A thunderstorm is defined as convection that has at least one stroke of lightning that produces audible thunder. You may have noticed that some thunderstorms have much more lightning and thunder than others. Why is this?

There are three factors that contribute to a storm having an exceptionally large amount of lightning and thunder. Each of these will be discussed individually.

HIGH INSTABILITY RELEASE: High instability is a condition in which the ambient tropospheric temperature decreases rapidly with height, especially in the top lower to mid-levels of the troposphere. When instability is high, thunderstorm updrafts will be more intense. The stronger the thunderstorm updraft, the deeper the thunderstorm column will be. As air rises in a thunderstorm it cools. When the storm height is very high, the top of the thunderstorm will cool to very cold temperatures. This intense cooling glaciates the top of the storm and this can be seen as the thunderstorm anvil. The glaciation process produces a charge differential in the storm cloud. In cases where very rapid and intense glaciation occurs (very high CAPE), lightning and thunder will be generated to a significant degrees. All thunderstorms have ice in the upper portions of the storm. How fast the ice develops, the depth of the icy portion of the storm and how quickly the precipitation moves within the cloud are important to the lightning process. There is still much research that needs to be done to fully understand this process.

HIGH MOISTURE CONTENT: Operational meteorologists determine the potential moisture a thunderstorm will have by examining lower tropospheric dewpoint and the precipitable water (PW) in the troposphere. Since thunderstorm updrafts often begin in the lower portions of the troposphere, it is most important to examine moisture there. Dewpoints of 60 F or greater in the lower troposphere will bring significant moisture into a storm. Dewpoints of 70 F or higher in the lower troposphere are not uncommon in the warm season maritime tropical environment. Low level moisture helps in that it increases instability. This in turn helps lead to a stronger storm updraft. An increase of moisture also means more ice can be produced when the moisture begins to glaciate in the updraft. Charge differential builds up more significantly as the mass of ice and water in the thunderstorm cloud increase.

WIND SHEAR: Wind shear is wind speed changing significantly with height and/or wind direction changing significantly with height. Wind shear enables a thunderstorm to last for a longer period of time since it helps displace the updraft from the downdraft. These thunderstorms are often in the form of multi-cell storms or supercell storms. Wind shear also increases turbulence within the thunderstorm. This violent mixing of precipitation in the air could help enhance charge separation in a storm.

Typical profile for highly active lightning storm: CAPE: 3,000 J/kg or greater, low level dewpoints greater than 65 F, PW 2.00 inches or greater, change in wind speed and direction with height.

雷暴被定義為至少有一次閃電產(chǎn)生可聽見雷聲的對(duì)流。 您可能已經(jīng)注意到，有些雷暴的閃電和雷聲比其他雷暴多得多。為什么會(huì)這樣？

有三個(gè)因素導(dǎo)致風(fēng)暴具有異常大量的閃電和雷聲。每 其中將單獨(dú)討論。

高不穩(wěn)定性釋放：高不穩(wěn)定性是環(huán)境對(duì)流層溫度降低的條件 隨著高度的增加而迅速增加，特別是在對(duì)流層的頂部、中下層。當(dāng)不穩(wěn)定性較高時(shí)，雷暴上升氣流會(huì)更加強(qiáng)烈。雷暴上升氣流越強(qiáng)，雷暴越深 列將是。當(dāng)空氣在雷暴中上升時(shí)，它會(huì)冷卻。當(dāng)風(fēng)暴高度非常高時(shí)，頂部 雷暴將冷卻到非常低的溫度。這種強(qiáng)烈的冷卻使風(fēng)暴的頂部變得冰冷，而這 可以看作是雷暴鐵砧。冰川作用在風(fēng)暴云中產(chǎn)生電荷差。 在發(fā)生非常快速和強(qiáng)烈的冰川作用（非常高的CAPE）的情況下，將產(chǎn)生閃電和雷聲 在很大程度上。所有雷暴的上部都有冰。冰的速度有多快 發(fā)展，風(fēng)暴冰冷部分的深度以及降水在云中移動(dòng)的速度 對(duì)閃電過程很重要。還有很多研究需要 要充分理解這個(gè)過程。

高含水量：業(yè)務(wù)氣象學(xué)家通過以下方式確定雷暴的潛在水分 檢查對(duì)流層下部露點(diǎn)和對(duì)流層中的可降水 （PW）。自雷雨以來 上升氣流通常從對(duì)流層的下部開始，最重要的是檢查那里的水分。 對(duì)流層下部 60 F 或更高的露點(diǎn)會(huì)給風(fēng)暴帶來大量水分。露點(diǎn) 對(duì)流層下層的70華氏度或更高，在暖季海洋熱帶環(huán)境中并不少見。 低水平的水分有助于 因?yàn)樗黾恿瞬环€(wěn)定性。這反過來又有助于導(dǎo)致更強(qiáng)的風(fēng)暴上升氣流。水分增加 這也意味著當(dāng)水分在上升氣流中開始冰化時(shí)，可以產(chǎn)生更多的冰。電荷差 隨著雷暴云中冰和水質(zhì)量的增加，積聚得更顯著。

風(fēng)切變：風(fēng)切變是風(fēng)速隨著高度和/或風(fēng)向的變化而顯著變化 顯著與高度有關(guān)。風(fēng)切變使雷暴能夠持續(xù)更長的時(shí)間，因?yàn)樗?有助于將上升氣流從下降氣流中置換出來。 這些雷暴通常以多單體風(fēng)暴的形式出現(xiàn) 或超級(jí)單體風(fēng)暴。風(fēng)切變也增加了雷暴中的湍流。這種暴力的混合 空氣中的降水有助于增強(qiáng)風(fēng)暴中的電荷分離。

高活躍雷暴的典型剖面：CAPE：3,000 J/kg 或更高，低水平露點(diǎn)大于 65 F， PW 2.00 英寸或更大，風(fēng)速和風(fēng)向隨高度變化。