NWS
Nashville Product Guide
The
National Weather Service in Nashville, Tennessee issues a variety
of products covering 39 counties in Middle Tennessee. These products
are used by the media, emergency managers, and the public. The
products are accessed through a variety of methods, including
the NOAA Weather Wire Service (NWWS), Family of Services (FOS),
the NWS AWIPS network, the Emergency Managers Weather Information
Network (EMWIN), and private vendors. This guide gives a summary
of the products, including necessary header information.
The
listing is broken down into Severe Weather Products,
Routine Public Products, Aviation
Weather Products, Fire Weather Products,
Hydrological Products, Climate
Products, and Other General Public Products.
- For NOAA
All Hazards Weather Radio for Middle Tennessee: Middle
Tennessee
- For NOAA
All Hazards Weather Radio Frequencies and SAME codes:
Severe
Weather Products
Hazardous
Weather Outlook
FOS/WMO Header: FLUS43 KOHX
AWIPS Header: OHXHWOOHX
The Hazardous Weather
Outlook, issued at least once daily by around 5:00 AM CST/CDT
and is updated as needed. The HWO highlights any expected hazardous
weather conditions over the next seven days. This includes, but
is not limited to, severe weather, flooding, extreme heat or cold,
winter weather, and dense fog.
Tornado
Warning
FOS/WMO Header: WFUS53 KOHX
AWIPS Header: OHXTOROHX
Tornado Warnings
are issued for expected tornadic activity over a county, or a
portion of a county. A warning may be issued based on Doppler
radar indications of a tornado, reports of a funnel cloud, or
observed tornado sightings. Tornado Warnings are typically valid
for 45 minutes or less.
Severe
Thunderstorm Warning
FOS/WMO Header: WUUS53 KOHX
AWIPS Header: OHXSVROHX
Severe Thunderstorm Warnings
are issued for storms which are producing or are expected to produce
winds of 58 mph or more, hail 3/4 inch or greater diameter, or
both. These are issued for counties or portions of counties, and
are typically an hour or less in length.
Severe
Weather Statement
FOS/WMO Header: WWUS53 KOHX
AWIPS Header: OHXSVSOHX
A Severe Weather Statement
is used to disseminate follow-up information on severe thunderstorm
and tornado warnings. This can include actual severe weather reports,
current radar information, and towns expected to be in the path
of the storms. This statement is also used to cancel warnings,
and to give follow-up information after a warning has expired.
Flash
Flood Warning
FOS/WMO Header: WGUS53 KOHX
AWIPS Header: OHXFFWOHX
The Flash Flood Warning
is issued when life or property-threatening, short-term
flooding is imminent. This can include flooding due to heavy rainfall
or due to a dam break. Flash Flood Warnings may be valid for up
to 6 hours, and can be extended as necessary.
Flash
Flood Statement
FOS/WMO Header: WGUS73 KOHX
AWIPS Header: OHXFFSOHX
The Flash Flood Statement
is issued to update the status of short-term flash flood situations.
It can contain information on reported rainfall, radar estimates
of rain, and forecast amounts of rain in the future.
Flood
Statement
FOS/WMO Header: WGUS83 KOHX
AWIPS Header: OHXFLSOHX
The Flood Statement
product can be issued for a number of reasons: 1) Follow-up information
on Flood Warnings, either county-based or river-based; or 2) Short-term
flooding which may cause an inconvenience, but is not considered
to be threatening ("urban and small stream flooding").
When issued for river flooding forecast purposes, they are issued
twice daily, usually between 10:00-11:00 AM and between 8:00-9:00
PM CST/CDT.
Watch
Outline Update
FOS/WMO Header: WOUS64 KWNS
AWIPS Header: MKCWOU# (# represents last digit of watch
number)
The Watch Outline Update is issued by the Storm Prediction Center
in Norman, OK. It is issued at the beginning and end of severe
thunderstorm and tornado watches, and indicates which counties
are specifically included in the watch. This product includes
all NWS offices affected by a particular watch.
Local
Storm Report
FOS/WMO Header: NWUS53 KOHX
AWIPS Header: OHXLSROHX
The Local Storm Report
product gives a detailed listing of observed severe weather across
the NWS Nashville area of responsibility. It is often issued during
a severe weather event, a few reports at a time, but it is always
issued after an event has ended containing a summary of all reports.
