陕西天气与记录 · Shaanxi weather and field notes

西安9月27日阴转中雨、28日小雨：秋迁记录怎样标注天气偏差与取消条件

Xi'an Turns from Overcast to Moderate Rain on September 27: Logging Weather Bias and Cancellation Rules During Autumn Migration

中央气象台9月27日08时预报，西安当天阴、25℃/19℃，夜间中雨；28日小雨、22℃/17℃，30日仍有小雨。本文不把天气变化当作“爆鸟”预测，而是说明城市湿地记录、能见度偏差和明确取消条件。
The NMC forecast issued at 08:00 on September 27 gives overcast conditions at 25°C/19°C followed by moderate rain at night, then light rain and 22°C/17°C on September 28, with more light rain indicated on September 30. This article treats weather as a survey variable rather than a promise of migration fallout and sets clear cancellation thresholds.

发布 Published 2026-09-27 · 来源日期 Source 2026-09-27 08:00
Xi'an Turns from Overcast to Moderate Rain on September 27: Logging Weather Bias and Cancellation Rules During Autumn Migration
适合季节 · SEASON

2026年9月27日至30日秋迁观测窗口；预报滚动更新，出发前必须复核
The September 27–30, 2026 autumn-migration window; forecasts update and must be rechecked before departure

地点范围 · AREA

西安依法开放、路面稳定且便于撤离的城市公园与正式湿地步道；降雨时不进入秦岭沟谷、河滩、芦苇地、未铺装岸线或封闭区域
Open Xi'an city parks and formal wetland paths with stable surfaces and easy exits; in rain avoid Qinling gullies, floodplains, reeds, unsealed shores and closed areas

涉及鸟种 · SPECIES

原始来源未公开具体鸟种
Species not listed by the source

中文 · CHINESE

预报是时间戳，不是鸟群承诺

9月27日08时城市预报显示，当天白天阴、最高25℃，夜间中雨、最低19℃；28日小雨、22℃/17℃；29日多云，30日再次有小雨。预报会滚动修订，本文数字只能对应这一发布时间。

阴雨和风向可能改变迁徙高度、停歇时间与观察能见度，但不能据此宣布某公园必有大群落鸟。真正可用的记录要同时写预报发布时间、现场起止天气、风、能见度、观察时长和覆盖范围。

把零记录与漏看分开

雨幕、逆光、起雾和镜片积水会降低远处小型鸟与水鸟的可探测性。当天没有记录到某鸟种，可能是鸟不在，也可能是看不清、观察时间缩短或路线被关闭；清单备注应明确这些限制。

优先在固定步道或观景平台重复同一条短线，以相同时间段和观察方法记录。不要为了补齐名单进入芦苇、滩涂或树下积水区，也不要用回放把隐蔽鸟叫出。

四类情况直接取消或撤离

雷电、能见度明显下降、积水或水位上涨、现场封闭或管理人员劝离，任何一项都应立即取消或撤离。中雨不适合秦岭沟谷、河滩和未铺装山路；城市路线也要避开水边陡坡、桥下和倒伏风险较高的老树。

使用防水外层、防滑鞋、镜头防雨罩和干燥袋，预留天黑前返程。车辆不因发现鸟而在桥梁、弯道或应急车道急停；雨后鸟群集中也不等于可以缩短距离。

ENGLISH · 英文

A forecast is timestamped evidence, not a flock promise

The city forecast issued at 08:00 on September 27 gives overcast conditions and 25°C by day, moderate rain and 19°C at night, light rain at 22°C/17°C on the 28th, cloud on the 29th and light rain again on the 30th. The figures belong only to that issue time.

Rain, cloud and wind may alter migration height, stopover timing and visibility, but they do not prove a fallout at a park. A useful record includes forecast issue time, actual start and end conditions, wind, visibility, effort and route coverage.

Separate a true absence from a detection limit

Rain curtains, backlight, fog and wet optics reduce detection of distant passerines and waterbirds. Failure to record a species may mean it was absent, or that visibility, effort and access were reduced. State those limits in the checklist.

Repeat one short route from a fixed path or platform at comparable times and with the same method. Never enter reeds, flats or flooded woodland to complete a list, and do not use playback to force a hidden bird into view.

Four conditions mean cancel or retreat

Lightning, materially reduced visibility, rising or standing water, and any closure or ranger instruction each require cancellation or retreat. Moderate rain rules out gullies, floodplains and unsealed mountain tracks; even urban routes should avoid steep water edges, underpasses and old trees at risk of falling branches.

Carry waterproof outerwear, grippy footwear, an optics cover and dry bag, and return before dark. Never stop on a bridge, bend or emergency lane for a bird. Post-rain concentration never permits a shorter viewing distance.