ATL: FRANKLIN - Post-Tropical - Discussion

[ElectricStorm]

Up to Cat 3

08L FRANKLIN 230828 0600 26.8N 70.6W ATL 100 956

[kevin]

First MH of the Atlantic season. And it looks like Franklin is ramping up a lot now. Look at those T#. CI# up to 5.7 (107 kt) and raw T# is already at 6.1 (117 kt). Wouldn't be surprised if the next recon finds a high-end cat 3 or already a cat 4.

Current Intensity Analysis



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 28 AUG 2023 Time : 061020 UTC
Lat : 26:40:12 N Lon : 70:36:36 W


CI# /Pressure/ Vmax
5.7 / 947.7mb/107.2kt


Final T# Adj T# Raw T#
5.7 5.8 6.1

Estimated radius of max. wind based on IR :N/A km

Center Temp : +11.8C Cloud Region Temp : -65.2C

[kevin]

[REDHurricane]

[Extratropical94]

Given the current forecast, 25 ACE units are reasonable depending on the exact timing of extratropical transition

[cycloneye]

The first major cane of the 2023 season.

...FRANKLIN BECOMES THE FIRST MAJOR HURRICANE OF THE 2023
ATLANTIC HURRICANE SEASON...

[kevin]

941.0 mb extrapolated!

[kevin]

Based on 111 kt FL, 101 kt SFMR the SW quadrant together with undersampling supports 105 - 110 kt. But based on the pressure I think it's already a cat 4. Further passes will probably show this. Either way Franklin is intensifying even faster than expected.

[aspen]

941.0 mb extrapolated!

Wow this is way stronger than I expected. With the pressure so low already, perhaps we’ll see a 125-130 kt peak.

[kevin]

NE quadrant: 123 kt FL, 110 kt SFMR. A blend supports 110 kt -> at least 115 kt based on the undersampling of a single pass. This is a cat 4.

[kevin]

Dropsonde 952 mb at the surface with 99 kt winds, supports 942 mb.

[kevin]

At least 75 nautical miles of hurricane force winds in the NE quadrant (ADT currently assumes 45 nm). In general Franklin seems to be significantly stronger than expected both based on models as well as based on live imagery.

[kevin]

Near-perfect circular eye atm. I know people are now paying attention to Idalia, but Franklin is very very impressive.

[aspen]

Near-perfect circular eye atm. I know people are now paying attention to Idalia, but Franklin is very very impressive.

https://i.imgur.com/zid9CCX.jpg

The eye just needs to warm up some more. I can definitely see a ~130 kt peak after this first pass this morning. The next pass will tell us how fast this is deepening.

[kevin]

I'll continue spamming more Franklin recon data in this thread for those who are interested . Another dropsonde in the eye measured 943 mb with 9 kt -> 942 mb.

[aspen]

I'll continue spamming more Franklin recon data in this thread for those who are interested . Another dropsonde in the eye measured 943 mb with 9 kt -> 942 mb.

And I’ll do so too. A drop in the NE eyewall found 117 kt surface winds. I think it’s safe to say we have a 115 kt/942 mbar Cat 4 hurricane.

[kevin]

I'll continue spamming more Franklin recon data in this thread for those who are interested . Another dropsonde in the eye measured 943 mb with 9 kt -> 942 mb.

And I’ll do so too. A drop in the NE eyewall found 117 kt surface winds. I think it’s safe to say we have a 115 kt/942 mbar Cat 4 hurricane.

Wow and cat 5 winds (137 kt) found higher in the eyewall at 941 mb (the eyewall surface pressure of the dropsonde was 955 mb). If those winds manage to mix down we might have a real monster.

[Hypercane_Kyle]

Definitely got a little kick too it!

[Woofde]

I've been focused on Idalia because of impacts, Franklin has really turned it up. Eye is getting very symmetrical.

[kevin]

Posting another IR image because Franklin is gorgeous right now.