I believe that it should have been an invest all day..at the very least, but as for it being a full-on depression, I have my reservations. However, I also believe that NHC has been remiss in not mentioning the Low sooner.

IMHO, we have a sub-tropical depression which has been highly-sheared on it's western quadrant, and which has not fully separated itself from a still-respectable front. Consequently, much of the cyclogenesis has been baroclinic. That said, clearly there has been a LLC all day long, banding, deep convection (in the eastern quadrant), a little bit of antic-cyclonic outflow, something of a warm-core. Hardly what I would expect a fair and ballanced NHC to let go basically unmentioned all day.

Who knows what the internal debates and decisions are. I would have thought 91L & 92L of last month would have receieved more attention from them, also.

92L reminded me quite a lot of the late-season named systems of last year, 91L appears to have closed-off right at landfall, and this non-Invest, Invest, sure passes the smell test of a hybrid system worthy of at least official notice as an Invest.

Edit: When you posted 91*L* of course I read into that Atlantic. I think you mean 91*E* and my reply is meant for the Carolinas northernmost low opps