Viewing archive of Saturday, 27 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 27 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 331 Issued at 2200Z on 27 NOV 1999

IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z

SOLAR ACTIVITY CONTINUED AT HIGH LEVELS. REGION 8771 (S14W78) PRODUCED AN X1/2B TENFLARE AT 27/1212Z. THIS REGION ALSO PRODUCED TWO OTHER SIGNIFICANT EVENTS - AN M2/1N AT 27/0301Z AND AN M1/1N AT 27/0549Z. THOUGH SOME DECAY WAS OBSERVED IN THE LAST 24 HOURS, THIS REGION RETAINS CONSIDERABLE SIZE AND MAGNETIC COMPLEXITY AS IT APPROACHES THE WEST LIMB. REGION 8778 (S14W19) CONTINUES IN A SLOW GROWTH PHASE AND PRODUCED A C5/1N FLARE AT 27/0452Z. A LARGE, 17 DEGREE FILAMENT ERUPTED FROM S50 NEAR CENTER DISK BETWEEN 26/1700 - 1930Z. NEW REGION 8782 (N11E01) WAS NUMBERED TODAY. NO OTHER SIGNIFICANT ACTIVITY WAS OBSERVED.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE AT MODERATE TO HIGH LEVELS. REGION 8771 (S14W78) SHOULD CONTINUE PRODUCING M-CLASS ACTIVITY AS IT ROTATES AROUND THE WEST LIMB. AN ISOLATED MAJOR FLARE IS POSSIBLE. REGION 8778 (S14W19) WILL LIKELY CONTINUE TO PRODUCE C-CLASS ACTIVITY AND HAS POTENTIAL FOR AN ISOLATED M-CLASS EVENT.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
THE GEOMAGNETIC FIELD WAS QUIET.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN AT QUIET LEVELS THROUGH DAY ONE, WITH UNSETTLED TO ACTIVE CONDITIONS LIKELY ON DAY TWO AND THREE. THERE IS POTENTIAL FOR A MINOR DISTURBANCE ON DAYS TWO AND THREE IN RESPONSE TO YESTERDAY'S PARTIAL HALO CORONAL MASS EJECTION OFF THE WEST LIMB. WE MAY ALSO HAVE TO CONTEND WITH THE EFFECTS OF A HIGH SPEED CORONAL HOLE STREAM BY DAY THREE.
III. Event Probabilities 28 NOV to 30 NOV
Class M55%40%40%
Class X10%05%05%
Proton05%05%05%
PCAFYELLOW
IV. Penticton 10.7 cm Flux
  Observed       27 NOV 169
  Predicted   28 NOV-30 NOV  160/150/145
  90 Day Mean        27 NOV 165
V. Geomagnetic A Indices
OBSERVED AFR/AP 26 NOV  002/004
ESTIMATED AFR/AP 27 NOV  005/008
PREDICTED AFR/AP 28 NOV-30 NOV  007/010-015/015-015/015
VI. Geomagnetic Activity Probabilities 28 NOV to 30 NOV
A. Middle Latitudes
Active15%25%25%
Minor storm05%10%10%
Major-severe storm01%05%05%
B. High Latitudes
Active20%30%40%
Minor storm10%20%20%
Major-severe storm05%10%10%

All times in UTC

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