Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined NR Number NRLY Nearly NRN Northern NRW Narrow NS Nova Scotia or nimbostratus NSC Nil significant cloud NSW Nil significant weather NTFY Notify NTFYD Notified NTL National NV Nevada NVA Negative vorticity advection NW Northwest NWB Northwest bound NWD Northward NWLY Northwesterly NWRN Northwestern NWS National Weather Service NY New York NXT Next O OAT Outside air temperature OBS Observe or observed or observation OBSC Obscure or obscured or obscuring OCFNT Occluded front OCLD Occlude OCLDS Occludes OCLDD Occluded OCLDG Occluding OCLN Occlusion OCNL Occasional or occasionally OCR Occur OCRD Occurred OCRG Occurring OCRS Occurs OCT October OFC Office OFP Occluded frontal passage OFSHR Offshore OH Ohio Appendix B: Contractions and Acronyms Page 11-21
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined OHD Overhead OK Oklahoma or we agree or it is correct OMTNS Over mountains ONSHR On shore OPA Opaque, white type of ice formation OPC Ocean Prediction Center OPN Open or opening or opened OPR Operator or operate or operative or operating or operational OR Oregon ORGPHC Orographic ORIG Original OSV Ocean station vessel OTLK Outlook (used in SIGMET messages for volcanic ash and tropical cyclones) OTP On top OTR Other OTRW Otherwise OUBD Outbound OUTFLO Outflow OVC Overcast OVNGT Overnight OVR Over OVRN Overrun OVRNG Overrunning OVTK Overtake OVTKG Overtaking OVTKS Overtakes P PA Pennsylvania PAC Pacific PATWAS Pilot’s automatic telephone weather answering service PBL Planetary boundary layer PCPN Precipitation PD Period PDMT Predominant PEN Peninsula PERM Permanent PGTSND Puget Sound PHYS Physical PIBAL Pilot balloon observation PIREP Pilot weather report Appendix B: Contractions and Acronyms Page 11-22
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined PL Ice pellets PLNS Plains PLS Please PLTO Plateau PLVL Present level PM Postmeridian PNHDL Panhandle PO Dust/sand whirls (dust devils) POS Positive POSLY Positively POSS Possible PPI Plan position indicator PPINA Plan position indicator not available (U.S. Weather Radar Report) PPINE Plan position indicator no echoes (U.S. Weather Radar Report) PPSN Present position PRBL Probable PRBLY Probably PRBLTY Probability PRECD Precede PRECDD Preceded PRECDG Preceding PRECDS Precedes PRES Pressure PRESFR Pressure falling rapidly PRESRR Pressure rising rapidly PRFG Aerodrome partially covered by fog PRI Primary PRIN Principal PRIND Present indications are PRJMP Pressure jump PROB Probability PROC Procedure PROD Produce PRODG Producing PROG Forecast PROGD Forecasted PROGS Forecasts PRSNT Present PRSNTLY Presently PRST Persist Appendix B: Contractions and Acronyms Page 11-23
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined PRSTS Persists PRSTNC Persistence PRSTNT Persistent PRVD Provide PRVDD Provided PRVDG Providing PRVDS Provides PS Plus PSG Passing PSN Position PSND Positioned PSR Primary surveillance radar PTCHY Patchy PTLY Partly PTNL Potential PTNLY Potentially PTNS Portions PUGET Puget Sound PVA Positive vorticity advection PVL Prevail PVLD Prevailed PVLG Prevailing PVLS Prevails PVLT Prevalent PWB Pilot weather briefing PWR Power Q QFE Atmospheric pressure at aerodrome elevation QN Question QNH Altimeter sub-scale setting to obtain elevation when on the ground QSTNRY Quasistationary QTR Quarter QUAD Quadrant QUE Quebec R R Right (runway identification) or rain (U.S. Weather Radar Reports) RA Rain RADAT Radiosonde additional data RAFC Regional area forecast centre RAG Ragged Appendix B: Contractions and Acronyms Page 11-24
