Viewing archive of Wednesday, 20 January 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Jan 20 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 020 Issued at 2200Z on 20 JAN 1999

IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z

SOLAR ACTIVITY WAS HIGH. A LONG DURATION M-5 X-RAY EVENT OCCURRED AT 20/2003Z. THE SOURCE OF THIS EVENT IS SUSPECTED TO BE FROM JUST BEHIND THE NORTHEAST LIMB DUE TO A CME REPORTED BY THE MAUNA LOA SOLAR OBSERVATORY. A TYPE IV, AND A TYPE II SWEEP WITH A SHOCK SPEED OF 800 KM/S WAS ASSOCIATED WITH THIS EVENT. AN 230 SFU TENFLARE WAS ALSO DETECTED. REGIONS 8439 (S23W29) AND 8440 (N19W25) CONTINUE TO EXHIBIT PLAGE FLUCTUATIONS AND POINT BRIGHTENINGS. SEVERAL MINOR C-CLASS X-RAY FLARES AND OPTICAL SUBFLARES ALSO OCCURRED DURING THE PERIOD. REGION 8442 (N24W55) HAS DECAYED FROM 11 SPOTS WITH A BETA-GAMMA DELTA MAGNETIC CLASSIFICATION DOWN TO 7 SPOTS AND A MORE SIMPLE BETA MAGNETIC CLASSIFICATION. NO NEW REGIONS WERE NUMBERED.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE MODERATE. REGIONS 8439 AND 8440 ARE CAPABLE OF PRODUCING ISOLATED M-CLASS EVENTS. ANOTHER ISOLATED EVENT COULD OCCUR FROM THE REGION JUST BEHIND THE NORTH EAST LIMB. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z: THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED. THERE IS A CHANCE OF A PROTON EVENT AT GREATER THAN 10MEV AS A RESULT OF TODAY'S M5 X-RAY EVENT. IF THE EVENT DOES OCCUR, PROTONS ARE EXPECTED AT GEOSYNCHRONOUS ORBIT IN ABOUT 24 TO 36 HOURS
III. Event Probabilities 21 JAN to 23 JAN
Class M60%50%50%
Class X10%10%10%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       20 JAN 172
  Predicted   21 JAN-23 JAN  178/185/185
  90 Day Mean        20 JAN 141
V. Geomagnetic A Indices
OBSERVED AFR/AP 19 JAN  003/005
ESTIMATED AFR/AP 20 JAN  008/008
PREDICTED AFR/AP 21 JAN-23 JAN  012/012-012/014-012/014
VI. Geomagnetic Activity Probabilities 21 JAN to 23 JAN
A. Middle Latitudes
Active25%25%25%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active35%35%30%
Minor storm15%15%10%
Major-severe storm01%01%01%

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