JPATS Weather - NETC

JPATS AVIATION WEATHER BOOKLET
KLCH TAF 032240Z 032323 01012G22KT 5SM HZ OVC006
BECMG 0002 01015G25KT 2SM -DZ BR OVC004 PROB40 0004 VRB25G35KT 2SM TSRA
VV002
FM0400 01012G20KT 2SM BR OVC004
BECMG 1516 01015G25KT 4SM HZ OVC008
FM1700 01010KT 5SM HZ OVC009;
KSHV TAF 032240Z 032323 36010KT 4SM BR OVC004 WS005/27050KT
TEMPO 2316 35015KT 2SM -FZDZ PL OVC020
FM1700 04008KT P6SM BKN025;
Figure 6-26 — Civilian TAF Examples
Additionally, there are some differences between military TAFs and International TAFs, which
are summarized in Table 6-7.
TAF Differences
U.S. Military TAF
International TAF
Forecast Period 24 Hours Forecast Period Variable
Wind Speed Knots Wind Speed Knots-, or Metersor
Kilometers-perhour
CAVOK not used
CAVOK used
Table 6-7 — Differences Between Military and International TAFs
The term CAVOK is similar to the term sometimes used among aviators, CAVU, which stands
for “Clear Air, Visibility Unlimited.” The term CAVOK stands for “Clear Air, Visibility O.K.”
and is not used in U.S. Military TAF reporting.
Determination of Ceiling in METARs and TAFs
In Chapter 5 we first introduced the concept of cloud layers and ceilings. As you may recall, the
definition of a ceiling is the height above the ground (AGL) ascribed to the lowest broken or
overcast layer; or the vertical visibility into an obscuring phenomenon (total obscuration).
Remember that partial obscurations, such as FEW000, or SCT000, do not constitute a ceiling.
Ceilings may be easy to determine in METAR, but more difficult in TAFs, since they usually
have more than one line. Therefore, it is important to carefully evaluate the ceiling by using the
appropriate time period, as will be discussed below in “Using TAFs for Flight Planning.” Once
the ceiling (and other cloud layers) has been determined, then one can move onward to
determining the type of flight plan (IFR or VFR) as well as whether an alternate landing airfield
is required.
6-24 Version 3.2/Dec 08