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Posted: Mon, Sep 13, 1993 9:44 AM EDT Msg: CGJD-5890-7843
CC: m.robinson(rec)
Subj: 2 NTIMs
WSHPNSNMC
NOUS41 KWBC 091839
NATIONAL TECHNICAL INFORMATION MESSAGE 93-36
NATIONAL WEATHER SERVICE HEADQUARTERS
235 PM EDT THU SEP 9 1993
TO: ALL NWS OFFICES, DOMESTIC DATA SERVICE SUBSCRIBERS,
FAA/WEATHER MESSAGE SWITCHING CENTER
FROM: MARY M. GLACKIN
CHIEF, SERVICES DEVELOPMENT BRANCH
SUBJECT: IMPLEMENTATION OF NEW NGM-BASED MOS SNOW FORECASTS
(THE FOLLOWING INFORMATION WAS PROVIDED BY BRENT BOWER OF THE
TECHNIQUES DEVELOPMENT LABORATORY.)
Effective with the 0000 UTC cycle on September 16, 1993, Nested
Grid Model (NGM)-based MOS snowfall amount guidance will be added
to the NGM MOS forecast bulletin. The NGM MOS guidance is
distributed under the WMO header of FOUS14 KWBC and under the
AFOS category of FWC. Users are referred to Technical Procedures
Bulletin (TPB) No. 408 for a description of the complete
FOUS14/FWC message, including the snowfall amount forecasts.
One line is being added to the NGM MOS message starting with the
characters "SNOW". This line provides forecasts of 6- and 12-h
(separated by a slash) categorical snow amount valid for periods
ending at the specified projections. The 6-h period forecast
projections are 12, 18, 24, 30, 36, 42, 48, 54, and 60 hours
after either 0000 or 1200 UTC. The 12-h period forecast
projections are 24, 36, 48, and 60 hours after either 0000 or
1200 UTC. The categories of snowfall amount for 6-h periods are
indicated by the following numbers: 0 = no snow; 1 = greater
than or equal to a trace to less than 2 inches; 2 = greater
than or equal to 2 inches. The categories of snowfall amount for
12-h periods are indicated by the numbers: 0 = no snow;
1 = greater than or equal to a trace to less than 2 inches; 2
greater than or equal to 2 to less than 4 inches; 4 = greater
than or equal to 4 to less than 6 inches; 6 = greater than or
equal to 6 inches. In the NGM MOS message, the snowfall amount
forecasts are displayed beneath the time of the day ending the
period for which they are valid. Note that the character "9"
denotes missing values. The snowfall amount guidance is
available in the message between September 16 and May 15, for
stations in the contiguous United States outside of southern
Florida and Central and southern California.
The categorical forecasts described above are prepared
objectively from MOS probabilistic forecasts of the categories
greater than a trace, greater than 2 inches, greater than
4 inches, and greater than 6 inches. The probabilities are not,
however, available in the NGM MOS message. Equations that
produce the probability forecasts were developed for each
forecast projection, both forecast cycles (0000 and 1200 UTC), a
number of regions in the contiguous United States, and one snow
season -- September 16 to May 15. The algorithm that selects the
categorical forecasts from the probabilities was designed to
maximize the threat score while not excessively under- or
over-forecasting individual categories. The categorical forecast
is determined by comparing the forecast probabilities to a set of
pre-determined "threshold" probabilities. Threshold
probabilities were derived for each forecast projection, cycle,
and region.
In tests on independent data, the NGM MOS snowfall amount
guidance was found to be generally more skillful than the LFM MOS
guidance. A TPB which specifically describes the new NGM MOS
snowfall amount guidance is being prepared and will be
distributed to TPB subscribers when it becomes available. If you
have any questions concerning this new guidance or the message
format, call Brent Bower at 301-713-1065 or Paul Dallavalle at
301-763-8151.
END - SENT - W/OM23
*******************************************************************
###################################################################
WSHPNSNMC
NOUS41 KWBC 091840
NATIONAL TECHNICAL INFORMATION MESSAGE 93-37
NATIONAL WEATHER SERVICE HEADQUARTERS
240 PM EDT THU SEP 09 1993
TO: ALL USERS OF THE AVIATION (AVN) MODEL AND THE MEDIUM
RANGE FORECAST (MRF) SYSTEM
FROM: MARY M. GLACKIN
CHIEF, SERVICES DEVELOPMENT BRANCH
SUBJECT: TIMELINESS OF THE AVIATION AND MEDIUM RANGE
FORECAST (MRF) MODELS
REFERENCE: NTIM 93-34, SUBJECT: DELAYS IN THE AVIATION AND
MEDIUM RANGE FORECAST (MRF) MODELS, DATED
AUGUST 12, 1993
(THE FOLLOWING INFORMATION WAS PROVIDED BY EUGENIA KALNAY, CHIEF
OF THE DEVELOPMENT DIVISION OF NMC.)
