Largest Tropical Cyclone

[Derek Ortt]

part of the cloud shield associated with Floyd was due to the trough, not Floyd

[MiamiensisWx]

I believe Floyd's circulation and wind field was largest when it was centered east of the Bahamas at peak intensity. Here is an excerpt from the 5:00 a.m. AST advisory on September 14, 1999. At the time, Floyd was reaching its maximum intensity with 135 kt winds and a measured central pressure of 922 mb. Later, the pressure dropped to 921 mb. The overall size of the wind radii lead to fears of the potential damage from a much larger Andrew version striking Florida. Various articles in the Palm Beach Post have compared the 1926 and 1928 SE FL hurricanes to Floyd.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 105 MILES...165 KM...
FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP
TO 290 MILES...465 KM.

http://www.nhc.noaa.gov/archive/1999/pub/PAL0899.023.html

The outer SLP pressure isobar expanded greatly when the hurricane passed over the Bahamas and remained east of Florida, interacting with that shortwave trough and turning north toward the Carolinas.

[mrbagyo]

JMA listed Typhoon Winnie's diameter of Gale force wind at 2,400 kms - that's larger than Tip.

Typhoon Winnie is the typhoon from the 1997 El Nino with gargantuan eye (you could fit the whole Taiwan on it)

[GSBHurricane]

Meanwhile, in the Atlantic, Olga 2001 checks in at 1,600 km, ousting the previous record holder (Sandy 2012 which was 1,360 km)

[Nuno]

I believe Floyd's circulation and wind field was largest when it was centered east of the Bahamas at peak intensity. Here is an excerpt from the 5:00 a.m. AST advisory on September 14, 1999. At the time, Floyd was reaching its maximum intensity with 135 kt winds and a measured central pressure of 922 mb. Later, the pressure dropped to 921 mb. The overall size of the wind radii lead to fears of the potential damage from a much larger Andrew version striking Florida. Various articles in the Palm Beach Post have compared the 1926 and 1928 SE FL hurricanes to Floyd.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 105 MILES...165 KM...
FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP
TO 290 MILES...465 KM.

http://www.nhc.noaa.gov/archive/1999/pub/PAL0899.023.html

The outer SLP pressure isobar expanded greatly when the hurricane passed over the Bahamas and remained east of Florida, interacting with that shortwave trough and turning north toward the Carolinas.

Andrew was still fresh on everyone's mind. We were getting ready to ride out Floyd in a building that had survived Andrew in Cutler Ridge had it actually struck Florida.

What is the largest Atlantic tropical cyclone that wasn't undergoing an extratropical transition or sub-tropical?

[CrazyC83]

I believe Floyd's circulation and wind field was largest when it was centered east of the Bahamas at peak intensity. Here is an excerpt from the 5:00 a.m. AST advisory on September 14, 1999. At the time, Floyd was reaching its maximum intensity with 135 kt winds and a measured central pressure of 922 mb. Later, the pressure dropped to 921 mb. The overall size of the wind radii lead to fears of the potential damage from a much larger Andrew version striking Florida. Various articles in the Palm Beach Post have compared the 1926 and 1928 SE FL hurricanes to Floyd.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 105 MILES...165 KM...
FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP
TO 290 MILES...465 KM.

http://www.nhc.noaa.gov/archive/1999/pub/PAL0899.023.html

The outer SLP pressure isobar expanded greatly when the hurricane passed over the Bahamas and remained east of Florida, interacting with that shortwave trough and turning north toward the Carolinas.

Andrew was still fresh on everyone's mind. We were getting ready to ride out Floyd in a building that had survived Andrew in Cutler Ridge had it actually struck Florida.

What is the largest Atlantic tropical cyclone that wasn't undergoing an extratropical transition or sub-tropical?

Some that I can think of that were quite large at relatively low latitudes (i.e. south of 30N and fully tropical) include Frances, Mitch, Opal, Gilbert, Hugo, Ike and Katrina. As far as the deeper tropics (i.e. south of the latitude of the Greater Antilles), Mitch perhaps? Although those would be more likely the monsoonal gyre storms.