Can 挟带 be pronunced as jiādài?
In ancient Chinese, 挟 can be used as 夹.


  挟（挾）jiā ㄐㄧㄚˉ ◎ 古同“夹”，从物体两边钳住。


And in Taiwan, 挾 has a pronunciation jiá (note that it's not jiā). So, the lyrics/pronunciation cannot be considered wrong.

PS Thanks for NS.X.'s pointing out that you cannot freely choose the pronunciation of a polyphonic character, it should depend on the context. That is correct, and I am sorry if I had misled anyone for my unclear statement.

That I said such pronunciation jiádài (Taiwanese) cannot be considered wrong, is because the persons who use jiádài may argue like this


  (Possible Argument for jiádài) The 挾 is an interchangeable character of 夾, though it's in ancient Chinese, I can use 挾帶 as 夾帶 without being wrong because modern dictionaries still list 挾jiá(note that again in mainland China it is 挟jiā) as one entry. And, 夾帶 has meaning 夾雜(be mixed up with), so
  
  
    the lyric 夢想夾帶眼淚 can be interpreted as a metaphor "dreams are mixed up with tears".
  
  
  And
  
  
    in the news, 颱風夾帶暴雨前進 can be interpreted as "the typhoon mixed up with rainstorms is moving forward".
  
  
  They both make sense.


Thus, it would be a little indiscreet to say it's wrong.

EDIT

Thanks for QuestionOverflow's brilliant question! I study the pronunciation of 挟带(挾帶) for a while, and here's my conclusion:


  
  In Taiwan, the pronunciations of 挾 are xié, xiá, or jiá. The formal pronunciation of 挾帶 should be xiédài, or xiádài (preferred). However, the not-so-formal pronunciation jiádài can be commonly heard in TV weather reports.
  In mainland China, the pronunciations of 挟 are xié or jiā. The formal pronunciation of 挟带 should be only xiédài.
  


Literature Evidence

For Case 2, the answer can be easily found in the authoritative dictionaries 《现代汉语词典》 or 《新华字典》.

However, Case 1 is much more complex, because there are many dictionaries in Taiwan and it's difficult to tell which one is the most authoritative. Here, I would consider the 中華民國教育部 重編國語辭典修訂本 (online) as the most authoritative one. In that dictionary, the entries for 挾 and 挾帶 are


Pronunciation xié.


  挾 部首　手　部首外筆畫　7　總筆畫　10
  
  
    注音一式① ㄒ｜ㄝˊ
    
    漢語拼音① xié
  
  
  【動】
  
  
  夾在腋下、懷夾。國語˙齊語：「時雨既至，挾其槍、刈、耨、鎛，以旦暮從事於田野。」孟子˙梁惠王上：「挾太山以超北海。」
  從旁箝夾。文選˙王粲˙登樓賦：「挾清漳之通浦兮，倚曲沮之長洲。」
  脅持。如：「要挾」。三國志˙卷三十五˙蜀書˙諸葛亮傳：「挾天子而令諸侯。」水滸傳˙第三十六回：「若是如此來挾我，只是逼宋江性命，我自不如死了。」
  持握、持有。戰國策˙趙策四：「位尊而無功，奉厚而無勞，而挾重器多也。」楚辭˙屈原˙九歌˙國殤：「帶長劍兮挾秦弓，首身離兮心不懲。」
  倚仗、倚持。如：「挾恃」。孟子˙萬章下：「不挾長，不挾貴。」清˙洪昇˙長生殿˙第三十齣：「況且弟兄姊妹挾勢弄權，罪惡滔天。」
  夾帶、夾雜。宋˙辛棄疾˙浣溪沙˙梅子熟時到幾回詞：「晚雲挾雨喚歸來。」
  懷藏、隱藏。如：「挾怨」。漢書˙卷五十六˙董仲舒傳：「秦繼其後，獨不能改，又益甚之，重禁文學，不得挾書。」元˙關漢卿˙望江亭˙第二折：「挾這讎氣，朦朧奏過聖人，要標取我的首級。」
  

Pronunciation xiá. ①之又音 means it is another acceptable formal pronunciation under the usage of case ①.


  挾 部首　手　部首外筆畫　7　總筆畫　10
  
  
    注音一式② （又音）ㄒ｜ㄚˊ 
    
    漢語拼音② （又音）xiá
  
  
  ①之又音。

Pronunciation jiá.


