Joint USAF/NOAA Report of Solar and Geophysical Activity 15 Jul 2003

SDF Number 196 Issued at 2200Z on 15 Jul 2003

IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity was low. Today’s activity consisted of a
few low-level C-class flares from Region 409 (N15E41). Region 409
showed growth with the development of new spots in the trailing
portion of the region. The penumbra in the region has developed to
form a compact distribution of spots, suggesting that a delta
configuration may form if the current trend continues. A seven
degree filament near (N41E11) disappeared between 1046 UTC and 1211
UTC. New Region 411 (N16E62) was assigned today.

IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate over the next three days, with Region 409 as the most
likely source of M-class flares. There is a slight chance for major
flare activity from Region 409 if the current trend continues.

IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
The geomagnetic field ranged from unsettled to minor storm levels. An
initially active geomagnetic field reached minor storm levels from
0000-0600 UTC. Active to minor storm levels were also observed
between 0900-1200 UTC. Conditions have been unsettled since 1200
UTC. The activity increase was seen in response to a jump in solar
wind velocity and density accompanied by a southward turning of Bz
between 14/2100 UTC and 15/0100 UTC. Solar wind conditions remained
elevated for the remainder of the day, ranging mostly between 550 to
600 km/s. The solar wind data appear to be consistent with a brief
interval of a co-rotating interaction region followed by a
high-speed, coronal-hole-driven solar wind stream. The greater than
2 MeV electron flux reached high levels during the past 24 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be active, with a chance for isolated minor storm
periods, during the next 24 hours as a solar coronal hole rotates
through a geoeffective position. A decline to unsettled to active
levels is expected on the second day and a return to mostly
unsettled levels is expected by the third day.

III. Event Probabilities 16 Jul-18 Jul

• Class M 40/40/40
• Class X 10/10/10
• Proton 05/05/05
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 15 Jul 126
• Predicted 16 Jul-18 Jul 125/123/121
• 90 Day Mean 15 Jul 126

V. Geomagnetic A Indices

• Observed Afr/Ap 14 Jul 013/015
• Estimated Afr/Ap 15 Jul 020/025
• Predicted Afr/Ap 16 Jul-18 Jul 020/025-015/020-010/015

VI. Geomagnetic Activity Probabilities 16 Jul-18 Jul

A. Middle Latitudes

• Active 50/40/30
• Minor storm 25/20/15
• Major-severe storm 05/05/05

B. High Latitudes

• Active 30/30/30
• Minor storm 35/25/20
• Major-severe storm 20/15/10