WEATHERGRAPH Observation and …

1 METAR Observation FORMATKLEX 162354Z 20004KT 1 1/2SM -RA BR FEW004 BKN030 OVC050 22/21 A3006 RMK AO2 RAE05B34 SLP173 P000260007 70112 T02221011 51006=KLEX, Lexington, Kentucky; 16th day of month; 2354 UTC; wind from 200 deg at 04knots; visibility 1 1/2 statute mile in light rain and fog; few clouds at 400 ft; broken layer at3000 ft; overcast layer at 5000 ft; temperature 22 deg C; dewpoint 21 deg C; altimetersetting (pressure) inches; A02 (automated station, type 2 which reports precip);rain ended at 05 minutes past hour and began at 34 minutes past hour; sea levelpressure mb; of precip in past hour; of precip in past 6 hours; inpast 12 hours; exact temp deg C; exact dewpoint deg C; pressure rising by Observation FORMAT68842 11682 72516 10176 20145 30126 40199 5101069903 72052 875// 555 91020=Port Elizabeth, South Africa (68842); precipitation data will be included (1); station type ismanned and weather is included (1); lowest cloud height is 1000 to 1500m above ground(6); visibility is 40 km (82); sky cover 7/8ths (7); wind direction 250 deg (250); wind speed16 kt (16); temperature deg C (10176); dewpoint deg C (20145); stationpressure is mb (0126); sea level pressure mb (0199); pressure tendencyrising then steady (1) changing by mb (10); precipitation amount is trace (990) over atime period of 18 hours (3); weather is recent drizzle (20); previous weather had beendrizzle (5) and clouds covering more than half of sky (2); low or middle cloud amount is 7/8ths (7); low cloud is stratocumulus (5); middle cloud is not visible (/); high cloud is notvisible (/).

2 Everything after the triple-digit group consists of regionally-defined , light ormoderate, with , light ormoderate. Rain or snow,but no or heavy snowor rain/snow with in past , moderate or heard duringpast hour but not , light. Thunderheard during past hourbut not andCUMULUS with bases atdifferent levels and notformed by spreading , then steady; orrising, then rising , steadily , then steady; orfalling, then falling , or 1 tenth , or 2 to 3 tenths , or 4 tenths , or 5 tenths , or 6 tenths , or 7 to 8 tenths , or 9 tenths completely coveredwith obscured (clouds notvisible due to rain, snow,fog, or other obscuration).H2 CIRRUS, dense, and inpatches/twisted sheaves,not invading or CIRRO-STRATUS, invading sky,bulk not 45 above , inpatches, ,invading sky and , formedby spreading out ,whose tops are clearlyfibrous or , notinvading sky, usuallydouble- , in theform of cumuliform tufts(castellanus).M9 ALTOCUMULUS, atmany layers (a chaoticsky).H7 CIRROSTRATUS,completely covering , notinvading the sky and notcompletely covering all othercirriform , atsingle level, ,semitransparent, thinenough to see , in continouslayer or shreds.

3 Nostratus of bad , notformed by the spreadingout of ,formed by the spreadingout of , topsare not fibrous, cirriform,or , ofconsiderable , with littlevertical development andseemingly , sky not visible, nochange during past , sky discernable, nochange during past duststorm orsandstorm, no changeduring past or sandstorm,severe, has increasedduring past drizzle or rain(not showers), not nowbut during past showers, not nowbut during past visible butnot reaching ground reaching theground not at or near thestation but at a generally formingor developing during duststorm orsandstorm, which hasdecreased during or sandstorm,increased during or sandstorm,no change during or sandstorm,decreased during of shallow fog atstation, not deeper than 2m (10 m at sea).12 Continuous shallow fogat station, not deeperthan 2 m (10 m at sea).13 Lightning visible, but nothunder rain and snow(not showers) during snow (notshowers) during rain (not freezing,not showers) during drizzle (notfreezing, not showers)during past , sky not discernable,and has become thinnerduring past , sky discernable,and has become thinnerduring past , moderate or heavy,not associated showers, , light, , light, intermittent,not , light, intermittent,not at a distance but notat station during , light, continous,not , moderate,intermittent, not , moderate,continuous, not , heavy,intermittent, not , heavy, continous,not , heavy, continous,not , heavy, intermittent,not , moderate,continuous, not , moderate,intermittent, not , light, continous, , light, , moderate, , moderate, , heavy, , heavy, showers, showersmixed, moderate showersmixed, showers, showers, moderateor snow or rain/snowmixed with hail.

