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Posted: Fri, Dec 4, 1992 5:34 PM EST Msg: GGJC-5473-3781
K.MIELKE(REC),
J.KEMPER(REC), L.MILLER.UCAR(REC), T.WHITTAKER(REC)
CC: G.TRAPP(REC)
Subj: NATIONAL TECH INFO MSG - MRF STAT. GUIDANCE
I sent out the following National Technical Information Message (AFOS PIL
WSHPNSWSH; WMO header NOUS41 KWBC) this afternoon. It is transmitted on all
AFOS loops, NWWS, the Family of Services' Domestic Data Service and the
International Data Service, Honolulu, WMSC/FAA (who forwards it to Alaska
Region), Montreal/Canadian AES, DARPA (whoever they are?), and the ISPAN text
lines. The message concerns the implementation of the new MRF statistical
guidance package to be implmented by TDL on Thurs. Dec. 10 in the 0000 UTC
cycle. I mailed out a "Dear Colleague" package and a yellow reference card
either Wed. before Thanksgiving or the day after Thanksgiving, which I told
you in last week's OMNET message on this subject. These packages were mailed
directly to offices in the Eastern, and Alaska Regions, and were mailed to the
regional HQ of hte other regions (115 copies to CR; 100 copies to SR; 91
copies to WR; and for Pacific Region - 1 copy to WSFO HNL and 5 copies to the
PR Director's office). Please ensure that these packages are mailed out from
the regional offices (where applicable, as soon as possible. I have already
gotten a call from WSO Spokane to say that they have not received their
package. I told them to call to check with the mail room in WRH.
Let me know ASAP if you have not received the "Dear Colleague" packages and
the yellow reference cards.
----------------------------------------------------------------------------
WSHPNSNMC
NOUS41 KWBC 041900
NATIONAL TECHNICAL INFORMATION MESSAGE 92-12
NATIONAL WEATHER SERVICE HEADQUARTERS
200 PM EST FRI DEC 4 1992
TO: ALL NWS OFFICES, DOMESTIC DATA SERVICE SUBSCRIBERS
FROM: MARY M. GLACKIN
CHIEF, SERVICES DEVELOPMENT BRANCH
SUBJECT: IMPLEMENTATION OF NEW MRF-BASED STATISTICAL GUIDANCE
FORECASTS
(THE FOLLOWING INFORMATION WAS PROVIDED BY JOHN JENSENIUS OF THE
TECHNIQUES DEVELOPMENT LABORATORY [TDL].)
On December 10, 1992 during the 0000 UTC cycle, a new statistical
forecast package will be implemented based on the National
Meteorological Center's (NMC's) Medium-Range Forecast (MRF)
model. The new medium range guidance is being developed by TDL.
Included in the new guidance package will be forecasts of daytime
maximum and nighttime minimum temperature, the probability of
precipitation for 12- and 24-h periods, and the mean opaque
cloudiness for 12-h periods. Guidance will be available for
periods ranging from 12 to 192 hours in advance. Forecasts of
mean wind speed for 12-h periods and forecasts of the conditional
probability of snow (given precipitation) will be added to the
message during the next 9 months as these forecasts become
available. Guidance will be transmitted for 205 stations in the
contiguous United States and 14 stations in Alaska. This new
message will be available once each day, between 0800 and 1000
UTC. In addition to the statistical forecasts, the
climatic normals for the 96-108 and 108-120 h periods, or for the
96-120 h period, will be included in the message.
The forecasts contained in the MRF-based statistical forecast
package are generated by equations developed through use of
either the perfect prog or Model Output Statistics (MOS)
techniques. Before being disseminated, however, all forecasts
are processed by a calibration program to remove bias and to tend
the forecasts toward normal climatic conditions. This
calibration procedure was designed to minimize the mean squared
error of the forecasts. Consequently, forecasts for the longer
range projections will approach normal climatic values.
The forecasts will be disseminated in collectives, grouped
according to the area of responsibility for "modernized" NWS
Weather Forecast Offices (WFOs). A separate bulletin will be
sent for each future WFO. A list of the bulletins, product
identifiers (both AFOS and WMO headers), and the stations
contained in each bulletin is included on a yellow reference
card, which was mailed with a "Dear Colleague" cover memo dated
November 20, 1992 to all NWS offices, Family of Services
subscribers, universities, and AMS broadcasters last week.
For AFOS users, the MRF statistical guidance will be available
under a new AFOS category - FMR (Forecast Medium Range). The
bulletins will be regionally routed to appropriate AFOS Regional
Distribution Circuits (refer to the "Dear Colleague" package for
the specific AFOS distribution).
For Family of Services users, the bulletins will be available to
the Domestic Data Service. The WMO headers are assigned from one
of the following five groups: FOXE## KWBC (eastern portion of
U.S.), FOXC## KWBC (central U.S.), FOXS## KWBC (southern U.S.),
FOXW## KWBC (western U.S.), and FOUS20 KWBC for Alaska. Refer to
the "Dear Colleague" package or the yellow reference card for the
complete list of WMO headers.
A sample forecast message is also shown on the reference card.
The example contains all forecasts that will eventually appear in
the messages. However, ON DECEMBER 10, ONLY THE MN/MX, POP12,
CLDS, AND POP24 LINES WILL BE AVAILABLE. Note that the
dates given near the top of the message are in terms of UTC and
that all forecasts, with the exception of min/max temperature,
are valid for periods defined with respect to UTC. The min and
max temperature forecasts are valid for nighttime and daytime
periods, respectively, based on local standard time. Conse-
quently, forecast values for the 0000-1200 UTC period, the
0000-0000 UTC period, and for minimum temperature actually span
two local dates.
A Technical Procedures Bulletin (TPB) describing this guidance is
in preparation. If you are on the TPB mailing list, this TPB
will be mailed to you automatically as soon as it is published.
If you are not on the mailing list for TPBs, and would like to
receive a copy of this one (or would like to be added to the
mailing list), call (301)-713-0462, or write to:
NOAA/National Weather Service
Office of Meteorology
Services Development Branch, W/OM23
1325 East West Highway, Rm. 13466
Silver Spring, MD 20910
You can also contact the same office to get copies of the "Dear
Colleague" memo and yellow reference card.
AFOS users will shortly receive an AFOS Change Notice (AFOS
header cccADADRG), which will contain the pertinent database
information in order to store these products. Similarly, DDS
subscribers will receive a General Notification Message to the
FOS (also known as a "GENOT"), under WMO header NOUS40 KWBC.
If you need further information on this new guidance, please call
John Jensenius of the Techniques Development Laboratory at
(301)-763-8151.
END - W/OM23 - C. ALEX
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