Hello
I got deferred from northwestern ED and I think its primarily because of my grades and test score
if the only thing that is changing in my application is first semester grades, appeal letter, and a more specific northwestern recommendation letter from my teachers, then are the odds of getting in regular very low?..
id appreciate any opinions 
We don’t know how many students NU deferred, or historically how many deferred students are accepted in the RD round.
But, knowing that NU’s RD acceptance rate was around 6.9% last year, it is unlikely you will be admitted. Of course still hope for the best, but make sure to shift your focus to other schools on your list. The process and the waiting is intense and difficult.
Good luck.
I also got deferred, but yesterday I talked with a former admission reader at the University of Chicago who found out from a Northwestern University admission reader that within the past couple of years the Northwestern deferral to admit rate is about 12 to 15 percent. This is admit rate is double that of regular decision, so make sure to send letters of continued interest and perhaps add some additional letters of recommendation. I also know that asking your high school guidance counselor to call Northwestern for flaws in your application can sometimes provide very valuable feedback. I am going to apply early decision two to Chicago, but I am holding out hope for Northwestern.