NOUS41 KWBC 101228
AAB
PNSWSH
Technical
Implementation Notice 11-46 AAB
National Weather
Service Headquarters Washington DC
828 AM EDT Tue
Jul 10 2012
To: Subscribers:
- Family of Services
- NOAA Weather Wire Service
- Emergency Managers Weather
Information Network
- NOAAPORT
Other NWS partners, users and NWS
employees
From: Tim McClung
Science Plans Branch Chief
Office of Science and Technology
Subject: Amended: Changes to Localized Aviation Model
Output
Statistics Program (LAMP)
Products: Effective
July 17, 2012.
Amended to set
the implementation date for Tuesday, July 17,
2012. Users are
cautioned that if a Critical Weather Day (CWD)
designation is in effect on July 17, this implementation
will be
delayed until the conclusion of CWD. You can monitor the CWD
status at the following webpage:
http://www.nco.ncep.noaa.gov/pmb/cwd/
Effective on
Tuesday, July 17, 2012, beginning with the 1600
Coordinated
Universal Time (UTC) run, the NWS Meteorological
Development
Laboratory (MDL) will update the Localized Aviation
Model
Output Statistics Program (LAMP) system.
The LAMP changes include:
1. Replacing the
current LAMP total sky cover guidance with
new opaque sky cover guidance, which is
dependent on cloud
opacity.
The LAMP sky
cover guidance predicts an estimate of the total
percentage of the sky covered by clouds in terms of the
five
categories reported in the METAR observations: clear,
few,
scattered, broken, or overcast. The current LAMP total
sky cover
guidance does not distinguish between opaque and
translucent
cloud cover.
The new LAMP sky
cover will produce an estimate of opaque clouds.
The anticipated
effect of this change will be to decrease the
number of broken or overcast forecasts and to
increase the number
of clear or few forecasts when only cirrus
clouds are expected.
This change will
make the LAMP guidance consistent with both the
NWS definition of
sky cover, as well as the Global Forecast
System
(GFS)-based MOS definition of sky cover. See TIN 07-34 for
details on GFS-based MOS opaque sky cover change.
http://www.nws.noaa.gov/os/notification/tin07-34juncloud.txt
The LAMP total
sky cover currently available in the LAMP public
text bulletins (known by their AWIPS ids LAV) and
labeled as CLD
will be replaced with the LAMP opaque sky cover.
The CLD label
will not change. Likewise, the LAMP total sky cover currently
available in the BUFR message will be replaced with
the LAMP
opaque sky cover. This change to the LAMP BUFR
message will be
transparent to users with no changes to the descriptors
in the
BUFR file.
2. Redeveloped
ceiling height and conditional ceiling height
equations to produce improved forecast guidance.
3. NWS will add
119 stations to the LAMP text bulletins and BUFR
products. These changes will be reflected in the new
equations
for opaque sky cover, and the redeveloped
ceiling height and
conditional ceiling height equations. These changes will
also be
reflected in the guidance for the following elements:
Precipitation
occurring on the hour
Precipitation in
a 6-hour period
Precipitation in
a 12-hour period
Thunderstorms in
a 2-hour period
Precipitation
type
Visibility
Conditional
visibility
Obstruction to
vision
These changes
will slightly alter the format of the LAV text
products because new lines will be added to the
existing
bulletins to accommodate the new stations. In
addition, some
stations might not have had guidance for all of the
above
elements prior to this change, and with this change,
guidance
will now be produced for those elements for those
stations.
These changes
will also alter the contents of the LAMP BUFR
messages because new guidance will be available. The
communication identifiers for the text and BUFR products
are
shown in Tables 1 and 2 below.
Table 1:
Communication identifiers for the GFS-based LAMP
products in ASCII format. Listed below are the WMO
heading and
the AWIPS identifier.
WMO heading AWIPS ID
----------- --------
FOUS11 KWNO LAVUSA
Table 2:
Communication identifiers for the GFS-based LAMP
products in BUFR format. Listed below are the WMO headings.
WMO heading Region
----------- ------
JSMF10 KWNO LAMP BUFR Pacific Region
JSMF11 KWNO LAMP BUFR Northeast Region
JSMF12 KWNO LAMP BUFR Southeast Region
JSMF13 KWNO LAMP BUFR North Central Region
JSMF14 KWNO LAMP BUFR South Central Region
JSMF15 KWNO LAMP BUFR Rocky Mountains Region
JSMF16 KWNO LAMP BUFR West Coast Region
JSMF17 KWNO LAMP BUFR Alaska Region
A Web page
providing additional details of these changes,
including a link to the list of new stations, is
online at:
www.nws.noaa.gov/mdl/gfslamp/docs/change_notice_01242012.php
If you have
technical comments or questions, please contact:
Judy Ghirardelli
National Weather
Service
Meteorological
Development Laboratory
301-713-0056 x194
Links to the LAMP
products and descriptions can found at:
http://www.nws.noaa.gov/mdl/gfslamp/gfslamp.shtml
National Public
Information Statements are online at:
http://www.weather.gov/os/notif.htm
$$