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

Tropical Storm / Hurricane Watch may be issued for #Bermuda this evening or sometime Tuesday for some impacts from Hurricane #Lee this week. These are time based issued (48hrs prior to TS winds start). As such NE US / Eastern Canada may have issued sometime Wednesday. 11Sept2023

Sunset over Hurricane #Lee and Hurricane #Margot in the Atlantic. 11Sept2023

Hurricane #Lee’s five day cone map history through 5pEDT/AST 10Sept2023

Hurricane #Lee intensifying once more. Expected to slow to a crawl moving generally WNW before its turn North later in the week. Center 375miles Northeast of Puerto Rico. Hurricane force winds extend about 40miles(65km) from center, Tropical Storm winds 160miles(260km). 10Sep2023

Hurricane #Lee still fighting wind shear as continues it's slow but steady march to the West-Northwest Saturday morning. 9Sep23

Tropical Storm #Margot fighting wind shear in the Eastern Atlantic. If can make it, will find a pocket to develop in further North as heads up between Bermuda and The Azores. 9Sept23

Tropical Storm #Jova (East Pacific) steadily winding down well West of Mexico. Storms are fading as can see on infrared satellite below and will become post-tropical before too much longer. 9Sept23

Some of those altitude drops when air recon enters eye of Hurricane #Lee… roller coaster! 1015aEDT 8Sept23