Meta tags:
Headings (most frequently used words):
precipitation, air, to, of, measurement, climate, the, contents, types, becomes, saturated, forms, causes, return, period, uneven, pattern, role, in, köppen, classification, effect, on, agriculture, change, changes, due, urban, heat, island, forecasting, see, also, references, external, links, cooling, its, dew, point, adding, moisture, raindrops, ice, pellets, hail, snowflakes, diamond, dust, occult, deposition, frontal, activity, convection, orographic, effects, snow, within, tropics, large, scale, geographical, distribution, hydrometeor, definition, satellite, estimates,
Text of the page (most frequently used words):
the (420), and (188), #precipitation (135), retrieved (94), from (87), 2009 (77), with (62), rain (54), water (53), 2008 (53), archived (52), original (50), air (50), are (48), snow (41), for (39), rainfall (38), edit (36), climate (35), ice (35), weather (34), can (33), which (31), that (31), cloud (29), temperature (28), wet (25), surface (23), hail (23), when (23), over (23), meteorological (22), national (22), 2007 (22), have (22), season (21), pdf (20), main (20), convective (19), university (19), within (19), due (19), clouds (18), atmospheric (18), doi (18), bibcode (18), meteorology (18), year (18), also (18), their (18), into (18), occurs (18), american (17), dry (17), they (17), droplets (17), tropical (16), pellets (16), freezing (16), will (16), this (15), global (15), heavy (15), falls (15), warm (15), such (15), areas (15), 2005 (14), society (14), storm (14), cooling (14), has (14), more (14), most (14), usually (14), service (13), forecast (13), snowflakes (13), see (13), than (13), article (13), large (13), not (13), fall (13), form (13), other (12), data (12), glossary (12), wikipedia (11), use (11), vapor (11), heat (11), condensation (11), changes (11), its (11), center (11), 2010 (11), 978 (11), isbn (11), measurement (11), gauge (11), cyclones (11), during (11), effect (11), earth (11), dust (11), cold (11), cylinder (11), may (10), states (10), layer (10), forecasting (10), time (10), 2006 (10), annual (10), snowfall (10), crystals (10), between (10), liquid (10), where (10), moisture (10), forms (10), using (9), all (9), united (9), point (9), convection (9), research (9), 2011 (9), satellite (9), across (9), area (9), north (9), tropics (9), orographic (9), showers (9), any (9), these (9), larger (9), about (8), page (8), fog (8), intensity (8), quantitative (8), used (8), region (8), 2002 (8), subtropical (8), based (8), 2012 (8), winds (8), stratiform (8), land (8), atmosphere (8), while (8), only (8), scale (8), 000 (8), types (8), one (8), outer (8), freeze (8), cyclone (8), mass (8), toggle (7), contact (7), links (7), different (7), pressure (7), significant (7), height (7), western (7), administration (7), increase (7), around (7), change (7), press (7), period (7), storms (7), island (7), seasons (7), associated (7), events (7), lake (7), diamond (7), likely (7), regions (7), process (7), classification (7), extreme (7), through (7), above (7), south (7), parts (7), there (7), becomes (7), drizzle (7), additional (6), articles (6), october (6), short (6), index (6), wind (6), humidity (6), dew (6), tornado (6), qpf (6), prediction (6), 1175 (6), journal (6), observations (6), robert (6), australia (6), michael (6), 2003 (6), köppen (6), each (6), information (6), 2000 (6), return (6), northern (6), measured (6), southern (6), world (6), climates (6), mid (6), winter (6), hailstone (6), causes (6), metar (6), raindrops (6), mixed (6), america (6), become (6), small (6), side (6), location (6), occur (6), once (6), ground (6), low (6), mountains (6), windward (6), bodies (6), millimetres (6), saturated (6), hailstones (6), drops (6), code (5), was (5), categories (5), wikidata (5), january (5), cs1 (5), list (5), english (5), 2020 (5), potential (5), bulb (5), equivalent (5), level (5), adiabatic (5), processes (5), flood (5), radar (5), space (5), nasa (5), urban (5), cities (5), summer (5), humid (5), high (5), 100 (5), june (5), central (5), standard (5), oceanic (5), seasonal (5), mountain (5), extratropical (5), near (5), graupel (5), deposition (5), science (5), two (5), physical (5), agriculture (5), falling (5), titan (5), cycle (5), monsoon (5), late (5), show (5), example (5), upward (5), downwind (5), some (5), total (5), thunderstorm (5), been (5), century (5), since (5), evaporation (5), latitudes (5), although (5), found (5), cool (5), duration (5), solid (5), mist (5), inner (5), flow (5), move (5), often (5), front (5), leeward (5), fronts (5), shape (5), grow (5), diameter (5), smaller (5), subsection (5), contents (4), search (4), available (4), terms (4), project (4), need (4), wayback (4), maint (4), nuclei (4), rate (4), hours (4), forecasts (4), april (4), kenneth (4), mediterranean (4), 2023 (4), network (4), what (4), 1016 (4), 119 (4), hydrometeor (4), environment (4), office (4), deserts (4), california (4), hurricane (4), characteristics (4), december (4), chapter (4), patterns (4), observed (4), hawaii (4), systems (4), occult (4), physics (4), 2004 (4), snowflake (4), light (4), thunderstorms (4), model (4), sleet (4), collision (4), coalescence (4), effects (4), lakes (4), term (4), various (4), help (4), amount (4), specified (4), tend (4), amounts (4), higher (4), estimates (4), both (4), probability (4), leads (4), greater (4), motion (4), increased (4), warming (4), kilometres (4), distribution (4), conditions (4), africa (4), oceans (4), along (4), less (4), average (4), per (4), increases (4), east (4), but (4), given (4), food (4), shortages (4), crops (4), before (4), plants (4), too (4), cause (4), zone (4), likelihood (4), event (4), called (4), possible (4), channels (4), including (4), colder (4), gauges (4), known (4), hydrometeors (4), particles (4), then (4), adding (4), melt (4), bring (4), order (4), mountainous (4), out (4), because (4), relatively (4), bands (4), frontal (4), resulting (4), lift (4), updraft (4), sub (4), motions (4), expressed (4), include (4), hide (4), sidebar (4), 110 (3), view (3), non (3), commons (3), pages (3), sister (3), 2022 (3), volume (3), multiple (3), maximum (3), globe (3), forest (3), number (3), lifted (3), free (3), lifting (3), analysis (3), solar (3), lightning (3), climatology (3), centre (3), current (3), three (3), models (3), 1029 (3), geophysical (3), river (3), 1999 (3), march (3), flight (3), drought (3), environmental (3), 2018 (3), bulletin (3), trends (3), adaptation (3), texas (3), commonwealth (3), ritter (3), wisconsin (3), stevens (3), west (3), 1997 (3), van (3), resolution (3), wettest (3), days (3), uneven (3), community (3), applications (3), measurements (3), program (3), machine (3), link (3), cite (3), 2015 (3), clockwise (3), hemisphere (3), weight (3), fluctuations (3), 1991 (3), quality (3), planet (3), guide (3), rainy (3), 1998 (3), wyoming (3), log (3), latitude (3), hydrometeorological (3), libbrecht (3), technology (3), size (3), severe (3), growth (3), bergeron (3), microphysics (3), 117 (3), local (3), virga (3), saturation (3), radiational (3), impact (3), system (3), changing (3), present (3), terrain (3), considered (3), topography (3), measure (3), activity (3), result (3), showing (3), wetter (3), drier (3), well (3), decrease (3), temperatures (3), generally (3), overall (3), common (3), recent (3), erosion (3), regime (3), mature (3), seen (3), important (3), pattern (3), much (3), typically (3), sometimes (3), equator (3), however (3), top (3), related (3), meaning (3), made (3), definition (3), blowing (3), filled (3), inside (3), until (3), either (3), frozen (3), added (3), melted (3), underneath (3), lead (3), trade (3), convergence (3), regimes (3), grows (3), forced (3), depth (3), wide (3), sides (3), caused (3), moist (3), cumulonimbus (3), ascent (3), needles (3), mean (3), largest (3), sizes (3), usage (3), create (3), enough (3), rise (3), condense (3), millimeters (3), content (3), units (3), polar (3), cubic (3), tools (3), add (2), languages (2), table (2), privacy (2), policy (2), wikimedia (2), foundation (2), inc (2), september (2), hidden (2), updating (2), long (2), value (2), deprecated (2), archival (2), names (2), authors (2), description (2), international (2), velocity (2), gradient (2), force (2), sea (2), mixing (2), relative (2), fire (2), parcel (2), instability (2), radiation (2), advection (2), general (2), map (2), predicted (2), definitions (2), projects (2), external (2), lin (2), hydrometeorology (2), application (2), letters (2), sensitivity (2), jack (2), georgia (2), aeronautics (2), goddard (2), protection (2), agency (2), spatial (2), scales (2), 2021 (2), february (2), mauseth (2), cacti (2), subarctic (2), steppe (2), encyclopædia (2), britannica (2), susan (2), woodward (2), radford (2), pmid (2), geiger (2), maps (2), observing (2), boulder (2), 105 (2), 104 (2), takes (2), learning (2), new (2), york (2), chris (2), laboratory (2), indiana (2), 2016 (2), inch (2), usgs (2), real (2), waiʻaleʻale (2), kauai (2), thinkquest (2), formation (2), owen (2), 