October Comes Early: Late September Multi-Hazard Hybrid Storm

[dendrite]

24 minutes ago, Damage In Tolland said:

European argued 60mph

6z euro has a period there Sat night where 925 gets up to 65-70kt over CT. It’s tough to see on the soundings but it looks like 55kt at 950 over you 6z Sun and the 950-sfc layer is moist adiabatic. 

[Damage In Tolland]

2 minutes ago, dendrite said:

6z euro has a period there Sat night where 925 gets up to 65-70kt over CT. It’s tough to see on the soundings but it looks like 55kt at 950 over you 6z Sun and the 950-sfc layer is moist adiabatic. 

It’s had that signal overnight Saturday into early Sunday for some very strong winds on and off . Almost like a 2nd pulse 

[Ginx snewx]

Congrats SCOOTER and Masswx

[Chrisrotary12]

1 hour ago, Damage In Tolland said:

This is not even the strongest period of winds . This is after midnight Saturday. Wow 

The 24 at ASH compared to 30s everywhere else is chef's kiss. These models are getting good.

[Chrisrotary12]

1 hour ago, Chrisrotary12 said:

I’d love to sneak In my Saturday AM round of golf. Not sure how I feel 

Really liked the overnight runs. Looks like might be able to sneak it in. Plus need to get in a crappy weather round ahead of the Mid-Am at Mt. Washington 1st week of October.

[kdxken]

8 minutes ago, Ginx snewx said:

Congrats SCOOTER and Masswx

Congratulations woodyard too.

[weatherwiz]

I'd also watch for models overall to perhaps miss some of the very early rain potential (which could have implications on overall flooding risk too). Wouldn't be shocked to see some rain and rain bands get in much earlier than indicated and the rainfall rates would be quite heavy. Maybe progressive movement limits totals but something to watch

[Ginx snewx]

Beast 

[WinterWolf]

3 minutes ago, Ginx snewx said:

Beast 

Great shot Steve.  Ya that’s looking nice now. 

[Typhoon Tip]

By small amounts ...some more coherent than others, the guidance were too deep/structurally evolved for what is observed at 12z

May or may not be indicative of much.  We'll see.  We may be disappointed in Now-cast ranges. I'm not completely sold on how far above pedestrian inclemency this will be.   I think the lunar tides and surface feed-back should be fun either way. 

Op ed that no one asked for but ... my original impression of this scenario from 2 or 3 days back was that it was dubiously too amplified in the guidance.  Two main reasons for suspecting so ... 

1,  the total S/W wave mechanics feeding into the region were very weak. As far as I can tell that still seems to be the case.  At the time this was a bit of a head scratch as to what was driving this ordeal.  The best I could surmise was that this was a very (if perhaps unusually so) non-linear in origin.

The circulation mode from the eastern Pac across N/A is technically is in a strong, albeit transient, negative PNAP.   The polar branch retreated N very quickly, earlier in the week - so fast it left a weakness pearled out from the S Lake through the mid Atlantic..  Similar to a "pinch cut-off" you see in April climo - but it is doing it amid a higher ambient height medium.  You realize, the hydrostats are in the mid 560s during this - we've been close to 90 F at the surface with 566 dm thickness before!  Yet, it's so raw..  It's bizarre, maybe some tized aspects going on...

Anyway, a ridge from James Bay clear to Florida  would be geophysically hard to maintain, particularly when the flow around it is not that strong.  So the heights inside 'implode' ...     My feel on that is that the models were over assessing this ambient, large scaled mass balancing response, as a total forcer. 

2,  the other reason is much simpler ... guidance et al tend to shed amplitude as they move events from the extended toward the short lead periods.  It's really quite a dependable corrective behavior.  It's never been abundantly clear why they do this, but I suspect it has something to do with not yet seeing the emergence of noise/offsets/and interferences that will inexorably arise - they only see the system with the most prominent physical signature out in time. If, then, the prominence is the only thing there is, they are maximizing it.   Something like this...

[Ginx snewx]

^^^'Cept model guidance has gotten stronger