108:
661:
882:
788:
344:
779:
670:
31:
50:. The island generates wave motion in the wind passing over it, creating regularly spaced orographic clouds. The wave crests raise and cool the air to form clouds, while the troughs remain too low for cloud formation. Note that while the wave motion is generated by orographic lift, it is not required. In other words, one cloud often forms at the peak. See
815:. Because some of the moisture that has condensed on the top of the mountain has precipitated, the foehn (or föhn) is drier, and the lower moisture content causes the descending air mass to warm up more than it had cooled down during ascent. The distinct cut-off line which forms along and parallel to the ridge line is sometimes known as a
445:
The highest precipitation amounts are found slightly upwind from the prevailing winds at the crests of mountain ranges, where they relieve and therefore the upward lifting is greatest. As the air descends the lee side of the mountain, it warms and dries, creating a rain shadow. On the lee side of the
691:
Downslope winds occur on the leeward side of mountain barriers when a stable air mass is carried over the mountain by strong winds that increase in strength with height. Moisture is removed and latent heat released as the air mass is orographically lifted. As the air mass descends, it is compression
877:. It forms above the mountain range, usually at the beginning of a chinook wind as a result of orographic lifting over the range. It appears when seen from downwind to form an arch over the mountain range. A layer of clear air separates it from the mountain.
417:. The cold Atlantic air mass flows up over the north western face to 3,500 feet (1,100 m) above sea level and is met by the warm Indian Ocean air mass from the south eastern back side of the mountain forming the famous "Table Cloth".
569:, due to Britain's prevailing wind coming from the South West. This explains the significant differences between the rainfall between North West and North East England. This impact also occurs to varying degrees to the east of the
761:
drawing in relatively humid air from the lower slopes of the mountain. This reduction in pressure compared to the surrounding air increases condensation, in the same manner as an aircraft's
750:
is formed as the air rises up the slope and will often envelope the summit. When the air is humid, some of the moisture will fall on the windward slope and on the summit of the mountain.
857:
if the air mass is close to the dew point. They are normally aligned at right-angles to the wind direction and are formed at altitudes up to 12,000 metres (39,370 ft).
430:
In
Colorado west of Denver maximum snowfall is recorded at relatively low elevations, around Idaho Springs, Genesee, Evergreen, and even as low as Golden and Castle Rock.
526:
811:
The leeward edge of an extensive mass of orographic clouds may be quite distinct. On the leeward side of the mountain, the air flowing downward is known as a
712:
depending on the region, provide examples of this type of wind, and are driven in part by latent heat released by orographic-lifting-induced precipitation.
628:
on the leeward coastal plain, both around 800 metres (2,600 ft). Conversely, if the polar front or rain event arrives from the south-east (the
823:). This is because the edge appears stationary and it often appears to have an abrupt wall-like edge. A foehn wall is a common feature along the
620:, the coastal plain remains dry and is significantly warmer than on the inland slopes at equivalent altitudes. This is evident when comparing
1050:
757:
is formed downwind of the upper slopes of isolated, steep-sided mountains. It is created by the low pressure areas in the downwind
99:
Orographic lifting can have a number of effects, including precipitation, rain shadowing, leeward winds, and associated clouds.
950:
379:
17:
864:
is a special form of the lenticular cloud with a base low enough that it forms around and covers the peak, capping it.
215:
of
Eastern and South Eastern Australia which forces cold, moist westerlies up the inland slopes, originating from the
1000:
1027:
589:
942:
1055:
605:
727:, are examples where orographic lifting has limited effect since there is limited moisture to remove in the
540:
447:
328:
263:, which face a prevailing westerly flow off the Pacific Ocean and are one of the wettest places on Earth.
93:
120:
300:
873:
is an extensive wave cloud. It has this special name in North
America where it is associated with the
327:. Places on the sea-facing side of coastal mountains see in excess of 140 inches (over 3.5 m) of
632:), then the coastal plain will be on the windward side and the inland slopes are on the leeward side.
841:
is sometimes formed downwind and below the level of the ridge. It has the appearance of the ragged
601:
446:
mountains, sometimes as little as 15 miles (25 km) away from high precipitation zones, annual
397:
146:
107:
903:
613:
1015:
386:
150:
743:
As air flows over mountain barriers, orographic lift can create a variety of cloud effects.
