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-------- Original Message --------
514
NOUS41 KWBC 221422
PNSWSH
Technical Implementation Notice 12-30
National Weather Service Headquarters Washington DC
1022 AM EDT Fri Jun 22 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: Upgrade to Short Range Ensemble Forecast System
Effective August 1, 2012
On or about Wednesday, August 1, 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 physic 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 NCEPs 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
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.YYYYMMD
D/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.YYY
YMMDD
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 will become available on the
NCEP ftp server once the model is running in parallel on the NCEP
central computing system by late June 2012. At this time the
parallel data will become available via the following URL's:
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@xxxxxxxx
or
Jun Du
NCEP/EMC
Camp Springs, Maryland 20746
Phone: 301-763-8000 x 7593
Email: Jun.Du@xxxxxxxx
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@xxxxxxxx
National NWS technical implementation notices are online at:
http://www.nws.noaa.gov/om/notif.htm
$$
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