Ashkenazi Y-DNA Haplogroup Q

Based upon the methodology posted here and using the sample set described here, as of January 2019 it appears that there are two ancestral Y-DNA lines in haplogroup Q found in the Ashkenazi Jewish population: (1) Q-Y2198; and (2) Q-YP1003.  Trees for each of those clusters are posted below.
Q-Y2198
Upstream SNPs: 
M242>L275>M378>L245>Y2209>Y2211>Y2200>Y2232>Y2197>Y2198
ISOGG Tree (2019): Q2a1a1a1a1
TMRCA (YFull Tree)
Q-Y2197: 1,300 ybp (900-1,650 ybp @95%) (Q-Y2197 and Q-Y2198 are at same level)
Q-Y2780: 900 ybp (600-1,250 ybp) (Q-Y2780 is on the same level as Q-Y2754)
Q-YP1004: 700 ybp (300-1,200 ybp)
Q-Y2750: 700 ybp (350-1,300 ybp)
TMRCA (JewishDNA.net)
Q-L245-Y2200 (AB-065): 741-912 CE (@95%)

The Q-Y2198 cluster follows the same pattern as many of the larger Ashkenazi clusters, with (1) a shared direct male ancestor dating back to about the second half of the first millenium CE, as evidenced by initial branching during that time frame; and (2) substantial branching within those subbranches that presumably dates back to the time when the Ashkenazi population began its massive expansion out of a small bottlenecked population, about 700 to 1,000 years ago.  

Q-YP1003
Upstream SNPs: 
M242>L275>M378>L245>Y2209>Y2211>Y2200>Y2232>YP1003
TMRCA (YFull Tree)
Q-YP1003: 1,400 ybp (1,000-1,850 ybp @95%)
Q-YP1071: 1,350 ybp (950-1,850 ybp @95%)
Q-BZ66: 850 ybp (450-1,500 ybp) (Q-BZ66 is one SNP downstream from Q-BZ58, which does not appear on YFull's YTree)
TMRCA (JewishDNA.net)
Q-L245-BZ3900 (AB-138): 821-1750 CE (@95%)

The Q-YP1003 cluster follows the same pattern as many of the larger Ashkenazi clusters, with (1) a shared direct male ancestor dating back to about the second half of the first millenium CE, as evidenced by initial branching during that time frame; and (2) substantial branching within those subbranches that presumably dates back to the time when the Ashkenazi population began its massive expansion out of a small bottlenecked population, about 700 to 1,000 years ago.  

Y-DNA SNPs Not Appearing on Trees Posted Above
In addition to the SNPs posted above, there are a number of SNPs identified through the methodology used on this website that do not appear in any of the trees posted above.  In some cases, primarily with regard to SNPs reported by Family Tree DNA based upon the results of Big Y testing or Geno 2.0 testing, the reported SNPs are ancestral to the SNPs set forth in one or more of the trees above; if the tested man is Ashkenazi on his direct male line, Big Y testing would likely determine that he belongs to one of the clusters set forth above. In other instances, it is possible that SNPs identify a small and/or undertested Ashkenazi cluster; further testing or information may identify such clusters.  Often, because the methodology used herein to identify potential Ashkenazi SNPs is overinclusive (especially for the 50 cM cohort but also, on occasion, for the 80 cM and 100 cM cohorts), SNPs set forth below do not reflect Ashkenazi (or Jewish) ancestry on the direct male line.  Finally, there are some SNPs (identified with "N/A") that do not appear on FTDNA's Y-DNA haplotree at all.

Upstream SNPs.  The following SNPs in the table above (identified in red) are upstream from SNPs found in one or more Ashkenazi Y-DNA clusters: L245, M242, M378, Y2200, and Y2232.  

If men who are reported based upon STR or Geno 2.0 testing as having these SNPs are of Ashkenazi descent on their direct male line, there is a high probability that such men belong to one of those Ashkenazi Y-DNA clusters.  However, a large proportion of the men reported as having these terminal SNPs are not of Ashkenazi descent on their direct male lines.

Other SNPs.  With the exception of the SNPs that are not on FTDNA's Y-DNA Haplotree (identified with "N/A"), it is unlikely that men reported as having terminal SNPs other than the upstream SNPs identified above are of Ashkenazi descent on their direct male lines.