Don't be caught off guard!
While NHC has 40% chance of developing sub-tropical characteristics, there's still going to be a Low pressure forming along the Southeast US coast bringing impactful gusty winds, heavy rain & coastal flooding this weekend. 21Sept2023 #NCwx #VAwx

Hurricane #Nigel finally has more of a classic hurricane look to it Tuesday morning, albeit with an incredibly distinct large eye. NHC forecasting system to turn out to sea before Bermuda (currently about 650miles (1,040km) ESE of Bermuda). 19Sept2023

While nothing concrete at this time, there are some slight hints in models of some Southeast US coast tropical development mischief possible for next weekend. 16Sept2023

Fairly good agreement in models for #TD15 to head Northwest in general direction of Bermuda, then turn out to sea. 16Sept2023

Tropical Storm #Margot still making loops West of The Azores in the Atlantic. Not in great shape with wind shear and dry air around it. 16Sept2023

65mph(100km/h) Post Tropical Cyclone #Lee in the Bay of Fundy just South of Saint John. 830pEDT/930pADT 16Sept2023

Another sunrise satellite view of #Lee Saturday morning.

Post-Tropical Cyclone #Lee (lost tropical characteristics but still hurricane like impacts) between Boston & Nova Scotia. About 2,400 no power MA, 17,000 Maine. 8aEDT 16Sept2023

Hurricane Sandy(2012) lessons learned: advisories/warnings continue after 'post-tropical' status.

Outer edge of Hurricane #Lee’s rain shield just East of Boston / Nantucket Friday evening. 835pEDT 15Sept2023

Tropical Depression Fifteen likely our next named Atlantic system (#TD15 was invest #97L). 11aEDT/AST 15Sept2023

Hurricane #Lee already looking extra-tropical (losing it’s Tropical Cyclone characteristics but still may be a powerful Hurricane like system) Friday morning. Clouds and storms being pulled Northward. 15Sept2023

After Hurricane #Lee we have invest #97L in the Atlantic. Fairly good model agreement on heading generally in direction of Bermuda and possibly turn out to sea thereafter. This far out in time will still watch for potential changes to that. 14Sept2023

Hurricane #Lee Thursday afternoon 14Sept

Hurricane #Lee about 245miles (395km) WSW of #Bermuda (radar: http://www.weather.bm/tools/graphics.asp

(Cont)
Are forecast storm positions from NHC improving? Cone getting smaller if they are?

Yes!

That improvement rate is slowing though. Improving the science of Hurricanes will help.

7-day cone? One day! NHC is testing in house now but error at that range still too great to publish.

(Cont)
The cone size is set so that 66% of the previous 5 year errors in storm center point positions falls within that area at each forecast point.
2023 cone represents 5yr average error(in miles) of:
12hr: 30
24hr: 45
36hr: 61
48hr: 77
60hr: 93
72hr: 114
96hr: 167
120hr: 236
(Cont)

Did you know?

Hurricane #Lee & #Margot cones are same size.

How?
NHC cone size is same for every storm, resized at start of each year. Each may look different based on storm movement speed, direction and map scale. Cone maps do not convey track confidence or storm size. (Cont.)

FYI:
Your apps/sites that show Hurricane #Lee rain “radar” are not actual but simulated radar as system is outside of any land based radar range currently.

Planes will fly around Hurricanes. Inevitably there’s always one that will fly right over high enough but not recommended.

With Tropical Storm Watch for Bermuda, official Hurricane #Lee updates from US National Hurricane Center(NHC) are issued every 3 hours at 2,5,8,11a/pEDT,AST (3,6,9,12a/pADT) at https://hurricanes.gov
8pEDT 12Sep:
Winds 115mph
Moving NW 7mph
Pressure 946mb
515miles SSW of Bermuda

Tropical Storm to near Hurricane force winds may arrive into Northeast US & Eastern Canada Friday evening & into the weekend. Watch likely issued later Wednesday or Thursday(time based issued). Expect potential tree/power issues anywhere 39mph+/- & higher. Exact detail still TBD. 12Sept23 Hurricane #Lee