Ana, Bill,--and Claudette?

By: Dr. Jeff Masters , 1:52 PM GMT on August 16, 2009

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After one of the slowest starts to hurricane season in the past twenty years, the hurricane season of 2009 has exploded with activity over the past 48 hours. This morning, Tropical Depression Four joined Ana and Bill in the Atlantic, and appears poised to become Tropical Storm Claudette later today. Indeed, this may already be Claudette, as morning's QuickSCAT pass showed top winds of 45 mph. NEXRAD radar animations out of Tallahassee, FL, show a small but well-organized tropical cyclone with plenty of heavy thunderstorm activity, and improving low-level spiral banding. Satellite loops show an area of intense thunderstorms with cold cloud tops expanding near the storm's center.


Figure 1. Current long-range radar out of Tallahassee, FL.

It's pretty amazing (and a little unnerving) how quickly this storm sprang up. TD 4 developed literally overnight, and has the potential to be a strong tropical storm by the time it makes landfall tonight along the Florida Peninsula. TD 4 reminds me of 2007's Hurricane Humberto, which became a hurricane just 24 hours after first appearing as a tropical depression. I don't think TD 4 has time to reach hurricane strength, since wind shear as diagnosed by the SHIPS model was moderate, 10 - 15 knots, but it does have time to strengthen into a 50 - 60 mph tropical storm before landfall. Given that the storm is so small, storm surge flooding should not exceed 3 -5 feet, and will not be the major hazard from TD 4; inland flooding from heavy rain of 3 - 6 inches is likely to be the main threat from the storm.

Tropical Storm Ana continues to struggle
Tropical Storm Ana continues to struggle. Dry air continues to plague the storm, thanks to the large area of Saharan air the storm is embedded in. Ana's heavy thunderstorms are limited to just one small spot near the center. Wind shear appears to have lessened some, though, since yesterday. Thunderstorms were not able to form at all near the center yesterday, since strong wind shear tends to blow a storm's heavy thunderstorms to one side of the storm, exposing the low-level center to view. With heavy thunderstorms building near the center this morning, shear appears to be less of a problem for the storm. Top winds seen by this morning's QuikSCAT pass were about 35 mph. The outer rain showers from Ana should appear on radar out of Martinique today.

Shear is low (5 - 10 knots), and is forecast to remain low for the next two days. SSTs are warm, 28°C, and will warm further over the next two days. However, there is so much dry air around Ana that significant strengthening appears unlikely. Nearly all of the models predict Ana will dissipate sometime in the next three days, though the HWRF and GFDL predict that this will happen because Ana will move over the rugged terrain of Hispaniola. Ana is likely not strong enough to survive an encounter with the big island that the Dominican Republic and Haiti share. At this time, it does not appear that Ana will be moist enough to cause a major flooding disaster on Hispaniola.


Figure 2. Water vapor image from this morning showing the large area of dry, Saharan air surrounding Ana, and lying to the northwest of Tropical Storm Bill. Image credit: NOAA/SSD

Tropical Storm Bill gathers strength
Tropical Storm Bill is gathering strength in the middle Atlantic Ocean, and appears poised to become a powerful Cape Verdes-type hurricane later this week. QuikSCAT data from this morning shows a large circulation with top winds of 35 - 40 mph. Water vapor imagery (Figure 2) shows that there is some dry air to the northwest of Bill, and this dry air is being drawn into Bill's center, slowing intensification. It will likely take another day before Bill can moisten the atmosphere enough to ward off the dry air, and allow more significant intensification.

Wind shear is low, 5 - 10 knots, and is forecast to be in the low to moderate range, 5 - 15 knots, for the next five days. Sea Surface Temperatures are about 27.5°C, and will remain in the 27.5 - 28°C range the next four days, then warm substantially as the storm nears the Lesser Antilles Islands. The combination of low wind shear and sufficiently warm SSTs should allow Bill to intensify steadily to hurricane strength by Wednesday.

The big news is that our most reliable computer model from last year--the ECMWF model--appears to have made the right call yesterday, forecasting that a major trough of low pressure would develop along the U.S. East Coast, turning Bill more to the north. All of the other models--with the notable exception of the UKMET model--have now jumped on the ECMWF bandwagon, forecasting that Bill will pass well north of the Lesser Antilles Islands. The UKMET has Bill hitting the islands, but is being discounted since it is an outlier. It currently appears that the trough approaching the U.S. East Coast will be strong enough to recurve Bill before it reaches the U.S., though it is too early to be confident of this. Several of the longer range models show Bill passing near Bermuda or Nova Scotia, Canada.

