Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Jul 2005

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 202 Issued at 2200Z on 21 Jul 2005

IA. Analysis of Solar Active Regions and Activity from 20/2100Z
to 21/2100Z: Solar activity was very low. A full halo CME was
observed in LASCO imagery at approximately 21/0354 UTC. This event
was determined to be backsided. The solar disk remains spotless.

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

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field ranged from quiet to minor storm levels. Mid
and high lattitudes experienced minor storming from 0000 to 0600
UTC, with high lattitudes experiencing further minor storming from
0900 to 1200 UTC. The storm conditions are the result of a coronal
hole high speed stream. Solar wind speed has been at about 550 km/s
thoughout the day. The greater than 2 MeV electrons at
geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be unsettled to active on 22 July as the coronal hole
high speed stream wanes. Quiet to unsettled conditions are expected
on 23 and 24 July.

III. Event Probabilities 22 Jul-24 Jul

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

IV. Penticton 10.7 cm Flux

• Observed 21 Jul 073
• Predicted 22 Jul-24 Jul 075/075/080
• 90 Day Mean 21 Jul 097

V. Geomagnetic A Indices

• Observed Afr/Ap 20 Jul 014/020
• Estimated Afr/Ap 21 Jul 020/030
• Predicted Afr/Ap 22 Jul-24 Jul 010/015-008/010-005/005

VI. Geomagnetic Activity Probabilities 22 Jul-24 Jul

A. Middle Latitudes

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

B. High Latitudes

• Active 30/25/20
• Minor storm 15/10/05
• Major-severe storm 05/05/01