Should I be excited?!

[Jonesy]

I previously found someone on a Genealogy website, that I suspected to be a relative.

From my previous, research, the person I thought was my grandfather's mother, was this person's great aunt.

Having made contact a number of times, she agreed to take an FTDNA swab and return the kit, and I did the same.

Well, my matches have arrived today. I have many, many matches, (mostly weak, I presume, i.e. shared cM of around 50 or less), except for my contact, with a shared cM of 147!

Can I now be sure we're related??

[salgo60]

Whats your question?
If the Total cM is a measurement of 2 people are related?

Answer Yes

but small segments can be IBS Identical by State

http://blog.kittycooper.com/2014/10/when-is-a-dna-segment-match-a-real-match-ibd-or-ibs-or-ibc/

[Jonesy]

Whats your question?

Does a shared cM of 147, definitely indicate that myself and person in question are related?

[georgian1950]

Does a shared cM of 147, definitely indicate that myself and person in question are related?

FTDNA Family Finder is very conservative in calling a match. If Family Finder says you are related, you can pretty well count on it. Usually the problem is figuring out how.

[khazaria]

FTDNA Family Finder is very conservative in calling a match. If Family Finder says you are related, you can pretty well count on it. Usually the problem is figuring out how.

Yes.
Jim Bartlett believes 95-96% of FTDNA matches are real.
Tim Janzen thinks the percentage is somewhat smaller, based on his phasing experiments, but due to FTDNA's conservative criteria I have found times when legitimate matches who belong to triangulating blocks sometimes only show up on SOME of the triangulating members' match lists here at FTDNA, but at Gedmatch they can be matched to everyone in it, because it has no 20 cM minimum total sharing requirement like here.

[MMaddi]

I previously found someone on a Genealogy website, that I suspected to be a relative.

From my previous, research, the person I thought was my grandfather's mother, was this person's great aunt.

Having made contact a number of times, she agreed to take an FTDNA swab and return the kit, and I did the same.

Well, my matches have arrived today. I have many, many matches, (mostly weak, I presume, i.e. shared cM of around 50 or less), except for my contact, with a shared cM of 147!

Can I now be sure we're related??

Yes, sharing 147 cM definitely indicates a fairly close relationship.

I share about 62 cM with a Family Finder match. He is a known, paper trail-proven 3rd cousin, once removed. So, I think it's fair to say that your match is certainly closer than my 3rd cousin, once removed.

Based on your description of the relationship (which I bolded above), you and the match should be 2nd cousins, once removed. Although FTDNA and 23andMe use different algorithms to estimate matches' relationship, I have a known, paper trail 2nd cousin, once removed at 23andMe with whom I share 110 cM and my sister shares 82 cM. FTDNA counts smaller segments in shared DNA that 23andMe wouldn't count, so what you share with this person is probably in line with what my sister and I share with our 2nd cousin, once removed.

To me it seems that this person is indeed your 2nd cousin, once removed. What is the estimate for the relationship that FTDNA gives?

[Armando]

I previously found someone on a Genealogy website, that I suspected to be a relative.

From my previous, research, the person I thought was my grandfather's mother, was this person's great aunt.

Having made contact a number of times, she agreed to take an FTDNA swab and return the kit, and I did the same.

Well, my matches have arrived today. I have many, many matches, (mostly weak, I presume, i.e. shared cM of around 50 or less), except for my contact, with a shared cM of 147!

Can I now be sure we're related??

Based on what Blaine Bettinger has found from 6,000 known relationships 147 cM can be as far as a 3rd cousin 1x removed but on average a 2nd cousin 1x removed shares 140 cM. You share slightly more than the average with your 2nd cousin 1x removed.

See this diagram http://www.isogg.org/w/images/0/02/S...ct-Image-2.png which is from http://www.isogg.org/wiki/Autosomal_DNA_statistics

Notice that 3rd cousin 2x removed has a max sharing of 122 cM so you are definitely related to that person.