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-------- Original Message --------
214
NOUS41 KWBC 091438
PNSWSH
Technical Implementation Notice 11-46
National Weather Service Headquarters Washington DC
938 AM EST Wed Nov 9 2011
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: Changes to Localized Aviation Model Output Statistics
Program (LAMP) Products: Effective January 24, 2012
Effective on Tuesday, January 24, 2012, beginning with the 1200
Coordinated Universal Time (UTC) run, 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, can be found
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
Judy.Ghirardelli@xxxxxxxx
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
$$
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