966:
679:
617:
521:
212:
135:
339:
systems, and therefore receive the moisture which is effectively squeezed from the clouds.
8:
869:
256:
936:
660:
570:
531:
510:
495:
312:
273:
996:
946:
546:
506:
205:
85:
81:
849:
845:
type but it is caused by a turbulent horizontal vortex, i.e. the air is very rough.
801:
762:
709:
593:
552:
373:
365:
316:
189:
43:
890:
831:
609:
462:
175:
724:
468:
406:
293:
285:
216:
39:
731:
or other air masses; the
Sirocco, Bora and Santa Ana are driven primarily by (
485:
1044:
1031:
908:
842:
636:
574:
491:
390:
324:
277:
269:
249:
182:
157:
142:
1018:
by Don White. Australian
Weather News. Willy Weather. Retrieved 24 May 2021.
382:, which gets the most rainfall of anywhere in the Eastern U.S. (90 inches ).
881:
874:
853:
are stationary lens-shaped clouds that are formed downwind of mountains by
697:
414:
369:
128:
47:
35:
886:
824:
720:
705:
517:
481:
440:
361:
223:
787:
812:
797:
766:
693:
683:
629:
536:
400:
231:
227:
51:
938:
Practical
Meteorology: An Algebra-based Survey of Atmospheric Science
854:
732:
597:
556:
458:
410:
281:
193:
168:
164:
156:
The mountains near Baja
California North – specifically La Bocana to
112:
69:
59:
828:
701:
640:
582:
566:
348:
332:
289:
260:
238:
197:
77:
65:
343:
716:
420:
352:
73:
778:
765:. The most famous such cloud forms routinely in the lee of the
758:
728:
621:
616:) and up the ranges are forced upwind the inland slopes of the
499:
424:
320:
308:
304:
201:
612:; as snow-bearing westerlies arriving from the southwest (the
625:
578:
476:
336:
245:
89:
30:
669:
560:
472:
565:
North East
England is in the eastern rain shadow of the
450:
can be as low as 8 inches (200 mm) per year.
27:
Air mass forced upwards as it moves over rising terrain
527:
Geography of the United States
Pacific Mountain System
163:
The windward slopes of Khasi and
Jayantia Hills (see
993:
Mountain Meteorology: Fundamentals and Applications
119:Precipitation induced by orographic lift occurs in
990:
351:enhanced by the Sun's angle, can visually mimic a
1042:
323:) see prevailing westerly flow off the northern
248:, which face a prevailing westerly flow off the
331:per year. These locales are on the side of the
178:, which receive by far the most rain in Arabia.
292:which face a prevailing westerly flow off the
72:to a higher elevation as it moves over rising
453:Areas where this effect is observed include:
111:Precipitation induced by orographic lift in
577:and along the England Wales borders and in
241:which also face a prevailing westerly flow.
986:
984:
982:
980:
978:
976:
393:(particularly the western facing slopes).
880:
342:
106:
46:, seen from above over the far southern
29:
973:
930:
928:
926:
924:
14:
1043:
934:
608:regions in Southeastern Australia in
185:that run along India's western coast.
921:
738:
1028:And the outlook for winter is … wet
380:Transylvania County, North Carolina
24:
520:of the United States, east of the
38:cloud pattern—analogous to a ship
25:
1067:
434:
92:and, under the right conditions,
42:—in the downwind zone behind the
786:
777:
668:
659:
650:
646:The Southern Alps of New Zealand
121:many places throughout the world
102:
1051:Land surface effects on climate
1021:
1009:
959:
943:University of British Columbia
796:Banner cloud formation on the
715:A similar class of winds, the
639:in the Land of Israel and the
355:resulting from orographic lift
13:
1:
914:
7:
995:. Oxford University Press.
991:Whiteman, C. David (2000).
897:
509:in Washington state, (i.e.
188:The northern slopes of the
10:
1072:
624:on the windward slopes to
494:in the Pacific Northwest (
438:
301:Northwestern United States
226:, which face a prevailing
145:in Utah. Specifically the
559:is in the rain shadow of
551:The leeward sides of the
335:which are in the path of
237:The mountains of western
174:The Western Highlands of
141:The western slope of the
134:The western slope of the
1034:. Retrieved 24 May 2021.