4 Thunderheard during past , or snow, but no , withduststorm or , severe,with , light, not associatedwith pellet showers,moderate or pellet showers, showers, moderateor needles, with orwithout grains, with orwithout crystals, with orwithout pellets (sleet).66 Freezing rain, rain, moderateor and snow mixed, and snow mixed,moderate or and rain mixed,moderate or and rain mixed, drizzle,moderate or drizzle, fog, sky fog, sky , sky not visible, hasbegun or become thickerduring past , sky visible, hasbegun or become thickerduring past snow, slight snow, snow, slight snow, , with orwithout precipitation, notnow but during past , not now but duringpast or hail and rain, notnow but during past showers, not nowbut during past , waterspout, orfunnel cloud observednow or during past squall now orduring the past heard but noprecipitation at reaching theground not at the stationbut suspended in theair, but not raised or sand raised devils now or withinpast or sandstormnot at station but of sky unchangedduring past generallydissolving during development notobserved/observableduring past reduced SYMBOLSN umbers indicate the weather code as used in synoptic weatherreports (ww.)

5 Present weather reported from a manned weatherstation, as defined in WMO Pub. No. 306-A).L7 STRATUS, of badweather (scud), and oftenwith orNIMBOSTRATUS. Thesun/moon can t be , in the form offilaments or hooks, notinvading the , often anvil-shaped and associatedwith , in the form ofhooks or filaments,invading the or CIRRO-STRATUS, invading sky,bulk 45 or more then , steadily or steady, thenrising; or rising then risingmore , then or rising, thenfalling; or falling, thenfalling more NOT USED0 Cloud covering half orless of sky covering bothmore than half and lessthan half of sky covering morethan half of skythroughout , or duststorm,or drifting or or thick , with orwithout low middle high Total sky covera Pressure trendW Past weatherCL Low cloudCM Middle cloudCH High cloud806312371 TOTAL SKY COVER 6/8 TEMPERATURE 80 FWEATHER Heavy rainVISIBILITY 1 statute mileDEWPOINT 63 FLOW CLOUD stratusLOW CLOUD COVER 3/8 LOW CLOUD HEIGHT 300-599 ftHIGH CLOUD cirrusMIDDLE CLOUD altocumulusWIND DIRECTION from NEWIND SPEED 25 mphPRESSURE mbPRESSURE CHANGE mbPRESSURE CHANGE falling then risingPAST WEATHER showersPRECIP TIME 3-4 hours ago6-HR PRECIP SYMBOLSThe numbers pertain to code representationsused in transmitted reports.

6 And thepictograms are used as part of a station SIZESF reefall FreefallSizeEquivalentVelocityEnergy1/4 Pea 25 mph ft-lbs1/2 Marble 35 ft-lbs3/4 Dime 43 ft-lbs1 Quarter 50 mph ft-lbs1 1/4 Half Dollar 56 mph ft-lbs1 1/2 Walnut 61 mph ft-lbs1 3/4 Golfball 66 mph ft-lbs2 Hen Egg 72 mph ft-lbs2 1/2 Tennis Ball 80 mph ft-lbs2 3/4 Baseball 85 mph ft-lbs3 Tea Cup 89 mph ft-lbs4 Grapefruit 106 mph ft-lbs4 1/2 Softball 117 mph ft-lbsFUJITA SCALEA scale of tornado : 40-72 mph. Twigs andbranches snap off trees. Somewindows : 73-112 mph. Pushes movingcars off road. Flips mobile : 113-157 mph. Uproots largetrees and rips roofs off : 158-206 mph. Severe lifted and thrown. : 207-260 mph. Levels : 261-318 mph. Incredibledamage. Foundations swept 1998 WEATHER GRAPHICS TECHNOLOGIES, Box 450211, Garland TX 75045 WIND SCALENoMphKtsDescription0 0-1 0-1 Smoke rises vertically1 1-3 1-3 Wind moves smoke but not wind vanes2 4-7 4-6 Wind felt on face; leaves rustle; wind vane moved3 8-12 7-10 Leaves and small twigs in constant motion; wind extendslight flag4 13-18 11-16 Dust and loose paper raised; small branches moved5 19-24 17-21 Small trees with leaves begin to sway6 25-31 22-27 Large branches in motion; whistling in telephone wires7 32-38 28-33 Whole trees in motion; resistance felt walking against wind8 39-46 34-40 Twigs broken off trees.

