Welcome to The National Weather Service Wilmington NC Frequently Ask Questions (FAQ) product page. Hopefully...
this page will answer some of the questions customers have about our products. To see these products...visit the
hurricane products page. You can also see a description of
flood...
miscellaneous...
marine and
winter products.
Click on the arrows to get a more detailed explanation of components of the products.
Click on the arrows to get a more detailed explanation of components of the products.
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The first part of the message is the WMO Heading. The WMO stands for The World Meteorological Organization. This line is used in the transmission and communicaiton of the message throughout the world. Find out more.
To interpret the code ...visit here.
AWIPS is the computer system The National Weather Service uses. AWIPS stands for the Advanced Weather Information Processing System.
The first part of the message is the WMO Heading. The WMO stands for The World Meteorological Organization. This line is used in the transmission and communicaiton of the message throughout the world. Find out more.
To interpret the code ...visit here.
AWIPS is the computer system The National Weather Service uses. AWIPS stands for the Advanced Weather Information Processing System.
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This section contains the Mass News Disseminator...MND. This contains the name of the issuing office...and the time and date the product was issued.
This section contains the Mass News Disseminator...MND. This contains the name of the issuing office...and the time and date the product was issued.
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This section contains a lot of important information. The UGC code stands for the Universl Geographic Code. This defines zones which are defined by counties most of the time. To see a breakdown of the county zone numbers in our area visit here.
This section also contains the VTEC code. VTEC stands for Valid Time Event Coding. VTEC is relatively new and is used to describe parameters of watches...warnings...and advisories explicitly. For more details about VTEC...visit here.
This section contains a lot of important information. The UGC code stands for the Universl Geographic Code. This defines zones which are defined by counties most of the time. To see a breakdown of the county zone numbers in our area visit here.
This section also contains the VTEC code. VTEC stands for Valid Time Event Coding. VTEC is relatively new and is used to describe parameters of watches...warnings...and advisories explicitly. For more details about VTEC...visit here.
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This is the main part of the product. First is the attribuiton line. The attirbution line states what product is being issued and the issuing office.
The next part is a brief description of why the product was issued...the potential impacts...and the specific meaning of a watch...warning...or advisory.
The last part of this section contains the call to action statements. These are brief statements informing or reminding people of what actions to take in preparation for the event and during the event.
This is the main part of the product. First is the attribuiton line. The attirbution line states what product is being issued and the issuing office.
The next part is a brief description of why the product was issued...the potential impacts...and the specific meaning of a watch...warning...or advisory.
The last part of this section contains the call to action statements. These are brief statements informing or reminding people of what actions to take in preparation for the event and during the event.
CLOSE WINDOW
Products end with the delimiter $$. This represents the end of the Universal Geographic Code. The last line is the name...initials...or number of the forecaster. As you can see...this is optional.
Products end with the delimiter $$. This represents the end of the Universal Geographic Code. The last line is the name...initials...or number of the forecaster. As you can see...this is optional.
Other Questions...
A 100% chance of rain...does it mean a lot of rain?
Not necessarily. The Probability of Precipitation(POP) or percent chance of rain means that measurable
rain...0.01 inches will fall at that location within a specific time period...usually 12 hours. So a 100% chance of rain
does not necessarily mean a lot of rain...just that the area will receive at least 0.01 within the specific time frame.
Isolated...Scattered...or Numerous...Slight...Chance...or Likely?
These are descriptive and qualifying terms that have been designated to match up with certain probability of
precipitation percentages(POPS). Isolated and or Slight Chance is used to describe a 20 percent
probability of precipitation. Scattered and or Chance is used to describe a 30 to 50 percent
probability of precipitation. Finally...Numerous or Likely is used to describe a probability of
precipitation of 60 to 70. There are no qualifying terms for an 80...90...or 100 probability of
precipitation.
How about confidence?
Many of our products reference a level in terms of percent of occurrence...such as 30...50...or 80 percent.
The important thing to remember is that these products are a forecast and these numbers
refer to a level of certainty or confidence. Usually an outlook is issued when confidence is
only 30 percent. A Watch is usually issued when to confidence rises to 50 percent or greater. When the
confidence level is high...80 percent or greater...a Warning is issued.
Partly Sunny or Partly Cloudy?
These expressions refer to a percentage of clouds covering the sky. For 5 percent or
less sky cover...Sunny or Clear is used. For ranges greater than 5 and less than or equal to 25 percent...Sunny or Mostly
Clear is used. Partly Cloudy or Mostly Sunny is used for greater than 25 percent to less than or equal to 50 percent cloud cover.
Partly Sunny or Mostly Cloudy is used for a sky cover percentage of greater than 50 percent or less than or equal to 69 percent.
Mostly Cloudy is used for the range of 69 to 87 percent. Finally...Cloudy or Overcast is used to
describe 87 percent or higher.
Severe thunderstorm...the official definition...
When we issue a severe thunderstorm warning...just what does it mean? A severe thunderstorm is one that
includes any combinaiton of the following:
Winds 58 MPH or higher
Tornadoes
Hail 3/4 of an inch in diameter or greater.
Why the seemingly strange number of 58 MPH? Well...this is equal to 50 knots. An important points to remember about what constitutes a severe thunderstorm is just because a thunderstorm contains a lot of lightning doesn't mean it is severe...once again...it has to contain one of the parameters above.
Winds 58 MPH or higher
Tornadoes
Hail 3/4 of an inch in diameter or greater.
Why the seemingly strange number of 58 MPH? Well...this is equal to 50 knots. An important points to remember about what constitutes a severe thunderstorm is just because a thunderstorm contains a lot of lightning doesn't mean it is severe...once again...it has to contain one of the parameters above.
Waterspout...tornado...or funnel cloud?
There are some subtle and not so subtle differences between a tornado...waterspout...and funnel cloud.
A tornado is a violently rotating column of air...pendant from a cumuliform cloud or underneath a cumuliform cloud...and often has a visible funnel cloud. To be classified as a tornado...the column of air has to be in contact with the cloud base and ground.
A funnel cloud is the same thing as a tornado with one important exception...that it is NOT in contact with the ground.
In general terms...a waterspout refers to a tornado over water. More specifically a waterspout refers to a small...relatively weak rotating column of air over water beneath a cumulonimbus or towering cumulus cloud.
A tornado is a violently rotating column of air...pendant from a cumuliform cloud or underneath a cumuliform cloud...and often has a visible funnel cloud. To be classified as a tornado...the column of air has to be in contact with the cloud base and ground.
A funnel cloud is the same thing as a tornado with one important exception...that it is NOT in contact with the ground.
In general terms...a waterspout refers to a tornado over water. More specifically a waterspout refers to a small...relatively weak rotating column of air over water beneath a cumulonimbus or towering cumulus cloud.
What are gradient winds?
Many of the marine products reference "gradient winds" in their description. These winds refer to the large scale
winds driven by the pressure difference between high and low pressure. Wind gusts from thunderstorms are not
considered gradient winds.
What is a segmented product?
A segmented product is used for a product where different segments apply to seperate geographical areas
but are all included within one product.
National Weather Service
Weather Forecast Office, Wilmington NC
2015 Gardner Drive
Wilmington, NC 28405
(910) 762-4289
Page Author:
Web Master's E-mail: ilm.webmaster@noaa.gov
Page Last Modified: April 30, 2008
Weather Forecast Office, Wilmington NC
2015 Gardner Drive
Wilmington, NC 28405
(910) 762-4289
Page Author:
Web Master's E-mail: ilm.webmaster@noaa.gov
Page Last Modified: April 30, 2008