Tuesday, August 11, 2009

Weekly Propagation Forecast Bulletins

Product: Weekly Highlights and Forecasts
:Issued: 2009 Aug 11 1921 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact: www.swpc.noaa.gov/weekly.html
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
03 - 09 August 2009

Solar activity was very low. No flares were observed. The visible disk was spotless.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal background levels.

The geomagnetic field was initially unsettled early on 3 August but decreased to quiet levels by mid-day. Conditions remained quiet until 0600-1500 UTC on 5 August when there was an increase to unsettled levels. Conditions returned to quiet levels for the remainder of 5 August, but then increased to unsettled to active levels between 0000-0900 UTC on 6 August, followed by quiet to unsettled levels from 0900-1800 UTC. Predominately quiet levels followed until 2100-2359 UTC on 7 August when there was an increase to unsettled levels. Quiet levels followed until 0600-1500 UTC on 9 August when there was another increase to generally unsettled levels with active to minor storm periods at high latitudes.

Observations from the ACE spacecraft showed that the increase early on 3 August was due to an extended negative Bz interval (minimum value of -6.5 nT at 02/2115 UTC) which was associated with a solar sector boundary crossing. The activity increases on 5 and 6 August appeared to be associated with the onset of a co-rotating interaction region (CIR) which was followed by a high speed stream from a negative polarity coronal hole. During the initial part of the CIR there was an extended negative Bz interval (minimum value of -4.9 nT at 05/0744 UTC), followed by a northward turning of Bz and strengthening of Bt (peak value 13.0 nT at 05/2130 UTC), followed by another southward Bz interval (minimum value of about -13.5 nT
06/0514 UTC).

The solar wind velocity observed during the high speed stream reached maximum values around 535 km/s at 06/1123 UTC. After a gradual decline in solar wind velocity there was another density and magnetic field enhancement late on 7 August (Bz minimum of about -4.2 nT at 07/1936 UTC) followed by a second increase in solar wind speed (peak of 533 km/s 08/0615 UTC) which caused the geomagnetic activity increase that occurred at that time. A similar structure was seen again early on 9 August with an extended interval from 0200-1040 UTC of negative Bz values (minimum of -4.4 nT at 09/0300 (UTC) and solar wind velocity reaching 481 km/s at 09/1120 UTC.

Forecast of Solar and Geomagnetic Activity
12 August - 07 September 2009

Solar activity is expected to be very low.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels during 21 - 22 August. Normal to moderate flux levels are expected during the rest of the period.

Geomagnetic field activity is expected to be quiet from 12 - 17 August. Activity is expected to increase to active levels on 18 August with a chance for minor storm levels due to a recurrent CH HSS. Activity is expected to decrease to unsettled levels on 19-21 August as the CH HSS subsides. Mostly quiet conditions are expected for 22 August - 07 September with the exception of 30 August and 02-03 September when recurrent effects are expected to increase activity to unsettled levels.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2009 Aug 11 1921 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact: www.swpc.noaa.gov/wwire.html
#
# 27-day Space Weather Outlook Table

# Issued 2009 Aug 11
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2009 Aug 12 67 5 2
2009 Aug 13 67 5 2
2009 Aug 14 67 5 2
2009 Aug 15 67 5 2
2009 Aug 16 67 5 2
2009 Aug 17 67 5 2
2009 Aug 18 67 20 4
2009 Aug 19 68 12 3
2009 Aug 20 68 8 3
2009 Aug 21 68 8 3
2009 Aug 22 68 5 2
2009 Aug 23 68 5 2
2009 Aug 24 68 5 2
2009 Aug 25 68 5 2
2009 Aug 26 68 5 2
2009 Aug 27 68 5 2
2009 Aug 28 68 5 2
2009 Aug 29 68 5 2
2009 Aug 30 68 8 3
2009 Aug 31 68 5 2
2009 Sep 01 68 5 2
2009 Sep 02 68 8 3
2009 Sep 03 68 8 3
2009 Sep 04 68 5 2
2009 Sep 05 68 5 2
2009 Sep 06 68 5 2
2009 Sep 07 68 5 2
(NOAA)