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined RAOB Radiosonde observation RCH Reach or reaching RCKY Rocky RCKYS Rockies RCMD Recommend RCMDD Recommended RCMDG Recommending RCMDS Recommends RCRD Record RCRDS Records RDC Reduce RDGG Ridging RDL Radial RDVLP Redevelop RDVLPG Redeveloping RDVLPMT Redevelopment RE… Recent (used to qualify weather phenomena, e.g. RERA = recent rain) REC Receive or receiver RECON Reconnaissance REF Reference to…or refer to… REP Report or reporting or reporting point RES Reserve REQ Request or requested RESP Response RESTR Restrict RGLR Regular RGN Region RGNS Regions RH Relative humidity RI Rhode Island RITE Right (direction of turn) RIOGD Rio Grande RLBL Reliable RLTV Relative RLTVLY Relatively RMK Remark RMN Remain RMND Remained RMNDR Remainder RMNG Remaining Appendix B: Contractions and Acronyms Page 11-25
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined RMNS Remains RNFL Rainfall ROFOR Route forecast (in aeronautical meteorological code) ROT Rotate ROTD Rotated ROTG Rotating ROTS Rotates RPD Rapid RPDLY Rapidly RPLC Replace or replaced RPT Repeat or I repeat (to be used in AFS as a procedure signal) RPTG Repeating RPTS Repeats RQMNTS Requirements RQR Require RQRD Required RQRG Requiring RQRS Requires RRA (or RRB, RRC…etc., in sequence) Delayed meteorological message (message type designator) RSG Rising RSN Reason RSNG Reasoning RSNS Reasons RSTR Restrict RSTRD Restricted RSTRG Restricting RSTRS Restricts RTD Delayed (used to indicate delayed meteorological message; message type designator) RTE Route RTN Return or returned or returning RTS Return to service RUC Rapid Update Cycle (model) RUF Rough RUFLY Roughly RVR Runway visual range RVS Revise RVSD Revised RVSG Revising Appendix B: Contractions and Acronyms Page 11-26
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined RVSS Revises RWY Runway S S South or southern latitude SA Sand SAP As soon as possible SARPS Standards and Recommended Practices (ICAO) SASK Saskatchewan SAT Saturday SATFY Satisfactory SB Southbound SBSD Subside SBSDD Subsided SBSDNC Subsidence SBSDS Subsides SC South Carolina or stratocumulus SCND Second SCSL Stratocumulus Standing Lenticular SCT Scattered SD South Dakota SE Southeast SEB Southeast bound SEC Seconds SECT Sector SELY Southeasterly SEP September SEPN Separation SEQ Sequence SER Service or servicing or served SERN Southeastern SEV Severe (used to qualify icing and turbulence reports) SEWD Southeastward SFC Surface SG Snow grains SGFNT Significant SGFNTLY Significantly SH… Showers (followed by RA = rain, SN = snow, PL = ice pellets, GR = hail, GS = small hail and/or snow pellets or combinations thereof, e.g. SHRASN = showers of rain and snow) SHFT Shift Appendix B: Contractions and Acronyms Page 11-27
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined SHFTD Shifted SHFTG Shifting SHFTS Shifts SHLD Shield SHLW Shallow SHRT Short SHRTLY Shortly SHRTWV Shortwave SHUD Should SIERNEV Sierra Nevada SIG Signature SIGMET Significant Meteorological Information (Information concerning en-route weather phenomena which may affect the safety of aircraft operations) SIGWX Significant weather SIMUL Simultaneous or simultaneously SKC Sky clear SKED Schedule or scheduled SLD Solid SLGT Slight SLGTLY Slightly SLP Slope SLPG Sloping SLW Slow SLY Southerly SM Statute mile SML Small SMLR Smaller SMRY Summary SMTH Smooth SMTHR Smoother SMTHST Smoothest SMTM Sometime SMWHT Somewhat SN Snow SNBNK Snow bank SNFLK Snowflake SNGL Single SNOINCR Snow increase SNOINCRG Snow increasing SOP Standard operating procedure Appendix B: Contractions and Acronyms Page 11-28
