[nws-changes] 20131031: udpates to RAP Analysis and Fcst System Fwd: ADMIN NOTICE NOUS41 KWBC

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: [nws-changes] 20131031: udpates to RAP Analysis and Fcst System Fwd: ADMIN NOTICE NOUS41 KWBC
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Thu, 31 Oct 2013 14:44:50 -0600

-------- Original Message --------

454
NOUS41 KWBC 311652
PNSWSH

National Weather Service Headquarters Washington DC
1252 PM EDT Thu Oct 31 2013

          -Family of Services
          -NOAA Weather Wire Service
          -Emergency Managers Weather Information Network
          -NOAAPORT
          Other NWS Partners, Users and Employees

          Chief, Science Plans Branch
          Office of Science and Technology

          Forecast System:  Effective December 17, 2013

Coordinated Universal Time (UTC) run, the National Centers for
Environmental Prediction (NCEP) will update the Rapid Refresh
(RAP) with Version 2.0.0.

on the synoptic scale including upper-level winds, temperature
and humidity, with specific local improvement to forecasts of
2-meter temperatures and dew points and 10-meter winds. This
implementation specifically includes:

- A major upgrade to the prediction model
- New parameters added to the output grids
- Update to the station list used for BUFR output soundings.

system which now includes options originally developed for the
Rapid Update Cycle (RUC). RUC preceded the RAP--the cloud
hydrometeor analysis, the assimilation of radar reflectivity
data, and the diabatic digital filter initialization. These
options have helped improve short-range forecasts.

This upgrade includes the following changes to the analysis:

a)  using the newest version of the GSI code from the GSI code
repository
b)  using GFS ensemble background error co-variances
c)  adjusting soil moisture and temperature based on atmospheric low-
level temperature and moisture increments
d)  adding PBL-based pseudo-innovations for surface moisture
observations
e)  assimilating lightning data
f)  improvements to snow trimming and addition of the capability of
adding snow where observational data shows snow cover that is absent
in the model background
g)  improving initialization of 3-d hydrometeor (cloud) fields from
building lower-tropospheric clouds and retaining cloud fraction
information from METAR and satellite cloud data
h)  modifying radar hydrometeor specification
i)  improving assimilation of GPS precipitable water data

Model Upgrade

The RAP model is a configuration of the Weather Research and
Forecasting (WRF) model, using the ARW core. This upgrade
includes the following changes:

a)  updating the Advanced Research WRF (ARW) core to version
3.4.1 from 3.2.1
b)  changing the soil model from 6 layers to 9
c)  updating version of the Thompson microphysics
d)  switching the PBL scheme from Mellor-Yamada-Zanjic (MYJ) to
Mellor-Yamada-Nakaniski/Niino (MYNN)
e)  fixing the radiation code bug to restore attenuation due to
3-d snow mixing ratio

Output Product Changes

(pgrb) at horizontal resolutions of 13, 20 and 40 km and output
on native levels (bgrb) at horizontal resolutions of 13 and
20 km.  RAP output is also available on a 32-km full domain grid,
an 11-km Alaska grid, and a 16-km Puerto Rico grid.  Data are
available on each grid for all forecast hours (0-18) of each
cycle.

The following additional parameters are added to the pgrb files
of all resolutions:
- 0-180 hPa "best" convective available potential energy and
convective inhibition
- 0-90 hPa "mixed" convective available potential energy and
convective inhibition
- cloud ceiling height
- simulated radar echo top
- Haines index
- thunder potential
- 0-6 km wind shear (u and v components)
- 80-m temperature, pressure, specific humidity, and u/v wind
components
- simulated brightness temperature for GOES East and GOES West
(Channels 3 and 4 for each)
- low, middle, high, and total cloud fractions
- planetary boundary layer height, computed using the Richardson
number

The following changes are made to all bgrb files:
- add the number of concentration of rain particles on all 50
model levels
- generate soil temperature and moisture content to reflect the
new distribution of soil levels.  Previous output was at 0, 5,
20, 40, 160, and 300 cm.  The new levels are at 0, 1, 4, 10, 30,
60, 100, 160 and 300 cm.

The following changes are made in all 32-km full domain files,
all 11-km Alaska files, and all 16-km Puerto Rico files:
- add height, temperature, relative humidity, and u and v wind
components at 50 and 75 hPa
- add simulated brightness temperature for GOES East and GOES
West (Channels 3 and 4 for each)
- add low, middle, high, and total cloud fractions
- add Haines index
- compute planetary boundary layer height using the Richardson
number

The following changes are made in all 32-km full domain files and
all 11-km Alaska files:
- generate soil temperature and moisture content to reflect the
new distribution of soil levels.  Previous output was at 0, 5,
20, 40, 160 and 300 cm.  The new levels are at 0, 1, 4, 10, 30,
60, 100, 160 and 300 cm.
- add instantaneous incoming surface long wave radiation flux

The following change is made in all 32-km full domain files and
in all 16-km Puerto Rico files:
- add 0-90 hPa "mixed" convective available potential energy and
convective inhibition
The BUFR output will add 28 new stations to the station time
series BUFR output relocate four existing sites. See TIN 13-35
for information on these additions.
Product Delivery Time Changes:

Due to running the analysis code with the GFS ensemble background
error covariances, the analysis output files will be posted up to
2 minutes later than in the current version. This delay, however,
is made up during the forecast because the products for the last
forecast hour should generally match the current delivery times.

No changes to data availability will occur with this upgrade.
RAP products are currently available on NOAAPORT, the NCEP
server, the NWS ftp server and on NOMADS.

A consistent parallel feed of data will be available on the NCEP
server by early November, via the following URLs

to the content, changes to content order, and volume changes.
These elements may change with future NCEP model implementations.
NCEP will make every attempt to alert users to these changes
before implementation.

      NCEP/Mesoscale Modeling Branch
      College Park, Maryland
      301-683-3695
      geoffrey.manikin@xxxxxxxx
or
      Stan Benjamin
      NOAA Earth System Research Laboratory/GSD
      Boulder, Colorado
      303-497-6387
      stan.benjamin@xxxxxxxx

please contact:

     NCEP/NCO Dataflow Team
     College Park, Maryland
     301-683-0567
     ncep.pmb.dataflow@xxxxxxxx