1996 (2), channel (2), hadley (2), circulation (2), cell (2), web (2), williams (2), today (2), background (2), eastern (2), pacific (2), jan (2), den (2), 1994 (2), study (2), sciences (2), phd (2), sources (2), particulates (2), pidwirny (2), introduction (2), costa (2), rica (2), montana (2), 3673951 (2), development (2), corporation (2), geerts (2), 2019 (2), dynamics (2), washington (2), encyclopedia (2), paul (2), regional (2), mars (2), forests (2), 2001 (2), institute (2), geographic (2), same (2), broad (2), times (2), julian (2), brimelow (2), 1520 (2), 1048 (2), alberta (2), station (2), via (2), internet (2), houze (2), 2179 (2), rainstorm (2), benmoshe (2), pokrovsky (2), khain (2), 2011jd016603 (2), masses (2), stratus (2), factors (2), academic (2), cassini (2), exploration (2), rains (2), planetary (2), ipcc (2), version (2), monthly (2), 1147 (2), difference (2), references (2), mixtures (2), concept (2), topics (2), expected (2), type (2), reaching (2), minimum (2), hour (2), synoptic (2), qpfs (2), upon (2), were (2), levels (2), image (2), combination (2), skill (2), determined (2), boundary (2), 116 (2), surrounding (2), induce (2), shower (2), rates (2), upwind (2), hot (2), white (2), portions (2), europe (2), asia (2), many (2), past (2), 1970s (2), especially (2), subtropics (2), suggested (2), salinity (2), implying (2), 1900 (2), increasing (2), globally (2), years (2), section (2), updated (2), soil (2), nutrients (2), diminish (2), animals (2), survival (2), strategies (2), previous (2), yet (2), developing (2), countries (2), noted (2), populations (2), first (2), harvest (2), least (2), survive (2), being (2), means (2), little (2), harmful (2), even (2), require (2), 107 (2), japan (2), middle (2), continents (2), basin (2), characterized (2), summers (2), winters (2), grassland (2), savanna (2), semi (2), arid (2), 750 (2), role (2), portion (2), describes (2), rare (2), percent (2), flooding (2), worse (2), single (2), provide (2), sensors (2), practical (2), record (2), tops (2), approximately (2), inversely (2), always (2), further (2), estimate (2), infrared (2), measuring (2), depends (2), blown (2), exist (2), lives (2), way (2), plastic (2), metal (2), markings (2), down (2), stick (2), fluid (2), 0098 (2), highest (2), outside (2), places (2), descending (2), ridges (2), upslope (2), locations (2), intertropical (2), geographical (2), source (2), very (2), personal (2), otherwise (2), receive (2), passage (2), break (2), early (2), improves (2), extent (2), cyclonic (2), those (2), strong (2), get (2), band (2), vertical (2), condenses (2), nimbostratus (2), range (2), just (2), forming (2), rising (2), indicate (2), squall (2), slow (2), comma (2), head (2), occluded (2), celestial (2), aloft (2), simple (2), crystal (2), pictures (2), expense (2), corresponding (2), together (2), aggregates (2), supercooled (2), like (2), part (2), back (2), french (2), word (2), sized (2), coding (2), shell (2), centimetres (2), melting (2), unless (2), does (2), coalesce (2), producing (2), descend (2), heating (2), mechanisms (2), conductive (2), evaporative (2), forces (2), stable (2), thus (2), density (2), involve (2), intense (2), freezes (2), condensed (2), thundersnow (2), precipitate (2), portal (2), wave (2), blizzard (2), devil (2), appearance (2), upload (2), file (2), history (2), read (2), norsk (2), bahasa (2), беларуская (2), account (2), donate (2), menu (2), topic, mobile, cookie, statement, statistics, developers, conduct, legal, safety, contacts, disclaimers, text, under, apply, site, you, agree, registered, trademark, profit, organization, creative, attribution, sharealike, license, rendered, parsoid, last, edited, 2026, utc, good, namespace, mismatch, webarchive, template, written, phenomena, https, org, php, title, oldid, 1374051411, yale, lux, nara, israel, czech, republic, bnf, france, gnd, authority, control, databases, pgf, barotropicity, baroclinity, chill, virtual, thermodynamic, anomaly, sst, ratio, humidex, haines, depression, parameter, stp, bulk, richardson, brn, mpl, lfc, helicity, fcl, equilibrium, conditional, symmetric, momentum, transport, inhibition, cin, energy, cape, precipitable, lcl, ccl, ccn, shear, vorticity, visibility, lapse, buoyancy, variables, gpcc, next, media, wiktionary, charles, achieving, technological, innovation, nowcasts, hydrological, modelling, simulation, reggiani, weerts, 2007jhm858, 2008jhyme, 76r, probabilistic, christian, keil, andreas, röpnack, george, craig, ulrich, schumann, l09812, 2008gl033657, 2008georl, 