I'll have an update later today.

Jeff Masters

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Quoting TideWaterWeather:


54 is flight level


I know. But if you reduce those down its at least around 45 knots.
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Max flight level winds on Ana so far is 37knot and 27 knot surface winds with SFMR
Member Since: October 28, 2006 Posts: 57 Comments: 30678
Quoting canesrule1:
how do u take an image of it?



the key called PRTSC (Print Screen) then paste it into an image editing software.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Claudette is showing us all just how dangerous the GoM is right now in regards to TC development.

Ana is supposed to be in the GoM come Tuesday as a depression?

That won't last for long. She could blow up into a monster by the time she makes landfall!!!!
Member Since: August 26, 2006 Posts: 10 Comments: 4020
.
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Quoting Drakoen:
Recon now finding 44 knot winds at the surface


So about 50 mph?
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.
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Quoting drg0dOwnCountry:

Claudette is following exactly the warmer SSTs. And those are the red spots - see the 15/08/09 map.

NOAA/AOML


Right. Temperatures are indeed high there. The map I remember seeing was a temperature anomaly map, which showed the northeast area as lower than normal.
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62 mph wind in the NE quadrant at flight level.
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Quoting TexasHurricane:


What does that say? Too small...


Time: 16:52:00Z
Coordinates: 16.6N 59.0833W
Acft. Static Air Press: 705.2 mb (~ 20.82 inHg)
Acft. Geopotential Hgt: 3,104 meters (~ 10,184 feet)
Extrap. Sfc. Press: 1013.0 mb (~ 29.91 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 117° at 25 knots (From the ESE at ~ 28.7 mph)
Air Temp: 9.3°C (~ 48.7°F)
Dew Pt: -13.9°C (~ 7.0°F)
Peak (10s) Flt. Lvl. Wind: 27 knots (~ 31.0 mph)
SFMR Peak (10s) Sfc. Wind: 22 knots* (~ 25.3 mph*)
SFMR Rain Rate: 0 mm/hr* (~ 0 in/hr*)
(*) Denotes suspect data
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting extreme236:
000
URNT12 KNHC 161655
VORTEX DATA MESSAGE AL042009
A. 16/16:43:20Z
B. 29 deg 04 min N
084 deg 56 min W
C. 925 mb 754 m
D. 35 kt
E. 285 deg 11 nm
F. 072 deg 28 kt
G. 302 deg 25 nm
H. EXTRAP 1008 mb
I. 20 C / 767 m
J. 23 C / 766 m
K. 9 C / NA
L. NA
M. NA
N. 1345 / 9
O. 0.02 / 1.5 nm
P. AF304 0104A CYCLONE OB 02
MAX FL WIND 28 KT NW QUAD 16:34:30Z
MAX OUTBOUND FL WIND 54 KT NE QUAD 16:44:40Z
SLP EXTRAP FROM 925 MB
;


