-------- Original Message --------
524
NOUS41 KWBC 191313
PNSWSH
Technical Implementation Notice 11-58, Amended
National Weather Service Headquarters Washington DC
914 AM EDT Mon Mar 19 2012
To National Weather Service (NWS) Offices
Federal Aviation Administration (FAA)
Family of Services (FOS) Subscribers
Other Customers of NWS Aviation Forecasts
From Cynthia Abelman
Chief, Aviation Services Branch
Subject: Amended: Graphical Turbulence Guidance Change
Effective Date Delayed
Note: The following changes have no impact on NOAA
Weather Wire Service Subscribers
Amended to delay this implementation for at least one week
due to the delay in the implementation of the Rapid Refresh
model. A notification will be sent out as soon as the new
date has been determined
See TIN 11-36, issued July 27, 2011, announcing the
intention to replace the RUC with the RAP, and the Public
Information Statement issued November 9, 2011, proposing to
remove some RUC output products.
http://www.nws.noaa.gov/os/notification/tin11-36ruc.htm
Effective late February/early March, 2012, 1200 Coordinated
Universal Time (UTC), the NWS Aviation Weather Center in
Kansas City, MO, will update the Graphical Turbulence
Guidance (GTG) product in conjunction with the
implementation of the Rapid Refresh (RAP) model. Thus
change impacts users as follows:
1. Resolution of the grid spacing will increase from 20KM
to 13KM.
2. As a result of increased resolution, the parameter Grid
ID (PDS OCTET 7), internal to the GRIB file, will change
to 130. For more information, see
http://www.nco.ncep.noaa.gov/pmb/docs/on388/tableb.html
3. Additional forecast hours valid at 04,05,07,08,10 and
11 hours
This change will affect the following WMO headers for GTG:
WMO FLIGHT
HEADER LEVEL
----------- -----
YVW*14 KKCI FL450
YVW*15 KKCI FL440
YVW*16 KKCI FL430
YVW*17 KKCI FL420
YVW*18 KKCI FL410
YVW*19 KKCI FL400
YVW*20 KKCI FL390
YVW*21 KKCI FL380
YVW*22 KKCI FL370
YVW*23 KKCI FL360
YVW*24 KKCI FL350
YVW*25 KKCI FL340
YVW*26 KKCI FL330
YVW*27 KKCI FL320
YVW*29 KKCI FL310
YVW*30 KKCI FL300
YVW*32 KKCI FL290
YVW*33 KKCI FL280
YVW*34 KKCI FL270
YVW*36 KKCI FL260
YVW*38 KKCI FL250
YVW*39 KKCI FL240
YVW*41 KKCI FL230
YVW*43 KKCI FL220
YVW*45 KKCI FL210
YVW*46 KKCI FL200
YVW*48 KKCI FL190
YVW*50 KKCI FL180
YVW*53 KKCI 170
YVW*55 KKCI 160
YVW*57 KKCI 150
YVW*60 KKCI 140
YVW*62 KKCI 130
YVW*65 KKCI 120
YVW*67 KKCI 110
YVW*70 KKCI 100
ZVW*50 KKCI Composite
WHERE * = A = 00 HOUR FORECAST
* = B = 01 HOUR FORECAST
* = C = 02 HOUR FORECAST
* = D = 03 HOUR FORECAST
* = E = 04 HOUR FORECAST
* = F = 05 HOUR FORECAST
* = G = 06 HOUR FORECAST
* = H = 07 HOUR FORECAST
* = I = 08 HOUR FORECAST
* = J = 09 HOUR FORECAST
* = K = 10 HOUR FORECAST
* = L = 11 HOUR FORECAST
* = M = 12 HOUR FORECAST
The Graphical Turbulence Guidance graphics are computer-
generated four-dimensional forecasts of information related
to the likelihood of encountering atmospheric turbulence.
The product provides forecasts for the 48 contiguous United
States, much of Canada and Mexico, and their respective
coastal waters at flight altitudes from 10,000 MSL to FL450
only; it does not provide forecasts from the surface to
10,000 ft. Users should also be aware that turbulence is a
highly dynamic phenomenon and, in case of rapidly changing
conditions, the product may not accurately convey a
significant hazard.
GTG may be used as a higher-resolution supplement to
AIRMETs and SIGMETs, but not as a substitute for the
turbulence information they provide. GTG-2 graphics are
authorized for use as an unrestricted, supplementary
weather product. The GTG-2 does not have the capability to
be amended. See the definition of primary and supplementary
weather products below.
GTG is produced automatically from the 13 KM Weather
Research and Forecasting Rapid Refresh (RAP) model runs.
GTG produces an Analysis 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
and 12-hour Turbulence Forecast every hour in GRIB format.
This product also provides a composite field representing
the maximum turbulence value between 10,000 and 45,000 feet
for each analysis and forecast.
The GTG graphics suite is automatically produced with no
human modifications. Information on the graphics is
determined from observational data, pilot weather reports,
upper air soundings, satellite soundings, automated
aircraft reports, and surface weather reports, all of which
are integrated with computer model output.
Late February/early March, 2012, Graphical Turbulence
Guidance output in Gridded Binary (GRIB) format will be
available through:
--NWS FTP servers at:
ftp://tgftp.nws.noaa.gov/SL.us008001/DC.avspt/DS.fipgb
--The Family of Services (FOS) High Resolution Data Service
and Server Access Service
--Satellite Broadcast Network (SBN) NOAAPORT channel
To obtain sample gridded GTG data, contact:
Robert Sallee
Senior Software Engineer - Aviation Weather Center
Kansas City, MO 64153
816-584-7256
Robert.sallee@xxxxxxxx
Questions regarding the new GTG product? contact:
M. Pat Murphy
Warning Coordination Meteorologist
Aviation Weather Center
Kansas City, MO 64153
816-584-7239
michael.pat.murphy@xxxxxxxx
National Technical Implementation Notices are online at:
http://www.nws.noaa.gov/om/notif.htm
$$