Viewing archive of Tuesday, 14 September 1999
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 1999 Sep 14 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 257 Issued at 2200Z on 14 SEP 1999IA. Analysis of Solar Active Regions and Activity from 13-2100Z to 14-2100Z SOLAR ACTIVITY WAS LOW. SEVERAL MINOR, MOSTLY OPTICALLY
UNCORRELATED C-CLASS X-RAY EVENTS OCCURRED THROUGHOUT THE PERIOD.
SMALL GROWTH WAS OBSERVED IN REGIONS 8690 (N15W34) AND 8699
(N21W11). NO SIGNIFICANT CHANGES WERE NOTED IN ANY OF THE REMAINING
FOUR SUNSPOT REGIONS. AN IMPRESSIVE PROMINENCE ERUPTION/CME ON THE
NW LIMB WAS OBSERVED FROM SPACE-BASED IMAGERY AT AROUND 14/0500UT.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO CONTINUE
AT LOW LEVELS. REGIONS 8690, 8692 (S27W14), 8699 (N21W11), AND 8700
(N14E59), ALL HAVE POTENTIAL FOR C-CLASS X-RAY ACTIVITY AND A SMALL
CHANCE FOR AN M-CLASS EVENT.
IIA. Geophysical Activity Summary 13-2100Z to 14-2100Z
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO MINOR STORMING. THIS
ONGOING DISTURBANCE, ASSOCIATED WITH A HIGH-SPEED CORONAL HOLE WIND
STREAM, CONTINUES TO PRODUCE PERIODS OF MINOR STORMING DURING LOCAL
NIGHTTIME HOURS,
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD WILL
CONTINUE AT QUIET TO ACTIVE LEVELS DURING LOCAL DAYLIGHT HOURS AND
UNSETTLED TO MINOR STORM DURING LOCAL NIGHTTIME. EFFECTS FROM THE
HIGH-SPEED CORONAL HOLE WIND STREAM WILL BEGIN TO DIMINISH TOMORROW;
HOWEVER, WE MAY EXPERIENCE ACTIVE TO MINOR STORM CONDITIONS ON DAY
TWO FROM CME'S OBSERVED DURING THE PAST TWO DAYS.
III. Event Probabilities 15 SEP to 17 SEP
| Class M | 20% | 20% | 20% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 14 SEP 156 Predicted 15 SEP-17 SEP 160/165/170 90 Day Mean 14 SEP 164
V. Geomagnetic A Indices
OBSERVED AFR/AP 13 SEP 023/038 ESTIMATED AFR/AP 14 SEP 022/025 PREDICTED AFR/AP 15 SEP-17 SEP 018/015-018/015-010/010
VI. Geomagnetic Activity Probabilities 15 SEP to 17 SEP
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 50% | 40% | 30% |
| Minor storm | 20% | 15% | 10% |
| Major-severe storm | 10% | 05% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 60% | 50% | 40% |
| Minor storm | 30% | 25% | 20% |
| Major-severe storm | 10% | 10% | 05% |
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