Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Aug 2002
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 228 Issued at 2200Z on 16 Aug 2002
IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity increased to high levels. Region 69
(S07E11) continues to grow at a gradual pace in both penumbral
coverage and magnetic complexity. This region produced the largest
flare during the period, a long duration M5/2n occurring at 16/1232
UTC with an associated 1600 sfu Tenflare and a Type II radio sweep
with an estimated shock velocity of 1836 km/s. Moderate to strong
discrete radio bursts and a strong Type IV radio sweep were also
associated with this flare. SOHO/LASCO reported a full-halo CME
surrounding the C2 occulting disk by 16/1254 UTC. Region 61 (now
beyond the west limb) produced an M2/Sf flare at 16/0611 UTC just
prior to exiting the disk. A Type II radio sweep with an estimated
shock velocity of 1450 km/s was associated with this flare. Region
78 (S13W39) produced an M1/Sf at 16/2333 UTC. Newly numbered region
81 (N17E61) was assigned today.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels. Region 69 has the potential to produce further
major flare activity.
IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:
The geomagnetic field was at unsettled to minor storm levels. A
slight indication of a weak shock passage at the ACE spacecraft was
observed at the beginning of the period. The greater than 2 MeV
electron flux at geo-synchronous orbit exceeded threshold at 16/1505
UTC, preliminary maximum flux was 1340 pfu at 16/1530 UTC.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled to active levels through most of day one
of the period. Minor to major storm conditions may begin as early
as day two of the period in response to the major flare and
associated CME mentioned in IA. Day three should see a return to
unsettled to active conditions as the potential effects from
expected shock subside. The greater than 2 MeV electron flux should
see a return to moderate levels by day one of the period.
III. Event Probabilities 17 Aug-19 Aug
Class M 75/75/75
Class X 15/15/15
Proton 10/10/10
PCAF yellow
IV. Penticton 10.7 cm Flux
Observed 16 Aug 214
Predicted 17 Aug-19 Aug 215/220/225
90 Day Mean 16 Aug 166
V. Geomagnetic A Indices
Observed Afr/Ap 15 Aug 018/019
Estimated Afr/Ap 16 Aug 020/020
Predicted Afr/Ap 17 Aug-19 Aug 020/020-050/070-018/020
VI. Geomagnetic Activity Probabilities 17 Aug-19 Aug
A. Middle Latitudes
Active 40/30/40
Minor storm 15/25/15
Major-severe storm 10/25/10
B. High Latitudes
Active 35/30/30
Minor storm 15/30/15
Major-severe storm 15/30/15