:Product: 20040501RSGA.txt :Issued: 2004 May 01 2200 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 122 Issued at 2200Z on 01 May 2004 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 01/2100Z: Solar activity has been low. There have been several C-class x-ray events, a C2.8 on 01 May at 0755 UTC, and a C9.5 at 1536 UTC, all from Region 601 (S09W34). This region has grown both in area and number of spots over the last 24 hours. Region 602 (S13W66) remains steady. Region 603 (S15W37) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to remain low. There is an increased chance for an isolated M-class x-ray event. IIA. Geophysical Activity Summary 30/2100Z to 01/2100Z: The geomagnetic field has been at unsettled to active levels. A combination of southward interplanetary magnetic field (IMF) and elevated solar wind speeds disrupted the Earth's magnetic field for most of 30 April and into 01 May. A transient passage combined with a solar sector boundary crossing appear to have influenced the magnetic field earlier on 30 April. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain at unsettled to active levels for the rest of 01 May. By 02 and 03 May, a high-speed solar wind stream associated with a coronal hole is expected to intersect the Earth's magnetic field. Activity should increase to minor storming late on 02 May and into early 03 May, dropping back down to active levels by 04 May as the high-speed stream passes. III. Event Probabilities 02 May-04 May Class M 20/20/15 Class X 01/01/01 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 01 May 094 Predicted 02 May-04 May 095/095/095 90 Day Mean 01 May 107 V. Geomagnetic A Indices Observed Afr/Ap 30 Apr 009/012 Estimated Afr/Ap 01 May 011/012 Predicted Afr/Ap 02 May-04 May 012/015-015/020-012/015 VI. Geomagnetic Activity Probabilities 02 May-04 May A. Middle Latitudes Active 30/35/30 Minor storm 15/20/15 Major-severe storm 01/05/01 B. High Latitudes Active 35/40/35 Minor storm 20/30/20 Major-severe storm 05/10/05