NOUS41 KWBC 311510
AAA
PNSWSH
Technical
Implementation Notice 12-30, Amended
National Weather
Service Headquarters Washington DC
1110 AM EDT Tue
Jul 31 2012
To: Subscribers:
-Family of Services
-NOAA Weather Wire Service
-Emergency Managers Weather
Information Network
-NOAAPORT
Other NWS Partners, Users and
Employees
From: Timothy McClung
Chief, Science Plans Branch
Office of Science and Technology
Subject: Amended Date: Upgrade to Short Range Ensemble
Forecast
System Effective August 21, 2012
Amended to
reschedule the implementation to Tuesday, August 21,
2012,
to allow for additional testing. Corrected erroneous
quotation marks in filename for new NMMB output
files. Also
added specifics about addition of 1-hourly output
to the NWS FTP
server.
On or about
Tuesday, August 21, 2012, beginning with the
1500 Coordinated
Universal Time (UTC) run, the National Centers
for Environmental Prediction (NCEP) will update
its Short Range
Ensemble
Forecast system (SREF).
SREF Modeling
System Changes:
1. Remove two of the four models currently used
in the SREF: the
Eta
and the Regional Spectral Model (RSM). A new model will be
added: the Non-hydrostatic Multiscale
Meteorological Model on the
B
grid (NMMB).
2. Upgrade two Weather Research and Forecasting
(WRF) model
cores in model version from WRF v2.2 to WRF v3.3:
Non-hydrostatic
Multiscale
Meteorological Model (NMM) and Advanced Research WRF
(ARW).
3. Increase the NMM and ARW horizontal
resolution from 32/35km
to 16km. The NMMB will also have a 16km
horizontal resolution.
4. Increase the number of WRF members for NMM
and ARW from 5
to 7. There will be 7 members for the new NMMB
model. The naming
convention of all the files will follow the pattern:
sref_MODEL.tCCz.pgrb???.PERT.fxx, where
MODEL is nmm, em, nmb
for the NMM, ARW and NMMB, respectively, CC is
the model cycle
(03, 09, 15, 21), ??? is the number of the grid the
data are on,
PERT is the
perturbation, represented by ctl, n1, p1, n2, p2, n3,
p3, and fxx is the
forecast hour.
5. Increase diversity by selecting physics
schemes used in
existing models: NAM, GFS, NCAR, HWRF and Rapid
Refresh (RAP).
6. Increase Initial Condition (IC) diversity by:
-Using RAP analysis as a control analysis
for the ARW, NAM
analysis used for
the NMMB, and GFS analysis used for
the NMM.
-Mixing IC perturbation schemes by using a
mix of the Global
Ensemble Transform with Rescaling (ETR),
regional Breeding
and blending
between the two.
-Increasing the Land Surface Initial States
(LSIS)
diversity by
using the LSIS from the NAM, GFS, and RAP.
7. New capabilities will be added in
post-processing SREF data:
-Bias correction (by frequency matching) of
the
precipitation
forecasts for both individual members and the
ensemble mean.
-Clustering with two methods, NCEP and
University of
Oklahoma, with output including a text
table about each
cluster's
membership and size, a GRIB output of probability
of each cluster,
and a GRIB output of cluster products for
the mean and
spread of thirty-nine fields, as well as the
probabilities for
2-meter temperature and 3hr-accumulated
precipitation.
-Performance ranking of each ensemble
member, providing
different weights
for different members in both text and
GRIB format.
-Statistical surface down-scaling from 16km
SREF to 5km NDGD
grid using the
5km Real-Time Mesoscale Analysis (RTMA)
fields.
8. Modified the snow liquid ratio from being
fixed at 10:1 to a
surface temperature dependency method.
Change to Current
Product Delivery Schedule:
Due to the
current high resource usage on the supercomputers run
by NCEP, this updated SREF system can be run
only in its defined
time window. In the event the NCEP production
suite is delayed,
the SREF may not be run for a given cycle to
preserve the
timeliness of other NCEP models. In this situation, no
SREF
output products will be disseminated, and that
cycle will not be
rerun later. NCEP does not anticipate this
situation occurring
often, but wanted to alert customers of the slight
possibility of
missing one cycle of SREF output. This SREF susceptibility to
cancellation will remain until NCEP’s upgrade to new
supercomputers in late 2013. We apologize for any
inconvenience
this causes our users.