967:"The upslope phenomenon"
461:block moisture from the
76:. As the air mass gains
753:When wind is strong, a
735:) compression heating.
696:, locally known as the
555:. The entire island of
268:The western uplands of
935:Stull, Roland (2017).
904:Atmospheric convection
894:
893:capped by a föhn wall.
614:Great Australian Bight
356:
116:
84:, which can raise the
80:it quickly cools down
55:
884:
387:Appalachian Mountains
346:
255:The mountains of the
110:
68:is forced from a low
33:
1056:Mountain meteorology
618:Great Dividing Range
372:, particularly with
213:Great Dividing Range
138:range in California.
123:. Examples include:
1030:by Kate Doyle from
398:Eastern seaboard of
153:Cottonwood Canyons.
88:to 100% and create
895:
870:chinook arch cloud
571:Grampian Mountains
532:Pacific Cordillera
511:Sequim, Washington
505:Areas east of the
490:Areas east of the
357:
274:Grampian mountains
167:) in the state of
131:in central Arizona
117:
56:
18:Orographic lifting
952:978-0-88865-283-6
850:Lenticular clouds
739:Associated clouds
692:heated. The warm
547:Canadian Prairies
507:Olympic Mountains
374:lake effect snows
222:The mountains of
86:relative humidity
16:(Redirected from
1063:
1035:
1025:
1019:
1013:
1007:
1006:
988:
971:
970:
963:
957:
956:
932:
802:lenticular cloud
790:
781:
763:wingtip vortices
672:
663:
594:Cumberland Plain
553:Hawaiian Islands
317:British Columbia
272:, including the
257:Chocó Department
21:
1071:
1070:
1066:
1065:
1064:
1062:
1061:
1060:
1041:
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1038:
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922:
917:
900:
808:
807:
806:
805:
793:
792:
791:
783:
782:
741:
725:Santa Ana winds
689:
688:
687:
686:
675:
674:
673:
665:
664:
653:
610:New South Wales
581:to the east of
463:Tibetan Plateau
443:
437:
423:mountain area,
319:, and Southern
192:leading to the
105:
64:occurs when an
28:
23:
22:
15:
12:
11:
5:
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1059:
1058:
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1001:
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919:
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911:
906:
899:
896:
885:A view of the
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878:
865:
858:
846:
835:
795:
794:
785:
784:
776:
775:
774:
773:
772:
771:
770:
751:
748:Orographic fog
740:
737:
677:
676:
667:
666:
658:
657:
656:
655:
654:
652:
649:
648:
647:
644:
633:
586:
563:
549:
543:
541:Central Valley
534:
529:
524:
514:
503:
488:
479:
469:Atacama Desert
465:
439:Main article:
436:
435:Rain shadowing
433:
432:
431:
428:
418:
407:Table Mountain
404:
394:
383:
377:
347:Windy evening
341:
340:
297:
294:Atlantic Ocean
286:Brecon Beacons
266:
264:
253:
242:
235:
220:
217:Southern Ocean
209:
186:
179:
172:
161:
154:
139:
132:
104:
101:
26:
9:
6:
4:
3:
2:
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1057:
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1046:
1033:
1032:The New Daily
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1024:
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1004:
1002:0-19-513271-8
998:
994:
987:
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948:
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940:
939:
931:
929:
927:
925:
920:
910:
909:Weather front
907:
905:
902:
901:
892:
888:
883:
876:
872:
871:
866:
863:
859:
856:
852:
851:
847:
844:
843:cumulus cloud
840:
836:
833:
830:
826:
822:
818:
814:
810:
809:
804:in New Mexico
803:
800:(left) and a
799:
789:
780:
768:
764:
760:
756:
752:
749:
