NOAA/USAF Report of Solar-Geophysical Activity 8 May 2000

Report of Solar-Geophysical Activity

:Issued: 2000 May 08 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 129 ISSUED AT 2200Z ON 08 MAY 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  07/2100Z

TO 08/2100Z:  SOLAR ACTIVITY BECAME LOW. REGION 8990 (N13E49) BEGAN

TO EMERGE AT A MODERATE PACE DURING THE PERIOD AND PRODUCED SEVERAL

LOW TO MID LEVEL C-CLASS EVENTS. A NEW REGION ROTATED OVER THE EAST

LIMB AND WAS NUMBERED AS REGION 8991 (N16E70). OVER THE PAST 36

HOURS, THERE WERE SEVERAL SIGNIFICANT FILAMENT ERUPTIONS FROM THE

SOUTH CENTRAL PORTION OF THE SUN. THESE FILAMENTS WERE LARGE AND

DENSE. A PARTIAL HALO WAS OBSERVED BY THE LASCO CORONAGRAPH SPANNING

FROM SE60-NW10 AT AROUND 08/0700Z. ANOTHER MASS EJECTION, THAT MAY

ALSO BE A PARTIAL HALO EVENT, BECAME VISIBLE AROUND 08/1800Z IN

ROUGHLY THE SAME LOCATION.

IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE PREDOMINANTLY

LOW. CONTINUED GROWTH IN REGION 8990 SHOULD INCREASE THE FREQUENCY

OF C-CLASS EVENTS. THERE IS A SLIGHT POSSIBILITY OF AN M-CLASS EVENT

FROM EITHER REGION 8990 OR 8991.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 07/2100Z TO 08/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO SLIGHTLY UNSETTLED.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD BE

QUIET TO SLIGHTLY UNSETTLED FOR 09-10 MAY AND THE FIRST HALF OF 11

MAY. ACTIVE TO MINOR STORM LEVELS ARE EXPECTED TO BEGIN LATE ON 11

MAY FROM THE ERUPTIONS MENTIONED ABOVE. STORM CONDITIONS SHOULD

CONTINUE THROUGH 12-13 MAY.

III.  EVENT PROBABILITIES 09 MAY-11 MAY

CLASS M    15/15/15

CLASS X    01/01/01

PROTON     01/01/01

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           08 MAY 137

PREDICTED   09 MAY-11 MAY  142/145/147

90 DAY MEAN        08 MAY 187

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 07 MAY  006/007

ESTIMATED AFR/AP 08 MAY  005/010

PREDICTED AFR/AP 09 MAY-11 MAY  005/008-005/008-018/012

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 09 MAY-11 MAY

A.  MIDDLE LATITUDES

ACTIVE                10/10/30

MINOR STORM           05/05/30

MAJOR-SEVERE STORM    01/01/15

B.  HIGH LATITUDES

ACTIVE                10/10/30

MINOR STORM           05/05/40

MAJOR-SEVERE STORM    01/02/20