NATIONAL TECHNICAL INFORMATION MESSAGE 94-04
NATIONAL WEATHER SERVICE HEADQUARTERS
345 PM EST FRI MAR 4 1994
TO: ALL NWS FIELD OFFICES, DOMESTIC DATA SERVICE
SUBSCRIBERS
FROM: JOHN F. MACHOWSKI
ACTING CHIEF, SERVICES DEVELOPMENT BRANCH
SUBJECT: CHANGE IN THE SATELLITE CLOUD PRODUCT SOFTWARE
(INFORMATION FOR THIS ANNOUNCEMENT HAS BEEN PROVIDED BY
CHUCK KLUEPFEL OF THE SYSTEMS REQUIREMENTS BRANCH OF THE OFFICE
OF METEOROLOGY)
Effective at 1900Z March 2, 1994, the software that is used in
the Satellite-derived Cloud Product (SCP) to derive total cloud
cover estimates above 12,000 feet MSL was changed. The new
software corrects some annoying bugs in the old program which
resulted in occasional, erroneous cloud top reports of "zero" at
some northern-tier stations--usually ACY and Y62. The new
software also contains an algorithm change with respect to the
"removal" of clouds below 12,000 feet MSL. While the output will
appear very similar to before, the technical experts at the
Cooperative Institute for Meteorological Satellite Studies,
located at the University of Wisconsin--Madison, believe that the
new algorithm will lead to improved estimates of cloud cover
above 12,000 feet. A new cloud cover category will be added to
the traditional CLR, SCT, BKN, and OVC categories. This new
category, abbreviated in the message as MCLR, stands for "mostly
clear." MCLR indicates the possible presence of an uncertain
amount of very thin, relatively transparent clouds.
More technical details will be contained in Technical Procedures
Bulletin 410, which is expected to go to press within the next
month.
The SCP reports have been disseminated as regional collectives
since June 1993. The AFOS PILs and WMO headers are listed below:
AFOS PIL WMO Header NWS Region
cccSCPER1 TBUS20 KWBC Eastern
cccSCPCR1 TBUS21 KWBC Central
cccSCPSR1 TBUS22 KWBC Southern
cccSCPWR1 TBUS23 KWBC Western
END