Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Jun 2003

SDF Number 172 Issued at 2200Z on 21 Jun 2003

IA. Analysis of Solar Active Regions and Activity from 20/2100Z
to 21/2100Z: Solar activity was at low levels. Region 388 (S03W19)
produced the largest flare of the period, a C2.5/Sf that occurred at
21/1313Z along with many lesser flares during the interval. This
region showed rapid growth during the period with a more than
doubling of the penumbral coverage. Region 386 (S07E04) produced
several lesser C-class flares today and has been in a steady decay
phase since yesterday. The delta magnetic structure is still intact
in the leading edge of the spot cluster. Region 387 (N18E23) was
fairly quiescent today although it still depicts a beta-gamma
magnetic complex. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at
low to moderate levels. Regions 386, 387, and 388 all have the
potential for producing M-class flare activity.

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field was at unsettled to minor storm levels.
Sustained periods of southward Bz along with elevated solar wind
speeds led to the occasional storming conditions. The greater than
2 MeV electron flux at geosynchronous orbit reached high levels
today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled to active levels. Isolated minor storm
conditions are possible throughout the period due to a recurrent
high speed coronal hole stream.

III. Event Probabilities 22 Jun-24 Jun

• Class M 30/30/30
• Class X 10/10/10
• Proton 05/05/05
• PCAF yellow

IV. Penticton 10.7 cm Flux

• Observed 21 Jun 115
• Predicted 22 Jun-24 Jun 115/115/115
• 90 Day Mean 21 Jun 126

V. Geomagnetic A Indices

• Observed Afr/Ap 20 Jun 010/012
• Estimated Afr/Ap 21 Jun 018/025
• Predicted Afr/Ap 22 Jun-24 Jun 012/015-015/015-012/012

VI. Geomagnetic Activity Probabilities 22 Jun-24 Jun

A. Middle Latitudes

• Active 25/35/25
• Minor storm 10/20/10
• Major-severe storm 01/05/01

B. High Latitudes

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

PLAIN

K-Indices:

On 16 June, it was determined that a scaling problem exists with the Boulder magnetometer instrument. While this problem, and its fix are being investigated the primary instrument for Boulder K-indices has been switched to the Boulder USGS (via Domsat) magnetometer, effective 1500 UTC on 16 June.

GOES Protons:

To ensure continued operational monitoring of important energetic particle data, it is necessary to reassign primary/secondary designations for the GOES Space Environment Monitor (SEM) detectors. GOES 11 (113W) is now the primary satellite for protons. GOES 12 will continue as the primary satellite for magnetometer, X-ray, and electron measurements. GOES 10 (135W) will be the secondary satellite for all SEM sensors – magnetometer, X-ray, and energetic particles. Because of the degraded state of the proton data on GOES-10, its designation as the secondary source for proton data is a short-term solution. More permanent solutions have been identified and are being evaluated. Users will be notified when we define and schedule a permanent fix. Further details can be found at http://www.sec.noaa.gov/GOES.html.