Viewing archive of Monday, 12 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 12 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 193 Issued at 2200Z on 12 JUL 1999IA. Analysis of Solar Active Regions and Activity from 11-2100Z to 12-2100Z SOLAR ACTIVITY WAS LOW. THERE ARE 12 SPOTTED REGIONS
ON THE DISK WITH ONLY SMALL C-CLASS FLARES BEING OBSERVED. THE MOST
SPECTACULAR EVENT OF THE DAY WAS THE DISAPPEARANCE OF A LARGE
FILAMENT NEAR S33E60 EARLY IN THE UT DAY. A CME OVER THE SOUTHEAST
LIMB OF THE SUN OBSERVED BY THE SOHO SPACECRAFT AROUND 0700UT
APPEARS TO BE ASSOCIATED WITH THIS EVENT. A TYPE II SWEEP WAS
REPORTED AT 11/1840UT, HOWEVER, NO OPTICAL REPORTS HAVE BEEN
ASSOCIATED WITH THIS EVENT. TWO NEW REGIONS WERE NUMBERED, REGION
8633 (N42E21) AND REGION 8634 (S18E69).
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
THERE IS A GOOD CHANCE FOR C-CLASS FLARES.
IIA. Geophysical Activity Summary 11-2100Z to 12-2100Z
THE GEOMAGNETIC FIELD HAS RANGED FROM QUIET TO ACTIVE LEVELS. THE
FIELD BECAME UNSETTLED TO ACTIVE FOLLOWING A SUDDEN IMPULSE AT
12/0218UT (20 NT AT BOULDER). THE FIELD IS CURRENTLY BACK AT QUIET
LEVELS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED FOR MOST OF THE PERIOD. ANY
TERRESTRIAL IMPACT FROM TODAY'S DISAPPEARING FILAMENT OR THE SOLAR
SOURCE OF THE TYPE II IS NOT EXPECTED UNTIL 16 JUL.
III. Event Probabilities 13 JUL to 15 JUL
| Class M | 30% | 30% | 30% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 12 JUL 154 Predicted 13 JUL-15 JUL 149/147/145 90 Day Mean 12 JUL 151
V. Geomagnetic A Indices
OBSERVED AFR/AP 11 JUL 002/006 ESTIMATED AFR/AP 12 JUL 013/010 PREDICTED AFR/AP 13 JUL-15 JUL 005/008-005/005-005/005
VI. Geomagnetic Activity Probabilities 13 JUL to 15 JUL
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 10% | 10% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 15% | 15% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
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