Report of Solar-Geophysical Activity 2 May 2000

Report of Solar-Geophysical Activity

:Issued: 2000 May 02 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 123 ISSUED AT 2200Z ON 02 MAY 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  01/2100Z

TO 02/2100Z:  SOLAR ACTIVITY WAS MODERATE.  REGION 8971 (N19W74)

PRODUCED AN M2/1N X-RAY EVENT AT 02/1451Z WITH AN ASSOCIATED 250 SFU

TENFLARE.  OTHERWISE, ONLY SEVERAL MINOR C-CLASS EVENTS OCCURRED

DURING THE PERIOD.  NO NEW REGIONS WERE NUMBERED.

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

PREDOMINATELY LOW WITH THE CHANCE OF ISOLATED M-CLASS ACTIVITY FROM

REGION 8970 (S13W78) OR 8971.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 01/2100Z TO 02/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE.  A SIGNIFICANT INCREASE IN

THE SOLAR WIND WAS OBSERVED WHEN A TRANSIENT PASSED THE ACE

SPACECRAFT AT APRROXIMATELY 02/1040Z.  THE SOLAR WIND VELOCITY

INCREASED FROM AROUND 600 TO MOMENTARILY OVER 900 KM/SEC.  ACTIVE

CONDITIONS OCCURRED SHORTLY AFTERWARDS.  THE SOLAR WIND SPEED SLOWLY

SUBSIDED AND LEVELED OFF AROUND 600 KM/SEC DURING THE END OF THE

PERIOD.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE PREDOMINATELY UNSETTLED TO ACTIVE WITH MINOR STORM

CONDITIONS POSSIBLE AT THE HIGH LATITUDES DURING THE FIRST HALF OF

THE PERIOD; THEN BECOMING MORE QUIET TO UNSETTLED DURING THE LAST

HALF OF THE PERIOD.

III.  EVENT PROBABILITIES 03 MAY-05 MAY

CLASS M    35/30/25

CLASS X    01/01/01

PROTON     01/01/01

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           02 MAY 153

PREDICTED   03 MAY-05 MAY  150/145/145

90 DAY MEAN        02 MAY 189

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 01 MAY  012/014

ESTIMATED AFR/AP 02 MAY  014/015

PREDICTED AFR/AP 03 MAY-05 MAY  015/020-012/012-010/010

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 03 MAY-05 MAY

A.  MIDDLE LATITUDES

ACTIVE                40/30/25

MINOR STORM           25/10/05

MAJOR-SEVERE STORM    05/01/01

B.  HIGH LATITUDES

ACTIVE                60/40/35

MINOR STORM           30/15/10

MAJOR-SEVERE STORM    10/05/01