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NOUS41 KWBC 021907
PNSWSH

Technical Implementation Notice 15-44
National Weather Service Headquarters Washington DC
310 PM EDT Wed Sep 2 2015

TO:      Subscribers:
         -Family of Services
         -NOAA Weather Wire Service
         -Emergency Managers Weather Information Network
         -NOAAPORT
         Other NWS Partners and Employees

FROM:    David Novak
         Director, Weather Prediction Center

SUBJECT: Change to the Product Definition Template Generating
         Process Identifier for the WPC Probabilistic
         Quantitative Precipitation Forecast and Percentile
         Precipitation Accumulation GriB2 files Effective
         October 15, 2015

Effective Thursday, October 15, 2015, at 1800 Coordinated
Universal Time (UTC), the National Centers for Environmental
Prediction`s (NCEP) Weather Prediction Center (WPC) will change
the Product Definition Template 4.9 Generating Process Identifier
for the WPC Probabilistic Quantitative Precipitation Forecast
(PQPF) Gridded Binary 2 (GriB2) files from 180 to 221.  This
change will resolve a decoding conflict between the PQPF and
WPC`s Quantitative Precipitation Forecasts.

Additionally, WPC will change the Product Definition Template
4.10 Generating Process Identifier for the WPC Percentile
Precipitation Accumulation GriB2 files to 221 for the 10th, 50th
and 90th Percentiles. This will allow the PQPF and all
Percentiles Forecasts to be consistent.

Table 1: Percentile Accumulation Generating Process ID Change

Percentile           Process ID Change
----------           -----------------
10th                 222 -> 221
50th                 224 -> 221
90th                 226 -> 221

Products Affected by this Implementation Notice
  WMO Headers follow
  Template T1 T2 A1 A2 ii cccc
     T1 = H
     T2 = E
     A1 = N
     A2 specifies the forecast hours as follows
  B=06; C=12; D=18; E=24; F=30; G=36; H=42; I=48;
  X=54; J=60; Y=66; K=72

ii specifies the exceedance probabilities for the Probabilistic
Quantitative Precipitation Forecast or the Percentile
Accumulation threshold

  11=6 hour Probability >= 0.01
  12=6 hour Probability >= 0.25
  13=6 hour Probability >= 0.50
  14=6 hour Probability >= 1.00
  15=6 hour Probability >= 2.00
  16=6 hour Probability >= 4.00
  17=24 hour Probability >= 1.00
  18=24 hour Probability >= 2.00
  19=24 hour Probability >= 4.00
  20=24 hour Probability >= 8.00
  21=24 hour Probability >= 16.00
  22=72 hour Probability >= 1.00
  23=72 hour Probability >= 2.00
  24=72 hour Probability >= 4.00
  25=72 hour Probability >= 8.00
  26=72 hour Probability >= 16.00
  51=6 hour 10th Percentile Accumulation
  52=6 hour 50th Percentile Accumulation
  53=6 hour 90th Percentile Accumulation
  54=24 hour 10th Percentile Accumulation
  55=24 hour 40th Percentile Accumulation
  56=24 hour 90th Percentile Accumulation
  57=72 hour 10th Percentile Accumulation
  58=72 hour 50th Percentile Accumulation
  59=72 hour 90th Percentile Accumulation
  cccc=KWNH

Users who ingest the GriB2 files may need to update their
procedures and scripts in order to properly decode the PQPF. The
GriB2 files are available at NOOAPORT.

No additional changes will be made to product contents or
availability for this implementation.

For more information, please contact

  David Novak,
  Director, NCEP WPC
  David.Novak@noaa.gov
  301-683-1484

National Technical Implementation Notices are online at:

  http://www.weather.gov/om/notif.htm

$$










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