Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 September 2014

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast

SDF Number 255 Issued at 2200Z on 12 Sep 2014

IA.  Analysis of Solar Active Regions and Activity from 11/2100Z to

12/2100Z: Solar activity has been at moderate levels for the past 24

hours. The largest solar event of the period was a M1 event observed at

11/2126Z. There are currently 7 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be moderate

with a chance for X-class flares on days one, two, and three (13 Sep, 14

Sep, 15 Sep).

IIA.  Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic

field has been at quiet to major storm levels for the past 24 hours.

Solar wind speed, as measured by the ACE spacecraft, reached a peak

speed of 672 km/s at 12/1534Z. Total IMF reached 31 nT at 12/1813Z. The

maximum southward component of Bz reached -15 nT at 12/1945Z. Protons

greater than 10 MeV at geosynchronous orbit reached a peak level of 126

pfu at 12/1555Z. Electrons greater than 2 MeV at geosynchronous orbit

reached a peak level of 504 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected

to be at active to severe storm levels on day one (13 Sep), unsettled to

minor storm levels on day two (14 Sep) and quiet to active levels on day

three (15 Sep). Protons are expected to cross threshold on days one and

two (13 Sep, 14 Sep) and are expected to cross threshold on day three

(15 Sep).

III.  Event probabilities 13 Sep-15 Sep

Class M    75/75/75

Class X    40/40/40

Proton     99/99/90

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           12 Sep 152

Predicted   13 Sep-15 Sep 150/150/150

90 Day Mean        12 Sep 130

V.  Geomagnetic A Indices

Observed Afr/Ap 11 Sep  016/013

Estimated Afr/Ap 12 Sep  026/047

Predicted Afr/Ap 13 Sep-15 Sep  040/050-018/025-011/012

VI.  Geomagnetic Activity Probabilities 13 Sep-15 Sep

A.  Middle Latitudes

Active                25/40/30

Minor Storm           35/25/10

Major-severe storm    35/05/01

B.  High Latitudes

Active                05/10/15

Minor Storm           15/20/30

Major-severe storm    85/65/40