54 is flight level
Member Since: Posts: Comments:
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 16th day of the month at 16:55Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Tropical Depression: Number 4 (flight originating in the North Atlantic basin)
Mission Number: 1
Observation Number: 02
A. Time of Center Fix: 16th day of the month at 16:43:20Z
B. Center Fix Coordinates: 29°04'N 84°56'W (29.0667N 84.9333W) (View map)
B. Center Fix Location: 88 miles (142 km) to the SSE (150°) from Panama City, FL, USA.
C. Minimum Height at Standard Level: 754m (2,474ft) at 925mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 35kts (~ 40.3mph)
E. Location of the Estimated Maximum Surface Wind: 11 nautical miles (13 statute miles) to the WNW (285°) of center fix
F. Maximum Flight Level Wind Inbound: From 72° at 28kts (From the ENE at ~ 32.2mph)
G. Location of Maximum Flight Level Wind Inbound: 25 nautical miles (29 statute miles) to the WNW (302°) of center fix
H. Minimum Sea Level Pressure: 1008mb (29.77 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 20°C (68°F) at a pressure alt. of 767m (2,516ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 766m (2,513ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 9°C (48°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 925mb (If this vortex is from mid 1990's or earlier 925mb might be incorrect. See note.)
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1.5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 28kts (~ 32.2mph) in the northwest quadrant at 16:34:30Z
Maximum Flight Level Wind Outbound: 54kts (~ 62.1mph) in the northeast quadrant at 16:44:40Z
Sea Level Pressure Extrapolation From: 925mb
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Recon now finding 44 knot winds at the surface
Member Since: October 28, 2006 Posts: 57 Comments: 30678
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 16th day of the month at 16:55Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Tropical Depression: Number 4 (flight originating in the North Atlantic basin)
Mission Number: 1
Observation Number: 02
A. Time of Center Fix: 16th day of the month at 16:43:20Z
B. Center Fix Coordinates: 29°04'N 84°56'W (29.0667N 84.9333W)
B. Center Fix Location: 88 miles (142 km) to the SSE (150°) from Panama City, FL, USA.
C. Minimum Height at Standard Level: 754m (2,474ft) at 925mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 35kts (~ 40.3mph)
E. Location of the Estimated Maximum Surface Wind: 11 nautical miles (13 statute miles) to the WNW (285°) of center fix
F. Maximum Flight Level Wind Inbound: From 72° at 28kts (From the ENE at ~ 32.2mph)
G. Location of Maximum Flight Level Wind Inbound: 25 nautical miles (29 statute miles) to the WNW (302°) of center fix
H. Minimum Sea Level Pressure: 1008mb (29.77 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 20°C (68°F) at a pressure alt. of 767m (2,516ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 766m (2,513ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 9°C (48°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 925mb (If this vortex is from mid 1990's or earlier 925mb might be incorrect. See note.)
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1.5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 28kts (~ 32.2mph) in the northwest quadrant at 16:34:30Z
Maximum Flight Level Wind Outbound: 54kts (~ 62.1mph) in the northeast quadrant at 16:44:40Z
Sea Level Pressure Extrapolation From: 925mb
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Quoting canesrule1:
Recon has just found 39MPH winds very close to Claudette's COC.


Nevermind, I guess there weren't any 68 mph winds... *looks around* oops.
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Quoting Weather456:
how do u take an image of it?
Quoting serialteg:
im sorry guys i dont see 50something knot winds flight level or anywhere on the google recon map program.


Its on the vortex message...
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GFS hinting at a low crossing the Yucatan in a week. Cannot tell if it is Ana's remnants or another wave (more likely at that latitude...I think).

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Peak surface winds of 45 knots

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting Weather456:


What does that say? Too small...
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Recon has just found 39MPH winds very close to Claudette's COC.
ok ok now i see. now, what does outbound mean in contrast to just maximum flight level wind.
Member Since: August 22, 2006 Posts: 2 Comments: 1988
VORTEX MESSAGE

40.3 mph SURFACE

1008 PRESSURE


Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 16th day of the month at 16:55Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Tropical Depression: Number 4 (flight originating in the North Atlantic basin)
Mission Number: 1
Observation Number: 02
A. Time of Center Fix: 16th day of the month at 16:43:20Z
B. Center Fix Coordinates: 29°04'N 84°56'W (29.0667N 84.9333W)
B. Center Fix Location: 88 miles (142 km) to the SSE (150°) from Panama City, FL, USA.
C. Minimum Height at Standard Level: 754m (2,474ft) at 925mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 35kts (~ 40.3mph)
E. Location of the Estimated Maximum Surface Wind: 11 nautical miles (13 statute miles) to the WNW (285°) of center fix
F. Maximum Flight Level Wind Inbound: From 72° at 28kts (From the ENE at ~ 32.2mph)
G. Location of Maximum Flight Level Wind Inbound: 25 nautical miles (29 statute miles) to the WNW (302°) of center fix
H. Minimum Sea Level Pressure: 1008mb (29.77 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 20°C (68°F) at a pressure alt. of 767m (2,516ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 766m (2,513ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 9°C (48°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 925mb (If this vortex is from mid 1990's or earlier 925mb might be incorrect. See note.)
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1.5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 28kts (~ 32.2mph) in the northwest quadrant at 16:34:30Z
Maximum Flight Level Wind Outbound: 54kts (~ 62.1mph) in the northeast quadrant at 16:44:40Z
Sea Level Pressure Extrapolation From: 925mb
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Quoting Skyepony:
Just wolk up...lol. Did I not call this since Hispanola? I see recon is in it now headed toward center. Yay. I know it's no major but glad this is finally being taken seriously.
Yep you did. Well done. Combine knowledge with horse sense (hehe) and you get someone who knows of what she speaks!
Member Since: August 19, 2008 Posts: 6 Comments: 2490
000
URNT12 KNHC 161655
VORTEX DATA MESSAGE AL042009
A. 16/16:43:20Z
B. 29 deg 04 min N
084 deg 56 min W
C. 925 mb 754 m
D. 35 kt
E. 285 deg 11 nm
F. 072 deg 28 kt
G. 302 deg 25 nm
H. EXTRAP 1008 mb
I. 20 C / 767 m
J. 23 C / 766 m
K. 9 C / NA
L. NA
M. NA
N. 1345 / 9
O. 0.02 / 1.5 nm
P. AF304 0104A CYCLONE OB 02
MAX FL WIND 28 KT NW QUAD 16:34:30Z
MAX OUTBOUND FL WIND 54 KT NE QUAD 16:44:40Z
SLP EXTRAP FROM 925 MB
;
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Member Since: July 24, 2005 Posts: 407 Comments: 19076
849. s1ecr
#814 - I use http://tropicalatlantic.com/recon/
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848. Relix
Quoting rmbjoe1954:


