Viewing archive of Saturday, 24 July 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 Jul 24 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 205 Issued at 2200Z on 24 JUL 1999

IA. Analysis of Solar Active Regions and Activity from 23-2100Z to 24-2100Z

SOLAR ACTIVITY BECAME HIGH DUE TO THE OCCURRENCE OF FIVE M-CLASS EVENTS. OPTICALLY UNCORRELATED M2 EVENTS OCCURRED AT 24/1112Z AND 24/1133Z. NEW REGION 8645 (S26E69) ROTATED ONTO THE DISK AND PRODUCED AN M1/SF AT 23/2300Z, AN M1/1N AT 24/0404Z, AND A LONG DURATION M3/SF AT 24/0756Z. WHILE STILL NOT FULLY VISIBLE, THIS REGION SHOWED ITSELF AS A MODERATE SIZE D CLASS SUNSPOT GROUP. IT IS VERY NEAR THE LOCATION OF OLD REGION 8611 THAT WAS ACTIVE LAST ROTATION. REGION 8636 (N21W13) PRODUCED SEVERAL C-CLASS SUBFLARES. OVERALL, THIS REGION WAS STABLE AND EXHIBITED MINOR MIXING OF POLARITIES.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD CONTINUE AT A MODERATE LEVEL. M-CLASS EVENTS ARE EXPECTED TO CONTINUE FROM REGION 8645 PRIMARILY DUE TO PERSISTENCE AND THE HISTORY OF THIS AREA. REGION 8636 IS EXPECTED TO PRODUCE ONLY ISOLATED M-CLASS EVENTS. THERE IS A SLIGHT POSSIBILITY OF MAJOR FLARES FROM THIS REGION AND TO A LESSER DEGREE FROM REGION 8645.
IIA. Geophysical Activity Summary 23-2100Z to 24-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND VELOCITY REMAINED ELEVATED ABOVE NORMAL AND OCCASIONALLY EXCEEDED 500 KM/S.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. NO SIGNIFICANT CORONAL MASS EJECTIONS WERE OBSERVED WITH THE RECENT ACTIVITY ON THE DISK AND EAST LIMB. THERE IS A SLIGHT POSSIBILITY OF AN ENERGETIC PROTON EVENT SHOULD REGION 8636 PRODUCE A MAJOR FLARE.
III. Event Probabilities 25 JUL to 27 JUL
Class M90%90%90%
Class X15%15%15%
Proton15%15%15%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       24 JUL 184
  Predicted   25 JUL-27 JUL  186/189/190
  90 Day Mean        24 JUL 156
V. Geomagnetic A Indices
OBSERVED AFR/AP 23 JUL  010/012
ESTIMATED AFR/AP 24 JUL  009/012
PREDICTED AFR/AP 25 JUL-27 JUL  010/012-008/010-008/008
VI. Geomagnetic Activity Probabilities 25 JUL to 27 JUL
A. Middle Latitudes
Active20%10%05%
Minor storm10%05%05%
Major-severe storm05%05%01%
B. High Latitudes
Active20%10%10%
Minor storm10%05%05%
Major-severe storm05%01%01%

All times in UTC

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