9812k, dependent, noreen, schwein, optimization, horizons, daniel, weygand, optimizing, output, helper, bushong, generation, verification, southeast, confirms, islands, dale, fuchs, london, guardian, spain, goes, tech, beat, division, nguyen, phu, thorstensen, andrea, sorooshian, soroosh, hsu, kuolin, aghakouchak, amir, ashouri, hamed, tran, hoang, braithwaite, dan, 697, 1541806, osti, bams, 0065, 2018bams, 689n, 689, indicators, 1993, michigan, 388, 472, 09511, human, accommodation, roberto, frisancho, james, burns, crop, living, bureau, brynn, schaffner, robinson, tisbury, elementary, school, lauren, springer, ogden, timber, 88192, 877, plant, driven, design, online, savannas, broadleaf, evergreen, rainforest, beck, hylke, mcvicar, tim, vergopolan, noemi, berg, alexis, lutsko, nicholas, dufour, ambroise, zeng, zhenzhong, jiang, xin, dijk, albert, miralles, diego, 724, 37872197, 10593765, pmc, 1038, s41597, 023, 02549, 2023natsd, 724b, scientific, 1901, 2099, constrained, cmip6, projections, angeline, pendergrass, reto, knutti, 988, half, median, stations, worldwide, 2018gl080298, 2018georl, 4511980p, 980, nature, daily, sustainability, tapiador, methods, datasets, atmosres, 012, 2013atmre, 131w, kidd, huffman, 353, 1002, met, 284, 2011meapp, 334k, 334, 2014, jaxa, gpm, mission, noaa, benefit, colorado, collaborative, rainguage, binghamton, lehmann, analytical, recording, raingauge, 220427159300201, 1047, waialeale, gage, lihue, team, 26634, oracle, education, thompson, video, productions, extremes, climatic, usa, outlook, subject, why, rotate, counter, landsea, liere, marti, ategbo, eric, alain, hoorweg, hartog, adel, hautvast, joseph, 488, 7947661, 1079, bjn19940049, 479, british, nutrition, significance, socio, economic, adult, body, benin, haynes, ridpath, taylor, francis, 6191, 638, monsoonal, efe, ogban, horsfall, jnr, akporhonor, variations, physico, chemical, resources, niger, delta, nigeria, 1807, 6445, hdl, applied, management, mei, zheng, dissertation, 378, 304619312, proquest, 2000phdt, 13z, rhode, hong, kong, elisabeth, benders, hyde, blue, biomes, physicalgeography, net, biosphere, toucanguides, travel, birkeland, karl, mock, cary, bridger, bowl, 286, jstor, 2307, 281, greg, byrd, yuh, lang, cambridge, 405, 521, 80875, mesoscale, hertzman, 1988, thesis, 1988phdt, 110h, dimensional, kinematics, rainbands, midlatitude, joan, von, ahn, joe, sienkiewicz, greggory, mcfadden, voluntary, ship, mariners, quikscat, adam, ganson, geology, death, valley, mares, 252, 8061, 3146, oklahoma, lydolph, 1985, rowman, littlefield, 333, 86598, diana, leone, honolulu, star, supreme, toby, carlson, routledge, 216, 551115, jim, lochner, ask, astrophysicist, david, roth, unified, manual, unsworth, wilshaw, 1989, pollutants, 238, 0168, 1923, 90097, 1989agfm, 221u, 221, agricultural, engineering, morphogenesis, educator, john, roach, true, reveals, jennifer, lawson, portage, 894110, hands, matter, colors, william, giant, big, frisbees, could, klesius, mystery, 0027, 9358, issn, 211, jacque, marshall, fact, sheet, gerhard, reuter, eugene, poolman, 1062, 0434, 017, mmhsia, 2002wtfor, 1048b, modeling, aggregate, ryan, jewell, evaluation, proximity, soundings, weatherquestions, com, entry, alaska, federal, aviation, norman, junker, ingredients, methodology, mcs, 2196, 0477, 078, spiroc, 1997bams, 2179h, paradox, oguntoyinbo, akintola, 1983, iahs, publication, 140, affecting, availability, mar, department, interior, tear, shaped, geological, survey, sirvatka, college, dupage, pinsky, turbulent, initiation, deep, simulations, spectral, phase, 2012jgrd, 6220b, atmospheres, geography, hydrosphere, jetstream, edward, reiley, carroll, shry, cengage, 7668, 1567, introductory, horticulture, bart, hurk, eleanor, blyth, knmi, coupling, spokane, fovell, los, angeles, approaches, peltier, plate, fmi, zentralanstalt, für, meteorologie, und, geodynamik, 1748, 2007jas2515, 2008jats, 1721k, 1721, determining, aerosols, attempt, dewpoint, margery, daw, 1933, weekly, melbourne, our, young, folk, jackson, 348, 050210, penrose, pearce, 548035, millennium, dore, mousavi, baygi, smith, hall, fowler, choularton, acid, snowdonia, 3326, atmosenv, 043, 2006atmen, 3316d, 3316, emmanouil, anagnostou, 300, 1017, s1350482704001409, 2004meapp, 291a, 291, algorithm, scanning, universe, saw, pole, sees, transform, graves, mckay, griffith, ferri, fulchignoni, reach, 357, pss, 001, 2008p, 346g, 346, seneviratne, sonia, zhang, xuebin, adnan, badi, ar6, wg1, chowdhury, wested, adler, gpcp, 1979, 1167, 1525, 7541, 004, tvgpcp, 2003jhyme, 