Reports of significant winter weather are also transmitted in
the LSR product. Data listed should be considered preliminary,
as further investigation may be necessary in some cases. This
product is used as input to the national Daily
Severe Weather Statistics compiled by the Storm Prediction
Center.
Special
Weather Statement
FOS/WMO Header: WWUS83 KOHX
AWIPS Header: OHXSPSOHX
The Special Weather Statement
is used to disseminate updated information regarding the cancellation
of severe weather watches (in the future, the Watch County Notification
WCN product will be used for this purpose). The SPS is
more often used to augment the current forecast and highlight
significant short-term weather that is not already covered in
an advisory, watch, or warning product. Examples include a line
of strong, but not severe, thunderstorms …or an area of
moderately intense snow showers.
Routine
Forecast Products
National
Digital Forecast Database/Grid-Point Forecasts
FOS/WMO Header: N/A
AWIPS Header: N/A
Forecasters in todays NWS issue forecasts in gridded form via
the National Digital Forecast Database (NDFD), which are updated
as necessary day or night. What this means is that you can get
a unique forecast for a specific point anywhere in the U.S. that
offers features such as hourly temperature and precipitation forecasts.
Experimental point forecasts are available for locations in the
NWS Nashville area of responsibility at this website.
Graphical forecasts in a map form are also available.
Outside entities can use this NDFD data to view weather parameters
that are important to them; an example would be a transportation
company interestested in the weather along a certain Interstate.
Visit the NDFD webpage
for details on how you can benefit from this powerful dataset.
What forecasters input into the NDFD is also used to generate
our routine text products, which are described below.
Zone
Forecast Product
FOS/WMO Header: FPUS53 KOHX
AWIPS Header: OHXZFPOHX
The Zone Forecast Product
gives specific forecasts for out to 7 days in the 39 counties
covered by the Nashville NWS office. The product is routinely
issued at 4:00 AM and 4:00 PM CST/CDT, and is updated as necessary.
Forecasts are broken up into "zones” or groups of counties
where the forecast weather is expected to be similar. When necessary,
a forecast section is headlined with a watch, warning or advisory
for hazardous weather.
Area
Forecast Discussion
FOS/WMO Header: FXUS63 KOHX
AWIPS Header: OHXAFDOHX
The Area Forecast Discussion
is issued normally by around 3:00 AM and 3:00 PM CST/CDT, and
at other times as weather changes. The forecaster gives their
analysis of the current weather situation, information on the
computer models, and forecast reasoning. The discussion includes
a listing of non-convective watches, warnings and advisories that
will be in effect, on the line following ".OHX WATCHES/WARNINGS/ADVISORIES...".
Area
Forecast Matrices
FOS/WMO Header: FOUS53 KOHX
AWIPS Header: OHXAFMOHX
The Area Forecast Matrix
product is a tabular listing of expected weather elements over
the next several days for groups of counties. It is similar to
the Model Output Statistics (MOS) guidance, but reflects forecaster
input into the process. Contents include expected temperature,
dew point, humidity, wind, sky condition, and precipitation chances
and amounts in 3 hourly increments for the first 60 hours of the
forecast, with 6 hourly increments thereafter. The AFM product
is issued twice daily by around 4:00 AM and 4:00 PM CST/CDT, and
is updated as necessary.
Point
Forecast Matrices
FOS/WMO Header: FOUS53 KOHX
AWIPS Header: OHXPFMOHX
The Point Forecast Matrix
product is a tabular listing of expected weather elements over
the next several days, at specific cities in Middle Tennessee
and south Central Indiana. It is similar to the Model Output Statistics
(MOS) guidance, but reflects forecaster input into the process.
Contents include expected temperature, dew point, humidity, wind,
sky condition, and precipitation chances and amounts in 3 hourly
increments for the first 60 hours of the forecast, with 6 hourly
increments thereafter. The PFM is issued twice daily by around
4:00 AM and 4:00 PM CST/CDT, and is updated as necessary.
Coded
Cities Forecast
FOS/WMO Header: FPUS43 KOHX
AWIPS Header: OHXCCFOHX
The Coded Cities Forecast
is normally issued by around 3:30 AM and 3:30 PM CST/CDT. It contains
coded forecasts of weather, temperature and precipitation chances
for Nashville (BNA), Clarksville (CKV), and Crossville (CSV).
The product is used as input to the national Selected
Cities Summary, issued by the National Centers for Environmental
Prediction (NCEP).
