MsgBox with range

Ok I have been searching for awhile doing a project for work. I am trying to create a macro that will display a message box when a value of B13 through AW13 is greater than 3.5. So if B13 is calculated higher than 3.5 I need a message to pop up saying Resample and later on if I get a value in J13 it to pop up saying the samething. I currently have it so it will pop up however, if B13 is higher than 3.5 then every time I enter more data the message continues popping up I only want it to pop up once per time it sees over 3.5 in those cells. I will attach my excel so you can see what I am referring to.Untitled.png

I see my formulas and code on the workbook, anyways using B10, B11, and B12 I have a formula on B13 that gives me a number. If this number is above 3.5 I need a messagebox to pop like displayed in my photo. The same formula is used across the whole page C10, C11, and C12 displays a value in C13. All the way to AW. I have no issue getting the message box to open as it should, my problem is it continues popping the box over and over everytime I type another number in doesn't matter where, it is like it continues to pop up from B13 when I only need it to open 1 time for B13 if it is above 3.5

This worked thankyou very much