1147a, scott, sistek, komo, informal, wintry, unusual, phenomenon, sun, shining, sunshower, pre, indian, ripening, mangoes, kerala, karnataka, mango, making, bacteria, bioprecipitation, basic, abbreviated, accumulated, measurable, threshold, valid, bound, 0000, 0600, 1200, 1800, climatological, fine, detail, starting, 1990s, hydrologic, simulate, rivers, throughout, lowest, decreases, generated, qualitative, basis, imagery, techniques, six, seven, verified, scores, 120, specific, 118, gmt, 115, five, day, warms, suburbs, rural, extra, partly, compared, 114, 113, appearing, atlanta, going, unique, sahel, prevalence, droughts, decreased, waters, lower, contiguous, greatest, 112, declined, statistically, trend, varied, widely, assessing, dataset, concluded, evidence, response, 111, decades, needs, reason, please, update, reflect, newly, sixth, assessment, report, 109, dramatic, therefore, effective, watering, regular, vital, healthy, devastating, kill, overly, fungus, varying, 108, 106, july, maritime, coasts, bordering, southeastern, accompanied, plentiful, round, resembles, lands, southwestern, chile, continuous, permafrost, 103, 102, setting, normal, located, widespread, india, malaysia, westerlies, steer, occasional, lie, roughly, degrees, 101, 270, biome, dfd, dfc, dfb, dfa, dwd, dwc, dwb, dwa, dsd, dsc, dsb, dsa, cfc, cfb, cfa, cwc, cwb, cwa, csc, csb, csa, bsk, bsh, bwk, bwh, particular, place, few, frequency, charts, historical, every, worst, extremely, though, unlikely, sensor, products, demonstrated, useful, visible, sounding, retrievals, sets, employ, now, thermal, micron, wavelength, primarily, give, typical, structure, heights, almost, altitudes, lot, variation, vigorous, smooth, topped, mathematical, schemes, algorithms, properties, feasible, includes, vast, expanses, ocean, remote, cases, social, technical, administrative, issues, prevent, dissemination, modern, largely, formations, composed, evaporates, spray, haze, networks, elsewhere, submitted, nearest, interested, cocorahs, varieties, overflow, flowing, designed, appropriate, after, discarded, remaining, gone, empty, removing, funnel, allowing, collect, anti, finished, accumulating, approached, lukewarm, fill, keeping, track, subsequently, subtracted, disdrometer, closely, tied, itself, ascending, branch, locales, colombia, amongst, make, exception, rule, consist, several, hundred, miles, inward, towards, direction, counterclockwise, take, enormous, toll, property, needed, path, worth, covering, months, euphemism, tourist, authorities, dispersed, rainforests, technically, equally, distributed, pronounced, poleward, mainly, afternoon, evening, freshwater, vegetation, significantly, trough, green, month, cairns, accumulates, ascend, squeeze, slopes, ruggedness, remains, challenge, southwest, curved, bringing, narrow, localized, understood, follows, efficiently, store, results, differences, warmth, transported, condensing, vertically, oriented, picture, produce, directly, affected, stronger, deeper, dangerous, exceeding, referred, extensive, weak, cools, produces, elongated, windstorms, mph, korean, peninsula, andes, blocks, arrives, continent, desertlike, argentina, creates, mojave, great, sierra, nevada, notable, second, affect, state, vary, considerably, divisible, face, northeast, sunnier, cover, kona, olau, 460, mount, ridge, subjected, consistent
Text of the page (random words):
ery small droplets is negligible hence clouds do not fall out of the sky precipitation will only occur when these coalesce into larger drops droplets with different sizes will have different terminal velocity that cause droplets collision and producing larger droplets turbulence will enhance the collision process 29 as these larger water droplets descend coalescence continues so that drops become heavy enough to overcome air resistance and fall as rain 30 raindrops have sizes ranging from 5 1 to 20 millimetres 0 20 to 0 79 in mean diameter above which they tend to break up smaller drops are called cloud droplets and their shape is spherical as a raindrop increases in size its shape becomes more oblate with its largest cross section facing the oncoming airflow contrary to the cartoon pictures of raindrops their shape does not resemble a teardrop 31 intensity and duration of rainfall are usually inversely related i e high intensity storms are likely to be of short duration and low intensity storms can have a long duration 32 33 rain drops associated with melting hail tend to be larger than other rain drops 34 the metar code for rain is ra while the coding for rain showers is shra 35 ice pellets edit main