Short
Term Forecast
FOS/WMO Header: FPUS73 KOHX
AWIPS Header: OHXNOWOHX
The Short Term Forecast
is issued as needed. It covers the expected weather conditions
for up to 6 hours in advance. It is meant to give very detailed,
narrative information which expands on the basic foundations of
the Zone Forecast, including details on timing and amounts of
precipitation.
Hazardous
Weather Outlook
FOS/WMO Header: FLUS43 KOHX
AWIPS Header: OHXHWOOHX
The Hazardous Weather
Outlook, issued routinely at least once daily by around 5:00
AM CST/CDT and is updated as needed. The HWO highlights any expected
hazardous weather conditions over the next seven days. This includes,
but is not limited to, severe weather, flooding, extreme heat
or cold, winter weather, and dense fog.
Non-Precipitation
Weather Message
FOS/WMO Header: WWUS73 KOHX
AWIPS Header: OHXNPWOHX
The Non-Precipitation
Weather Message is used to issue watches, advisories, warnings,
cancellations, or updates for various weather phenomena. These
include: Dense fog, high winds, excessive heat indices or wind
chill, frost and freeze during the growing season which is defined
locally as when daylight saving time is in effect, and blowing
dust. Definitions of the various NPW products can be found
here. This product
is generally issued every 6 hours until the phenomena ends.
Winter
Weather Message
FOS/WMO Header: WWUS43 KOHX
AWIPS Header: OHXWSWOHX
The Winter Weather Message
is used to issue watches, advisories, warnings, cancellations,
or updates for various winter weather phenomena. It is generally
issued every 6 hours until the phenomena ends. Details on the
various winter weather products can be found on our website.
Tabular
State Forecast for Middle Tennessee
FOS/WMO Header: FPUS64 KOHX
AWIPS Header: OHXSFTOHX
The Tabular State Forecast
for Middle Tennessee is issued twice daily, normally between
4:00 and 5:00 AM/PM central time year-round. It gives specific
temperature forecasts for 39 locations in Middle Tennessee for
the next 7 days, as well as a one-word summary of the weather
conditions expected.
Regional
Weather Summary
FOS/WMO Header: AWUS83 KOHX
AWIPS Header: OHXRWSOHX
The Weather Summary
gives a brief overview of the weather across Middle Tennessee
and south central Indiana over the past 12 hours, and an outlook
of expected weather conditions over the Ohio Valley the next 12
to 24 hours. Expected positions of weather systems, forecasts
of precipitation, and temperatures are included. The product is
issued once per day; normally by around 5:00 AM CST/CDT.
State
Weather Summary (Tennessee)
FOS/WMO Header: AWUS83 KOHX
AWIPS Header: OHXRWSTN
The State Weather Summary
gives a brief overview of the weather across the state of Tennessee
over the past 12 hours, and an outlook of expected weather conditions
for the state in the next 12 to 24 hours. Expected positions of
weather systems, forecasts of precipitation, and temperatures
are included. The product is issued once per day; normally by
around 4:30 PM CST/CDT.
Aviation
Weather Products
Terminal
Aerodrome Forecast (TAF)
FOS/WMO Header: FTUS43 KOHX
AWIPS Headers: OHXTAFBNA (Nashville International Airport)
and OHXTAFCSV (Crossville)
These coded messages, for aviation interests, are issued routinely
4 times a day, by 0540, 1140, 1740 and 2340 UTC, and updated as
necessary. The forecasts contain information related to wind,
visibility, weather hazards, and cloud levels for a 24 hour period.
The latest TAFs: [ KOHX
] [ KLEX ] [
KBWG ]
Fire
Weather Products
Fire
Weather Planning Forecast
FOS/WMO Header: FNUS53 KOHX
AWIPS Header: OHXFWFOHX
The Fire Weather Planning
Forecasts are issued daily by around 5:00 AM CST/CDT. During
the “fire weather seasons” a second forecast is issued
by around 4:00 PM CST/CDT. A headline may be added to the top
of the forecast, denoting significant weather, or for the issuance
of a Red Flag Warning or Fire Weather Watch. The synopsis will
briefly cover locations of fronts and systems which produce the
weather. The first 36 hours of the forecast will contain specific
weather elements such as temperatures, wind direction and speed,
maximum and minimum relative humidity, precipitation amounts,
mixing heights, and transport wind speeds and direction. The extended
three to seven-day forecast is a general forecast which mentions
the possibility of precipitation and high and temperatures for
each day. Note that the fire weather seasons are currently
defined as: February 15 through April 30, and October 1 through
December 15. These dates may change depending on the severity
of the fire season.
