Hurricane Franklin

[Clancy]

 

[Clancy]

Franklin's forecast now out. Looks to stay away from CONUS but could impact Hispaniola, which is highly vulnerable to tropical cyclone impacts.

 

[JayF]

All Make sure all of the discussion regarding Franklin is here for historical purposes.

 

[Casuarina Head]

Franklin has just been upgraded to a 65-knot hurricane, and to be honest I am somewhat surprised. Convection has been pulsating rather than persisting, a well-defined eye has been lacking, the low- and mid-level centres have remained unaligned, and only SFMR has supported hurricane-force winds. After all, a lower factor, if I recall correctly, is or should be used to reduce flight-level to 10-m winds in the subtropics than in the tropics, so FL winds have arguably only supported ~55 knots at the surface. In the past the specialists at the Hurricane Centre would await further organisation prior to upgrading a system to hurricane-status. Personally, I still think that Franklin is a moderate to strong tropical storm, though it will likely become a hurricane within the next few days.

 

[Taylor Campbell]

Franklin has just been upgraded to a 65-knot hurricane, and to be honest I am somewhat surprised. Convection has been pulsating rather than persisting, a well-defined eye has been lacking, the low- and mid-level centres have remained unaligned, and only SFMR has supported hurricane-force winds. After all, a lower factor, if I recall correctly, is or should be used to reduce flight-level to 10-m winds in the subtropics than in the tropics, so FL winds have arguably only supported ~55 knots at the surface. In the past the specialists at the Hurricane Centre would await further organisation prior to upgrading a system to hurricane-status. Personally, I still think that Franklin is a moderate to strong tropical storm, though it will likely become a hurricane within the next few days.

Yeah, most likely to be our first major of the season.

 

[OHWX97]

I know Idalia's hogging all the attention for obvious reasons, but Franklin managed to rapidly intensify into a powerful category 4 hurricane this morning. Current maximum sustained winds are estimated at 145mph, minimum pressure at 937mb. Residents of Bermuda should pay very close attention as it may pass uncomfortably close to the island on Wednesday.

 

[JayF]

in 2009 Hurricane Bill went on to hit the UK as a Post Tropical Storm. With Franklin becoming a 4, I am worried that this will do the same. Don't sit on it as a going out to sea to fizzle just yet.

 

[Casuarina Head]

I don’t think that this is really 125 knots. The cloud-tops are too warm for so strong a system outside the deep tropics. Moreover, the peak flight-level winds were only 131 knots, and if I recall correctly the conversion-factor is lower north of 25°N. So the actual winds would be considerably < 120 knots. I am suspicious of situations in which the SFMR is consistently higher than the FL winds. Also, satellite indicates a lot of dry air nearby, which might prevent winds from mixing effectively. I think that the current MSW are more likely on the order of 110–115 knots than 125 knots.

 

[warneagle]

I know Idalia's hogging all the attention for obvious reasons, but Franklin managed to rapidly intensify into a powerful category 4 hurricane this morning. Current maximum sustained winds are estimated at 145mph, minimum pressure at 937mb. Residents of Bermuda should pay very close attention as it may pass uncomfortably close to the island on Wednesday.
View attachment 21524

Strongest August hurricane outside the Gulf since Dorian.

 

[OHWX97]

Strongest August hurricane outside the Gulf since Dorian.

And it could get even stronger, likely nowhere near Dorian at its peak, but the NHC does forecast Franklin nearing category 5 intensity in 12 hours.

FORECAST POSITIONS AND MAX WINDS

INIT 28/1500Z 27.8N 71.0W 125 KT 145 MPH
12H 29/0000Z 29.0N 71.2W 135 KT 155 MPH
24H 29/1200Z 30.7N 70.8W 130 KT 150 MPH
36H 30/0000Z 32.5N 69.6W 120 KT 140 MPH
48H 30/1200Z 34.5N 67.4W 110 KT 125 MPH
60H 31/0000Z 36.3N 64.1W 100 KT 115 MPH
72H 31/1200Z 38.7N 59.9W 90 KT 105 MPH
96H 01/1200Z 44.5N 49.7W 75 KT 85 MPH
120H 02/1200Z 51.8N 39.8W 65 KT 75 MPH...POST-TROP/EXTRATROP

 

[Taylor Campbell]

A beauty, and another classic example of under forecast intensity guidance.

 

[Casuarina Head]

^ Now at least there can be no doubt that this is a high-end Category-4, with its Dorian-like presentation. Aircraft indicate an intensity of ~130 knots/926 mb.

 

[JBishopwx]

 

[bjdeming]

This could go in either thread, but Franklin's seems more appropriate just now (less distracting from emergencies):

 

[bjdeming]

"My pal Idalia will be dropping in, too, maybe." -- Franklin