Customer announcement about upcoming changes to geomagnetic products and services

UPDATE: To ensure a smooth transition for all of our customers, the change in geomagnetic products originally scheduled for November 16th has been postponed until December 12th.
On December 12, 2011 the Space Weather Prediction Center (SWPC) will be making numerous changes to its geomagnetic product suite. SWPC’s nowcast and forecast products, alerts, watches, and warnings will transition to be based on an estimate or prediction of the Planetary indices Kp and Ap. Currently all of these products are based off of the K-index computed from the Boulder magnetometer and the A-index from Fredericksburg, Virginia.

A new, near-real time estimated Kp index is now possible thanks to the cooperative efforts between SWPC and data providers from around the world. Current contributors include the U.S. Geological Survey, the British Geological Survey, the Institut de Physique du Globe de Paris, and the Korea Communications commission. Near real-time magnetometer data is processed and used to estimate the Kp index on a minute-by-minute basis using the technique published by Takahashi et al., 2001 (JGR 106, A10, pp 21017). The new, near-real time, NOAA estimated Kp index will be the basis of geomagnetic alerts and warnings issued by SWPC, beginning on December 12. This change will bring the alerts and warnings into conformity with the NOAA space weather scales.

In addition, SWPC will begin to produce Ap and Kp forecasts as our primary quantity used to predict geomagnetic activity for the current day through three-day ahead forecasts. These predictions will become the basis for SWPC’s geomagnetic watch products, beginning on December 12. As with the alerts and warnings, this also brings SWPC geomagnetic watch products into conformity with the NOAA scales.

Users should note the NOAA’s Kp and Ap forecasts will appear on a new web page and will be a new, separate product from the Solar Geophysical Activity Report and Forecast (SGARF). This is because the SGARF is a joint product with the USAF and therefore will continue to have the USAF’s Ap forecast, but not NOAA’s Ap forecast. New activity probabilities for the planetary level of activity will also be produced which will have activity level descriptors that are consistent with the NOAA scales. The new NOAA Kp and Ap forecasts and associated probability forecasts will appear at the following link: New Web Page

The nowcast and forecast Kp/Ap parameters will be incorporated throughout SWPC products, web pages, and product subscription services. A detailed list of product changes can be found here: Product Changes

Detailed web page changes may be found here: Web Page Changes

Detailed PSS changes may be found here: PSS changes

Please note that forecasts for A-Fredericksburg, for mid-latitude K-indices, and for high latitude K-indices will continue to be supported but will be derived from the Ap and Kp forecasts using climatology tables.

Also note that joint NOAA-USAF products will remain unchanged and any references to the Kp or Ap in those products should be understood to be the USAF Kp/Ap predicted, estimated, or observed index. In addition, SWPC is considering the removal of the geomagnetic probabilities from the SGARF because the activity level descriptors are inconsistent with the NOAA scales. The change would only affect the SGARF; SWPC would continue to provide the mid and high latitude probability forecasts on the web page and in the 3 Day Space Weather Predictions text product (daypre.txt) so that users will have continuity. We are soliciting customer input concerning this change and are planning to make a final decision by December 2011. Please forward your comments to SWPC customer support at : SWPC.CustomerSupport@noaa.gov.

New Web Page (Content) for NOAA Ap/Kp forecasts

NOAA 3-day Geomagnetic Forecasts

NOAA Ap Index forecast
Observed Ap 04 Oct 006
Estimated Ap 05 Oct 018
Predicted Ap 06 Oct-08 Oct 015-008-008

NOAA Geomagnetic Activity Probabilities 06 Oct-08 Oct
Active                45/20/20
Minor storm           25/05/05
Moderate storm        05/01/01
Strong-Extreme storm  01/01/01

NOAA Kp Index forecast 06-08 Oct
                       Oct 06        Oct 07        Oct 08
00-03UT                   3             2             2
03-06UT                   3             1             1
06-09UT                   3             3             1
09-12UT                   3             2             1
12-15UT                   3             2             2
15-18UT                   3             2             2
18-21UT                   3             2             3
21-00UT                   3             2             3

Table of product changes

Table of web page changes

Table of Product Subscription Service changes (PSS)