article ice pellets an accumulation of ice pellets ice pellets sleet in us usage are a form of precipitation consisting of small translucent balls of ice ice pellets are usually but not always smaller than hailstones 36 they often bounce when they hit the ground and generally do not freeze into a solid mass unless mixed with freezing rain the metar code for ice pellets is pl 35 ice pellets form when a layer of above freezing air exists with sub freezing air both above and below this causes the partial or complete melting of any snowflakes falling through the warm layer as they fall back into the sub freezing layer closer to the surface they re freeze into ice pellets however if the sub freezing layer beneath the warm layer is too small the precipitation will not have time to re freeze and freezing rain will be the result at the surface a temperature profile showing a warm layer above the ground is most likely to be found in advance of a warm front during the cold season 37 hail edit main article hail a large hailstone about 6 centimetres 2 4 in in diameter like other precipitation hail forms in storm clouds when supercooled water droplets freeze on contact with condensation nuclei such as dust or dirt the storm s updraft blows the hailstones to the upper part of the cloud the updraft dissipates and the hailstones fall down back into the updraft and are lifted again hail has a diameter of 5 millimetres 0 20 in or more 38 within metar code gr is used to indicate larger hail of a diameter of at least 6 4 millimetres 0 25 in gr is derived from the french word grêle smaller sized hail as well as snow pellets use the coding of gs which is short for the french word grésil 35 stones just larger than golf ball sized are one of the most frequently reported hail sizes 39 hailstones can grow to 15 centimetres 6 in and weigh more than 500 grams 1 lb 40 in large hailstones latent heat released by further freezing may melt the outer shell of the hailstone the hailstone then may undergo wet growth where the liquid outer shell collects other smaller hailstones 41 the hailstone gains an ice layer and grows increasingly larger with each ascent once a hailstone becomes too heavy to be supported by the storm s updraft it falls from the cloud 42 snowflakes edit main article snowflake snowflake viewed in an optical microscope snow crystals form when tiny supercooled cloud droplets about 10 μm in diameter freeze once a droplet has frozen it grows in the supersaturated environment because water droplets are more numerous than the ice crystals the crystals are able to grow to hundreds of micrometers in size at the expense of the water droplets this process is known as the wegener bergeron findeisen process the corresponding depletion of water vapor causes the droplets to evaporate meaning that the ice crystals grow at the droplets expense these large crystals are an efficient source of precipitation since they fall through the atmosphere due to their mass and may collide and stick together in clusters or aggregates these aggregates are snowflakes and are usually the type of ice particle that falls to the ground 43 guinness world records list the world s largest snowflakes as those of january 1887 at fort keogh montana allegedly one measured 38 cm 15 in wide 44 although the ice is clear scattering of light by the crystal facets and hollows imperfections mean that the crystals often appear white in color due to diffuse reflection of the whole spectrum of light by the small ice particles 45 the shape of the snowflake is determined broadly by the temperature and humidity at which it is formed 43 rarely at a temperature of around 2 c 28 f snowflakes can form in threefold symmetry triangular snowflakes 46 the most common snow particles are visibly irregular although near perfect snowflakes may be more common in pictures because they are more visually appealing no two snowflakes are alike 47 as they grow at different rates and in different patterns depending on the changing temperature and humidity within the atmosphere through which they fall on their way to the ground 48 the metar code for snow is sn while snow showers are coded shsn 35 diamond dust edit main article diamond dust diamond dust also known as ice needles or ice crystals forms at temperatures approaching 40 c 40 f due to air with slightly higher moisture from aloft mixing with colder surface based air 49 they are made of simple ice crystals hexagonal in shape 50 the metar identifier for diamond dust within international hourly weather reports is ic 35 occult deposition edit