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APPENDIX C.
LAWRS
REQUIREMENTS
Paragraph 1-8a contains the applicability of
procedures and practices in the order to limited aviation weather
reporting station (LAWRS) personnel.
1. PURPOSE
This appendix is an extract from the body of this
order and contains the general requirements for LAWRS observers.
References to the order are provided for the details.
2. GENERAL
a. A limited aviation weather
reporting station (LAWRS) is a facility where observations are taken,
prepared and transmitted by certified FAA air traffic control
specialists on a limited basis. At these facilities, various degrees
of automated sensors and/or other automated equipment may be
available. However, when on duty, the LAWRS observer has the complete
responsibility for the surface aviation weather elements in the METAR/SPECI.
b. General observing requirements
that apply to all observers, including LAWRS, are included in
Chapter 3, General Procedures.
3. REQUIREMENTS
LAWRS observers at different locations have differing
observing requirements based upon whether or not an automated
observation system is available, and the type of system they have. This
appendix states minimum requirements for what the LAWRS observer must
put into the observation. The observation can be augmented beyond the
stated requirements. Table C-1, LAWRS Requirements for Body of METAR,
gives the requirements for what the LAWRS observer must manually put in
the body of the observation, and Table C-2, LAWRS Requirements for
Remarks Section, gives the requirements for what the LAWRS observer must
insert in the remarks section. Additive and automated maintenance data
included in the remarks section may be added by an automated system, but
are not required to be augmented or backed up by LAWRS. Table C-3, LAWRS
Requirements for SPECIs, lists SPECI criteria and LAWRS requirements.
Listed with each element in these tables is a paragraph reference for
how to code the particular element. Details on the procedures for
observing each element are given in the appropriate chapter (e.g.,
tornadic activity procedures are included in Chapter 11, Weather
Phenomena; variable visibility procedures are given in Chapter 9,
Visibility).
4. REQUIREMENTS FOR LAWRS WITHOUT
AN AUTOMATED SYSTEM
At locations without an automated weather observing
system, LAWRS observers shall take METAR/SPECI observations in
accordance with general instructions for all observers and for manual
observers found in Chapters 3 and 7. Specific instructions are
found in Chapters 8 through 17. The last column in tables C-1
through C-3 in this appendix gives an outline of the requirements for
completely manual LAWRS observations.
5. PROCEDURES FOR LAWRS WITH ASOS
a. Augmenting ASOS Observations. An
outline of the requirements for augmentation is provided in
tables C-1 through C-3 of this appendix. More detail is given in
Chapters 4 and 5. LAWRS observers shall augment the following weather
phenomena at ASOS sites:
(1) Thunderstorm (at non-ALDARS
sites)
(2) Tornadic activity (including
tornado, waterspout, and funnel cloud)
(3) Hail
(4) Virga
(5) Volcanic ash
(6) Operationally significant
remarks as deemed appropriate by the observer
b. ASOS Backup. If portions of, or
the complete ASOS observation is unavailable due to sensor/system
malfunction, communications failure, erroneous data and/or
non-representative data (see paragraph 2.5, Backup Requirements,
for definitions for each case), LAWRS shall backup, at a minimum, the
following weather elements at ASOS sites: (Tables C-1 through C-3
provide an outline of backup requirements for LAWRS.)
(1) Wind
(2) Visibility to 10 miles
(3) Present weather &
obscurations (thunderstorms, at ALDARS sites), see Figure 6-6
(4) Sky condition to 12K feet
(5) Temperature/dew point
(6) Altimeter setting
c. Documentation requirements,
equipment requirements, and examples of augmented and backup
observations are given in Chapters 4, 5 and 6.
6. PROCEDURES FOR LAWRS WITH AWOS
a. Augmenting AWOS Observations.
At facilities where AWOS is the automated system, the augmentation
shall be manually entered into the system via the Operator Terminal
keyboard for transmission. (Note: Augmentation is not possible at AWOS
facilities without an Operator Terminal keyboard.) An outline of the
requirements for AWOS augmentation is provided in tables C-1
through C-3 of this appendix. More detail is given in Chapters 4
and 5. LAWRS observers at AWOS sites shall augment the following
weather phenomena:
(1) Thunderstorm (at non-ALDARS
sites)
(2) Precipitation occurring at
the point of observation, limited to type plus intensity in
accordance with the allowable reports listed in Figure 6-6
(3) Obstructions to vision
(alone or in combination with precipitation) at the point of
observation in accordance with the allowable reports listed in
Figure 6-6
(4) Tornadic activity
(including tornado, waterspout, and funnel cloud)
(5) Hail
(6) Virga
(7) Volcanic ash
(8) Operationally significant
remarks as deemed appropriate by the observer
At AWOS sites, all augmentation reports shall be
manually input into the remarks portion of the report, prefixed with the
phrase "WEA:", and shall be limited to 80 characters including
spaces. Entry of these reports shall be in accordance with
procedures prescribed in the AWOS Observers Handbook or FAA approved
manufacturer’s equipment manual.
b. AWOS Backup. If portions of, or the
complete AWOS observation is unavailable due to sensor/system
malfunction, communications failure, erroneous data and/or
non-representative data (see paragraph 2-5, Backup Requirements, for
definitions for each case), LAWRS shall provide, at a minimum, backup
information for the following weather elements at AWOS sites: (Tables
C-1 through C-3 provide an outline of backup requirements for LAWRS.)
(1) Wind
(2) Visibility to 10 miles
(3) Thunderstorms (at ALDARS
sites)
(4) Sky condition to 12K feet
(5) Temperature/dew point
(6) Altimeter setting
Of the 4 modes on AWOS type III configuration,
Mode 3 and Mode 4 allow elements within the observation to be
backed up. Operation in Mode 3 permits the LAWRS observer to
reflect the errant value as missing with the correct value entered into
the remarks section. Operation in Mode 4 permits the LAWRS observer
to replace the errant value where it falls in the observation. Details
are in the AWOS Operator Instructions.
c. Documentation and equipment
requirements and examples of augmented and backup observations are
given in Chapters 4, 5 and 6.
Table C-1. LAWRS Requirements
for Body of METAR
|
LAWRS Requirements for Body of METAR |
|
Element
|
LAWRS
w/
ASOS |
LAWRS
w/
AWOS |
LAWRS
w/o
AWOS/
ASOS |
|
Type of Report (METAR/SPECI) (Ref: para. 15-7) |
|
|
X |
|
Station Identifier (CCCC) (Ref: para. 15-8) |
|
|
X |
|
Date/Time (YYGGggZ) (Ref: para. 15-9) |
|
|
X |
|
Report Modifier (AUTO or COR) (Ref: para. 15-10) |
|
|
X4 |
|
Wind (dddff(f)GfmfmKT) (dndndnVdxdxdx)
(Ref: para. 15-11) |
B |
B |
X |
|
Visibility (VVVVVSM) (Ref: para. 15-12) |
B |
B |
X5 |
|
Runway Visual Range (RDRDR/VRVRVRVRFT
or RDRDR/VNVNVNVNVVXVXVXVXFT)
(Ref: para. 15-13) |
|
|
D |
|
Present Weather (w'w') (Ref: para. 15-14) |
A1 B2 |
A3 |
X |
|
Sky Condition (NsNsNshshshs
or VVhshshs or CLR/SKC)
(Ref: para. 15-15) |
B |
B |
X |
|
Temperature/Dew Point (T'T'/T'dT'd) (Ref:
para. 15-16) |
B |
B |
X |
|
Altimeter (APHPHPHPH)
(Ref: para. 15-17) |
B |
B |
X |
|
Footnotes:
A = Required to augment automated system.
B = Required to backup automated system.
C = Not backed up by LAWRS.
X = Required.
D = Required at designated stations only.
1. Augment thunderstorm (at non-ALDARS sites), tornadic
activity, hail, and volcanic ash
2. See paragraph 6-10 and table 6-6. Augment as normal. (see
note 1.)
3. Augment thunderstorm, tornadic activity, hail and volcanic
ash.
Augment precipitation plus intensity in accordance with the
allowable reports listed in table 6-6.
Augment obstructions to vision (alone or in combination with
precipitation) at the point of observation in
accordance with
the allowable reports listed in table 6-6.
4. If applicable.
5. Tower visibility replaces surface visibility.
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Table C-2. LAWRS Requirements
for Remarks Section
|
LAWRS Requirements for Remarks Section of
Observation
(Automated, Manual, and Plain Language) |
|
Element |
LAWRS
w/
ASOS |
LAWRS
w/
AWOS |
LAWRS
w/o
AWOS/
ASOS |
|
Volcanic Eruptions (Ref: para. 15-20) |
A |
A |
X |
|
Tornadic Activity (Tornadic activity_B/E(hh)mm LOC/DIR_(MOV))
(Ref: para. 15-21) |
A1 |
A |
X |
|
Type of Automated Station (AO1, AO2) (Ref: para. 15-22) |
|
|
|
|
Peak Wind (PK WND dddff(f)/(hh)mm) (Ref: para. 15-23) |
|
|
|
|
Wind Shift (WSHFT_(hh)mm) (Ref: para. 15-24) |
A |
A |
A |
|
Tower or Surface Visibility (TWR VIS) (SFC VIS) (Ref: para.
15-25) |
A2 |
A4 |
|
|
Variable Prevailing Visibility (VIS minVmax) (Ref: para. 15-26) |
|
|
X |
|
Sector Visibility (VIS_ dd_vv) (Ref: para. 15-27) |
|
|
D |
|
Visibility at Second Location (VIS vv location) (Ref: para.
15-28) |
|
|
D |
|
Lightning ({FREQ}_ LTG{TYPE}_{LOC})(Ref: para. 15-29) |
A |
A |
X |
|
Beginning/Ending Time of Precipitation
(WX)B(mm)E(mm) (Ref: para. 15-30) |
A1 |
|
|
|
Beginning/Ending Time of Thunderstorms
(TS)B(mm)E(mm) (Ref: para. 15-31) |
A1 |
|
X |
|
Thunderstorm Location (TS_LOC_(MOV_DIR)) (Ref: para. 15-32) |
A |
A |
X |
|
Hailstone Size (GR_{INCHES})(Ref: para. 15-33) |
A |
A |
X |
|
Virga (VIRGA_{Direction})( Ref: para. 15-34) |
A3 |
A3 |
X3 |
|
Variable Ceiling (CIG minVmax) (Ref: para. 15-35) |
|
|
X |
|
Obscurations (w’w’_(NsNsNs)
hshshs) (Ref: para. 15-36) |
|
|
X |
|
Variable Sky Condition (NsNsNs(hshshs)_V_NsNsNs)
(Ref: para. 15-37) |
|
|
X |
|
Significant Cloud Types (Ref: para. 15-38) |
|
|
X |
|
Ceiling Height at Second Location (CIG_ {height}_{LOC}) (15-39) |
|
|
|
|
Pressure Rising or Falling Rapidly (PRESRR) (PRESFR) (15-40) |
|
|
|
|
Sea-Level Pressure (SLPppp) (SLPNO) (Ref: para. 15-41) |
|
|
|
|
Aircraft Mishap (ACFT_ MSHP) (Ref: para. 15-42) |
|
|
D |
|
No SPECI Reports Taken (NOSPECI) (Ref: para. 15-43) |
|
|
D |
|
Snow Increasing Rapidly (SNINCR_(ii)/(ii)) (NA LAWRS) (15-44) |
|
|
|
|
Other Significant Information (Plain Language) (Ref: para.
15-45) |
|
|
D |
|
Additive and Automated Maintenance Data (NA LAWRS) (15-46) |
|
|
|
|
Footnotes:
A = Required to augment automated system.
B = Required to backup automated system.
X = Required.
D = Required at designated stations only.
1. Beginning/end time done automatically by ASOS (for
tornadic activity, thunderstorms, and hail).
2. Tower visibility can be either in remarks or the body of
the observations, based upon which visibility
is lower.
3. Direction of virga from station is optional.
4. For AWOS, tower visibility will always be in remarks.
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Table C-3. LAWRS Requirements
for SPECIs
|
LAWRS Requirements for
SPECI |
|
SPECI Criteria |
LAWRS
w/
ASOS |
LAWRS
w/o AWOS/
ASOS |
|
Wind Shift - Wind
direction changes by 45 degrees or more in less than 15 minutes
and the wind speed is 10 knots or more throughout the wind shift. |
B |
X |
|
Visibility - Surface
visibility as reported in the body of the report decreases to less
than, or if below, increases to equal or exceed: 3 miles, 2 miles,
1 mile, and 1/ 2 mile or the lowest
standard instrument approach procedure minimum as published in the
National Ocean Survey (NOS) U.S. Terminal Procedures. |
A2 |
X |
|
Runway Visual Range - The highest
value from the designated RVR runway decreases to less than, or if
below, increases to equal or exceed 2,400 feet during the
preceding 10 minutes. Note: Criteria applies to automated RVR
reporting only. |
C |
NA LAWRS |
|
Tornado, Funnel Cloud, Or Waterspout -
is observed or disappears from sight. |
A |
X |
|
Thunderstorm - begins (a SPECI report
is not required to report the beginning of a new thunderstorm if
one is currently reported) or ends. |
A |
X |
|
Precipitation - hail begins or ends;
freezing precipitation begins, ends, or changes intensity; ice
pellets begin, end, or change intensity at manual stations. |
A4 |
X |
|
Squall - Wind suddenly increases at
least 16 knots and is sustained at 22 knots or more for at least
one minute. |
B |
X |
|
Ceiling - When the
height of the base of clouds covering five oktas or more (e.g.,
broken and overcast) of the sky forms or dissipates below,
decreases to less than or, if below, increases to equal or exceed:
3,000 ft., 1,500 ft., 1,000 ft., 500 ft., and 200 ft. or the
lowest standard instrument approach procedure minimum as published
in the National Ocean Survey (NOS) U.S. Terminal Procedures. |
B |
X |
|
Sky Condition - A
layer of clouds or obscuring phenomena aloft is present below
1,000 feet and no layer aloft was reported below 1,000 feet in the
preceding METAR or SPECI observation. |
B |
X |
|
Volcanic Eruption -
When eruption is first noted. |
X |
X |
|
Aircraft Mishap -
Upon notification of an Aircraft Mishap unless there has been an
intervening observation. |
Note 5 |
X |
|
Miscellaneous - Any
other meteorological situation which, in the opinion of the
observer, is critical. |
IR |
IR |
|
B - LAWRS backs up SPECI initiation
X - LAWRS initiates SPECI
A - LAWRS initiates SPECI to produce report
IR - LAWRS initiates SPECI if required
C = Not backed
up by LAWRS.
Note 1. SPECIs are not a capability of the AWOS. (AWOS produces
METARs every 20 minutes.)
Note 2. LAWRS augments tower visibility producing SPECI; backs up surface visibility to produce SPECI.
Note 3. At designated sites only.
Note 4. LAWRS observer augments to produce SPECI for hail; backs
up initiating SPECI for freezing precipitation.
Note 5. LAWRS initiates archive action only. In addition, LAWRS
will take a backup observations (but will not
transmit) if elements of the automated system require backup
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