Run improvement - is this a reasonable goal

I agree completely with the "maybe" answer, as there are just way too many variables.  However, IN GENERAL, given the details you provided I would say that it does not sound totally unreasonable.

You're young (28-ish I guess... based on HS 10 years ago).

You have some weight to lose (less weight = more speed)

You have 8 months to dedicate to training (a long time for a HM)

You are new to running (great improvements come quickly at the beginning)

All that said I would say that you have a good chance of meeting your goal.  I might think that 1:30 is a stretch, 1:40-ish should be fairly do-able though.

 "In short, I believe that it's better to let the times come to you, rather than trying to chase them. With experience, you can start to set short-term goals that are based on time, but trying to set a goal far in the future can be troublesome.

That's a drop from a 9:20 mm to a 6:50 mm. That's a LOT.

Yes it's very reasonable.

where do you live?  June in some parts of the country (like where I live in TX), the weather does not lend itself to running "fast" halfs like you could in the winter.

That said, if you've never done a 13.1, realistically I wouldn't set too ambitious of time goals.  Just go out and try to feel good for the first 9-10 miles, because that's when the race really starts.  Go as hard as you can the last 5k.  Once you get pacing down you can pretty evenly split the entire race, but it will take some experience racing to do so.

I just giggled reading your post... then your sig block!  

While I respect your admirable goal, I don't think it's realistic, even with losing another 10-15 lbs.  It's just too short a time and you are starting out with 9:20 min/mile (maybe adjust to 9:00 min/mile on a non-hilly, flatter course).  Going to roughly 7:54 min/mile for 13.1 miles to hit 1:40 at the high end of your goal is a lofty expectation.  

That being said, if you do get it done, 1:40 is more realistic than 1:30.

With this I'm not sure the cart isn't still before the horse (as Scout said). It's fine if you want to ask to see what's possible, but this seems to still hint at defending a goal. You shouldn't be looking at a goal time for this race until well into spring time (given it's a June race). Then you'll have a lot more training in and see how you've been progressing.

It's already been stated, but your goal is misdirected. Given that, a 1:30 is not a reasonable goal here and you set yourself up for frustration and, likely, injury by trying to hit it. Just asking the question that casually tosses out 1:30 and 1:40 in the same framework indicates a lack of necessary understanding for what those two time marks feel like. Those are two very different races.

Big jumps are not at all uncommon for new racers. Jumping from 2:00 to 1:45 will not be at all unheard of. Sub 1:40 could also happen on a magic day where it all comes together. This assumes consistent run training between now and the race (I'd build to feel comfortable at 35 miles per week at minimum ... preferably closer to 45).

Dropping from 1:40 to 1:30 is going to take a lot more run-focussed work than dropping to 1:45 will.

Add me to the group that encourages more miles run well within your comfortable heart rate zones. Don't "test" yourself by trying to run your routes faster each week. Just run. A lot.

 

This is a very unscientific comment, I did not really try to think about your goals and whether they are reasonable or not, but I found this quote quite inspirational I once read somewhere

 “When it is obvious that the goals cannot be reached, don’t adjust the goals, adjust the action steps.” – Confucius

I got a kick out of that as well.  Only one thing to add: In addition to running lots/mostly easy/sometimes hard, I think you'll need to start getting serious about speed sessions once a week.

Scout:  Welcome back!  I haven't noticed a post from you in months.

fyi 1:40 is actually 7:38 miles.  I just happened to know since I did 1:43:30 at my last race and that is around 7:54 miles.

going from 2:00 to 1:45 would be something more reasonable for OP imo, anything better would be gravy but trying to go under 1:40 might be a setup for injury/failure.

Nope no freak genetics in play, but I should mention that the 2:06 was my 1st time even running a half marathon distance.  Prior to that training run my longest runs were 10 and 11 miles, which were each done once in the weeks leading up to the race.