occult deposition occurs when mist or air that is highly saturated with water vapour interacts with the leaves of trees or shrubs it passes over 51 causes edit frontal activity edit main article weather front stratiform or dynamic precipitation occurs as a consequence of slow ascent of air in synoptic systems on the order of cm s such as over surface cold fronts and over and ahead of warm fronts similar ascent is seen around tropical cyclones outside of the eyewall and in comma head precipitation patterns around mid latitude cyclones 52 a wide variety of weather can be found along an occluded front with thunderstorms possible but usually their passage is associated with a drying of the air mass occluded fronts usually form around mature low pressure areas 53 precipitation may occur on celestial bodies other than earth when it gets cold mars has precipitation that most likely takes the form of ice needles rather than rain or snow 54 convection edit convective precipitation convective rain or showery precipitation occurs from convective clouds e g cumulonimbus or cumulus congestus it falls as showers with rapidly changing intensity convective precipitation falls over a certain area for a relatively short time as convective clouds have limited horizontal extent most precipitation in the tropics appears to be convective however it has been suggested that stratiform precipitation also occurs 33 52 graupel and hail indicate convection 55 in mid latitudes convective precipitation is intermittent and often associated with baroclinic boundaries such as cold fronts squall lines and warm fronts 56 orographic effects edit see also orographic lift and precipitation types orographic precipitation orographic precipitation occurs on the windward upwind side of mountains and is caused by the rising air motion of a large scale flow of moist air across the mountain ridge resulting in adiabatic cooling and condensation in mountainous parts of the world subjected to relatively consistent winds for example the trade winds a more moist climate usually prevails on the windward side of a mountain than on the leeward or downwind side moisture is removed by orographic lift leaving drier air see katabatic wind on the descending and generally warming leeward side where a rain shadow is observed 28 in hawaii mount waiʻaleʻale on the island of kauai is notable for its extreme rainfall as it has the second highest average annual rainfall on earth with 12 000 millimetres 460 in 57 storm systems affect the state with heavy rains between october and march local climates vary considerably on each island due to their topography divisible into windward ko ʻ olau and leeward kona regions based upon location relative to the higher mountains windward sides face the east to northeast trade winds and receive much more rainfall leeward sides are drier and sunnier with less rain and less cloud cover 58 in south america the andes mountain range blocks pacific moisture that arrives in that continent resulting in a desertlike climate just downwind across western argentina 59 the sierra nevada range creates the same effect in north america forming the great basin and mojave deserts 60 61 snow edit main article snow lake effect snow bands near the korean peninsula in early december 2008 extratropical cyclones can bring cold and dangerous conditions with heavy rain and snow with winds exceeding 119 km h 74 mph 62 sometimes referred to as windstorms in europe the band of precipitation that is associated with their warm front is often extensive forced by weak upward vertical motion of air over the frontal boundary which condenses as it cools and produces precipitation within an elongated band 63 which is wide and stratiform meaning falling out of nimbostratus clouds 64 southwest of extratropical cyclones curved cyclonic flow bringing cold air across the relatively warm water bodies can lead to narrow lake effect snow bands those bands bring strong localized snowfall which can be understood as follows large water bodies such as lakes efficiently store heat that results in significant temperature differences larger than 13 c or 23 f between the water surface and the air above 65 because of this temperature difference warmth and moisture are transported upward condensing into vertically oriented clouds see satellite picture which produce snow showers the temperature decrease with height and cloud depth are directly affected by both the water temperature and the large scale environment the stronger the temperature decrease with height the deeper the clouds get and the