Current Product
Output Changes:
1. Change to product generating process ID in
the GRIB encoding
of individual SREF members output products on
the NCEP server.
Currently all
SREF members are labeled with process ID 84. Now
the ID's will be:
-NMB 111
-NMM 112
-ARW 116
The generating
process ID of the SREF ensemble products,
currently 113, will stay the same.
2. Additions to several probability
to the ensemble products:
-Probability of CAPE > 250
-Probability of visibility < 9654ft
-Probability of ceiling < 1830ft
-Probability of lower-level wind shear >
20kt/2000ft
-Probability of light fog
-Probability of moderate fog
-Probability of dense fog
3. Addition of 600hPa U, V, ABSV, HGT, T and RH
to the ensemble
mean and spread.
4. Addition of bias corrected precipitation
fields to
individual members and the ensemble mean.
New Product
Outputs:
1. The temporal resolution for the CONUS (grid
212) domain will
increase from 3-hourly to hourly for forecast hours
0-39. Due to
the new 1-hourly temporal resolution files, all
ensemble output
products will be renamed to reflect that they are
3-hourly.
-NCEP server:
ensprod/sref.tCCz.pgrb212.(spread|mean|prob)_1hrly.grib2
ensprod/sref.tCCz.pgrb???.(spread|mean|prob)_3hrly.grib2
ensprod_biasc/sref.tCCz.pgrb212.(spread|mean|prob)_3hrly.grib2
-NWS server:
Current filenames
in -
SL.us008001/ST.opnl/MT.sref_CY.YY/RD.YYYYMMDD/PT.grid_DF.gr2/fh.x
xxx_pt.*_gr.212 contain 3-hourly forecast hours.
With this
implementation
fh.3hrly_pt.*_gr.212 -- new name for 3-hourly forecast
hours
fh.1hrly_pt.*_gr.212 -- new 1-hourly forecast hours
2. Probability products from the Storm
Prediction Center (SPC)
for severe thunderstorm, lightning, dry
lightning and fire
weather parameters.
-NCEP server:
ensprod/sref.tCCz.pgrb212_SPC.prob_1hrly.grib2
ensprod/sref.tCCz.pgrb???_SPC.prob_3hrly.grib2
3. Forecast uncertainty/confidence information
for forty fields
for all grids:
-max, min, mode,
10-25-50-75-90% (ZZZ in filename below)
-NCEP server:
ensprod/sref.tCCz.pgrb212.ZZZ_1hrly.grib2
ensprod/sref.tCCz.pgrb???.ZZZ_3hrly.grib2
ensprod_biasc/sref.tCCz.pgrb212.ZZZ_3hrly.grib2
4. Ensemble mean Binary
Universal Form for the Representation of
meteorological data (BUFR) sounding products
-NCEP server:
bufr/srefmean.tCCz.bufrsnd.tar.gz
bufr/srefmean.tCCz.class1.bufr.tm00
5. NMB ctl, n1, n2,
n3, p1, p2, p3 members will be added
-NCEP server:
pgrb/sref_nmb.tCCz.pgrb???.PERT.fxx.grib2
pgrb_biasc/sref_nmb.tCCz.pgrb212.PERT.fxx.grib2
bufr/nmb_PERT.tCCz.bufrsnd.tar.gz
bufr/nmb_PERT.tCCz.class1.bufr.tm00
6. Addition of a 16km North American domain
(grid 132). Due to
the increased resources required to generate
them, the ensemble
files will be outputted approximately 1 hour later
than the
current SREF output.
-NCEP server:
pgrb/sref_MODEL.tCCz.pgrb132.PERT.fxx.grib2
pgrb/sref_MODEL.tCCz.pgrb132.PERT.grib2
ensprod/sref.tCCz.pgrb132.ZZZ_3hrly.grib2
7. Addition of a NDFD 5km CONUS domain (grid
197).
