occurred at 20/0159 UTC. Region 743 (S08W70) produced multiple
B and C-class flares during the period. The largest was a C2 x-ray
event that occurred at 20/1152 UTC. There was some decay in spot
area today and the beta-gamma magnetic structure weakened but
remains intact. Region 744 (S12E01) is a rapidly forming DSO beta
group and was numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels.
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was at quiet to unsettled levels.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly quiet to unsettled levels. Isolated
active periods may be possible at higher latitudes on 22 and 23
March, due to a potentially geoeffective coronal hole.
III. Event Probabilities 21 Mar-23 Mar
- Class M 10/10/05
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 20 Mar 089
- Predicted 21 Mar-23 Mar 085/080/080
- 90 Day Mean 20 Mar 098
V. Geomagnetic A Indices
- Observed Afr/Ap 19 Mar 009/014
- Estimated Afr/Ap 20 Mar 004/006
- Predicted Afr/Ap 21 Mar-23 Mar 004/008-004/012-006/015
VI. Geomagnetic Activity Probabilities 21 Mar-23 Mar
A. Middle Latitudes
- Active 15/15/15
- Minor storm 01/01/05
- Major-severe storm 01/02/01
B. High Latitudes
- Active 20/25/30
- Minor storm 05/05/10
- Major-severe storm 01/05/05
