:Product: 0626RSGA.txt :Issued: 2008 Jun 26 2203 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 178 Issued at 2200Z on 26 Jun 2008 IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity was very low. No flares occurred during the past 24 hours and the solar disk continues to be spotless. IB. Solar Activity Forecast: Solar activity is expected to be very low. IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field ranged from quiet to active levels during the past 24 hours. Conditions were initially unsettled but increased to predominantly active levels from 0000-1500Z. A particularly notable substorm was observed between 0900-1200Z, which elevated some high latitude sites to storm level activity. Activity levels have declined to quiet to unsettled levels since 1500Z. Solar wind signatures showed an increase in velocity from initial values of about 500 km/s to about 650 km/s by 0800Z. Solar wind velocity continued to be elevated in the 600-650 km/s range through the remainder of the day. The solar wind observations were all consistent with a high speed stream from a favorably positioned coronal hole. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly quiet to unsettled with a chance for isolated active periods for the first day (27 June) while the solar wind velocity remains elevated. Conditions are expected to decline to quiet to unsettled levels for the second day (28 June) and predominantly quiet for the third day (29 June). III. Event Probabilities 27 Jun-29 Jun Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 26 Jun 065 Predicted 27 Jun-29 Jun 065/065/065 90 Day Mean 26 Jun 069 V. Geomagnetic A Indices Observed Afr/Ap 25 Jun 010/012 Estimated Afr/Ap 26 Jun 012/015 Predicted Afr/Ap 27 Jun-29 Jun 010/010-007/008-005/005 VI. Geomagnetic Activity Probabilities 27 Jun-29 Jun A. Middle Latitudes Active 40/20/10 Minor storm 10/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 50/25/10 Minor storm 15/10/01 Major-severe storm 05/01/01