Viewing archive of Saturday, 28 August 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 Aug 28 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 240 Issued at 2200Z on 28 AUG 1999
IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z
SOLAR ACTIVITY REMAINED HIGH. REGION 8674 PRODUCED AN
IMPULSIVE X1/ AT 28/1805Z. THIS EVENT WAS ACCOMPANIED BY A 1000 SFU
BURST AT 2695 MHZ, STRONG TYPE II EMISSION, AND MAUNA LOA OBSERVED A
CORONAL MASS EJECTION AT SW60. REGION 8674 ALSO PRODUCED AN M1/1F AT
28/0102Z WITH A 290 SFU BURST AT 2695 MHZ. THIS REGION WAS STABLE IN
AREA AND MAGNETICALLY COMPLEX, ESPECIALLY IN THE TRAILER WHERE A
DELTA CONFIGURATION AND HIGH GRADIENTS EXISTED. RECENT VECTOR
MAGNETOGRAPH DATA SHOWED SIGNIFICANT SHEAR ONLY IN THAT AREA. OTHER
REGIONS WERE GENERALLY STABLE WITH THE EXCEPTION OF NEW REGION 8681
(N21E09). THIS REGION EMERGED RAPIDLY DURING THE PERIOD AND CONSISTS
OF BRIGHT PLAGE AND MANY SMALL SPOTS. SEVERAL CORONAL MASS EJECTIONS
WERE OBSERVED DURING THE PERIOD. AT THIS TIME, NONE APPEAR TO BE
DIRECTED SQUARELY AT THE EARTH.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE MODERATE TO
HIGH. REGION 8674 WILL CONTINUE TO PRODUCE M-CLASS EVENTS AND
OCCASIONAL X-CLASS EVENTS. SEVERAL OTHER REGIONS POSSESS THE
CAPABILITY OF PRODUCING ISOLATED M-CLASS EVENTS - CONTINUED GROWTH
IN NEW REGION 8681 WOULD PUT IT IN THAT CATEGORY AS WELL.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
THE GEOMAGNETIC FIELD REMAINED AT QUIET TO ACTIVE LEVELS. THE EARTH
CONTINUED TO EXPERIENCE A HIGH SPEED LOW DENSITY SOLAR WIND STREAM.
ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT REACHED HIGH
LEVELS NEAR 28/1200Z.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD BE
AT QUIET TO SLIGHTLY ACTIVE LEVELS FOR MOST OF THE 29-30 AUG PERIOD.
ON 31 AUG, A WEAK DISTURBANCE IS EXPECTED AS A RESULT OF THE X1/CME
EVENT MENTIONED ABOVE. HOWEVER, IT IS EXPECTED THAT THE EARTH WILL
RECEIVE ONLY AN OBLIQUE HIT FROM THIS EVENT AND ISOLATED ACTIVE
CONDITIONS ARE EXPECTED ON THAT DAY. ENERGETIC ELECTRON FLUXES
SHOULD REMAIN AT HIGH LEVELS FOR AT LEAST THE NEXT 2-3 DAYS. THERE
IS A MODERATE POSSIBILITY OF AN ENERGETIC PROTON EVENT DURING THE
PERIOD FROM REGION 8674.
III. Event Probabilities 29 AUG to 31 AUG
Class M | 80% | 80% | 80% |
Class X | 50% | 50% | 50% |
Proton | 40% | 40% | 40% |
PCAF | GREEN
|
IV. Penticton 10.7 cm Flux
Observed 28 AUG 248
Predicted 29 AUG-31 AUG 240/238/225
90 Day Mean 28 AUG 168
V. Geomagnetic A Indices
OBSERVED AFR/AP 27 AUG 009/013
ESTIMATED AFR/AP 28 AUG 013/010
PREDICTED AFR/AP 29 AUG-31 AUG 010/010-010/010-012/012
VI. Geomagnetic Activity Probabilities 29 AUG to 31 AUG
A. Middle Latitudes |
Active | 10% | 20% | 20% |
Minor storm | 05% | 10% | 10% |
Major-severe storm | 01% | 05% | 05% |
B. High Latitudes |
Active | 10% | 25% | 25% |
Minor storm | 05% | 15% | 15% |
Major-severe storm | 01% | 05% | 05% |
All times in UTC
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