Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Sep 2003

By SpaceRef Editor
September 18, 2003
Filed under , ,

SDF Number 261 Issued at 2200Z on 18 Sep 2003

IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity was low. A single C-class event, a C1 at
0801 UTC, marked the most significant activity of the day. There
are five spotted regions on the disk and all are simple and stable.

IB. Solar Activity Forecast: Solar activity is expected to be low.

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was at active to major storm levels. The
effects of the high speed — 850 km/s — solar wind continue again
today. The greater than 2 MeV electrons at geosynchronous orbit
reached high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at active to minor storm levels early, then calm to
unsettled to active conditions by the end of the forecast interval.
The influence of the high speed solar wind stream should diminish
over the next three days.

III. Event Probabilities 19 Sep-21 Sep
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Sep 109
Predicted 19 Sep-21 Sep 110/110/110
90 Day Mean 18 Sep 120

V. Geomagnetic A Indices
Observed Afr/Ap 17 Sep 035/061
Estimated Afr/Ap 18 Sep 025/040
Predicted Afr/Ap 19 Sep-21 Sep 020/035-015/025-015/020

VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep
A. Middle Latitudes
Active 50/40/40
Minor storm 20/15/15
Major-severe storm 05/05/05
B. High Latitudes
Active 50/50/50
Minor storm 25/20/20
Major-severe storm 05/05/05

SpaceRef staff editor.