Viewing archive of Sunday, 27 June 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 Jun 27 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 178 Issued at 2200Z on 27 JUN 1999
IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z
SOLAR ACTIVITY WAS MODERATE. REGION 8592 (N22W33), A
SIMPLE SINGLE SPOT HSX GROUP, PRODUCED AN M1/2N FLARE TODAY AT
0844Z. THE EVENT WAS ACCOMPANIED BY A TYPE IV RADIO SWEEP. NEW
REGION 8611 (S26E60) EMERGED TODAY AND PRODUCED SOME SUBFLARE
ACTIVITY. REGION 8598 (N23W11) CONTINUES TO BE THE LARGEST REGION ON
THE DISK. THERE IS EVIDENCE OF EMERGING NEGATIVE MAGNETIC FLUX IN
THE MIDDLE OF A STRONG POSITIVE POLARITY FIELD WHICH HAS LED TO THE
FORMATION OF A DELTA SPOT NEAR THE CENTER OF THIS EXTENDED SUNSPOT
REGION. A VERY SLOW, LONG DURATION RISE AND DECAY IN THE X-RAY FLUX
OCCURRED BETWEEN 1815-2030Z, PEAKING AT THE C3 LEVEL; THE EVENT WAS
ASSOCIATED WITH SUBFAINT INTENSITY PLAGE IN REGION 8598. REGION 8602
(N17E22) AND 8603 (S16E29) ARE ALSO OF RESPECTABLE SIZE; BOTH
REGIONS PRODUCED A COUPLE SUBFLARES TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE. REGION 8598 SHOWS GOOD POTENTIAL FOR PRODUCING M-CLASS
FLARES. REGIONS 8602, 8603, AND 8606 COULD ALSO POSSIBLY CONTRIBUTE
AN M-FLARE. THERE IS A POSSIBILITY FOR A MAJOR FLARE OR PROTON
PRODUCING FLARE FROM 8598.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO ACTIVE LEVELS, WITH SOME
MINOR STORM INTERVALS AT HIGH LATITUDES. AN INITIALLY QUIET TO
UNSETTLED GEOMAGNETIC FIELD BECAME MORE DISTURBED AFTER 1200Z; AFTER
WHICH MIDDLE LATITUDES WERE MOSTLY ACTIVE AND HIGH LATITUDES WERE AT
ACTIVE TO MINOR STORM LEVELS. ACE OBSERVATIONS SHOW AN OSCILLATING
BZ COMPONENT WHICH BEGAN TO HAVE SOME NEGATIVE INTERVALS AFTER
0900Z.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO PERSIST AT ACTIVE LEVELS FOR THE NEXT 12 HOURS, AFTER
WHICH UNSETTLED LEVELS ARE EXPECTED TO PREVAIL. UNSETTLED WITH A
POSSIBILITY FOR ACTIVE IS FORECAST FOR THE SECOND DAY BECAUSE A NEW
DISTURBANCE IS POSSIBLE ON THE 29TH DUE TO THE PARTIAL HALO CORONAL
MASS EJECTION THAT OCCURRED ON THE 24TH. GENERALLY UNSETTLED
CONDITIONS ARE EXPECTED TO PREDOMINATE ON THE THIRD DAY.
III. Event Probabilities 28 JUN to 30 JUN
Class M | 75% | 75% | 75% |
Class X | 20% | 20% | 20% |
Proton | 25% | 25% | 25% |
PCAF | GREEN
|
IV. Penticton 10.7 cm Flux
Observed 27 JUN 207
Predicted 28 JUN-30 JUN 200/200/200
90 Day Mean 27 JUN 143
V. Geomagnetic A Indices
OBSERVED AFR/AP 26 JUN 014/017
ESTIMATED AFR/AP 27 JUN 018/020
PREDICTED AFR/AP 28 JUN-30 JUN 015/015-015/010-010/010
VI. Geomagnetic Activity Probabilities 28 JUN to 30 JUN
A. Middle Latitudes |
Active | 35% | 35% | 20% |
Minor storm | 15% | 15% | 05% |
Major-severe storm | 05% | 05% | 01% |
B. High Latitudes |
Active | 35% | 35% | 30% |
Minor storm | 20% | 20% | 10% |
Major-severe storm | 10% | 10% | 05% |
All times in UTC
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