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined SPC Storm Prediction Center SPCLY Especially SPD Speed SPECI Aviation selected special weather Report (in aeronautical meteorological code) SPECIAL Special meteorological report (in abbreviated plain language) SPKL Sprinkle SPLNS Southern Plains SPRD Spread SPRDG Spreading SPRDS Spreads SPRL Spiral SQ Squall SQL Squall line SR Sunrise SRG Short range SRN Southern SRND Surround SRNDD Surrounded SRNDG Surrounding SRNDS Surrounds SRY Secondary SS Sunset or sandstorm SSE South-southeast SSELY South-southeasterly SSERN South-southeastern SSEWD South-southeastward SSW South-southwest SSWLY South-southwesterly SSWRN South-southwestern SSWWD South-southwestward ST Stratus STAGN Stagnation STBL Stable STBLTY Stability STD Standard STDY Steady STFR Stratus Fractus STF Stratiform STG Strong STGLY Strongly Appendix B: Contractions and Acronyms Page 11-29
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined STGR Stronger STGST Strongest STM Storm STMS Storms STN Station STNR Stationary STS Status SUB Substitute SUBTRPCL Subtropical SUF Sufficient SUFLY Sufficiently SUG Suggest SUGG Suggesting SUGS Suggests SUN Sunday SUPG Supplying SUPR Superior SUPSD Supersede SUPSDG Superseding SUPSDS Supersedes SVC Service message SVRL Several SW Southwest SWB Southwest bound SWD Southward SWWD Southwestward SWLY Southwesterly SWRN Southwestern SX Stability index SXN Section SYNOP Synoptic SYNS Synopsis SYS System T T Temperature TAF Terminal aerodrome forecast TAIL Tail wind TB Turbulence (PIREPs only) TC Tropical Cyclone TCNTL Transcontinental Appendix B: Contractions and Acronyms Page 11-30
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined TCU Towering cumulus TDA Today TDO Tornado TEMPO Temporary or temporarily TEND Trend forecast THK Thick THKNG Thickening THKNS Thickness THKR Thicker THKST Thickest THN Thin THNG Thinning THNR Thinner THNST Thinnest THR Threshold THRFTR Thereafter THRU Through THRUT Throughout THSD Thousand THTN Threaten THTND Threatened THTNG Threatening THTNS Threatens THU Thursday TIL Until TL… Till (followed by time by which weather change is forecast to end) TMW Tomorrow TN Tennessee TNDCY Tendency TNDCYS Tendencies TNGT Tonight TNTV Tentative TNTVLY Tentatively TO To…(place) TOC Top of climb TOP Cloud top TOPS Tops TOVC Top of overcast TPC Tropical Prediction Center TPG Topping Appendix B: Contractions and Acronyms Page 11-31
Aviation Weather Services, Advisory Circular 00-45G, Change 1 (July 2010) Contraction or Acronym Subject Defined TR Track TRBL Trouble TRIB Tributary TRKG Tracking TRML Terminal TRMT Terminate TRMTD Terminated TRMTG Terminating TRMTS Terminates TRNSP Transport TRNSPG Transporting TROF Trough TROFS Troughs TROP Tropopause TRPCD Tropical continental air mass TRPCL Tropical TRRN Terrain TRSN Transition TS Thunderstorm (in aerodrome reports and forecasts, TS used alone means thunder heard but no precipitation at the aerodrome) TS… Thunderstorm (followed by RA = rain, SN = snow, PL = ice pellets, GR = hail, GS = small hail and/or snow pellets or combinations thereof, e.g. TSRASN = thunderstorm with rain and snow) TSFR Transfer TSFRD Transferred TSFRG Transferring TSFRS Transfers TSNT Transient TUE Tuesday TURB Turbulence TURBT Turbulent TWD Toward TWDS Towards TWI Twilight TWR Aerodrome control tower or aerodrome control TWRG Towering TX Texas TYP Type of aircraft TYPH Typhoon U Appendix B: Contractions and Acronyms Page 11-32