Friday, April 01, 2011

Weekly Propagation Forecast Bulletins

Product: Weekly Highlights and Forecasts:Issued: 2011 Mar 29 1817 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 21 - 27 March 2011
Solar activity ranged from very low to moderate levels. Region 1176 (S16, L=199, class/area Fki/420 on 26 March) rotated onto the visible disk on 21 March, and produced a long duration C4 flare. Low levels of activity continued through the 22nd. Activity increased to moderate levels from 23-25 March as Region 1176 produced one M1 flare each day (23/0217Z, 24/1207Z, 25/2322Z). Partial halo CMEs associated with the M1 flares on the 24th and 25th were observed The first had an estimated plane-of-sky speed of 421 km/s; the second was accompanied by Type II (673 km/s), Type IV, and 10.7 cm (170 sfu) radio emissions. A fast (approx. 850 km/s), asymmetric, partial halo CME was observed on 26 March was attributed to Region 1180 (N25, L=162, class/area Hsx/070 on 26 March), but was not expected to be potentially geoeffoective. Only the CME from the 24th was expected to have geoeffective potential. Of the four remaining active regions, Region 1178 (S15, L=172, class/area Dai/130) was the largest.

The greater than 10 MeV proton flux at geosynchronous orbit rose above 10 pfu on 21 March at 1950Z and reached a maximum of 14 pfu on 22 March at 0130Z and ended that day at 0335Z. The most likely source of the event was a flare and back-sided CME.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal levels throughout the period.

The geomagnetic field was quiet for the majority of the period, except for a few instances of unsettled conditions on 24 March due to Coronal Hole (CH) high speed stream (HSS) effects.

Forecast of Solar and Geomagnetic Activity 30 March - 25 April 2011

Solar activity is forecast to be low for the period with C-class flares expected and a chance for M-class flares exists based on the size and magnetic complexity of Regions 1176 and 1183 (N15, L= 136, class/area Eai/250 on 28 March). Region 1176 is expected to remain on the disk through 05 April and Region 1183 will rotate off on 09 April, if it does not decay prior. Old Region 1169 which is anticipated to return on 31 March produced an M4.2/1N flare during the last rotation. Imagery from STEREO-B spacecraft as well as brightening on the east limb on GOES 15 SXI and NASA SDO AIA 193 suggest that the region may remain prominent this rotation as well.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 01-02 April.

Geomagnetic activity is expected to range from quiet to unsettled levels. Unsettled levels are expected 30 - 31 March, 07 - 09 April, and 18 - 19 April, with a slight chance for an isolated active to minor storm period at high latitudes due to anticipated recurrent coronal holes. Predominantly quiet levels are expected for the
remainder of the period.

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2011 Mar 29 1817 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 2011-03-29
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2011 Mar 30 130 10 3
2011 Mar 31 135 10 3
2011 Apr 01 140 8 3
2011 Apr 02 135 5 2
2011 Apr 03 135 5 2
2011 Apr 04 135 5 2
2011 Apr 05 130 5 2
2011 Apr 06 130 5 2
2011 Apr 07 125 8 3
2011 Apr 08 120 8 3
2011 Apr 09 110 8 3
2011 Apr 10 100 5 2
2011 Apr 11 95 5 2
2011 Apr 12 95 5 2
2011 Apr 13 90 5 2
2011 Apr 14 88 5 2
2011 Apr 15 88 5 2
2011 Apr 16 90 5 2
2011 Apr 17 100 5 2
2011 Apr 18 100 8 3
2011 Apr 19 105 10 3
2011 Apr 20 110 5 2
2011 Apr 21 115 5 2
2011 Apr 22 115 5 2
2011 Apr 23 115 5 2
2011 Apr 24 120 5 2
2011 Apr 25 120 5 2
(NOAA)