:Product: 0429RSGA.txt :Issued: 2011 Apr 29 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 119 Issued at 2200Z on 29 Apr 2011 IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity has been at low levels for the past 24 hours. Region 1203 (N18E64) produced the largest event of the period, a C3 flare at 29/0026Z. Region 1200 (S17E05) regained spots and has developed into a beta group. IB. Solar Activity Forecast: Solar activity is expected to be at low levels for the next two days (30 April - 01 May). Very low to low levels are expected on day three (02 May) as Regions 1199 (N18W62) and 1195 (S15W65) rotate off the west limb. IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field has been at predominantly quiet levels for the past 24 hours. However, late in the summary period, unsettled conditions were observed. Measurements by the ACE spacecraft showed an increase in solar wind speed from around 350 - 450 km/s. The total interplanetary magnetic field increased from 5 - 18 nT over the period with the negative component peaking at -10 nT. These changes in solar wind indicate the arrival of a coronal hole high-speed stream (CH HSS). IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active with isolated periods at minor storm levels for the next three days (30 April - 02 May) as a CH HSS becomes geoeffective. III. Event Probabilities 30 Apr-02 May Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 29 Apr 110 Predicted 30 Apr-02 May 110/105/105 90 Day Mean 29 Apr 107 V. Geomagnetic A Indices Observed Afr/Ap 28 Apr 001/003 Estimated Afr/Ap 29 Apr 007/008 Predicted Afr/Ap 30 Apr-02 May 010/010-012/012-010/010 VI. Geomagnetic Activity Probabilities 30 Apr-02 May A. Middle Latitudes Active 35/40/35 Minor storm 10/10/10 Major-severe storm 01/01/01 B. High Latitudes Active 40/45/40 Minor storm 10/15/15 Major-severe storm 01/05/05