NOAA/USAF Report of Solar-Geophysical Activity 18 June 2000

Report of Solar-Geophysical Activity

:Issued: 2000 Jun 18 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 170 ISSUED AT 2200Z ON 18 JUN 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  17/2100Z

TO 18/2100Z:  SOLAR ACTIVITY WAS HIGH. REGION 9033 (S25W85) PRODUCED

AN X1/SF FLARE AT 18/0159Z WITH AN ASSOCIATED 300 SFU TENFLARE, A

245 MHZ RADIO BURST OF 11000 SFU, AND A TYPE II RADIO SWEEP WITH A

SPEED OF 660 KM/S. A BRIGHT SURGE ON THE LIMB WAS ALSO OBSERVED WITH

THIS EVENT REACHING A RADIAL EXTENT OF .21 RV, AND THE SOHO/LASCO

IMAGERY INDICATED AN ASSOCIATED CME. A 30 DEGREE FILAMENT AT N55E62

DISAPPEARED BETWEEN 17/1928Z AND 18/1158Z. A NEW REGION WAS NUMBERED

TODAY AS REGION 9052 (S29W10).

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

TO MODERATE. THE POSSIBILITY OF AN ISOLATED X-CLASS FLARE REMAINS.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 17/2100Z TO 18/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. GOES GT 10 MEV PROTON

FLUXES BECAME SLIGHTLY ENHANCED DURING THE EVENT MENTIONED IN PART

IA, BUT REMAINED BELOW EVENT THRESHOLD AND RETURNED TO BACKGROUND

LEVELS.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE QUIET TO UNSETTLED. ISOLATED PERIODS OF ACTIVE

CONDITIONS ARE POSSIBLE FOR THE FORECAST PERIOD AS A RESULT OF THE

CME ACTIVITY OVER THE PAST THREE DAYS.

III.  EVENT PROBABILITIES 19 JUN-21 JUN

CLASS M    50/50/50

CLASS X    10/10/10

PROTON     10/10/10

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           18 JUN 188

PREDICTED   19 JUN-21 JUN  185/180/175

90 DAY MEAN        18 JUN 188

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 17 JUN  006/010

ESTIMATED AFR/AP 18 JUN  010/012

PREDICTED AFR/AP 19 JUN-21 JUN  008/010-008/010-008/010

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 19 JUN-21 JUN

A.  MIDDLE LATITUDES

ACTIVE                10/10/10

MINOR STORM           01/01/01

MAJOR-SEVERE STORM    01/01/01

B.  HIGH LATITUDES

ACTIVE                15/15/15

MINOR STORM           05/05/05

MAJOR-SEVERE STORM    01/01/01