[DOC] [TLE] Weather Definitions - Central Ohio Weather Alerts (COWA) [PAR] A Dense Fog Advisory is issued when fog reduces visibility to 1/8 mile or less 
over a ... Derechos are associated with bands of rapidly moving showers or 
thunderstorms variously known as bow echoes, ... mph (93 km/h) or greater along 
most of its length, then the event may be classified as a derecho. ... -No official 
definition. [DOC] [TLE] Glossary - NOAA's National Weather Service [PAR] Jun 25, 2009 ... USA.gov is the U.S. government's official web portal to all federal, state and .... "
delta", which is formed where a stream drops its debris load on entering a body of 
quieter water. ... Dense Fog Advisory: Issued when fog reduces visibility to 1/8 
mile or less over a ... It is also known as a "dryline" or "dry front". [DOC] [TLE] ACCESSIBILITY: Publications and forms are available - U.S. Air Force [PAR] Jan 31, 2010 ... tower visibility reports for air traffic control operations, including Air Force 
Reserve ... replace, substitute, or supersede official regulations, procedures, or 
directives. ..... accordance with these instructions; anything less will reduce its .... 
but not 1 1/16, 2 1/8, or 3  because they are not reportable values. [DOC] [TLE] Weather Glossary and Terminology - Timeanddate.com [PAR] Visibilities of 1/8 mile or less over a widespread area are criteria for a Blowing 
Dust Advisory. ... Blowing snow: Wind driven snow that reduces visibility to six 
miles or less causing ... Also called a thunderstorm cloud, it is frequently 
accompanied by heavy ... Dense fog: A fog in which the visibility is less than one-
quarter mile. [DOC] [TLE] Instrument Procedures Handbook - Federal Aviation Administration [PAR] takeoffs with reduced visibility is that pilots are challenged in maintaining ... 
provide procedures for establishing Airport Low-Visibility. Operations (LVO) and... [DOC] [TLE] Pepper Ridge North Valley's - Weather Glossary Page - D to G [PAR] Dense Fog Advisory - Advisory issued when fog reduces visibility to 1/8 mile or 
less, ..... Its lower boundary is often called the critical level of escape, where gas 
..... area about getting official SKYWARN training and riding along with someone
... [DOC] [TLE] WeatherBank Toolbar [PAR] ANTARCTIC OCEAN: Although not officially recognized as a separate ocean 
body, ... When this air mass moves from its source region, it may become more 
shallow in ... In the Northern Hemisphere, it is known as the aurora borealis or 
Northern ..... DENSE FOG ADVISORY: Advisory issued when fog reduces 
visibility to 1/8... [DOC] [TLE] Tiffin Weather : Glossary [PAR] Visibilities of 1/8 mile or less over a widespread area are criteria for a Blowing 
Dust Advisory. ... Blowing snow: Wind driven snow that reduces visibility to six 
miles or less ... Also called a thunderstorm cloud, it is frequently accompanied by 
heavy ... Dense fog advisory: Issued when fog is expected to reduce visibility to 1/
4... [DOC] [TLE] Blizzard - Wikipedia [PAR] Visibility reduced by blowing snow during a blizzard. A blizzard is a severe 
snowstorm characterized by strong sustained winds of at least 35 mph .... It gets 
its name from the direction the wind is coming from. ... The Storm of the Century, 
also known as the Great Blizzard of 1993, was a large cyclonic storm that formed 
over the... [DOC] [TLE] Fish & Wildlife Branch Research Permit Environmental Condition ... [PAR] Dec 21, 2013 ... airborne spray may begin to reduce visibility. Some branches break off trees, and 
.... Such pellets falling from thunderstorms are often called "soft hail." ... Official 
weather observations list sleet as "ice pellets." In ..... Visibilities of 1/8 mile or less 
over a ..... Density Of Air- The mass of air divided by its volume. [DOC] [TLE] The South Central Texas Weekend Weather Forecast - 12/31/2010 ... [PAR] Dec 31, 2010 ... Patchy dense 'sea' fog, particularly along coastal areas, will be possible ... what is 
called 'radiational cooling' Sunday night the weather conditions, ... The Current 
Weather Data For South Central Texas And It's Gulf ... Patchy dense 'sea' fog

Question: It's officially called dense when it reduces visibility to 1/8 mile
Answer: fog