-NCEP server:
ensprod_ndgd/sref.tCCz.pgrb197.ZZZ_ds_3hrly.grib2
Current Product
Output Removals:
1. All Eta and RSM members will be removed.
-NCEP server:
pgrb/sref_eta.tCCz.prgb???.???.fxx.grib2
pgrb/sref_eta.tCCz.prgb???.???.grib2
pgrb/sref_rsm.tCCz.prgb???.???.fxx.grib2
pgrb/sref_rsm.tCCz.prgb???.???.grib2
pgrb_biasc/sref_eta.tCCz.prgb212.???.grib2
pgrb_biasc/sref_rsm.tCCz.prgb212.???.grib2
bufr/eta_???.tCCz.bufrsnd.tar.gz
bufr/eta_???.tCCz.class1.bufr.tm00
bufr/rsm_???.tCCz.bufrsnd.tar.gz
bufr/rsm_???.tCCz.class1.bufr.tm00
2. As part of this implementation, the NWS will
remove the SREF
GEMPAK data sets
from the NCEP server.
-NCEP servers:
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/sref/prod/sref.YYYYMMDD/CC/gempak/*
There will be a
few changes in the SREF product data files. With
the addition of new levels/parameters, the order
of placement
within each GRIB file may change. The products
delivered over
NOAAPORT will not
change in format or content. The products
disseminated via the NWS and NCEP servers will have some
changes
in content with no expected delay of delivery
time. Due to the
expected temporal changes, there will be a
significant increase
in data volume. A slight increase in file size
should be noted
for the bias corrected members and mean product.
These products
are available at the following locations:
NOAAPORT/AWIPS:
The following
domains will be disseminated: CONUS grid 212,
Alaska grid 216
and Eastern North Pacific grid 243
NCEP server:
The following
domains will be disseminated: CONUS grid 212,
Alaska grid 216,
Eastern North Pacific grid 243, High Resolution
North America
grid 221, North American grid 132 and NDFD CONUS
grid 197
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/sref/prod/sref.YYYYMMDD/CC
or
http://www.ftp.ncep.noaa.gov/data/nccf/com/sref/prod/sref.YYYYMMDD/CC
NWS server:
The following
domains will be disseminated: CONUS grid 212
ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.sref_CY.CC/RD.YYYYMMDD
where YYYYMMDD is the date and CC is the model
cycle (03, 09,
15, 21)
Please reference
NCEP's products information page for more detail
on current file outputs and format:
http://www.nco.ncep.noaa.gov/pmb/products/sref/
For more
information on the generating process ID see:
http://www.nco.ncep.noaa.gov/pmb/docs/on388/tablea.html
A consistent
parallel feed of data is currently available on the
NCEP ftp server
which can be accessed via the following URLs:
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/sref/para
or
http://www.ftp.ncep.noaa.gov/data/nccf/com/sref/para
The Environmental
Modeling Center (EMC) Mesoscale Modeling Branch
(MMB) has a
publicly available web site which can provide users
more information concerning the SREF modeling
system as well as
other NCEP regional modeling systems:
http://www.emc.ncep.noaa.gov/mmb/mesoscale.html
All users should
ensure their decoders are flexible and are able
to adequately handle changes in content,
parameter fields
changing order, changes in the scaling factor
component within
the Product Definition Section of the GRIB files
and any volume
changes which may be forthcoming. These elements may
change with
future NCEP model implementations. NCEP will make
every attempt
to alert users to these changes prior to any
implementations.
For questions
regarding the scientific content of the modeling
system please contact:
Geoff Dimego
NCEP/EMC
Camp Springs, Maryland 20746
Phone: 301-763-8000 x 7221
Email: Geoff.Dimego@noaa.gov
or
Jun Du
NCEP/EMC
Camp Springs, Maryland 20746
Phone: 301-763-8000 x 7593
Email: Jun.Du@noaa.gov
For questions
regarding the dataflow aspects of these data sets
please contact:
NCEP/NCO Dataflow Team
Camp Springs, Maryland 20746
Phone: 301-763-8000 x 7198
Email: ncep.list.pmb-dataflow@noaa.gov
National NWS
technical implementation notices are online at:
http://www.nws.noaa.gov/om/notif.htm
$$