09/15/08: Joint USAF/NOAA Report of Solar and Geophysical Activity. SDF Number 259 Issued at 2200Z on 15 Sep 2008 IA.  Analysis of Solar Active Regions and Activity from  14/2100Z to 15/2100Z:  Solar activity was very low. No flares were observed during the past 24 hours. The visible disk remained spotless. IB.  Solar Activity Forecast:  Solar activity is expected to be very low. IIA.  Geophysical Activity Summary 14/2100Z to 15/2100Z: The geomagnetic field was predominately unsettled to active. An isolated quiet period was observed at 15/0000Z. The increase in activity is in response to a favorably positioned coronal hole high speed stream. Solar wind speed measured at the ACE spacecraft indicated an increase from approximately 390 km/s to 610 km/s during the forecast period. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels today. IIB.  Geophysical Activity Forecast:  The geomagnetic field is expected to be predominately quiet to unsettled with isolated active conditions on day one (16 September). Predominately quiet with isolated unsettled conditions are expected on days two and three (17-18 September) as the coronal hole effects subside. III.  Event Probabilities 16 Sep-18 Sep Class M    01/01/01 Class X    01/01/01 Proton     01/01/01 PCAF       Green IV.  Penticton 10.7 cm Flux Observed           15 Sep 068 Predicted   16 Sep-18 Sep  066/066/066 90 Day Mean        15 Sep 066 V.  Geomagnetic A Indices Observed Afr/Ap 14 Sep  004/006 Estimated Afr/Ap 15 Sep  015/015 Predicted Afr/Ap 16 Sep-18 Sep  007/008-005/005-005/005 VI.  Geomagnetic Activity Probabilities 16 Sep-18 Sep A.  Middle Latitudes Active                20/10/10 Minor storm           01/01/01 Major-severe storm    01/01/01 B.  High Latitudes Active                25/10/10 Minor storm           05/01/01 Major-severe storm    01/01/01 Latst Mauna Loa image. Credit: NOAA - courtesy of USAF/NOAA