Viewing archive of Sunday, 23 August 1998
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 1998 Aug 23 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 235 Issued at 2200Z on 23 AUG 1998IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z SOLAR ACTIVITY WAS MODERATE. REGION 8307 (N31E22)
PRODUCED AN M2/1N FLARE AT 23/0934Z WITH A 2695 MHZ BURST OF 500
SFU. THIS REGION BEGAN A DECAY TREND DURING THE PERIOD. THE DELTA
CONFIGURATION REMAINED IN THE NORTHERN PORTION OF THE REGION BUT
OVERALL, THE MAGNETIC COMPLEXITY IS DECREASING. REGION 8310 (N24E33)
PRODUCED A C3/SF FLARE AT 23/1125Z.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BECOME
LOW TO MODERATE. CONTINUED DECAY AND SIMPLIFICATION IN REGION 8307
COULD RESULT IN A RAPID DECREASE OF FLARE PRODUCTION. ONLY
OCCASIONAL M-CLASS EVENTS ARE EXPECTED FOR THE NEXT THREE DAYS.
X-CLASS FLARES REMAIN SLIGHTLY POSSIBLE FROM THIS REGION THAT
PRODUCED A TOTAL OF 4 X-CLASS EVENTS EARLY IN ITS VISIBLE HEMISPHERE
TRANSIT.
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
THE GEOMAGNETIC FIELD WAS UNSETTLED AT MIDDLE LATITUDES AND UNSETTLED
TO MINOR STORM LEVELS AT HIGH LATITUDES. THE MOST DISTURBED PERIOD
WAS FROM 23/0000-0900Z. RECENT SOLAR WIND DATA SHOW AN INCREASE OF
SOLAR WIND VELOCITY TO NEAR 600 KM/S AND DECREASE OF DENSITY TO 2-3
P/CC. THESE PARAMETERS INDICATE THE EARTH IS EMBEDDED IN A CORONAL
HOLE STREAM. MAGNETIC DATA IMPLICATE THE EQUATORWARD EXTENSION OF
THE NORTHERN CORONAL HOLE AS THE SOURCE OF THIS STREAM. THE
ENERGETIC (GT 10 MEV) PROTON ENHANCEMENT THAT BEGAN ON 20 AUG
CONTINUED THROUGH THE PERIOD AT A FLUX OF APPROXIMATELY 2 PFU.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD
CONTINUE AT PREDOMINANTLY UNSETTLED TO ACTIVE LEVELS THROUGH 24 AUG.
MINOR STORM INTERVALS ARE POSSIBLE DURING THAT TIME. A SLIGHTLY MORE
INTENSE DISTURBANCE IS EXPECTED ON 25-26 AUG AS A RESULT OF THE M9
FLARE AND SUSPECTED CME OF 22 AUG. ACTIVE TO MINOR STORM LEVELS WITH
ISOLATED PERIODS OF MAJOR STORMING ARE POSSIBLE FOR THAT PERIOD. THE
PROTON ENHANCEMENT SHOULD DECAY SLOWLY OVER THE NEXT SEVERAL DAYS.
III. Event Probabilities 24 AUG to 26 AUG
| Class M | 55% | 55% | 55% |
| Class X | 20% | 20% | 20% |
| Proton | 20% | 20% | 20% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 23 AUG 126 Predicted 24 AUG-26 AUG 127/128/130 90 Day Mean 23 AUG 116
V. Geomagnetic A Indices
OBSERVED AFR/AP 22 AUG 013/023 ESTIMATED AFR/AP 23 AUG 015/020 PREDICTED AFR/AP 24 AUG-26 AUG 020/020-025/020-025/030
VI. Geomagnetic Activity Probabilities 24 AUG to 26 AUG
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 40% | 30% | 30% |
| Minor storm | 20% | 30% | 30% |
| Major-severe storm | 05% | 15% | 15% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 40% | 30% | 30% |
| Minor storm | 25% | 30% | 30% |
| Major-severe storm | 10% | 20% | 20% |
All times in UTC
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