Local Modeling at NWS Riverton, WY

(updated October 29, 2013)

The National Weather Service (NWS) Weather Forecast Office (WFO) in Riverton, WY runs the Weather Research and Forecasting (WRF) model on a daily basis to provide more detailed forecast guidance in and around Wyoming. Several domains have been configured and the output from each run can be viewed on the Internet.

#1 - A larger domain is run at 4 km horizontal resolution using the Nonhydrostatic Mesoscale Model (NMM) core.  For the nighttime run (06Z cycle), the initial and boundary conditions are provided by the Global Forecast System (GFS) 0.5 degree (~40 km) forecast data.  For the daytime run (18Z cycle), the initial and boundary conditions are provided by the North American Mesoscale (NAM) model 12 km forcast data.  The WRF NMM forecast data is available out 72 hours.

#2 - A smaller domain is also run at 4 km horizontal resolution using the Advanced Weather WRF (ARW) core.  The WRF ARW uses Local Analysis and Prediction System (LAPS) data (2.5 km horizontal resolution) and supplemental Rapid Refresh (RAP) data (13 km horizontal resolution data) for the initial conditions.  Like the WRF NMM, the WRF ARW uses GFS data for the nighttime run (06Z cycle) and NAM data for the daytime run (18Z cycle).  Because of the increased computer resource demands of the ARW core, the WRF ARW runs out 42 hours (increase from 36 on 03/05/13).

#3 - An even larger domain is run at 5 km horizontal resolution using the Nonhydrostatic Mesoscale Model (NMM) core.  This outer domain has a one-way nest run at ~1.5 km horizontal resolution as well.  This domain is only run once per day during the daytime starting at 12Z (18Z for the inner domain). The initial and boundary conditions are provided by the North American Mesoscale (NAM) model 12 km forcast data.  The outer domain is available out 72 hours; the inner domain is available for 12 hours (18Z -> 06Z).

#4 - A similar sized domain as #3 is run at 6 km horizontal resolution using the Advanced Weather WRF (ARW) core.  This outer domain also has a one-way nest run at 2 km horizontal resolution.  This domain only run once per day during the nighttime starting at 00Z (06Z for the inner domain). The initial and boundary conditions are provided by the North American Mesoscale (NAM) model 12 km forcast data.  The outer domain is available out 48 hours; the inner domain is available for 12 hours (06Z -> 18Z).

Production Schedule:

RIW WRF output from each model (#1 & #2) is available two times per day. As model data becomes available, it will be uploaded to the Internet. Be sure to check the "Cycle time" label in the lower portion of each image to determine which model run is being viewed. Below is a timetable outlining the average time the final images become available on this page: 

Cycle: Start time Final images available:
06Z NMM 0400Z (1000pm MDT) 0845Z (245am MDT)
06Z ARW 1000Z (400am MDT) 1400Z (800am MDT)
18Z NMM 1500Z (900am MDT) 1945Z (145pm MDT)
18Z ARW 2015Z (215pm MDT) 0030Z (630pm MDT)

NEW - RIW WRF output from each model (#3 & #4) is available one time per day. As model data becomes available, it will be uploaded to the Internet. Be sure to check the "Cycle time" label in the lower portion of each image to determine which model run is being viewed. Below is a timetable outlining the average time the final images become available on this page:  

Cycle: Start time Final images available:
00Z ARW 0330Z (930pm MDT) 1200Z (600am MDT)
12Z NMM 1530Z (930am MDT) 0000Z (600pm MDT)

Detailed Information:

Original NMM Core: 41 vertical levels, pressure top of 50 mb, no cumulus scheme (explicit convection), Ferrier microphysics, Mellor-Yamada-Janjic PBL scheme, Noah Land Surface Model, GFDL Longwave and Shortwave radiation schemes.

domain of RIW WRF NMM core

Original ARW Core: 41 vertical levels, pressure top of 50 mb, no cumulus scheme (explicit convection; changed from Kain-Fritsch convective scheme on July 18, 2012), Thompson et al. microphysics (for WRF V3.1; changed from Lin et al. microphysics on July 11, 2012), Yonsei University PBL scheme, Noah Land Surface Model, RRTM Longwave radation and Dudhia Shortwave radiation.  A twice Digital Filter Initialization (DFI) is also used with the Dolph filter (40 minutes backward, 20 minutes forward).

domain of RIW WRF ARW core

 

NEW NMM Core: 45 vertical levels, pressure top of 50 mb, Kain-Fritsch cumulus scheme for the outer domain [no cumulus scheme (explicit convection) for the inner domain], Ferrier microphysics, Mellor-Yamada-Janjic PBL scheme, Noah Land Surface Model, GFDL Longwave and Shortwave radiation schemes.

domains of new RIW WRF NMM core

NEW ARW Core: 45 vertical levels, pressure top of 50 mb, Kain-Frtsch cumulus scheme for the outer domain [no cumulus scheme (explicit convection) for the inner domain], Thompson et al. microphysics, Yonsei University PBL scheme, Noah Land Surface Model, Dudhia Longwave and Shortwave radiation schemes.

new domains of RIW WRF ARW core

 

Image Information:

Images of model output are created using GrADS.  As the model is running, autopost-processing creates images as the data becomes available.  The interface can be used to view the WRF model data through three drop-down menus with similar image controls.  Simply make a selection using one of the drop-down menus (more info below) and the images will downloaded (this may take some time).  Start the animation by clicking the ">" under Frame Controls, or step through each image by clicking the ">|" under Frame Controls.

1)  Synoptic Scale (or full domain) menu - through this drop-down menu, you can view WRF model data for many of the output fields, such as mean sea-level pressure, near surface temperature, dewpoint, and relative humidity, 10m wind and wind gusts, hourly and run-total precipitation, composite reflectivity, upper air data on the 250, 500, 700, and 850 mb planes, and a host of convective parameters.

2)  Zoomed Images menu - this menu contain many of the same images found in the Synoptic Scale menu, but zoomed in to a particular area predefined by WFO staff.  Examples of areas are a) around Rock Springs for the National High School Finals Rodeo, b) the Cody Foothills area to monitor high wind conditions, c) a mountainous region around a large wildfire such as the Fontenelle Fire of 2012, and d) Natrona and Johnson counties for severe convective activity.  Note that the zoomed in area is defined by RWI staff and is not user-configurable via the Internet.  Also, some of the image types in the Syntopic Scale menu are not in the Zoomed Images menu because the particular field does not provide more information on the smaller scale (such as 250mb height/wind).

3)  Forecast Soundings menu - this menu provides forecast soundings for 25 different locations around Wyoming.  These soundings indicate vertical detail of temperature, dewpoint, and wind.  They also show a variety of parameters including precipitable water, high-level total totals, and LI and CAPE from both the lowest level and the most unstable level.

If you have any suggestions for improvement, please contact the RIW WFO NWS staff using the contact information below.

Contact Information:

For more information about WRF local modeling at the Riverton, WY WFO, please contact the Science and Operations Officer, Brett McDonald, at brett.mcdonald@noaa.gov or 307-857-3898x766.

Fore more information about the WRF Environmental Modeling System (EMS), please refer to the NWS Science & Training Resource Center.


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.