Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Jul 2005
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Jul 18 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 199 Issued at 2200Z on 18 Jul 2005
IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity decreased to very low levels. The
visible disk was spotless today. Old Region 790 (S10 L=013)
produced low level B-class flares very early in the period from
beyond the solar west limb. The disk and limbs were fairly
quiescent during the period. No new regions were numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
very low levels.
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field has ranged from quiet to major storm levels.
The elevated conditions may have resulted from the X1 flare and
associated full halo CME that occurred on 14 July. The greater than
10 MeV proton flux that began on 14/0245Z, had a peak flux of 134
pfu at 15/0345Z, and ended at 18/1015Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly unsettled to isolated active levels
on 19 July. A recurrent high speed coronal hole stream is expected
to become geoeffective on 20 July with active to minor storming
conditions anticipated and isolated major storming possible. A
decrease to predominantly unsettled to active levels can be expected
on 21 July..
III. Event Probabilities 19 Jul-21 Jul
- Class M 01/01/01
- Class X 01/01/01
- Proton 20/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 18 Jul 072
- Predicted 19 Jul-21 Jul 070/075/075
- 90 Day Mean 18 Jul 097
V. Geomagnetic A Indices
- Observed Afr/Ap 17 Jul 015/022
- Estimated Afr/Ap 18 Jul 022/035
- Predicted Afr/Ap 19 Jul-21 Jul 008/015-020/025-012/015
VI. Geomagnetic Activity Probabilities 19 Jul-21 Jul
A. Middle Latitudes
- Active 20/40/25
- Minor storm 05/20/15
- Major-severe storm 01/15/05
B. High Latitudes
- Active 35/40/35
- Minor storm 15/30/15
- Major-severe storm 05/20/05
