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Technical Implementation Notice 13-16

National Weather Service Headquarters Washington DC

719 AM EDT Thu Jul 25 2013

To:†††††† Subscribers:

††††††††† -Family of Services

††††††††† -NOAA Weather Wire Service

††††††††† -Emergency Managers Weather Information Network

††††††††† -NOAAPORT

††††††††† Other NWS Partners, Users and Employees

From:†††† Timothy McClung

††††††††† Science Plans Branch Chief

††††††††† Office of Science and Technology

Subject:Amended to Reschedule the Effective Date for the

††††††††† Hybrid Single-Particle Lagrangian Integrated

††††††††† Trajectory (HYSPLIT) upgrade to July 25, 2013 to

††††††††† Corresponds with the Transition of the NCEP

††††††††† Production Suite to the WCOSS Supercomputer

Effective on Thursday, July 25, 2013, beginning with the

1200 Coordinated Universal Time (UTC) run, the National Centers

for Environmental Prediction (NCEP) will upgrade the HYSPLIT

modeling system including smoke, dust, and volcanic ash.


The NOAA Air Resources Laboratory HYSPLIT subversion number 339

will be implemented as NCEP version 7.0.0 on NCEPís new Weather

and Climate Operational Supercomputing System (WCOSS), scheduled

to become the operational machine on July 25, 2013.A separate

TIN will be issued announcing the operational switch to the

WCOSS system. In the event that switch date is changed, this TIN

will be modified to reflect that change in implementation date.


Forecasts from the updated HYSPLIT model were made available

through a parallel feed from WCOSS starting June 19, 2013. The

smoke and dust HYSPLIT GRIB products from the parallel feed are

disseminated via the NCEP website:

and the products will be displayed through NCEPís website:

Current operational HYSPLIT model will continue providing

forecasts through NCEP Central Computing System (CCS) until the

WCOSS machine goes live on July 25, 2013.At that time updated

WCOSS smoke and dust predictions will be distributed through

and displayed at

The scientific enhancements include the following:

-- Improved wet removal by reducing in-cloud particle wet

removal coefficient, allowing wet removal to occur only when

both precipitation and clouds are defined in the same grid cell,

and turned off precipitation field spatial interpolation

-- revised horizontal puff dispersion rate to be more consistent

with particle dispersion

-- set Kanthar-Clayson vertical mixing parameterization as


-- maximum plume rise limits relaxed

-- fires pre-processer modified for daily emission cycling


The model has been tested with these updates for all HYSPLIT

applications at NCEP. Overall the results showed generally

similar results, except for simulations of the wet deposition

from the Fukushima nuclear power plant incident of 2011, in

which significant improvements occurred.†††


There are no changes to existing products or their contents.


More details about the HYSPLIT are available at:


For questions regarding these updated predictions, please


Ivanka Stajner


Silver Spring, MD 20910

301 713 9001 x 185

NWS National Technical Implementation Notices are online at: