Attachment 7 - NWS-J100-AR-SW001.pdf

NWS-J100-AR-SW001

Revision - B

Specification

For

National Weather Service (NWS)

Radiosonde Observation Software

Department Of Commerce

National Oceanic And Atmospheric Administration

National Weather Service

Office Of Observations

1325 East West Highway

Silver Spring, MD 20910

Contents

1.0 SCOPE

2.0 APPLICABLE DOCUMENTS

Government Documents Non-Government Documents

3.0 REQUIREMENTS

General Requirements

Performance Requirements IT Security Ground System Requirements Observation Parameters

Observation Functions Upper Air Data Products

3.7.1. No Data Message

3.7.2. Radiosonde Additional Data (RADAT)

3.7.3. WMO Coded Messages

3.7.4. Binary Universal Form for data Representation (BUFR)

3.7.5. Archive Product

3.7.6. Visual and Audible Indications

3.7.7. Message Dissemination

Message Dissemination Methods Data Quality Control

Data Display Post Flight Functions

4.0 Acronyms

5.0 Glossary

No Data Message

Clouds/WX Codes

RADAT

Archive Product

IT Security Controls Algorithms

Tables

Table 1: Site Specific Information

Table 2: Pre-Flight Information

Table 3: Surface Observation Information

Table 4: Message Transmission Parameters

Table 5: Upper Air Data Products Generation and Dissemination

Table 6: Data Quality Control

Table 7: Termination Due to Missing Temperature or Pressure Data

Table 8: Flight Summary Report Data

Figures

Figure 1: Sounding Workstation

1.0 SCOPE

This specification defines the requirements for the NWS radiosonde observation software for the

NWS Upper Air Network radiosonde observing system.

2.0 APPLICABLE DOCUMENTS

The following documents form a part of this specification to the extent specified herein. In the event of conflict between the documents referenced herein and this specification, the contents of this specification shall be the superseding requirement.

Government Documents

Reference No. Title

National Weather Service Manual

NWSM 10-1401

Operations and Services Upper Air Program NWSPD 10-14

Rawinsonde Observations, dated June 2010

NWS-J100-AR-RS003 Specification For 403 Radiosondes

NWS-J100-AR-SP003

Specification For The Global Positioning System Automatic

Radiosonde Observing System (AROS)

FAA Regulations CFR Title 14, Part 101 Moored Balloons, Kites, Amateur Rockets and Unmanned

Free Balloons

NOAA IT Security Manual 212-1301 NOAA Information Technology Security Manual 212-1301

NIST SP 800-53 Revision 4 Security and Privacy Controls for Federal Information

Systems and Organizations Revision 4

OMB Circular A-130 Office of Management and Budget Circular A-130

Non-Government Documents

Reference No. Title

WMO-No. 306 World Meteorological Organization (WMO)

Manual on Codes.

FM-94

WMO Manual on Codes, Volume I.1, International Codes, Part B-Binary Codes, WMO-No.306, FM 94-IX Ext

FM 35

WMO Manual on Codes, Volume I.1, International Codes, Part A - Alphanumeric Codes

WMO- No. 386 WMO Manual on the Global Telecommunication System

Copies of WMO documents are available from http://www.wmo.int http://www.wmo.int/

3.0 REQUIREMENTS

General

This specification defines the requirements for the NWS radiosonde observation software.

Whenever a specific paragraph of this specification is referenced, all subparagraphs of the referenced paragraph shall also apply.

Software Description

The Radiosonde Observation Software is a critical component of the NWS Upper Air Network radiosonde observing system, which provides an accurate, near real-time, three-dimensional state of the atmosphere for use in weather forecasting. The Radiosonde Observation Software runs on the sounding workstation, which is part of the ground system. The Radiosonde Observation

Software receives and processes radiosonde data from preflight to termination. Radiosonde

Observation Software provides data quality control, and encodes and transmits Upper Air products to designated locations. The Radiosonde Observation Software displays and allows the modification of system information and station parameter information.

Figure 1: Sounding Workstation

General Requirements

The Radiosonde Observation Software performs system initialization and diagnostics, communicates with peripheral devices, process meteorological data, monitor ground system performance, and disseminate data products.

ASSW 32378 All system functions shall be locally and remotely controllable by authorized

NWS users only.

Performance Requirements

ASSW 32381 The Radiosonde Observation Software shall have a minimum service availability of 99.0%.

IT Security

ASSW 32383 The Radiosonde Observation Software shall comply with:

A. Federal Information Security Management Act (44 U.S.C.3544)

B. OMB’s implementing policies including Appendix III of OMB Circular A-

C. National Institute of Standards and Technology (NIST) SP 800-53 Rev 4.

D. DOC IT Security Program Policy

E. NOAA IT Security Manual 212-1301 version 5.6

F. Security Controls for Federal Information Systems as outlined in Appendix

E.

ASSW 32389 The Radiosonde Observation Software shall be configurable to control role-based permission access levels as outlined in security control AC-3 of the

Recommended Security Controls for Federal Information Systems outlined in

Appendix E.

ASSW 32390 The Radiosonde Observation Software shall operate on a Windows (Microsoft

Windows 7 or newer) or Linux (Red Hat Enterprise Linux 7 or newer)

Operating System (OS).

ASSW 32391 The Radiosonde Observation Software shall allow for modification or updates by installation of new sounding software, OS and firmware on a monthly basis.

Ground System Requirements

ASSW 32396 For radiosondes with pressure sensors, the Radiosonde Observation Software shall remove the surface pressure error between the radiosonde and the system barometer and bring the pressure measurement to within ± 0.1 hPa of the station’s barometer.

ASSW 32397 The radiosonde release point pressure correction from the height of the system barometer to the height of the release point shall be at a resolution of 0.01 hPa and allow corrections up to ± 5.0 hPa.

ASSW 32399 During initialization, the Radiosonde Observation Software shall identify an available channel within the 400-406 MHz frequency range.

ASSW 32400 The Radiosonde Observation Software system shall timestamp observation data based on the sounding workstation and/or GPS time.

ASSW 32401 After initializing, the Radiosonde Observation Software shall automatically set the internal clock to Coordinated Universal Time (UTC) time.

ASSW 32402 The Radiosonde Observation Software shall have the capability to abort/delay processing prior to balloon inflation.

Observation Parameters

ASSW 32408 The Radiosonde Observation Software shall allow the entry and modification of the site-specific information, as identified in Table 1, for the generation of

Upper Air data products.

Table 1: Site Specific Information

Station Name (e.g. Sterling, VA) WBAN Number (e.g. 93734)

WMO Number (e.g. 69001) Base Pressure (hPa) (e.g. 85)

WMO Region (e.g. 4) Station ID (i.e. KIAD)

WFO ID (e.g. KHQA) Release Latitude (dd:mm:ss)

AWIPS XXX (FAA ID) (e.g. HQA) Release Longitude (dd:mm:ss)

Station Latitude (dd:mm:ss) Release Elevation (MSL)

Station Longitude (dd:mm:ss) Release Point Pressure Correction (hPa)

Station Elevation (MSL)

ASSW 32410 The Radiosonde Observation Software shall record pre-flight information as identified in Table 2, prior to flight.

Table 2: Pre-Flight Information

Observation Date and Time (UTC) Observer Initials

Ascension/Flight Number (3-digits) Release Number (1, 2, or 3)

Radiosonde Type Radiosonde Serial Number

Balloon Manufacturer (Kaymont-Totex and other)

Parachute (Yes/No)

Balloon Weight (600, 800, or other in grams)

Balloon Type (GP26 and other)

Gas Volume or Nozzle Lift (gm) Train Length (ft.)

Balloon Age (Months) Train Regulator (Yes/No)

Lighting Unit (Yes/No)

ASSW 32407 The Radiosonde Observation Software shall allow manual data entry of the pre-flight information as identified in Table 2, prior to flight.

ASSW 32412 The Radiosonde Observation Software shall display the surface observation information, identified in Table 3, from the surface weather equipment.

Table 3: Surface Observation Information

Surface Pressure (hPa) Temperature (°C)

Surface Dry-bulb Temperature (°C) Surface Dewpoint Temperature (°C)

Surface Relative Humidity (%) Surface Wet-bulb Temperature (°C)

Release Point Pressure (hPa) Previous Temperature (°C)

Wind Direction (°) Wind Speed (Knots)

Cloud Code - (Appendix B) Weather Code - (Appendix B)

ASSW 32409 The Radiosonde Observation Software shall calculate and record the surface dewpoint temperature from received surface RH or Wet bulb data if a dewpoint measurement is not available.

ASSW 32411 The Radiosonde Observation Software shall allow for the entry and modification of LDAD parameters as identified in Table 4, used for message transmission.

Table 4: Message Transmission Parameters

Primary Transmission Method

• User Name

• Password

• Host IP Address

• Private Key Location (where to call from)

Secondary Transmission Method

• User Name

• Password

• Host IP Address

• Private Key Location (where to call from)

Tertiary Transmission method

• User Name

• Password

• Host IP Address

• Private Key Location (where to call from)

WMO Header (BUFR Surface to Termination (DD2))

WMO Header (FZL)

WMO Header (MAN)

WMO Header (SGL)

WMO Header (ABV)

WMO Header (BUFR Surface to 100 hPa.(DD1))

ASSW 32414 The first level data in the WMO messages and Archive Product shall be the surface observation information listed in Table 3.

Observation Functions

ASSW 32420 The Radiosonde Observation Software shall support a second release within 30 minutes after flight termination.

ASSW 32423 Radiosonde Observation Software shall have the ability to manually and automatically pause the launch at any time during preflight.

ASSW 32425 The Radiosonde Observation Software shall record the time at which the radiosonde is launched.

ASSW 32426 The Radiosonde Observation Software shall provide the capability to change the launch detection time.

ASSW 32416 If the launch detection time is modified, the Radiosonde Observation Software shall recalculate the processed data based on the new launch time.

ASSW 32427 The Radiosonde Observation Software shall support a second or third release of the same ascension number and observation time following an unsuccessful sounding.

ASSW 32428 The Radiosonde Observation Software shall determine when a sounding is successful, based on (1) the temperature being present for 3.0 minutes of the first 5.0 minutes of the flight, (2) the pressure decreasing by at least 5 hPa during the first 5.0 minutes of the flight, and (3) the flight reaching 400hPa before terminating.

ASSW 32417 The release window for synoptic observations (00:00, 06:00, 12:00, and 18:00

UTC) shall be 60 minutes before to 29 minutes after the assigned observation time.

ASSW 32385 For synoptic observations, if the release occurs within the release time window, the Radiosonde Observation Software shall log the flight as a 00:00, 06:00, 12:00, or 18:00 UTC observation.

ASSW 32386 For synoptic observations, if the release occurs early, a second or more before the release time window, the Radiosonde Observation Software shall log the flight as a 23:00, 05:00, 11:00, or 17:00 UTC observation.

ASSW 32387 For synoptic observations, if the release occurs late, a second or more beyond the release time window, the Radiosonde Observation Software shall log the flight as a 01:00, 07:00, 13:00, or 19:00 UTC observation.

ASSW 32388 The release window for non-synoptic observations shall be 30 minutes before to

29 minutes after the assigned observation time.

ASSW 32393 For non-synoptic observations, if the release occurs within the release time window, the Radiosonde Observation Software shall log the flight with the non-synoptic hour (e.g. for non-synoptic hour 03:00, record 03:00 UTC).

ASSW 32394 For non-synoptic observations, if the release occurs early, a second or more before the release time window, the Radiosonde Observation Software shall log the flight with the previous non-synoptic hour (e.g. for non-synoptic hour

03:00, record 02:00 UTC).

ASSW 32395 For non-synoptic observations, if the release occurs late, a second or more before the release time window, the Radiosonde Observation Software shall log the flight with the next non-synoptic hour (e.g. for non-synoptic hour 03:00, record 04:00 UTC).

Upper Air Data Products

ASSW 32430 The Radiosonde Observation Software shall keep track of the number of times

WMO messages have been transmitted (manually or automatically).

(Note: In the event the messages are transmitted more than once, the header will be modified to reflect the number of re-transmits. This modification will be an automatically generated incremental number utilizing the last two digits in the date and time parameter of the header. Also appended to the end of the header a "COR" will be added).

ASSW 32431 The Radiosonde Observation Software shall provide the capability to generate and disseminate Upper Air data products as configured.

ASSW 32432 In the event of premature termination the Radiosonde Observation Software shall generate and disseminate Upper Air products up to the termination level.

3.7.1. No Data Message

ASSW 32437 The Radiosonde Observation Software shall generate and disseminate a No

Data Message as described in Appendix A in the event where a sounding cannot be conducted.

3.7.2. Radiosonde Additional Data (RADAT)

ASSW 32442 The Radiosonde Observation Software shall generate the sounding data into a

RADAT message as described in Appendix C.

3.7.3. WMO Coded Messages

ASSW 32447 The Radiosonde Observation Software shall generate the sounding data into a

WMO Coded Message in accordance with the WMO Manual on Codes (WMO-

No.306), FM 35 for both Regions IV and V. Note: For sites in Region V apply the low level winds and stability index as specified for region IV.

ASSW 32449 The Radiosonde Observation Software shall code heights appearing in the

WMO coded messages using units of geopotential meters.

ASSW 32450 The Radiosonde Observation Software shall select a temperature level as significant and include in the TTBB if the Greatest Departure of Linearity exceeds ± 0.5 °C for pressures from surface to 100 hPa.

ASSW 32451 The Radiosonde Observation Software shall select a temperature level as significant and include in the TTDD if the Greatest Departure of Linearity exceeds ± 1.0 °C for pressures from 100 hPa to termination.

ASSW 32452 The Radiosonde Observation Software shall select a relative humidity level as significant and include in either the TTBB or TTDD (depending on the pressure at that level) if the Greatest Departure of Linearity exceeds ±5% for all pressures.

3.7.4. Binary Universal Form for data Representation (BUFR)

ASSW 32454 The Radiosonde Observation Software shall generate the sounding data into a

BUFR (03-09-52) message in accordance with the WMO Manual on Codes

(WMO-No.306), FM 94 for both Regions IV and V. (Note: For sites in Region

V apply the low level winds and stability index as specified for region IV)

ASSW 32456 The BUFR (03-09-52) message shall be formatted in accordance with the

WMO Manual on Codes (WMO-No.306), Volume I.2 Part C, Regulation

B/C25.

ASSW 32458 The BUFR message header shall be configurable in the WMO format of T1T2A1A2ii, as defined by WMO Manual 386.

3.7.5. Archive Product

ASSW 32464 The Radiosonde Observation Software shall generate the sounding data into an

Archive Product as described in Appendix D.

ASSW 32419 The Radiosonde Observation Software shall format the individual H, T, and B

(03-09-6x) files as described in Appendix D.

ASSW 32465 The Radiosonde Observation Software shall code heights appearing in the

Archive Product using units of geopotential meters.

ASSW 32466 The Radiosonde Observation Software shall provide the capability to disseminate on a flight by flight basis the H, T, B (03-09-06x), and C (03-09-

52) files in a compressed file (e.g. *.zip) named as indicated below.

XXXXYYMMDDHH.zip

XXXX is the Station ID

YY = Year

MM = Month

DD = Day of Month

HH = Hour

Example: kmpx17092600.zip

ASSW 32418 The Radiosonde Observation Software shall provide the capability to disseminate on a monthly basis the H, T, B (03-09-06x), and C (03-09-52) files in a compressed file (e.g. *.zip) named as indicated below.

XXXXMMYY.zip

XXXX is the Station ID

MM = Month

YY = Year

Example: kmpx0917.zip

3.7.6. Visual and Audible Indications

ASSW 32421 The Radiosonde Observation Software shall provide a visual and audible indication the messages (No Data, BUFR, WMO Coded, and RADAT) have been generated.

3.7.7. Message Dissemination

ASSW 32440 The Radiosonde Observation Software shall have the capability to disseminate all message types (Archive, No Data, BUFR, and WMO Coded) in accordance with Table 5.

Table 5 identifies the flight level when Upper Air data products are automatically generated and disseminated.

Table 5: Upper Air Data Products Generation and Dissemination

Message Message

Identifier

Contents Height

Range

Included

Height

Transmitted*

Format Reference

Freezing

Levels

FZL RADAT Release to

400hPa

400hPa Coded FMH3

Appendix

E. Table

Mandatory

Levels

MAN TTAA Release to

100hPa

70hPa Coded WMO-No.

306 & FM

Significant

Levels

SGL TTBB &

PPBB

Release to

100hPa

70hPa Coded WMO-No.

306 & FM

Above

100hPa

Levels

ABV TTCC &

TTDD &

PPDD

Release to

Termination

Termination Coded WMO-No.

306 & FM

BUFR

Flight Data

DD1 High

Resolution

BUFR

Release to

100hPa

70hPa WMO 3-

09-52

WMO-No.

306 & FM

BUFR

Flight Data

DD2 High

Resolution

BUFR

Release to

Termination

Termination WMO 3-

09-52

WMO-No.

306 & FM

Archive

Products

.H, .B, .T, & .C files

Release to

Termination

After

Termination

Variable see

Reference

Appendix

D

Message Dissemination Methods

ASSW 32472 The Radiosonde Observation Software shall have the capability to disseminate data through a SSH File Transfer Protocol (SFTP) via a modem or LAN connection.

ASSW 32473 The SFTP connection shall be compatible with FIPS 140-2 compliance Crypto

Keys as outlined in security control SC-12 of the Recommended Security

Controls for Federal Information Systems found in Appendix E.

ASSW 32474 The Radiosonde Observation Software shall have the capability to disseminate sounding data via email.

ASSW 32475 The Radiosonde Observation Software shall save the Upper Air Data Products locally as comma-separated values (CSV) text file(s) for BUFR and WMO

Coded Messages.

Data Quality Control

ASSW 32477 The Radiosonde Observation Software shall perform quality control to determine valid data, for the parameters identified in Table 6, as described in

Appendix G.

Table 6: Data Quality Control

Data Plausibility Check PTU Gross Limits Check

Element Profile Quality Control Super adiabatic lapse rates

Inversions Ascension Rates

Miscellaneous Checks Surface Observation Quality Control

Temporal/Time Quality Control Excessive Temperature Change

Excessive Height Change Large Element Shifts

ASSW 32479 Missing raw and processed data shall be indicated by a unique set of characters, which are not in the measurement range of values expected for the observation parameter.

ASSW 32480 The Radiosonde Observation Software shall process missing, rejected, and deleted PTU processed data as described in Appendix G.

ASSW 32481 The Radiosonde Observation Software shall terminate a flight automatically when the radiosonde data indicates excessive missing data in accordance with the criteria listed in Table 7.

Table 7: Termination Due to Missing Temperature or Pressure Data

Excessive Minutes of Missing Data

Temperature Pressure

4 minutes (Cumulative)

No Temperature in first 10 minutes of flight

4 minutes (Cumulative)

No Pressure in first 10 minutes of flight

6 minutes (Cumulative)

No Temperature in first 25 minutes of flight

10 minutes (Cumulative)

No Pressure in first 25 minutes of flight

Excessive Minutes of Missing Data

Temperature Pressure

12 minutes (Cumulative)

No Temperature in first 60 minutes of flight

24 minutes (Cumulative)

No Pressure in first 60 minutes of flight

16 minutes (Cumulative)

No Temperature in flight

40 minutes (Cumulative)

No Pressure in flight

3 minutes (Consecutive)

No Temperature in flight

10 minutes (Consecutive)

No Pressure in flight

ASSW 32485 For detected erroneous data, that exceed thresholds identified in Appendix G, the Radiosonde Observation Software shall provide a visual indication of erroneous data along with the beginning and end time (mm:ss) of when the erroneous data occurred.

ASSW 32486 For super adiabatic lapse rates, that exceed the thresholds identified in

Appendix G, the Radiosonde Observation Software shall provide a visual indication of the temperature lapse rate value to the nearest 0.1C/km and a beginning and end time (mm:ss) of when the sounding occurred.

Data Display

ASSW 32488 The Radiosonde Observation Software shall display the current system status and diagnostic information for all connected subsystems and communication equipment.

ASSW 32490 The Radiosonde Observation Software shall display the processed Upper Air data products by default.

ASSW 32491 The Radiosonde Observation Software shall display the radiosonde observation data in tables, including as a minimum, raw PTU tabular, processed tabular, WMO products (FZL, MAN, SGL, ABV), and BUFR.

ASSW 32492 The Radiosonde Observation Software shall display, at a minimum, processed data in plots, Skew-T (surface to 100 hPa), Stuve (surface to 5 hPa), and vertical profile plots of temperature, dewpoint, relative humidity, pressure and winds with respect to flight time.

ASSW 32489 The Radiosonde Observation Software shall display trajectory and vertical profile plots of temperature, dewpoint, relative humidity, pressure and winds from five minutes before balloon launch to one minute after flight termination.

ASSW 32493 The Radiosonde Observation Software shall provide the capability to pan and zoom plots.

ASSW 32494 The Radiosonde Observation Software shall allow the capability to export the time-stamped tabular data from each radiosonde observation as CSV text files.

Post Flight Functions

ASSW 32496 All radiosonde observation data shall be a discrete incrementally time-stamped value representing the measured radiosonde data from a single non-overlapping radiosonde-sampling period.

ASSW 32497 The Radiosonde Observation Software shall save all sounding data accessible for analysis (e.g., telemetry, raw, processed, etc.).

ASSW 32498 The Radiosonde Observation Software shall automatically detect and assign a flight termination reason to each flight as specified in Appendix D Table 9.17.

ASSW 32499 The Radiosonde Observation Software shall allow for the modification of the flight termination reason after the flight has completed.

ASSW 32500 The Software shall locally save logs pertaining to system status, antenna status and software debugger as CSV text files.

ASSW 32501 The Radiosonde Observation Software shall automatically send the complete flight file to a configurable SFTP address for off-site analysis.

ASSW 32502 The Radiosonde Observation Software shall generate a Flight Summary Report that includes, at a minimum, the data identified in Table 8.

Table 8: Flight Summary Report Data

WMO # Date of balloon mfg Balloon mfg/lot #

Station ID Termination Reason Minimum Temperature

(C)

Ascension number Showalter Stability Index Total PTU Intervals

Release number Freezing Level Crossings Total Wind Intervals

Day/month/year Flight Duration (min) Missing & Rejected

Pressure

Observation Hour Slant Range (m) Missing & Rejected

Temperature

Release Time Termination GPH (PTU,m) Missing & Rejected RH

Radiosonde Frequency Termination Pressure (hPa) Missing & Rejected

Wind Data

Radiosonde WMO ID Last Wind GPH (m) Radiosonde Serial #

Operator Initials

(minimum of 3 characters)

Max Wind [Level, Elapsed Time

(min), Speed (knots), Direction, GPH (m)]

Mean Low Level Wind

(Surface to 5000 feet, 5000 to 10,000 feet)

Tropopause Levels

[Level, Elapsed Time

(min), Height (m), Pressure (hPa), Temperature (C)]

Radiosonde ascent rate averages

(Surface to 400 hPa, 400 hPa to

Termination, surface to termination, Surface to 100 hPa, 100 hPa to Termination)

ASSW 32504 The Radiosonde Observation Software shall maintain an accessible database that includes information from the flight summary report.

ASSW 32505 The Radiosonde Observation Software shall allow a configurable file name structure to include site ID, release number, ascension number, and message type (e.g., BUFR, RADAT, Mandatory and Significant Levels).

4.0 Acronyms

Acronym Definition

AROS Automatic Radiosonde Observing System

BUFR Binary Universal Form for the Representation of meteorological data

DOC Department of Commerce hPa Hectopascal

FIPS Federal Information Processing Standards

FISMA Federal Information Security Management Act

FTP File Transfer Protocol

GHP Geopotential Height

IT Information Technology

LAN Local Area Network

NCEI National Centers for Environmental Information

NCEP National Centers for Environmental Prediction

NIST National Institute of Standards and Technology

NOAA National Oceanic and Atmospheric Administration

NWS National Weather Service

OMB Office of Management and Budget

PDB Precision Digital Barometer

PTU Pressure, Temperature, Relative Humidity

RADAT Radiosonde Additional Data

RH Relative Humidity

SFTP SSH File Transfer Protocol

Acronym Definition

SSH Secure Shell

UTC Coordinated Universal Time

WMO World Meteorological Organization

5.0 Glossary

BUFR is an acronym for Binary Universal Form for the Representation of meteorological data.

It is a binary code designed to represent, employing a continuous binary stream, any meteorological data. The BUFR format will be used for all data transfers to both NCEI and

NCEP.

C File is high-resolution formatted flight data, containing multiple datasets, in the Binary

Universal Form for the Representation of Meteorological Data Format (BUFR) (3-09-52). The C file is an archive product that is generated at the end of a flight for transfer to NCEI.

Corrected Data refers to the data derived from the raw data by the application of a correction approved by the NWS. Currently, the only data for which a correction is known to be applicable is the temperature which may be corrected for the effects of solar radiation.

Launch Detection is the start of the radiosonde observation and the second data point of the processed data.

Meteorological Data see Raw Data.

No Data Message indicates either; the flight failed at release and no data above surface is available or a flight will not be taken.

Non-synoptic Observation includes any observations outside of 00:00, 06:00, 18:00, and 12:00

UTC.

Preflight includes entering the administrative information, recording the surface observation information, conducting a preflight radiosonde check, and controlling the ground system equipment used to receive radiosonde communications and power on and initialize the radiosonde for use in conducting a radiosonde observation.

Processed Data is Radiosonde Meteorological Measurements which have been transformed from the original measurement(s) into Time Stamped Final Value(s) utilizing some or all of the following processes.

1. Outlier removal.

2. 6 to ten second moving average.*

3. Less than one consecutive minute of interpolation.**

4. Solar/IR Temperature Correction.

5. Baseline (pre-flight determined) Pressure Correction.

6. Release Point Pressure Correction.

7. Flight Train Pendulum Movement Reduction averaging.

8. Any other vendor corrections to raw data to compensate for environmental factors.

* Moving average outside of 6 to ten seconds is not permitted.

** One minute (or more) of interpolation is not permitted.

NOTE: Processed Data is used to generate the WMO Coded Message Products.

RADAT are messages transmitted as part of an observation contains information relating to freezing levels (zero crossings).

Raw Data refers to the value of the physical parameters measured over one radiosonde sample period. The raw data is pressure in hPa, temperature in degrees Celsius, and relative humidity in percent. Each raw data value is derived directly from the radiosonde measurement for a single, non-overlapping sample interval. Raw data values may be arrived at by some form of averaging, provided that the averaging time is less than or equal to the reporting period, and each reported value derives from independent data. Raw values are not smoothed or interpolated.

Successful Sounding is determined when the following happens (1) If the temperature is present for 3.0 minutes of the first 5.0 minutes of the flight, (2) Pressure must decrease by at least 5 hPa during the first 5.0 minutes of the flight, and (3) the flight reaches 400hPa before termination.

Synoptic Observation includes synoptic observation times 00:00, 06:00, 18:00, and 12:00 UTC.

Telemetry Data refers to the radiosonde data transmitted to the ground from the radiosonde.

This data is converted to the values reported by the AROS through the application of vendor specific algorithms which typically require coefficients from the calibration data for the radiosonde. Telemetry data will be different for each type of radiosonde and will depend on the measurement and telemetry techniques used.

Unsuccessful Sounding refers to a flight that doesn’t meet the successful sounding criteria.

No Data Message

No Data Messages

If a flight fails at release and no data above surface is available or a flight will not be taken, the observer must send a No Data Message. The (TTAA), (TTBB), and (TTDD) messages must all be sent with the appropriate 101 groups when a flight was missed or no data is available above the surface.

No Message example: USUS97 KQHC 270000

MANHQC

72403 TTAA 7700/ 72403 51515 10142=

The No Data Message shall include the (TTAA), (TTBB), and (TTDD) messages with the appropriate 101 groups when a flight was missed or no data is available above the surface. The

101 group is added after the 51515 message in the TTAA, TTBB and TTDD messages. The table below lists the possible 101 code figures.

NOTE: There are two different procedures that should be followed when a flight is missed.

1. When a flight is not possible for any reason, the observer must use the No Data option and add the proper 101 groups for the reason for no data.

2. When a flight is missed and another was possible, but not allowed - The observer must add a 10148 group after the 51515 message in the TTAA, TTBB and TTDD messages.

The 10148 group signifies that an ascent was not authorized.

The 10148 group should only be used when a second release is possible, but not allowed by

NCEP or other approving authorities.

No Data 101 Group Code figures 101AdfAdf - Miscellaneous Regional Data

AdfAdfCode Figures Definition

40 - 59 Reason for no report or an incomplete report

40 Report not filed

41 Incomplete report; full report to follow

42 Ground equipment failure

43 Observation delayed

44 Power failure

45 Unfavorable weather conditions

46 Low maximum altitude (less than 1500 feet above ground)

47 Leaking balloon

48 Ascent not authorized for this period

49 Alert

50 Ascent did not extend above 400 hPa level

51 Balloon forced down by icing conditions

53 Atmospheric interference

54 Local interference

55 Fading signal*

56 Weak signal*

57 Preventive maintenance

58 Flight equipment failure (transmitter, balloon, attachments, etc.)

59 Any reason not listed above

* Fading signals differ from weak signals in that "fading signals" are first received satisfactorily, then become increasingly weaker, and finally become too weak for reception, while "weak signals" are weak from the beginning of the ascent.

Clouds/WX Codes

This appendix provides the necessary tables and specific instructions to format the Clouds/Wx code. The Cloud/Wx code shall be entered in the Radiosonde Observation Software preflight information and it shall encode the cloud group in to the WMO Coded Messages 41414 code group.

For those already familiar with synoptic code, you will notice some departure from conventional

WMO coding procedures. If you simply observe the elements requested and report them according to tables provided in this text, the intent of the Clouds/Wx entry will be fully met.

Getting Started

The Cloud/WX entry is a nine-digit, mandatory group. All nine digits shall be entered, regardless of the presence or absence of clouds or significant weather conditions.

The WMO format for entry of clouds and weather has been modified by the NWS to meet

NCDC requirements. All stations using RRS software will follow this modified format, regardless of location; i.e., stations in either WMO Region IV or WMO Region V. A description of the nine-digit format follows:

1. Clouds/Wx group format: NhCLhCMCHWWWW

Nh = Amount (in oktas) of the sky covered by all low clouds (CL) observed or the amount of sky covered by all the middle clouds (CM) observed. In no case will the amounts of the low and middle clouds be combined to report Nh. Use Table B-1 to report the amount of low or middle cloud coverage.

CL = Type of low cloud, based on the priority given in Table B-2. A solidus (/) is reported if CL clouds are not visible owing to fog or similar obscuring phenomena.

Note: Clouds are divided into three families, classified as low, middle, or high. The general height ranges for these are: surface to 6500 feet for low; 6500 feet to 20000 feet for middle; and above 20000 feet for high. Remember, these ranges are not absolute, but given as a guide only. More consideration may be given to the cloud form than the height in many cases. Each cloud family is coded with a single digit, 0 through

9. The code figure 0 is used to indicate that clouds are not present for a given family.

h = Height of the base of the lowest cloud observed. The height reported is with respect to the surface. The height is coded as a solidus (/) if there is a total surface-based obscuration that prevents an observation of the clouds. Use Table B-3 for the cloud base height.

CM = Type of middle cloud, based on priority given in Table B-4. A solidus (/) is reported if CM clouds are not visible owing to fog or similar obscuring phenomena, or because of a continuous layer of lower clouds.

CH = Type of high cloud, based on priority given in Table B-5. A solidus (/) is reported if CH clouds are not visible owing to fog or similar obscuring phenomena, or because of a continuous layer of lower clouds.

WWWW = Present weather coded in two groups of WW. These code groups are found in Table B-6. The coding starts with 99 (the highest priority) and descends to 00 (the lowest priority). Note that code figure 17 is placed out of numerical sequence to highlight its relative coding priority. You should note that present weather codes for some weather phenomena are events that have occurred during the past hour, not at observation time. When entering WWWW, go down Table B-6 and use the first and second applicable code figures. Note that two WW groups must always be coded, even if that means using the same code figure twice.

Table B-1: Amount of Low/Middle Cloud Nh

Code Figure

Cloud Amount in Oktas (eights) Cloud Amount in Tenths

0 0 0

1 1 okta or less, but not zero 1/10 or less, but not zero

2 2 oktas 2/10 - 3/10

3 3 oktas 4/10

4 4 oktas 5/10

5 5 oktas 6/10

6 6 oktas 7/10 -8/10

7 7 oktas 9/10 or more, but not

10/10

8 8 oktas 10/10

9 Sky obscured by fog and/or other meteorological phenomena

/ Cloud cover is indiscernible for reasons other than fog or other meteorological phenomena, or observation is not made

Note: If there are any breaks in the sky at all, such as an overcast with a mackerel sky

(altocumulus perlucidus or stratocumulus perlucidus), Nh would be encoded as 7.

If there are only a few patches of low or middle cloud in the sky, Nh cannot be encoded as 0 but is encoded as 1. A partial obscuration does not affect the coding of Nh. A total obscuration is coded as 9, not 8 (overcast sky).

Table B-2 Coding of Low Cloud, CL

This table presents the specifications for type of low cloud, CL, in order of priority. Go down the table and use the first applicable code figure.

Code Figure Coding Criteria

(a) Cumulonimbus present, with or without other CL clouds

CL = 9 If the upper part of at least one of the cumulonimbus clouds present is clearly fibrous or striated, use CL = 9.

CL = 3 If the upper part of none of the cumulonimbus clouds present is clearly fibrous or striated, use CL = 3.

(b) No cumulonimbus present

CL = 4 If stratocumulus formed by the spreading out of cumulus is present, use CL = 4.

CL = 8 If the CL code figure 4 is not applicable and if cumulus and stratocumulus clouds with bases at different levels are present, use

CL= 8.

CL = 2 If the CL code figures 4 and 8 are not applicable and if cumulus clouds of moderate or strong vertical extent are present, use CL = 2.

CL = 1 If the CL code figures 4, 8, and 2 are not applicable: use CL = 1, if the

CL clouds present are predominantly1 cumulus with little vertical extent and seemingly flattened or ragged cumulus other than of bad weather2, or both;

CL = 5 Use CL = 5, if among the CL clouds present, stratocumulus other than that formed by the spreading out of cumulus is predominant;

CL = 6 Use CL = 6, if the CL clouds present are predominantly stratus in a more or less continuous sheet or layer, or in ragged shreds (other than ragged stratus of bad weather), or both;

CL = 7 Use CL = 7, if the CL clouds present are predominantly pannus (ragged shreds of stratus of bad weather or ragged cumulus of bad weather), or both.

0 No CL Clouds -- No cumulus, cumulonimbus, stratocumulus, or stratus

/ CL clouds not visible owing to fog or similar obscuring phenomena.

1Consideration of predominance is restricted to the clouds corresponding to CL code figures 1, 5, 6 and 7, which have the same priority. Clouds of any one of these four specifications are said to be predominant when their sky cover is greater than that of the clouds of any of the other three specifications.

2'Bad weather' denotes the conditions which generally exist during precipitation and a short time before and after

Table B-3: Height of Cloud Base Above Ground, h

Code Figure Reportable Heights (ft)

0 0 or 100

1 200 or 300

2 400 to 600*

3 700 to 900*

4 1000 to 1900*

5 2000 to 3200*

6 3300 to 4900*

7 5000 to 6500**

8 7000 to 8000**

9 8500 or higher or no clouds

/ unknown or base of clouds below surface of station

* reported in 100 foot increments

** reported in 500 foot increments

Note: This group is used to report the height of the base of the lowest cloud seen, regardless of cloud amount. The height reported is with respect to the surface.

The lowest cloud height is coded with a solidus (/) if there is a total surface-based obscuration that prevents an observation of the clouds.

Table B-4: Coding of Middle Clouds, CM

This table presents the specifications for type of middle cloud, CM in order of priority. Go down the table and use the first applicable code figure.

(a) Altocumulus present

CM = 9 If the sky is chaotic, use CM = 9.

CM = 8 If the CM code figure 9 is not applicable and if altocumulus with sprouting in the form of turrets or battlements or altocumulus having the appearance of small cumuliform tufts is present, use

CM = 8.

CM = 7 If the CM code figures 9 and 8 are not applicable and if altostratus or nimbostratus is present together with altocumulus, use CM = 7.

CM = 6 If the CM code figures 9, 8, and 7 are not applicable and if altocumulus formed by the spreading out of cumulus or cumulonimbus is present, use CM = 6.

CM = 5 If the CM code figures 9, 8, 7, and 6 are not applicable, and if the altocumulus present is progressively invading the sky, use CM = 5.

*There are several definitions of CM = 7 and each has a different priority; therefore CM = 7 appears several times in this code table.

CM = 4 If the CM code figures 9, 8, 7, 6, and 5 are not applicable, and if the altocumulus present is continually changing in appearance, use

CM = 4.

CM = 7 If the CM code figures 9, 8, 6, 5, and 4 are not applicable and if the altocumulus present occurs at two or more levels, use CM = 7.

CM = 7,3 If the CM code figures 9, 8, 6, 5, and 4 are not applicable and if the altocumulus present occurs at one level, use CM = 7 or 3 depending on whether the greater part of the altocumulus is respectively opaque or semi-transparent.

(b) No altocumulus present

CM = 2 If nimbostratus is present or if the greater part of the altostratus present is opaque, use CM = 2.

CM = 1 If there is no nimbostratus and if the greater part of the altostratus present is semi-transparent, use CM = 1.

0 No CM Clouds -- No altocumulus, altostratus, or nimbostratus.

/ CM clouds not visible owing to fog or similar obscuring phenomena, or because of a continuous layer of lower clouds.

Table B-5: Coding of High Cloud CH

This table presents the specifications for type of high cloud, CH, in order of priority. Go down the table and use the first applicable code figure.

CH = 9 If cirrocumulus is present alone or is more than the combined sky cover of any cirrus and cirrostratus present, use CH = 9.

(a) Cirrostratus present

CH = 7 If the cirrostratus covers the whole sky, use CH = 7.

CH = 8 If the cirrostratus does not cover the whole sky and is not invading the celestial dome, use CH = 8.

CH = 6 If the cirrostratus is progressively invading the sky and if the continuous veil extends more than 45 degrees above the horizon but does not cover the whole sky, use CH = 6.

CH = 5 If the cirrostratus is progressively invading the sky but the continuous veil does not reach 45 degrees above the horizon, use CH = 5.

(b) CH = 9 not applicable and no cirrostratus present

CH = 4 If the cirrus clouds are invading the sky, use CH = 4.

CH = 3 If the CH code figure 4 is not applicable and if dense cirrus which originated from cumulonimbus is present in the sky, use CH = 3.

CH = 2, 1 Use CH = 2, if the combined sky cover of dense cirrus, of cirrus with sproutings in the form of small turrets or battlements and of cirrus in tufts is greater than the combined sky cover of cirrus in the form of filaments, strands or hooks;

Use CH = 1, if the combined sky cover of cirrus in the form of filaments, strands or hooks is greater than the combined sky cover of dense cirrus, of cirrus with sproutings in the form of small turrets or battlements and of cirrus in tufts.

0 No CH Clouds -- No cirrus, cirrostratus, or cirrocumulus

/ CH clouds not visible owing to fog or similar obscuring phenomena, or because of a continuous layer of lower clouds.

Table B-6: Coding of Present Weather, WW

This table presents the specifications for present weather, WW, in order of priority. Go down the table and use the first and second applicable code figures. The code figure with the higher priority is reported as the first

WW group and the code with the lower priority is the second WW group. (This convention is followed even if the higher priority code describes weather that occurred during the preceding hour but not at the time of observation.) Note that two WW groups must always be coded, even if that means using the same code figure twice.

WW = 99-50 Used for precipitation at the station at the time of observation.

WW = 99-80 Used for showery precipitation or precipitation with current or recent thunderstorms.

NOTE: By U.S. definition, a thunderstorm is occurring at the station when thunder is first heard.

IMPORTANT: Never release a balloon/radiosonde while a thunderstorm is occurring. See

Chapter 11.

99 Thunderstorm, severe, with hail, small hail, or snow pellets at time of observation.

There may or may not also be rain or snow or a mixture of rain and snow of any intensity.

98 Thunderstorm at time of observation combined with duststorm at time of observation.

There must also be some sort of precipitation at the time of observation, but it may not be seen because of poor visibility. Judgment must be used.

97 Thunderstorm, severe without hail, small hail, or snow pellets but with rain and/or snow at time of observation.

The rain or snow may be of any intensity.

96 Thunderstorm with hail, small hail, or snow pellets at time of observation.

There may or may not be rain or snow or a mixture of rain and snow of any intensity.

