Viewing archive of Monday, 18 September 2000
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 2000 Sep 18 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 262 Issued at 2200Z on 18 SEP 2000
IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z
SOLAR ACTIVITY WAS LOW. A NUMBER OF C-CLASS SUBFLARES
OCCURRED IN REGIONS 9165 (N14W40), 9166 (S14E24), AND 9167 (N12E57).
DECAY IN REGION 9165 HAS SLOWED AND THE AREA RETAINS SOME MAGNETIC
COMPLEXITY. REGION 9166 CONTINUES TO GROW SLOWLY AND IS PRESENTLY AN
E-TYPE SUNSPOT GROUP WITH SOME MIXED POLARITIES. NEW REGION 9169
(N08E70) IS A LARGE SUNSPOT GROUP ROTATING AROUND THE EAST LIMB, AND
IS ABUTTED TO THE SOUTHEAST OF REGION 9167. SO FAR IT HAS NOT
PRODUCED SIGNIFICANT FLARES BUT IT APPEARS TO BE A CAPABLE REGION;
HOWEVER, ITS LIMB PROXIMITY MAKES ANALYSIS DIFFICULT.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. FLARE ACTIVITY IS EXPECTED FROM REGIONS 9165, 9166,
9167, AND 9169.
IIA. GEOPHYSICAL ACTIVITY SUMMARY 17/2100Z TO 18/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM ACTIVE TO MAJOR STORM LEVELS AT
MIDDLE LATITUDES AND ACTIVE TO SEVERE STORM LEVELS AT HIGH
LATITUDES. THE MOST DISTURBED PERIOD OCCURRED FROM 17/2100 UTC TO
18/0300 UTC. THE GEOMAGNETIC FIELD APPEARS TO BE UNDER THE INFLUENCE
OF A HIGH-SPEED CORONAL HOLE STREAM, PUNCTUATED WITH THE PASSAGE OF
CME MATERIAL. THE MOST DISTURBED PERIOD WAS ASSOCIATED WITH A CME.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT ACTIVE TO STORM LEVELS. THE HIGH-SPEED STREAM IS
EXPECTED TO PERSIST AND ANOTHER CME IS EXPECTED TO ARRIVE EITHER
LATE ON SEP 18 OR EARLY ON SEP 19.
III. Event Probabilities 19 SEP to 21 SEP
Class M | 50% | 50% | 50% |
Class X | 05% | 05% | 05% |
Proton | 05% | 05% | 05% |
PCAF | GREEN
|
IV. Penticton 10.7 cm Flux
Observed 18 SEP 204
Predicted 19 SEP-21 SEP 210/215/220
90 Day Mean 18 SEP 177
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 SEP 032/040
ESTIMATED AFR/AP 18 SEP 035/045
PREDICTED AFR/AP 19 SEP-21 SEP 040/055-030/040-020/020
VI. Geomagnetic Activity Probabilities 19 SEP to 21 SEP
A. Middle Latitudes |
Active | 10% | 15% | 30% |
Minor storm | 30% | 30% | 15% |
Major-severe storm | 60% | 50% | 35% |
B. High Latitudes |
Active | 10% | 15% | 30% |
Minor storm | 30% | 30% | 15% |
Major-severe storm | 60% | 50% | 35% |
COMMENTS
EFFECTIVE 2 OCT 2000, SEC WILL ISSUE ITS TEXT PRODUCTS IN MIXED
CASE VS. ALL UPPER CASE. THIS CHANGE WILL BE VISIBLE ON ALL SEC
PRODUCT DELIVERY SYSTEMS EXCEPT FOR TELETYPE CIRCUITS. ONLY THE
CASE OF THE TEXT IN EACH PRODUCT WILL CHANGE, NOT THE FORMAT OR
SPACING WITHIN THE PRODUCT. FOR DETAILS SEE OUR WEB SITE AT
SEC.NOAA.GOV/MIXEDCASE.HTML
All times in UTC
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