Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Feb 2005
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Feb 18 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 049 Issued at 2200Z on 18 Feb 2005
IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity was low. Regions 732 (N15W90) and 735
(S09W32) were responsible for several low level C-class flares.
Region 732 produced the largest C-flare; a C2.3 at 17/2344Z.
IB. Solar Activity Forecast: Solar activity is expected to be low.
Region 735 is still capable of producing C-class events.
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was at quiet to minor storm levels. Activity
was due to the effects of a high speed stream from a geoeffective
coronal hole. Solar wind speed at ACE showed an increase to
approximately 600 km/s by 18/1600Z and then decreased slightly to
550 km/s by the end of the period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be unsettled to active with the possibility of isolated
minor storm levels on 19 February due to the arrival of the CME
observed on LASCO imagery on 17 February. Expect quiet to active
conditions on 20 February and quiet to unsettled conditions on 21
February.
III. Event Probabilities 19 Feb-21 Feb
- Class M 15/15/15
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 18 Feb 104
- Predicted 19 Feb-21 Feb 100/100/095
- 90 Day Mean 18 Feb 101
V. Geomagnetic A Indices
- Observed Afr/Ap 17 Feb 007/006
- Estimated Afr/Ap 18 Feb 017/027
- Predicted Afr/Ap 19 Feb-21 Feb 015/030-012/015-010/008
VI. Geomagnetic Activity Probabilities 19 Feb-21 Feb
A. Middle Latitudes
- Active 30/25/20
- Minor storm 15/15/10
- Major-severe storm 10/05/05
B. High Latitudes
- Active 30/30/20
- Minor storm 30/15/10
- Major-severe storm 15/10/01