95 Thunderstorm without hail, small hail, or snow pellets, but with rain and/or snow at time of observation.

WW = 94-91 Used if there was a thunderstorm during the past hour, and there is some sort of precipitation at the time of observation. In order to have this situation, the last thunder heard must have been more than 15 minutes before the observation, but less than 1 hour 15 minutes before the observation.

94 Moderate or heavy snow or rain and snow mixed or hail, small hail, or snow pellets at time of observation. Thunderstorm during previous hour but not at time of observation.

93 Light snow or rain and snow mixed or hail, small hail, or snow pellets at time of observation. Thunderstorm during previous hour but not at time of observation.

92 Moderate or heavy rain at time of observation. Thunderstorm during previous hour but not at time of observation.

No other forms of precipitation.

91 Light rain at time of observation. Thunderstorm during previous hour but not at time of observation.

No other forms of precipitation.

WW = 90-80 Used to report showery precipitation that is not associated with a thunderstorm.

Showers fall from cumuliform clouds that are, by nature, isolated. Because of this, individual showers do not last very long. Code figure 89 is not reported under United States rules.

90 Moderate or heavy shower(s) of hail, with or without rain or rain and snow mixed, not associated with thunder.

88 Moderate or heavy shower(s) of snow pellets or small hail, with or without rain or rain and snow mixed.

All of the precipitation must be moderate or heavy.

87 Light shower(s) of snow pellets or small hail, with or without rain or rain and snow mixed.

All of the precipitation must be light.

WW = 86-85 Used if only snow showers are observed at the station at the time of observation.

86 Snow shower(s), moderate or heavy.

85 Snow shower(s), light.

WW = 84-83. Used if mixed rain showers and snow showers are observed at the station at the time of observation

84 Moderate or heavy shower(s) of rain and snow mixed. Intensity of either may be moderate or heavy.

83 Light shower(s) of rain and snow mixed. Intensity of both must be light.

WW = 82-80. Used to report rain showers at the time of observation.

82 Violent rain shower(s).

Report a rain shower as violent if the rate of fall is at least 1.0" per hour or 0.10" in 6 minutes

81 Moderate or heavy rain shower(s).

80 Light rain shower(s).

WW = 79-50 Use code figures 79-50 for precipitation that is not showery.

WW = 79-70 Use code figures 79-70 to report solid precipitation not in showers.

WW = 79-76 Use code figures 79-76 to report types of solid, non-showery precipitation.

79 Ice Pellets.

Use this code figure regardless of the intensity of the ice pellets and regardless of whether the ice pellets are mixed with another type of precipitation.

78 Isolated star-like snow crystals with or without fog or ice fog.

77 Snow grains with or without fog or ice fog.

Use this code figure regardless of intensity.

76 Diamond dust (ice crystals) with or without fog or ice fog.

WW = 75-70 Use code figures 75-70 to report snow that is not in the form of showers at the station at the time of the observation. The code figure selected depends on a combination of intensity and whether the snow is intermittent or continuous.

75 Continuous fall of snowflakes, heavy at time of observation.

74 Intermittent fall of snowflakes, heavy at time of observation.

73 Continuous fall of snowflakes, moderate at time of observation.

72 Intermittent fall of snowflakes, moderate at time of observation.

71 Continuous fall of snowflakes, light at time of observation.

70 Intermittent fall of snowflakes, light at time of observation.

WW = 69-60 Code figures 69-60 are generally used to report rain.

WW = 69-66 Use code figures 69-66 to report liquid precipitation that is mixed with snow or is freezing.

69 Rain or drizzle and snow, moderate or heavy.

68 Rain or drizzle and snow, light.

67 Rain, freezing, moderate or heavy.

66 Rain, freezing, light.

WW = 75-70 Use code figures 75-70 to report snow that is not in the form of showers at the station at the time of the observation. The code figure selected depends on a combination of intensity and whether the snow is intermittent or continuous.

65 Rain, not freezing, continuous, heavy at time of observation.

64 Rain, not freezing, intermittent, heavy at time of observation.

63 Rain, not freezing, continuous, moderate at time of observation.

62 Rain, not freezing, intermittent, moderate at time of observation.

61 Rain, not freezing, continuous, light at time of observation.

60 Rain, not freezing, intermittent, light at time of observation.

WW = 55-50 Use code figures 55-50 to report drizzle (but not freezing drizzle or drizzle mixed with rain) at the station at the time of observation.

55 Drizzle, not freezing, continuous, heavy at time of observation.

54 Drizzle, not freezing, intermittent, heavy at time of observation.

53 Drizzle, not freezing, continuous, moderate at time of observation.

52 Drizzle, not freezing, intermittent, moderate at time of observation.

51 Drizzle, not freezing, continuous, light at time of observation.

50 Drizzle, not freezing, intermittent, light at time of observation.

WW = 49-00 Use code figure 49-00 when no precipitation is occurring at the station at the time of observation.

WW = 49-40 Use code figures 49-40 only if there is fog. The fog may be made of water droplets or ice crystals (ice fog). The visibility in fog or ice fog must be less than 5/8 mi. If the visibility is 5/8 mi or more, use code figure 10. The code figure used will depend on whether the fog has changed during the past hour and whether the sky can be seen (blue sky, stars or higher clouds).

49 Fog depositing rime, sky invisible.

Fog that deposits rime will be made up mostly of super-cooled water droplets, not ice crystals.

48 Fog, depositing rime, sky visible.

47 Fog or ice fog, sky invisible. Fog has begun or has become thicker during the preceding hour.

46 Fog or ice fog, sky visible. Fog has begun or has become thicker during the preceding hour.

45 Fog or ice fog, sky invisible. Fog has shown no appreciable change during the preceding hour.

44 Fog or ice fog, sky visible. Fog has shown no appreciable change during the preceding hour.

43 Fog or ice fog, sky invisible. Fog has become thinner during the preceding hour.

42 Fog or ice fog, sky visible. Fog has begun or has become thinner…