雨がひどいのでローソンの駐車場まで迎えに来てください。って英語でなんて言うの？

"It's pouring!Please pick me up at Lawson's parking lot ?"
"Pouring" means it is raining heavily.

"Please come and get me at the parking lot at Lawson's ?Its raining cats and dogs here!"
raining cats and dogs = This means that the rain is coming down hard.

Car park (UK) = car lot (US)
To pour down = water, as with rain to shower down on someone.
"The rain poured down on us, soaking us to the bone."
If the rain is 'pouring down' or 'raining cats and dogs' it means that you are experiencing very heavy rainfall at that moment.
To pour is a verb used to explain the process of a volume of water coming out of a receptacle. For example: "John poured himself a cup of tea."

All of these statements are fine to ask a friend but if you are asking someone in a position above you, the last statement, "Would you mind picking me up from the Lawsons by the station, please? It's raining really hard and I don't want to walk in this bad weather" is most polite.

There are SO MANY expressions for heavy rain...since it often rains in Britain!
So the English language is filled with a rich variety of colloquial expressions.
From heavy downpours to falling in floods etc etc..
So enjoy the use of colorful idioms when you get the opportunity;-)

A) Please pick me up at Lawson's it's pouring outside!
Pick me up - Fetch me
Pouring - raining a lot / the rain is pouring down

B) Pick me up at Lawson's it's storming .
*Storming - a large amount of rain

I hope this helps :-)

The word instead means you planned to meet somewhere but due to the weather you want to be picked up at Lawson. Instead of saying "raining hard" you should say "raining heavily"

1. Can you pick me up at the parking lot of Lawson? it's raining heavily.
   If it's raining a lot you can also say 'it's raining heavily'.

2. Please come get me at the parking lot of Lawson, the rain is pouring
   We can also say the rain is pouring to describe heavy rainfall.

If you wanted to ask someone to come pick you up at a Lawson parking lot because it is raining very hard, you could say either of the following: "It is raining really hard, would you be able to pick me up at the Lawson's parking lot please?" or "It is pouring down with raining, is it possible that you could come pick me up?".

Pick me up/ collect me/ come for me/ come get me. These all mean that you need a ride/lift.
Can you pick me up at Lawson's? Can you come for me at 5 pm?

Pouring rain- Raining very hard.