  挾 部首　手　部首外筆畫　7　總筆畫　10
  
  
    注音一式③ ㄐ｜ㄚˊ
    
    漢語拼音③ jiá
  
  
  【動】
  
  
  通達。詩經˙大雅˙大明：「天位殷適，使不挾四方。」
  夾取。通「夾」。莊子˙駢拇：「問臧奚事，則挾策讀書。」舊五代史˙卷一二七˙周書˙盧文紀傳：「旭旦以箸挾之，首得文紀之名。」
  
  
  【形】 周匝、周遍。荀子˙禮論：「於是其中焉方皇周挾，曲得其次序，是聖人也。」楊倞˙注：「浹，匝也。」

挾帶 xié dài with the meaning "carry".


  夾持攜帶。如：「歹徒挾帶毒品闖關，被海關緝查人員當場查獲。」

攜挾帶 xī jiá dài with the meaning "cheating in an examination".


  考試作弊。



Thus, consider the meaning of 挾帶 in the context of weather report, formally, it should be pronounced as xiédài or xiádài(preferred) in Taiwan.

Why xiádài is preferred in Taiwan

I find an article written by Prof. Pei-Jung Huang (Dept. of Chinese language and literature, National Taiwan University) on this website. It mentions:


  根據臺灣《國語一字多音審定表》（教育部出版）及大陸《普通話四讀詞審音表釋例》，兩岸的字音差異頗多，茲舉十例如下：[...]
  
  
    二、聲母、韻母或聲調不同的：（前面是臺灣讀音，後面是大陸讀音）[...]
    
    21．挾持、挾制、挾帶（ㄒㄧㄚˊ／ㄒㄧㄝˊ）  
  


That is to say, xiádài is preferred in Taiwan, according to the official document 臺灣《國語一字多音審定表》. And in the 國語小字典, 挾 is only given the pronunciation xiá.


  【挾】手-7-10
  
  注音    ㄒ｜ㄚˊ
  
  (1)   用手臂夾在腋下。如：「挾帶」。
  (2) 以威勢壓迫。如：「挾持」、「挾制」、「要挾」、「挾天子以令諸侯」。
  (3) 暗藏於心。如：「挾怨」、「挾嫌」、「挾恨」、「挾隙」。


Distinction between 挟带(挾帶) and 携带(攜帶)


挟带


  
  携带；混杂在他物中秘密携带。 宋 梅尧臣 《和王仲仪咏瘿二十韵》：“挟带岁月深，冒犯风霜冷；厌恶虽自知，剖割且谁肯。” 清 富察敦崇 《燕京岁时记·黄花鱼》：“京师三月有黄花鱼，即石首鱼。初次到京时，由 崇文门 监督照例呈进，否则为私货。虽有挟带而来者，不敢卖也。”
  谓以强力带着。 王愿坚 《普通劳动者》：“一阵疾风挟带着沙土扑过，大白点子雨急骤地撒落下来，打在沙土上。”
  犹夹杂，带有。 鲁迅 《坟·从胡须说到牙齿》：“其中大半是因为他们耽误了我的父亲的病的缘故罢，但怕也很挟带些切肤之痛的自己的私怨。”
  

携带


  
  [carry;bring;take along]
  随身带着
  
  
    携带行李
  
  经受或容许以特定方式带
  
  
    易于携带的负载
  
  [pack]∶作为部分经常装备佩带
  [wear]∶手里拿着
  
  
    携带一根手杖
  
  



Thus, though they have similar meanings, 携带 can be only used to describe such an action or a status of humans, or, of something that is compared to humans in a metaphor. 挟带 emphasizes more about the action than the status, and can be used for anything/anybody. The phrase 挟带暴雨 is Case 2 of 挟带 in the explanations above, meaning "carrying (the rainstorm) with strong force".

Video Material Evidence for the Formal Pronunciation xiádài in Taiwan


One official introductory video about typhoon made by the Central Weather Bureau of Taiwan. 挾帶 is pronounced as xiádài at 0:05-0:06.


  颱風是源自於熱帶海洋上的劇烈天氣系統，會挾帶(xiádài)著狂風及豪雨前進 ...

A piece of weather news made by New Tang Dynasty Asia Pacific TV. 挾帶 is pronounced as xiádài at around 0:05.
A piece of Apple Daily news in Taiwan. 挾(帶) is pronounced as xiá at 0:00.


  挾1500毫米暴雨 ...



The Not-So-Formal Examples of jiádài


https://www.youtube.com/watch?v=ONcmt4TIalc


  Around 0:05. 明天起將挾帶暴雨侵台

http://www.youtube.com/watch?v=iREbExawzeQ


  0:08-0:12 其中，西半部依然挾帶豐沛水汽進入台灣

https://www.youtube.com/watch?v=03_2kam1MrY


  0:24-0:28 天秤颱風從東部登陸台灣，挾帶著強風豪雨