NOUS41 KWBC 211159


Technical Implementation Notice 13-16

National Weather Service Headquarters Washington DC

758 AM EDT Fri Jun 21 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:Hybrid Single-Particle Lagrangian Integrated Trajectory

††††††††† (HYSPLIT) Model Update Effective July 16, 2013

Effective on or about Tuesday, July 16, 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 16, 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 will be made available through a

parallel feed from WCOSS starting around 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 16, 2013.At that time, updated WCOSS smoke and dust

predictions will be distributed through

and displayed at

The scientific enhancements include the following:

-- Improving wet removal by reducing the 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 turning off

†† precipitation field spatial interpolation

-- Revising horizontal puff dispersion rate to be more consistent with

†† particle dispersion

-- Setting Kanthar-Clayson vertical mixing parameterization as default

-- Relaxing maximum plume rise limits

-- Modifying fires pre-processer 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 contact:

Ivanka Stajner


Silver Spring, MD 20910

301 713 9001 x185

NWS National Technical Implementation Notices are online at: