Fiona | 130 mph and 932 mb peak | Extremely powerful Bomb Cyclone

[Iceresistance]

Spoiler

...TROPICAL DEPRESSION FORMS OVER THE TROPICAL ATLANTIC... ...INTERESTS IN THE LEEWARD ISLANDS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM...

11:00 AM AST Wed Sep 14
Location: 16.6°N 49.6°W
Moving: W at 14 mph
Min pressure: 1009 mb
Max sustained: 35 mph

Yep! It wasn't even on the AOI just 2 days ago!

 

Spoiler

Visible satellite imagery shows that the circulation associated with the area of low pressure in the tropical Atlantic has become better defined. The associated convection has persisted overnight and this morning, and although it is confined to the eastern portion of the circulation it has enough organization to classify the system as a tropical depression. The initial intensity is set at 30 kt, which is a little above the latest TAFB Dvorak classification of T1.5, but in line with overnight scatterometer data. Moderate westerly shear and a dry mid-level atmosphere are expected to prevent significant intensification, but some modest strengthening is possible over the next day or two, and the NHC forecast calls for the depression to become a tropical storm tonight or Thursday.

After the system moves into the eastern Caribbean, the westerly shear is forecast to increase somewhat and the global models suggest that the system could struggle to maintain its closed circulation after that time. The NHC intensity forecast is a little above the IVCN intensity forecast, and maintains the system as a tropical cyclone through the forecast period. Weakening is indicated by day 5 when the system is forecast to interact with Hispaniola. The depression is moving westward or 280/12 kt. The cyclone is forecast to move slightly north of due westward along the south side of a low to mid-level ridge that is anchored over the central and western Atlantic.

Although the track guidance is tightly clustered, there are some differences in forward speed with the ECMWF much faster than the GFS. The NHC forecast lies near the middle of the guidance envelope and is near the TVCA and GFEX consensus aids to account for the differences in the forward speed.

Key Messages:
1. The system is expected to move through the Leeward Islands on Friday or Friday night, bringing heavy rainfall and possible wind impacts. Interests in the Leeward Islands should monitor the progress of the depression as tropical storm watches could be required for some islands later today.
2. The system could move near or over portions of the Virgin Islands, Puerto Rico, and Hispaniola this weekend and early next week, potentially bringing heavy rainfall and some wind impacts to these areas, and interests there should monitor the progress of the depression.

FORECAST POSITIONS AND MAX WINDS
INIT 14/1500Z 16.6N 49.6W 30 KT 35 MPH
12H 15/0000Z 16.7N 51.5W 35 KT 40 MPH
24H 15/1200Z 16.8N 53.9W 40 KT 45 MPH
36H 16/0000Z 16.9N 56.5W 40 KT 45 MPH
48H 16/1200Z 17.0N 59.3W 40 KT 45 MPH
60H 17/0000Z 17.1N 62.0W 40 KT 45 MPH
72H 17/1200Z 17.4N 64.6W 40 KT 45 MPH
96H 18/1200Z 18.0N 68.5W 40 KT 45 MPH
120H 19/1200Z 19.1N 71.7W 30 KT 35 MPH...INLAND

$$
Forecaster Brown

 

Edited September 14, 2022 by Iceresistance

[StretchCT]

This will grab some attention - luckily it's weakening and moving quickly. the gusts aren't too bad. Barely cat 1 as it hits LI

 

 

Edited September 14, 2022 by StretchCT

[Iceresistance]

33 minutes ago, StretchCT said:

This will grab some attention - luckily it's weakening and moving quickly. the gusts aren't too bad. Barely cat 1 as it hits LI

 

 

12z CMC has this south, way south into the GOM as a strengthening hurricane.

[clm]

5 hours ago, StretchCT said:

This will grab some attention - luckily it's weakening and moving quickly. the gusts aren't too bad. Barely cat 1 as it hits LI

 

 

 

Agree that this will grab attention.  Looks like that Low and High swooping in from Canada and midwest may push it out further than going over Long Island.  Also agree it doesn't look to be developing into anything strong.

 

[snowlover2]

We now have Fiona.

Quote

Tropical Storm Fiona Tropical Cyclone Update
NWS National Hurricane Center Miami FL       AL072022
945 PM AST Wed Sep 14 2022

...DEPRESSION STRENGTHENS TO A TROPICAL STORM...

Satellite data indicate that the depression has strengthened to a 
tropical storm with maximum winds estimated to be near 50 mph (85 
km/h).  This will be incoporated in the next advisory that will be 
released before 11 pm AST (0300 UTC).

SUMMARY OF 945 PM AST...0150 UTC...INFORMATION
----------------------------------------------
LOCATION...16.8N 52.0W
ABOUT 645 MI...1040 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES

$$
Forecaster Cangialosi

 

 

[Iceresistance]

She is really overperforming.

[StretchCT]

Visualization of the shear and dry air mentioned in the discussion

 

Edited September 15, 2022 by StretchCT

[StretchCT]

Here is the ASCAT mentioned in the disco 

[clm]

2 hours ago, Iceresistance said:

She is really overperforming.

I'll say.  She was never that good at the Copacabana as Lola's understudy.

Looks like she's fighting to hit the east coast and not having much luck.

 

[Iceresistance]

The Outflow is almost perfect! 😮

 

[so_whats_happening]

That convection is trying so desperately to get over the low and mid level circulation, but beautiful looking storm none the less.

 

Maybe Bermuda? 

That trough over/near Greenland is going to pretty strong. The 00z Euro presents and interesting chance of it getting trapped underneath a ridge and a trough swinging into the midwest (positive tilt). 06z GFS caught on to a similar idea. Either way northern Lesser Antilles and PR region need to watch this.

[StretchCT]

Center of circulation is outrunning the convection aka, the convection is being sheared off. 

Interestingly the shear forecast became favorable.

 

GFS 12z Sounding for 18z today not really loaded up on shear either. Though RH of 68% isn't terribly high.  

 

No Vort message yet but there is a 46kt sfmr wind and 52kt flight wind on an HDOB

ADT showing center relative to convection 

Doesn't think highly of it

Edited September 15, 2022 by StretchCT

[StretchCT]

Lapse of the dry air

 

[clm]

Surprised the Euro is showing this storm to stay alive after going over the islands and Florida like that.  You'd think they'd rip it apart.

GFS and Euro at different odds.

 

[MaineJay]

EPS tropical storm strike probabilities.

[Iceresistance]

Fiona is now looking really good, but now has multiple LLCs

[StretchCT]

Still early for visibles, but seems either the center is slowing or is relocating under the convection. 

Raw T# is 4 which is about a cat one. Constraint is on.  CI and Adj T are 3.5 and 3.6 which is close to 55-60kts. Land interaction will skew ADT though. http://tropic.ssec.wisc.edu/real-time/storm.php?&basin=atlantic&sname=07L&invest=NO&zoom=4&img=1&vars=11111000000000000000000&loop=0&llval=OFF

[Iceresistance]

Pressure is falling inside Fiona, but the dry air is causing issues.

[StretchCT]

Radar looks pretty organized 

[Iceresistance]

Recon has found a stronger Fiona, she's now at 65 mph and 994 MB. 

Edited September 18, 2022 by Iceresistance
Wrong Tense

[Iceresistance]

Recon has found 70 mph and 991 MB, hurricane landfall now possible in Puerto Rico.

[Iceresistance]

She's now a hurricane!

[StretchCT]

PR getting the bad side.  Another cane with a wide eye. Have to check recon for its diameter  

 

Edited September 18, 2022 by StretchCT

[StretchCT]

Last vortex with the eye being 40nm wide.

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 18th day of the month at 14:40Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5303
Storm Name: Fiona
Storm Number & Year: 07 in 2022 (flight in the North Atlantic basin)
Mission Number: 11
Observation Number: 16

A. Time of Center Fix: 18th day of the month at 14:12:00Z
B. Center Fix Coordinates: 17.30N 66.34W
B. Center Fix Location: 79 statute miles (127 km) to the SSW (193°) from San Juan, Puerto Rico (U.S.).
C. Minimum Height at Standard Level: 3,000m (9,843ft) at 700mb
D. Minimum Sea Level Pressure: 988mb (29.18 inHg) - Extrapolated
E. Dropsonde Surface Wind at Center (Undecoded): NA
F. Eye Character: Open in the west
G. Eye Shape & Diameter: Circular with a diameter of 40 nautical miles (46 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 63kts (72.5mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 26 nautical miles (30 statute miles) to the NE (36°) of center fix at 14:04:30Z
J. Maximum Flight Level Wind Inbound: From 129° at 73kts (From the SE at 84.0mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 29 nautical miles (33 statute miles) to the NE (37°) of center fix at 14:03:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 52kts (59.8mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 20 nautical miles (23 statute miles) to the SW (224°) of center fix at 14:18:00Z
N. Maximum Flight Level Wind Outbound: From 300° at 48kts (From the WNW at 55.2mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 17 nautical miles (20 statute miles) to the SW (224°) of center fix at 14:17:00Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 7°C (45°F) at a pressure alt. of 3,045m (9,990ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 16°C (61°F) at a pressure alt. of 3,054m (10,020ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 7°C (45°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Level: 700mb
T. Navigational Fix Accuracy: 0.02 nautical miles
T. Meteorological Accuracy: 1 nautical mile

Remarks Section:

Maximum Flight Level Wind: 73kts (~ 84.0mph) which was observed 29 nautical miles (33 statute miles) to the NE (37°) from the flight level center at 14:03:30Z
Sea Level Pressure Extrapolation From: 700mb

[StretchCT]

Sat with lightning.  It almost looks like it's turning in on itself, perhaps reforming the eye.  

A piece of the convection on the western wall breaks off and starts rotating north.