We are pleased to announce that the delays of Aviation model
forecast products that resulted from the August 11, 1993
implementation of a new parameterization of cumulus convection,
and an increase in vertical resolution from 18 to 28 levels, have
been abated. Aviation products are now being delivered from NMC
as early as they were BEFORE the implementation.
Forecast output from the MRF model is still being delayed
approximately an hour, however, a recent survey of both internal
(NWS) and external users indicated that this output is not as
time-critical as the Aviation model and is not imposing a serious
hardship. We will continue to monitor completion times of both
models, and make necessary adjustments to the production cycle as
required.
Questions or comments pertaining to the delivery times of both
models may be given to Wayman Baker who can be reached at
(301)-763-8005. We appreciate your cooperation and patience
while we instituted the changes which resulted in a more timely
delivery of the Aviation model.
END - SENT - W/OM23
Posted: Mon, Sep 13, 1993 9:40 AM EDT Msg: KGJD-5890-7781
Subj: PNSWSH MESSAGE
WSHPNSWSH
ADMN81 KWBC 101847
PUBLIC INFORMATION STATEMENT ...PART 1 OF A 2-PART MESSAGE...
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
245 PM EDT FRI SEP 10 1993
TO: NATIONAL WEATHER SERVICE (NWS) EMPLOYEES, FAMILY OF
SERVICES (FOS) SUBSCRIBERS, NOAA WEATHER WIRE SERVICE
(NWWS) SUBSCRIBERS, OTHER NWS PRODUCT USERS
FROM: DONALD R. WERNLY, CHIEF, WARNING AND FORECAST BRANCH,
OFFICE OF METEOROLOGY, NWS HEADQUARTERS
SUBJECT: FORMAT OF THE PUBLIC ZONE FORECAST PRODUCT
...PART 1 OF A 2-PART MESSAGE...
With implementation of the zone forecast reconfiguration on
October 1, 1993, at 1200 Coordinated Universal Time (UTC), the
following format changes will occur. See accompanying examples
for details.
(1) Plain language zone names will be added to the NWS Central
and Southern Regions' zone forecast products (see examples 1-3).
Since the Eastern, Western, Alaska and Pacific Regions have been
using zone names for years, this format change will standardized
this feature nationwide. The names will appear alphabetically
within each zone grouping. Note also that any zones from out-of-
state are further identified with their two-letter state
identification (see examples 2 and 3).
(2) Certain cities within a zone grouping may be identified in
zone forecast products in the line immediately after the zone
name line(s). This OPTION will be exercised primarily for zone
forecasts in the Central Region, but may be used elsewhere in
time (see example 2).
(3) As a test bed for future NWS services, Weather Service
Forecast Office (WSFO) Oklahoma City (at Norman) will add to all
zone forecast issuances an extra period to the 1- and 2-day
section followed by appended extended forecast periods (see
example 3).
If you have any questions about this or any other aspects of the
zone reconfiguration, please contact Rod Becker or Ron Berger of
my staff at (301) 713-0090 or write us at
NOAA/NWS, Warning and Forecast Branch (W/OM11)
1325 East West Highway
Silver Spring, MD 20910
The format changes are effective October 1, 1993 at 1200 UTC.
The following examples show only one forecast grouping for
illustration.
EXAMPLE 1: This is part of an Arkansas zone forecast product
issued by WSFO Little Rock from the Southern Region SHOWING ZONE
NAMES. This example uses AFOS PIL/NWWS identifier LITZFPAR (the
FOS identifier is FPUS5 KLIT).
LITZFPAR
TTAA00 KLIT 012130
ARKANSAS ZONE FORECASTS
NATIONAL WEATHER SERVICE LITTLE ROCK AR
430 PM CDT FRI OCT 1 1993
ARZ001>003-010>012-020300-
BENTON-BOONE-CARROLL-MADISON-NEWTON-WASHINGTON-
430 PM CDT FRI OCT 1 1993
.TONIGHT...
.SATURDAY...
.SATURDAY NIGHT...
.SUNDAY...
$$
(end of example 1)
EXAMPLE 2: This is part of an Iowa zone forecast product issued
by WSFO Des Moines from the Central Region showing zone names and
the OPTIONAL CITIES IDENTIFICATION. Note also the two-letter
state identification for out-of-state zones only. This example
uses AFOS PIL/NWWS identifier DSMZFPIA (FOS id is FPUS5 KDSM).
DSMZFPIA
TTAA00 KDSM 011524
IOWA ZONE FORECASTS
NATIONAL WEATHER SERVICE DES MOINES IOWA
1024 AM CDT FRI OCT 1 1993
IAZ002>005-013>015-020>024-031>035-043>049-NEZ013>015-SDZ071-
012130-
BOONE-BUENA VISTA-CALHOUN-CARROLL-CHEROKEE-CLAY-CRAWFORD-
DAKOTA NE-DICKSON-DIXON NE-EMMET-GREENE-HUMBOLDT-IDA-KOSSUTH-
MARSHALL-MONONA-OBRIEN-OSCEOLA-PALO ALTO-PLYMOUTH-POCAHONTAS-SAC-
STORY-THURSTON NE-UNION SD-WEBSTER-WOODBURY-
INCLUDING THE CITIES OF...SPENCER...SIOUX CITY...FORT
DODGE...AMES
1024 AM CDT FRI OCT 1 1993
.THIS AFTERNOON...
.TONIGHT...
.SATURDAY...
$$
(end of example 2)
END OF PART 1 OF 2...PART 2 WILL FOLLOW IMMEDIATELY
*****************************************************************
#################################################################
WSHPNSWSH
ADMN81 KWBC 1848
PUBLIC INFORMATION STATEMENT ...PART 2 OF A 2-PART MESSAGE...
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
250 PM EDT FRI SEP 10 1993
TO: NATIONAL WEATHER SERVICE (NWS) EMPLOYEES, FAMILY OF
SERVICES (FOS) SUBSCRIBERS, NOAA WEATHER WIRE SERVICE
(NWWS) SUBSCRIBERS, OTHER NWS PRODUCT USERS
FROM: DONALD R. WERNLY, CHIEF, WARNING AND FORECAST BRANCH,
OFFICE OF METEOROLOGY, NWS HEADQUARTERS
SUBJECT: FORMAT OF THE PUBLIC ZONE FORECAST PRODUCT
...PART 2 OF A 2-PART MESSAGE...
EXAMPLE 3: This is part of a zone forecast product for most of
central and western Oklahoma and a small part of north Texas
issued by WSFO Oklahoma City from the Southern Region showing
zone names and EXTENDED FORECAST PERIODS. Note the two-letter
state identification for out-of-state zones only. Note also the
addition of the SUNDAY NIGHT period to the 1- to-2-day part of
the forecast. With this addition, MONDAY, the first period of
the extended forecast, will be a 12-hour forecast. The other two
extended forecast periods will be 24-hour forecasts. This
example uses AFOS PIL/NWWS identifier OKCZFPOKC (FOS identifier
is FPUS5 KOKC).
OKCZFPOKC
TTAA00 KOKC 012130
ZONE FORECASTS
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
430 PM CDT FRI OCT 1 1993
OKZ037-038-044-TXZ083-085-086-020500-
COMANCHE-COTTON-HARDEMAN TX-TILLMAN-WICHITA TX-WILBARGER TX-
430 PM CDT FRI OCT 1 1993
.TONIGHT...
.SATURDAY...
.SATURDAY NIGHT...
.SUNDAY...
.SUNDAY NIGHT... (additional new 12-hour period)
.EXTENDED FORECAST...
.MONDAY... (12-hour forecast)
.TUESDAY... (24-hour forecast)
.WEDNESDAY... (24-hour forecast)
$$
The above example's format will be the same for the late evening
issuance (about 9:30 p.m. local time). For the other issuances
(about 4:30 a.m. and 10:30 a.m.), the 1- to 2-day forecast
periods would appear as follows. Assume TODAY is Tuesday for
this case.
4:30 a.m.
.TODAY... (or .THIS AFTERNOON... for 10:30 a.m. issuance)
.TONIGHT...
.WEDNESDAY...
.WEDNESDAY NIGHT...
.EXTENDED FORECAST...
.THURSDAY... (12-hour forecast)
.FRIDAY... (24-hour forecast)
.SATURDAY... (24-hour forecast)
$$
(end of example 3)
END OF PART 2 OF 2
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