Viewing archive of Sunday, 21 November 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 Nov 21 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 325 Issued at 2200Z on 21 NOV 1999
IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z
SOLAR ACTIVITY INCREASED TO MODERATE LEVELS. REGION
8765 (S12W60) PRODUCED THREE M-CLASS FLARES, AN M1/1N AT 21/0014Z
ASSOCIATED WITH A 280 SFU TENFLARE, AN M2/SN AT 21/1017Z, AND AN
M3/2N AT 21/1820Z ASSOCIATED WITH A 270 SFU TENFLARE. THIS REGION
SHOWED A SLIGHT DECREASE IN MAGNETIC FIELD INTENSITY, BUT REMAINED
LARGE AND STRUCTURALLY COMPLEX, POSSIBLY INCLUDING A MAGNETIC DELTA
CONFIGURATION WITHIN ITS INTERIOR SPOTS. REGION 8771 (S16E01) SHOWED
A MAGNETIC DELTA CONFIGURATION WITHIN ITS TRAILER PORTION AND
UNDERWENT MINOR DEVELOPMENT. IT PRODUCED AN M3/2B FLARE AT 20/2235Z
ASSOCIATED WITH A TYPE II RADIO SWEEP (EST. VELOCITY 700 KM/SEC).
REGION 8768 (N16W65) SHOWED A MINOR INCREASE IN SPOT COUNT DURING
THE PERIOD AND PRODUCED ISOLATED SUBFLARES, NONE OF WHICH WERE
ASSOCIATED WITH SIGNIFICANT X-RAY EMISSION. REGION 8766 (N18W36)
DECAYED SLIGHTLY. THE REMAINING REGIONS WERE SMALL AND STABLE
INCLUDING NEWLY NUMBERED REGIONS 8777 (S26E40) AND 8778 (S14E62).
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO REMAIN
AT MODERATE LEVELS. REGIONS 8765 AND 8771 ARE EXPECTED TO PRODUCE
M-CLASS FLARES. THERE IS ALSO A CHANCE FOR A MAJOR FLARE, ESPECIALLY
FROM REGION 8765.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
GEOMAGNETIC FIELD ACTIVITY RANGED FROM QUIET TO MINOR STORM LEVELS. A
BRIEF PERIOD OF ACTIVE TO MINOR STORM LEVELS OCCURRED AROUND
21/0600Z FOLLOWING A 3-HOUR PERIOD OF SUSTAINED SOUTHWARD IMF BZ.
THE GEOMAGNETIC FIELD WAS AT QUIET TO UNSETTLED LEVELS DURING THE
REST OF THE PERIOD. THE GREATER THAN 2 MEV ELECTRON FLUX BRIEFLY
REACHED HIGH LEVELS LATE IN THE PERIOD.
IIB. Geophysical Activity Forecast
GEOMAGNETIC FIELD ACTIVITY IS
EXPECTED TO RANGE FROM QUIET TO ACTIVE LEVELS. ACTIVE LEVELS ARE
POSSIBLE DURING 23 NOVEMBER DUE TO CORONAL HOLE EFFECTS. THE GREATER
THAN 2 MEV ELECTRON FLUX IS EXPECTED TO BE AT MODERATE TO HIGH
LEVELS.
III. Event Probabilities 22 NOV to 24 NOV
Class M | 80% | 80% | 80% |
Class X | 20% | 20% | 20% |
Proton | 15% | 15% | 15% |
PCAF | YELLOW
|
IV. Penticton 10.7 cm Flux
Observed 21 NOV 210
Predicted 22 NOV-24 NOV 195/185/170
90 Day Mean 21 NOV 167
V. Geomagnetic A Indices
OBSERVED AFR/AP 20 NOV 007/009
ESTIMATED AFR/AP 21 NOV 015/010
PREDICTED AFR/AP 22 NOV-24 NOV 012/015-015/018-012/015
VI. Geomagnetic Activity Probabilities 22 NOV to 24 NOV
A. Middle Latitudes |
Active | 25% | 35% | 25% |
Minor storm | 10% | 15% | 10% |
Major-severe storm | 01% | 01% | 01% |
B. High Latitudes |
Active | 30% | 40% | 30% |
Minor storm | 15% | 20% | 15% |
Major-severe storm | 01% | 01% | 01% |
All times in UTC
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