greater the precipitation rate becomes 66 in mountainous areas heavy snowfall accumulates when air is forced to ascend the mountains and squeeze out precipitation along their windward slopes which in cold conditions falls in the form of snow because of the ruggedness of terrain forecasting the location of heavy snowfall remains a significant challenge 67 within the tropics edit main article wet season see also monsoon and tropical cyclone rainfall distribution by month in cairns showing the extent of the wet season at that location the wet or rainy season is the time of year covering one or more months when most of the average annual rainfall in a region falls 68 the term green season is also sometimes used as a euphemism by tourist authorities 69 areas with wet seasons are dispersed across portions of the tropics and subtropics 70 savanna climates and areas with monsoon regimes have wet summers and dry winters tropical rainforests technically do not have dry or wet seasons since their rainfall is equally distributed through the year 71 some areas with pronounced rainy seasons will see a break in rainfall mid season when the intertropical convergence zone or monsoon trough move poleward of their location during the middle of the warm season 32 when the wet season occurs during the warm season or summer rain falls mainly during the late afternoon and early evening hours the wet season is a time when air quality improves 72 freshwater quality improves 73 74 and vegetation grows significantly soil nutrients diminish and erosion increases 32 animals have adaptation and survival strategies for the wetter regime the previous dry season leads to food shortages into the wet season as the crops have yet to mature developing countries have noted that their populations show seasonal weight fluctuations due to food shortages seen before the first harvest which occurs late in the wet season 75 tropical cyclones a source of very heavy rainfall consist of large air masses several hundred miles across with low pressure at the centre and with winds blowing inward towards the centre in either a clockwise direction southern hemisphere or counterclockwise northern hemisphere 76 although cyclones can take an enormous toll in lives and personal property they may be important factors in the precipitation regimes of places they impact as they may bring much needed precipitation to otherwise dry regions 77 areas in their path can receive a year s worth of rainfall from a tropical cyclone passage 78 large scale geographical distribution edit see also earth rainfall climatology on the large scale the highest precipitation amounts outside topography fall in the tropics closely tied to the intertropical convergence zone itself the ascending branch of the hadley cell mountainous locales near the equator in colombia are amongst the wettest places on earth 79 north and south of this are regions of descending air that form subtropical ridges where precipitation is low 80 the land surface underneath these ridges is usually arid and these regions make up most of the earth s deserts 81 an exception to this rule is in hawaii where upslope flow due to the trade winds lead to one of the wettest locations on earth 82 measurement edit see also rain gauge disdrometer and snow gauge standard rain gauge the standard way of measuring rainfall or snowfall is the standard rain gauge which can be found in 10 cm 3 9 in plastic and 20 cm 7 9 in metal varieties 83 the inner cylinder is filled by 2 5 cm 0 98 in of rain with overflow flowing into the outer cylinder plastic gauges have markings on the inner cylinder down to 1 4 mm 0 0098 in resolution while metal gauges require use of a stick designed with the appropriate 1 4 mm 0 0098 in markings after the inner cylinder is filled the amount inside is discarded then filled with the remaining rainfall in the outer cylinder until all the fluid in the outer cylinder is gone adding to the overall total until the outer cylinder is empty these gauges are used in the winter by removing the funnel and inner cylinder and allowing snow and freezing rain to collect inside the outer cylinder some add anti freeze to their gauge so they do not have to melt the snow or ice that falls into the gauge 84 once the snowfall ice is finished accumulating or as 30 cm 12 in is approached one can either bring it inside to melt or use lukewarm water to fill the inner cylinder with in order to melt the frozen precipitation in the outer cylinder keeping track of the warm fluid added which is subsequently subtracted from the overall ...
|
