NOAA/USAF Report of Solar-Geophysical Activity 14 Apr 2000

:Product: Report of Solar-Geophysical Activity

:Issued: 2000 Apr 14 2200 UT

# Prepared jointly by the U.S. Dept. of Commerce, NOAA,

#Space Environment Center and the U.S. Air Force.

#

JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY

SDF NUMBER 105 ISSUED AT 2200Z ON 14 APR 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  13/2100Z

TO 14/2100Z:  SOLAR ACTIVITY REMAINED AT LOW LEVELS. REGION 8948

(S15W63) PRODUCED A LONG-DURATION C1 PARALLEL-RIBBON FLARE AT

13/2130Z ASSOCIATED WITH A SMALL FILAMENT DISAPPEARANCE AND A

PARTIAL-HALO CME. THIS REGION, WHICH REMAINED IN A STATE OF GRADUAL

DECAY, ALSO PRODUCED A C7/1F FLARE AT 14/0816Z. REGIONS 8955

(S22E33) AND 8960 (N19W31) SHOWED MINOR GROWTH DURING THE PERIOD.

THE REMAINING REGIONS WERE STABLE. NO NEW REGIONS WERE ASSIGNED.

IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.

THERE IS A FAIR BUT DIMINISHING CHANCE FOR AN ISOLATED LOW-LEVEL

M-CLASS FLARE FROM REGION 8948.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 13/2100Z TO 14/2100Z:

GEOMAGNETIC FIELD ACTIVITY WAS AT MOSTLY QUIET LEVELS. THE GREATER

THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS AT MODERATE TO

HIGH LEVELS.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  GEOMAGNETIC FIELD ACTIVITY IS

EXPECTED TO INCREASE TO MOSTLY ACTIVE LEVELS ON 16 APRIL IN RESPONSE

TO THE PARTIAL-HALO CME MENTIONED ABOVE. UNSETTLED CONDITIONS ARE

EXPECTED FOR THE REMAINDER OF THE PERIOD. THE GREATER THAN 2 MEV

ELECTRON FLUX IS EXPECTED TO DECREASE TO NORMAL TO MODERATE LEVELS

SOMETIME DURING THE PERIOD.

III.  EVENT PROBABILITIES 15 APR-17 APR

CLASS M    30/30/25

CLASS X    05/05/01

PROTON     05/05/01

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           14 APR 165

PREDICTED   15 APR-17 APR  165/160/160

90 DAY MEAN        14 APR 184

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 13 APR  003/008

ESTIMATED AFR/AP 14 APR  003/004

PREDICTED AFR/AP 15 APR-17 APR  012/012-018/020-010/012

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 15 APR-17 APR

A.  MIDDLE LATITUDES

ACTIVE                30/40/30

MINOR STORM           10/20/10

MAJOR-SEVERE STORM    01/05/01

B.  HIGH LATITUDES

ACTIVE                35/45/35

MINOR STORM           20/25/20

MAJOR-SEVERE STORM    05/10/05