Fire
Weather Station Forecasts
FOS/WMO Header: FNUS83 KOHX
AWIPS Header: OHXFWMOHX
The National Fire Danger Rating System (NFDRS) is a quantitative
means for evaluating the fire danger across vast areas. This complex
model of fuel and weather parameters processes daily weather observations
and fuel moisture as input, and fire managers receive numeric
output danger over a given area. Fire
Weather Station forecasts are routinely issued during the
spring and autumn fire seasons to be input into the NFDRS. The
station forecast provides specific information on expected weather,
temperature, humidity, maximum and minimum values, and lightning
activity levels. The FWM is issued daily only during the spring
and fall fire weather seasons, and is transmitted by around 3:30
PM CST/CDT. The fire weather seasons are currently defined as:
February 15 through April 30, and October 1 through December 15.
These dates may change depending on the severity of the fire season.
Fire
Weather Watch
FOS/WMO Header: WWUS83 KOHX
AWIPS Header: OHXRFWOHX
Fire Weather Watches
are used to alert users of the possible development of a Red Flag
event within the next three days. A Red Flag event is defined
as an event where ten-hour fuel stick moisture must be 8% or less,
along with afternoon relative humidity levels 25% or below, and
20-foot winds are expected to exceed 15 mph. All three requirements
must be met for at least a couple hours.
Red
Flag Warning
FOS/WMO Header: WWUS83 KOHX
AWIPS Header: OHXRFWOHX
Red Flag Warnings
are issued to warn an impending or ongoing Red Flag event, when
rapid fire spread is likely due to favorable weather conditions.
A Red Flag event is defined as an event where ten-hour fuel stick
moisture must be 8% or less, along with afternoon relative humidity
levels 25% or below, and 20-foot winds are expected to exceed
15 mph. All three requirements must be met for at least a couple
hours.
Hydrological
Products
Flood
Watch
FOS/WMO Header: WGUS63 KOHX
AWIPS Header: OHXFFAOHX
The Flood Watch is
issued when heavy rainfall is forecast to cause significant or
widespread flooding. This is usually issued at least 6 hours in
advance of the expected event, and on occasion as much as a day
or two in advance in high confidence situations. Updates to an
ongoing flood watch are also issued under the FFA product. If
the event is still a few days away, a Hydrologic Outlook may be
issued instead, to give a heads-up to the potential of heavy rainfall.
Flood
Warning
FOS/WMO Header: WGUS43 KOHX
AWIPS Header: OHXFLWOHX
The Flood Warning
product is issued when river levels are expected to rise to potentially
damaging levels. Flood Warnings can also be used when overland
flooding is expected to persist for many hours.
Flood
Statement
FOS/WMO Header: WGUS83 KOHX
AWIPS Header: OHXFLSOHX
The Flood Statement
product can be issued for a number of reasons: 1) Follow-up information
on Flood Warnings, either county-based or river-based; or 2) Short-term
flooding which may cause an inconvenience, but is not considered
to be threatening ("urban and small stream flooding").
When issued for river flooding forecast purposes, they are issued
twice daily, usually between 10:00-11:00 AM and between 8:00-9:00
PM CST/CDT.
Hydrologic
Outlook
FOS/WMO Header: FGUS73 KOHX
AWIPS Header: OHXESFOHX
The Hydrologic Outlook
is used to give an outlook of heavy rainfall and possible flooding
more than 36 or 48 hours out in the forecast. In the late winter
and early spring, this product can give information on the possibility
of flooding due to snowmelt and expected springtime precipitation.
Hydrologic
Summary
FOS/WMO Header: SRUS43 KOHX
AWIPS Header: OHXRVAOHX
The Hydrologic Summary
product is issued daily around 9:30 AM CST/CDT. It contains observed
river and lake levels, along with precipitation amounts across
Middle Tennessee.
Climate
Products
Daily
Climatological Summaries:
FOS/WMO Header: CDUS43 KOHX
AWIPS Headers: OHXCLIBNA (Nashville), OHXCLICKV
(Clarksville), and OHXCLICSV (Crossville)
Climatological summaries for data collected at Nashville,
Clarksville, and
Crossville are issued
twice daily (1:30 AM CST/2:30 AM CDT, and 4:30 PM CST/CDT). These
summaries contain information on temperatures, degree days, precipitation,
wind, climatological normals, and records.
