This weather glossary contains information on more than 2000 terms,
phrases and abbreviations used by the National Weather Service (NWS)...
the government agency who makes weather forecasts, and issues weather advisories, watches, and warnings, for the United States, and its
territories.

Many of these terms and abbreviations are used by NWS forecasters to communicate between each other and have been in use for many years and
before many NWS products were directly available to the public. It is the purpose of this glossary to aid you in better understanding NWS products.

***

January Thaw
A period of mild weather popularly supposed to recur each year in late
January.

Jet
A fast-moving wind current surrounded by slower moving air.

Jet Max
(or Jet Streak) A point or area of relative maximum wind speeds within a
jet stream.

Jet Streak
Same as Jet Max; a point or area ("streak") of relative maximum wind
speeds within a jet stream.

Jet Stream
(abbrev. JSTR) Relatively strong winds concentrated in a narrow stream
in the atmosphere, normally referring to horizontal, high-altitude
winds. The position and orientation of jet streams vary from day to
day. General weather patterns (hot/cold, wet/dry) are related closely
to the position, strength and orientation of the jet stream (or jet
streams). A jet stream at low levels is known as a low-level jet.

Jet Stream Cirrus
A loose term for filamentous cirrus that appears to radiate from a point
in the sky, and exhibits characteristics associated with strong vertical
wind shear, such as twisted or curved filaments.

Jet Wind Speed Profile
A vertical wind speed profile characterized by a relatively narrow
current of high winds with slower moving air above and below. A large
wind (speed) shear occurs above and below the jet axis.

Jetty
In hydrologic terms, a structure (e.g.; a pier, or mole of wood or
stone) extending into a sea, lake, or river to influence the current
or tide or to protect a harbor.

JMA
Japanese Meteorological Agency

Jokulhlaup
In hydrologic terms, an Icelandic term meaning glacier dammed lake
outburst flood.

JSTR
Jet Stream - Relatively strong winds concentrated in a narrow stream
in the atmosphere, normally referring to horizontal, high-altitude
winds. The position and orientation of jet streams vary from day to
day. General weather patterns (hot/cold, wet/dry) are related closely
to the position, strength and orientation of the jet stream (or jet
streams). A jet stream at low levels is known as a low-level jet.

Juvenile Water
In hydrologic terms, water formed chemically within the earth and
brought to the surface in intrusive rock.

J\/kg
Joules per kilogram, unit commonly used to represent CAPE and CIN.
--- SBBSecho 3.11-Win32
* Origin: The Thunderbolt BBS - tbolt.synchro.net (57:57/10)
þ Synchronet þ Eye of The Hurricane BBS - hurrican.synchro.net