Wednesday, August 01, 2012

Weekly Propagation Forecast Bulletins


Product: Weekly Highlights and Forecasts
:Issued: 2012 Jul 30 1421 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 23 - 29 July 2012

Solar activity was at very low to high levels through the period. The summary period began at very low to low levels from 23 - 26 July, with multiple low level C-class events observed. An increase to moderate levels was observed on 27 July, as Region 1532 (S22, L= 183, class/area Fho/510 on 28 July) produced an M2/Sf x-ray event at 1726 UTC. Associated with this event were distinct radio frequency bursts as well as a Type II (estimated shock speed of 2099 km/s) and Type IV Radio sweeps, as well as a coronal mass ejection (CME). After careful analysis, the associated CME was determined to not be Earth directed. On 28 July, and increase to high levels was observed as Region 1532 produced an M6/2n x-ray flare at 28/2056 UTC.

Associated with this event were both Type II (estimated shock speed of 1387 km/s) and Type IV radio sweeps, discrete radio frequency spikes, and a 370 sfu Tenflare. Imagery supported a CME liftoff with this event, however due to the location of Region 1532, very little effects are expected at Earth. On the last day of the forecast period, 29 July, a return to moderate levels was observed, as Region 1532 produced an M2/1n x-ray event at 29/0622 UTC.

A greater than 10 MeV proton event at geosynchronous orbit began at 23/1545 UTC, reached a maximum flux of 12 pfu at 23/2145 UTC, and ended at 24/1800 UTC. This event was due to flare activity from old Region 1520 (S16, L=086) which was almost 40 degrees beyond the west limb.

The greater than 2 MeV electron flux at geosynchronous orbit was at high levels from 23 - 28 July. A decrease to moderate levels was observed on 29 July.

Geomagnetic field activity was at mostly quiet to unsettled levels throughout the summary period with isolated periods of minor storm levels observed at high latitudes on 23, 24, and 28 July. Activity on 23 July was at quiet to unsettled levels with solar wind speeds, as measured by the ACE spacecraft, hovering around 450 km/s. On 24 July, solar wind speeds increased to almost 600 km/s, as a coronal hole high speed stream (CH HSS), became geoeffective. With these elevated solar winds, quiet to unsettled levels were observed with an isolated period at minor storm levels observed at high latitudes. As effects of the CH HSS waned, solar wind speeds declined and remained between 380 and 500 km/s for the remainder of the period. With solar wind speeds around nominal levels, mostly quiet to unsettled levels also prevailed through 29 July.

Forecast of Solar and Geomagnetic Activity 30 July - 25 August 2012

Solar activity is expected to be at low to moderate levels from 30 July - 15 August as Region 1532 and old Region 1520 (S16, L=086) rotate across the visible disk. A decrease to mostly low levels is expected from 16 - 23 August. As Region 1532 rotates back onto the visible disk on 23 August, an increase to low to moderate levels is expected for the remainder of the forecast period.

A greater than 10 MeV proton event at geosynchronous orbit is possible from 30 July - 18 August as Region 1532 and old Region 1520 traverse the visible disk.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels throughout the period since most of the coronal hole structures have dissipated.

Geomagnetic field activity is expected to be at predominantly quiet levels from 30 July - 19 August and 22 - 23 August. Quiet to unsettled levels are expected from 20 - 21 August and 24 - 25 August as weak CH HSS become geoeffective.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2012 Jul 30 1421 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 2012-07-30
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2012 Jul 30 132 12 3
2012 Jul 31 135 8 3
2012 Aug 01 138 5 2
2012 Aug 02 140 10 3
2012 Aug 03 150 8 3
2012 Aug 04 155 5 2
2012 Aug 05 155 5 2
2012 Aug 06 155 5 2
2012 Aug 07 155 5 2
2012 Aug 08 150 5 2
2012 Aug 09 150 5 2
2012 Aug 10 140 5 2
2012 Aug 11 130 5 2
2012 Aug 12 120 5 2
2012 Aug 13 120 5 2
2012 Aug 14 110 5 2
2012 Aug 15 100 5 2
2012 Aug 16 95 5 2
2012 Aug 17 90 5 2
2012 Aug 18 90 5 2
2012 Aug 19 95 5 2
2012 Aug 20 95 8 3
2012 Aug 21 95 8 3
2012 Aug 22 100 5 2
2012 Aug 23 110 5 2
2012 Aug 24 120 8 3
2012 Aug 25 130 8 3
(NOAA)