Monthly
Climatological Summaries:
FOS/WMO Header: CXUS53 KOHX
AWIPS Header: OHXCLMBNA (Nashville)
Preliminary climatological summaries for the past month are issued
on the 1st of each month, normally before 12:00 PM CST/CDT, for
Nashville. The summaries
include average temperature and maximum observed values, degree
days, precipitation, and comparisons to normal.
Record
Report
FOS/WMO Header: SXUS73 KOHX
AWIPS Headers: OHXRERBNA (for Nashville specific records)
and OHXRERCSV (for Crossville specific records)
The Record Report
is issued when record conditions have been observed from Middle Tennessee and south central Indiana official observing sites.
Regional
Temperature and Precipitation Table
FOS/WMO Header: ASUS63 KOHX
AWIPS Header: OHXRTPOHX
The Regional Temperature
and Precipitation Table is issued twice daily: between 9:00
and 10:00 AM CST (10:00 and 11:00 AM CDT), and again between 7:30
and 8:30 PM CST (8:30 and 9:30 PM CDT). It contains basic climate
information from around Middle Tennessee from airport observation
sites and cooperative observers. The data primarily consists of
high and low temperatures, and measured precipitation, including
snow depth if applicable.
Tennessee
Temperature and Precipitation Roundup
FOS/WMO Header: ASUS63 KOHX
AWIPS Header: OHXRTPTN
The State Temperature
and Precipitation Table is issued twice daily no later than
7:30 AM/PM CST (8:30 AM/PM CDT). It lists the maximum and minimum
temperatures along with precipitation and snow depth (if applicable)
for select cities across Tennessee.
General
Public Products
Hourly
Weather Roundup (Tennessee)
FOS/WMO Header: ASUS43 KOHX
AWIPS Header: OHXRWRTN
The hourly weather roundup
provides the most recent hourly weather observations at selected
locations across Tennessee. Due to occasional delays in data transmission,
the roundup is issued twice an hour; directly at the top of
the hour, and again at eight minutes past the hour.
Present weather, temperature, dew point, relative humidity, wind
direction and speed, atmospheric pressure, and pressure tendency
are included. The remarks section will include additional information
such as the heat index, wind chill, and any obstructions to visibility.
Nashville
Air Quality Index
FOS/WMO Header: AEUS73 KOHX
AWIPS Header: OHXAQIOHX
The Metropolitan Nashville Air Pollution Control District monitors
air quality at various locations around Nashville, Tennessee.
At minimum four times each weekday, the Air
Quality Index is issued by NWS Nashville which includes the
current air quality, the elevated pollutant, the current pollution
category, and a short-term forecast for the pollution index. In
the case of dangerous pollutants, health advisories or alerts
would be included at the end of the product.
Public
Information Statement
FOS/WMO Header: NOUS43 KOHX
AWIPS Header: OHXPNSOHX
The Public Information
Statement is used for a variety of purposes. They include
notifications of winter storm accumulations of snow and/or ice,
storm damage surveys, severe weather safety rules, media advisories,
and NOAA All Hazards Weather Radio outages.
Civil
Emergency Message
FOS/WMO Header: WOUS43 KOHX
AWIPS Header: OHXCEMOHX
Civil Emergency Messages
are used to inform the public of a non-weather related, hazardous
emergency. An example would be a chemical spill where hazardous
vapors are being released. The product is issued at the request
of an official agency, such as local government officials or state
emergency management.
Earthquake
Report
FOS/WMO Header: SEUS63 KOHX
AWIPS Header: OHXEQROHX
An Earthquake Report
is issued upon occurrence of an earthquake being felt or causing
damage in Middle Tennessee. The information is relayed to the
U.S. Geological Survey, who establishes the official Richter Scale
reading for the quake.
Aircraft
Accident Report
FOS/WMO Header: NOUS53 KOHX
AWIPS Header: OHXOAVOHX
The Aircraft Accident
Report includes weather details around the time that a significant
aircraft incident occurs in Middle Tennessee.
Radar
Outage Notification
FOS/WMO Header: NOUS63 KOHX
AWIPS Header: OHXFTMOHX
This message is to
inform NWS offices, vendors, and users of WSR-88D data that the
radar at Old Hickory (KOHX) has experienced an outage (either
planned or unexpected). It includes reasons for the outage if
known, expected outage time, and a statement of which surrounding
radars can be used for radar information in Middle Tennessee.