Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Dec 2003

By SpaceRef Editor
December 20, 2003
Filed under , ,

Prepared jointly by the U.S. Dept. of Commerce, NOAA, Space Environment Center and the U.S. Air Force.

Updated 2003 Dec 20 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 354 Issued at 2200Z on 20 Dec 2003

IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity has been low. Region 525 (N09E17)
produced several C-class flares, including a C2.6/Sf at 20/0016Z.
New Region 529 (SN47) at N09W18 was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Regions 525 and 528 (N09E49) are expected to produce
C-class flares, and are capable of producing isolated M-class

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field has been at quiet to major storm levels.
Increased solar wind speed was observed by the ACE spacecraft at
20/0000Z. Wind speed increased from just over 300 km/s to 500 km/s
as of this writing, due most likely to a coronal hole moving into
geoeffective position. The greater than 2 MeV electron flux at
geosynchronous orbit began the period at high levels, but has been
cycling above and below the high threshold level since the arrival
of increased solar wind speed.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to active, with isolated minor storm conditions
on 21-22 December due to persistent effects from the geoeffective
coronal hole.

III. Event Probabilities 21 Dec-23 Dec

  • Class M 25/25/25
  • Class X 05/05/05
  • Proton 01/01/01
  • PCAF Green

IV. Penticton 10.7 cm Flux

  • Observed 20 Dec 130
  • Predicted 21 Dec-23 Dec 130/135/140
  • 90 Day Mean 20 Dec 135

V. Geomagnetic A Indices

  • Observed Afr/Ap 19 Dec 001/007
  • Estimated Afr/Ap 20 Dec 012/018
  • Predicted Afr/Ap 21 Dec-23 Dec 015/020-010/015-010/010

VI. Geomagnetic Activity Probabilities 21 Dec-23 Dec

A. Middle Latitudes

  • Active 35/30/30
  • Minor storm 20/15/10
  • Major-severe storm 05/05/01

B. High Latitudes

  • Active 45/40/40
  • Minor storm 25/25/20
  • Major-severe storm 10/10/05

SpaceRef staff editor.