Joint USAF/NOAA Report of Solar and Geophysical Activity 19 Jun 2003

SDF Number 170 Issued at 2200Z on 19 Jun 2003

IA. Analysis of Solar Active Regions and Activity from 18/2100Z
to 19/2100Z: Solar activity decreased to very low levels. Flare
activity was limited to several B-class flares. Region 386 (S07E30)
lost penumbral coverage over the period although it does retain a
delta magnetic structure in the dominant lead spot. Region 387
(N18E49) grew in both penumbral coverage and magnetic complexity
since yesterday, a gamma structure is now evident in the trailing
portion of the spot group. Newly numbered Region 388 (S03E08)
produced a minor B-class flare early in the period.

IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels. Region 386 remains capable of producing an
isolated major flare.

IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z:
The geomagnetic field was at predominantly active levels today.
Minor storm conditions were observed at both middle and high
latitudes between 19/0000 and 0300Z due to the influence of a
recurrent high speed coronal hole stream. The greater than 10 MeV
proton flux exceeded event threshold at 18/2050Z (reached a max of
24 pfu at 19/0450Z), ended at 19/1900Z and after careful review the
event is believed to have been the result of the M6.8 x-ray flare
from June 17. The greater than 2 MeV electron flux reached moderate
levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly unsettled to active levels through
the interval. Minor storm conditions may exist due to a transient
passage during the first half of day one in response to the M6.8
x-ray flare from June 17.

III. Event Probabilities 20 Jun-22 Jun

• Class M 50/50/50
• Class X 15/15/15
• Proton 25/15/15
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 19 Jun 123
• Predicted 20 Jun-22 Jun 125/125/125
• 90 Day Mean 19 Jun 124

V. Geomagnetic A Indices

• Observed Afr/Ap 18 Jun 036/054
• Estimated Afr/Ap 19 Jun 023/025
• Predicted Afr/Ap 20 Jun-22 Jun 020/025-020/025-012/020

VI. Geomagnetic Activity Probabilities 20 Jun-22 Jun

A. Middle Latitudes

• Active 40/40/25
• Minor storm 15/15/10
• Major-severe storm 10/10/05

B. High Latitudes

• Active 50/50/40
• Minor storm 20/20/15
• Major-severe storm 10/10/10

PLAIN

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.

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. 99999