746:
745:
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734:
730:
726:
722:
718:
713:
711:
707:
703:
699:
695:
685:
681:
671:
662:
651:Leeward winds
645:
642:
638:
637:Judean Desert
634:
631:
627:
623:
619:
615:
611:
607:
603:
599:
595:
591:
590:Central Coast
587:
584:
580:
576:
575:Herefordshire
572:
568:
564:
562:
558:
554:
550:
548:
544:
542:
538:
535:
533:
530:
528:
525:
523:
522:Sierra Nevada
519:
515:
512:
508:
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501:
497:
493:
492:Cascade Range
489:
487:
483:
480:
478:
474:
470:
466:
464:
460:
456:
455:
454:
451:
449:
448:precipitation
442:
429:
426:
422:
419:
416:
412:
408:
405:
402:
399:
395:
392:
391:West Virginia
388:
384:
381:
378:
375:
371:
367:
363:
359:
358:
354:
350:
345:
338:
334:
330:
329:precipitation
326:
325:Pacific Ocean
322:
318:
314:
310:
306:
302:
298:
295:
291:
287:
283:
279:
278:Lake District
275:
271:
270:Great Britain
267:
265:
262:
258:
254:
251:
250:Pacific Ocean
247:
244:The southern
243:
240:
236:
233:
230:flow off the
229:
225:
221:
218:
214:
210:
207:
203:
199:
195:
191:
187:
184:
183:Western Ghats
180:
177:
173:
170:
166:
162:
159:
158:Laguna Hanson
155:
152:
148:
144:
143:Wasatch Range
140:
137:
136:Sierra Nevada
133:
130:
126:
125:
124:
122:
114:
109:
103:Precipitation
100:
97:
95:
94:precipitation
91:
87:
83:
82:adiabatically
79:
75:
71:
67:
63:
61:
53:
49:
45:
44:Île Amsterdam
41:
37:
32:
19:
1023:
1016:Rain Shadows
1011:
992:
961:
937:
875:Chinook wind
868:
861:
848:
838:
820:
816:
755:banner cloud
754:
747:
742:
714:
698:Chinook wind
690:
486:Rhone valley
452:
444:
415:South Africa
370:Pennsylvania
129:Mogollon Rim
118:
98:
58:
57:
48:Indian Ocean
36:gravity wave
887:Front Range
839:rotor cloud
825:Front Range
706:Diablo wind
684:wave clouds
682:(left) and
606:South Coast
518:Great Basin
482:Switzerland
441:Rain shadow
362:ski country
224:New Zealand
1045:Categories
915:References
817:foehn wall
813:foehn wind
798:Matterhorn
767:Matterhorn
710:Nor'wester
694:foehn wind
630:Tasman Sea
557:Kaho'olawe
537:California
496:Washington
401:Madagascar
364:region of
313:Washington
232:Tasman Sea
60:Orographic
52:wave cloud
862:cap cloud
855:lee waves
821:föhn wall
733:adiabatic
680:cap cloud
598:Illawarra
459:Himalayas
411:Cape Town
333:mountains
282:Snowdonia
194:Black Sea
171:in India.
169:Meghalaya
165:Mawsynram
113:Andalusia
70:elevation
898:See also
829:Colorado
759:vortices
702:Bergwind
641:Dead Sea
604:and the
583:Dartmoor
567:Pennines
366:New York
349:twilight
290:Dartmoor
261:Colombia
239:Tasmania
228:westerly
198:Bulgaria
190:Pontides
78:altitude
66:air mass
891:Rockies
889:of the
832:Rockies
827:of the
729:Saharan
717:Sirocco
421:Oppland
353:tornado
206:Georgia
74:terrain
999:
949:
719:, the
622:Batlow
602:Monaro
500:Oregon
425:Norway
321:Alaska
309:Oregon
305:Canada
202:Turkey
147:Little
90:clouds
626:Cooma
579:Devon
573:, in
477:Chile
337:storm
246:Andes
196:, in
176:Yemen
997:ISBN
947:ISBN
819:(or
723:and
721:Bora
635:The
588:The
561:Maui
545:The
516:The
498:and
475:and
473:Peru
467:The
457:The
396:The
385:The
368:and
360:The
303:and
299:The
288:and
211:The
204:and
181:The
149:and
127:The
62:lift
40:wake
708:or
704:or
539:'s
484:'s
471:in
389:in
259:in
151:Big
1047::
975:^
945:.
941:.
923:^
867:A
860:A
837:A
700:,
678:A
600:,
596:,
592:,
413:,
409:,
315:,
311:,
284:,
280:,
276:,
200:,
96:.
34:A
1005:.
969:.
955:.
834:.
769:.
643:.
585:.
513:)
502:)
427:.
403:.
376:.
307:(
296:.
252:.
234:.
219:.
208:.
160:.
115:.
54:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