7 Wind generally impedes progress9 47-54 41-47 Slight structural damage occurs (chimney pots and slateremoved)10 55-63 48-55 Trees uprootedCONVERSIONSMPH = knots x x = MPH x x = knots x x F = ( Deg C x ) + 32( ( Deg K - ) x ) + 32 Deg C = ( Deg F - 32 ) x K - K = Deg C + ( ( Deg F - 32 ) x ) + = inches x = mb x FRONTWARM FRONTOGENESISWARM FRONTOLYSISCOLD FRONTCOLD FRONTOGENESISCOLD FRONTOLYSISTROUGHRIDGEOCCLUDED FRONTSTATIONARY FRONTDRYLINELHHIGH PRESSURECENTERLOW PRESSURECENTERTIME ZONESThis chart shows how to convert aUTC hour to a local : subtract 5 (4 for daylight saving)Central: subtract 6 (5 for daylight saving)Mountain: subtract 7 (6 for daylight saving)Pacific: subtract 8 (7 for daylight saving)SURFACE STATION PLOTWEATHERGRAPH Observation and PlottingWEATHERGRAPH Observation and PlottingRevision 3 This chart may be reproduced for personal use. Regarding distribution activities, such as offering this file on your website, or printing copies for use by schools, universities, and agencies, we grantpermission providing we receive prior notification at.

8 All other use, including resale, is strictly prohibited without secured written permission from us. All rights ATMOSPHEREThe premier software package for detailed weather analysis. Unlimited 30-day trial! ONE-STOP FORECASTING SHOPS ince 1992 we ve offered the largest collection of meteorological software tools available, including freeware apps. Wenow offer books dedicated to forecasting topics. Working on a case study? We have data archives that beat NCDC hands-down for price and quality. There s much more available. Come check us out!Weather Graphics Technologies RULESq A major short wave trough moving A into B out of a long wave trough A deepens B fills the long wave A major short wave ridge moving A into B out of a long wave ridge A builds B weakens the long wave A jet streak moving A toward B through C away from the axis of a long wave trough will cause it to A deepen and remain quasi-stationary B progress C fill and progress more A jet streak moving A toward B through C away from the axis of a long wave ridge will cause it to A build and remain quasi-stationary B progress C weaken and progress more An upper trough oriented NW-SE has negative tilt and tends to deepen.

9 One oriented NE-SW has positive tilt and tends to The stronger the westerly component of the upper-level wind, the faster the wave Cold air advection deepens upper-level troughs and weakens upper-level Warm air advection builds upper-level ridges and fills upper-level Moisture in a parcel may increase due to these factors: upper divergence, warm air advection, frontal lift, orographic lift, boundary-layer convergence, colder air moving over a warmer surface, advection over a new moisture source, and on-shore Moisture in a parcel may decrease due to these factors: upper convergence, cold air advection, adiabatic drying, warm air movingover a cold surface, and offshore Cold fronts will move at roughly 85% of the 850 mb flow in the cold air behind the cold Warm fronts will move at roughly 70% of the 850 mb flow in the cold air ahead of the warm Dynamic lows tend to have a surface motion of 70% of the 700 mb flow or 50% of the 500 mb HURRICANE SCALECat 1 Minimal damagePressure >980 mb (> ); winds 74-95 mph; storm surge 4-5 primarily to shrubbery, trees, foliage, and unanchored mobile homes.

10 No realdamage to other structures. Some damage to poorly-constructed signs. Low-lyingcoastal roads inundated, minor pier damage, some small craft torn from moorings inexposed 2 Moderate damagePressure 965-979 mb ( ); winds 96-110 mph; storm surge 6-8 damage to shrubbery and tree foliage; some trees blown down. Majordamage to exposed mobile homes. Extensive damage to poorly-constructed damage to roofing materials on buildings; some window and door damage. Nomajor damage to buildings. Coastal roads and low-lying escape routes are cut byrising water two to four hours before the arrival of the storm. Considerable damage topiers. Small craft torn from 3 Extensive damagePressure 945-964 mb ( ); winds 111-130 mph; storm surge 9-12 torn from trees. Large trees and signs blown down. Some structural damageto small buildings. Mobile homes destroyed. Serious flooding at coast. Largestructures near coast damaged by battering waves and floating debris. Low-lyingescape routes cut by rising water three to five hours before storm 4 Extreme damagePressure 920-944 mb ( ); winds 131-155 mph; storm surge 13-18 trees blown down.