-------- Original Message --------
051
NOUS41 KWBC 191830
PNSWSH
Technical Implementation Notice 13-42
National Weather Service Headquarters Washington DC
130 PM EST Tue Nov 19 2013
To: Subscribers:
-Family of Services (FOS)
-NOAA Weather Wire Service
-Emergency Managers Weather Information Network
-NOAAPORT
Other NWS Users and Employees
From: Mark Tew
Chief, Marine and Coastal Weather Services Branch
Subject: Temporal Resolution of Forecasts for Hazards,
Significant Wave Heights, Wind Direction, Speed and
Gusts on the Oceanic Domain in the Experimental
National Digital Forecast Database (NDFD) Will Increase
Effective December 18, 2013
Effective Wednesday December 18, 2013 at 1400 Coordinated
Universal Time (UTC), NDFD hazards, significant wave height, wind
direction, speed and gusts provided on the oceanic domain will
become available in experimental status at 3-hour resolution
through Day 3 instead of the current 6 hour resolution. Days 4-6
will remain at 6-hour temporal resolution.
This change will enable NDFD oceanic users to access finer
resolution forecasts from the Ocean Prediction Center and most
Weather Forecast Offices. The effective resolution from the
Tropical Analysis and Forecast Branch (TAFB) and Honolulu
Forecast Office (HFO) will not increase at this time.
The significant wave height grid is the average wave height,
trough to crest, of the one-third highest waves valid for the top
of the designated hour.
-Significant wave height is the combination of wind waves and
swell.
-Wind Direction is the 10-meter wind direction using 36 points
of a compass valid at the top of the indicated hour.
-Wind Speed is defined as the sustained 10-meter wind speed, in
knots, valid at the top of the indicated hour.
-Wind gust is the maximum 3-second wind speed, in knots, forecast
to occur within a 2-minute interval at a height of 10 meters.
This change primarily affects users who pull NDFD elements in the
Gridded Binary 2 (grib2) format from the NWS file transfer
protocol (FTP) server, either via the internet or the FOS server
access service, and users who pull HTML files from the NWS
hypertext transfer protocol (http) server. Those users will now
be able to access oceanic forecasts for Day 1-3 at a finer
temporal resolution.
These grids will continue to be available from the NDFD in
grib2 files via http and ftp, and in graphics via a map viewer at
the experimental site below:
preview.weather.gov/graphical
Information on accessing and using NDFD elements is online at:
http://ndfd.weather.gov/technical.htm
If December 18, 2013, is a critical weather day, this
implementation may be postponed. Users will be notified of that
decision via another Technical Implementation Notice (TIN) as far
in advance as possible.
For general questions regarding NDFD data, please email:
nws.ndfd@xxxxxxxx
For technical questions regarding NDFD data, please contact:
David Ruth
Chief, Mesoscale Prediction Branch
National Weather Service
Office of Science and Technology
Silver Spring Maryland 20910
david.ruth@xxxxxxxx
For questions regarding this notice, please contact:
David Soroka
Manager Marine and Coastal Weather Services Branch
National Weather Service
Office of Climate Water and Weather Services
Silver Spring Maryland 20910
david.soroka@xxxxxxxx
TINs specifically related to the NDFD are online at:
http://www.weather.gov/ndfd/tins.htm
National TINs are online at
http://www.weather.gov/os/notif.htm
$$