Viewing archive of Wednesday, 15 December 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Dec 15 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 349 Issued at 2200Z on 15 DEC 1999

IA. Analysis of Solar Active Regions and Activity from 14-2100Z to 15-2100Z

SOLAR ACTIVITY CONTINUED AT A LOW LEVEL. REGION 8798 (S14E49) PRODUCED FREQUENT INTENSITY FLUCTUATIONS AND OCCASIONAL LOW LEVEL C-CLASS EVENTS. THE LARGEST WAS A C2/SF AT 15/1417Z. THIS REGION BEGAN TO GROW AT A MODERATE PACE DURING THE PERIOD. IT IS ALSO IN CLOSE PROXIMITY TO REGION 8799 (S09E48). CONTINUED GROWTH IN 8799 WOULD RESULT IN A MERGING OF THESE TWO REGIONS. SEVERAL SMALL FILAMENTS IN THE NORTHERN HEMISPHERE FADED DURING THE PERIOD. AN ERUPTIVE PROMINENCE WAS REPORTED BY THE MAUNA LOA OBSERVATORY FROM SE35 NEAR 15/1930Z. RECENT SOLAR X-RAY IMAGES SHOWED A SMALL TO MODERATE SIZE REGION ABOUT TO ROTATE OVER THE NORTHEAST LIMB.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD REMAIN GENERALLY LOW. REGION 8798 SHOULD CONTINUE TO PRODUCE C-CLASS EVENTS. THERE IS AN INCREASING POSSIBILITY OF AN M-CLASS EVENT FROM THE 8798/8799 COMPLEX. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 14/2100Z TO 15/2100Z: THE GEOMAGNETIC FIELD WAS QUIET FOR THE ENTIRE PERIOD. SOLAR WIND VELOCITY WAS LOW AND BZ WAS PREDOMINANTLY NORTHWARD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD BE QUIET TO UNSETTLED FOR THE NEXT THREE DAYS.
III. Event Probabilities 16 DEC to 18 DEC
Class M 20%25%30%
Class X 05%05%05%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       15 DEC 179
  Predicted    16 DEC-18 DEC  182/182/181
  90 Day Mean        15 DEC 168
V. Geomagnetic A Indices
OBSERVED AFR/AP 14 DEC  003/003
ESTIMATED AFR/AP 15 DEC  001/008
PREDICTED AFR/AP 16 DEC-18 DEC  005/010-008/008-008/008
VI. Geomagnetic Activity Probabilities 16 DEC to 18 DEC
A. Middle Latitudes
Active10%10%10%
Minor storm 05%05%05%
Major-severe storm 01%01%01%
B. High Latitudes
Active10%10%10%
Minor storm 05%05%05%
Major-severe storm 01%01%01%

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