What direction?


Haven't seen them but I am certain to the north
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Quoting canesrule1:
Recon just found 37MPH winds close to Claudette's COC.


Higher than that from what I saw in the vortex message.
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The highest winds found in Claudette is 40mph so far
Member Since: October 28, 2006 Posts: 57 Comments: 30678
Quoting IKE:


That for Claudette?


If so, that almost makes it a hurricane- about 68 miles an hour. If that is the case, it wouldn't take long to become a hurricane... :(
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Member Since: July 3, 2005 Posts: 427 Comments: 129396
Quoting yonzabam:


GOM ssts are actually quite low in that area compared to the western side.

Claudette is following exactly the warmer SSTs. And those are the red spots - see the 2009/08/15 map.

NOAA/AOML
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Quoting IKE:


That for Claudette?


Yep. That's for Claudette.
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Quoting IKE:


That for Claudette?


Yup
Member Since: October 28, 2006 Posts: 57 Comments: 30678
wow, people here are such hypocrites at times... i get blocked yesterday for pointing out someones innacurate predicition and now you guys are playing this game today?? seriously guys, maybe hypocrite isnt the right word, fickle
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Looks like C might head up the coast and wind up coming on land somewhere around in the Freeport/Red Bay area. Doesn't look like much more than a typical tropical storm for us. I guess BeachFoxx, Ike, AubiesGirl et al can hold down the fort! Headed out for the work week - will be checking back later.
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I have a new tropical update made ar 9edt, tia for viewing
I am going to be in tropics chatLink
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Looks like a Panama City landfall is in order. It also looks like it could ride along the coastline a little bit before making official landfall. Looks like im going to get the NE side of this along with IKE. This is going to be a fun night.
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Quoting Hurricanman:
TD 4 is looking impressive today:
Visible - Northern Gulf


TD 4 is Now Tropical Storm Claudette
Member Since: July 3, 2005 Posts: 427 Comments: 129396
Recon just found 37MPH winds close to Claudette's COC.
Quoting hurricane23:
12z models for tiny ana have shifted some.


Did you see the BAMS track?
Member Since: October 28, 2006 Posts: 57 Comments: 30678
Quoting Hurricanman:
TD 4 is looking impressive today:
Visible - Northern Gulf


Its Claudette now btw, been on the NHC site for awhile. :)
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832. IKE
Quoting Dan187:
In addition to the 55kt flight level winds (925mb), SFMR estimated 59kt surface winds, pressure was extrap 1008


That for Claudette?
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting hurricane23:
12z models for tiny ana have shifted some.


What direction?
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First recon pass would suggest an intensity of 45-50 knots so far depending on their flight level reduction %.
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hope the character burnt is okay probally computer problems dang machines
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Quoting FLWeatherFreak91:
Can someone post the link to the Google Earth app for tracking the recon flights? Thanks


i hope youre not the same person that i quoted with the link the last time

http://tropicalatlantic.com/recon/ge/Recon_Data_for_the_Atlantic_Basin.kmz

if so you really need to improve your F5 (refresh) skills :)

Quoting Dan187:
In addition to the 55kt flight level winds (925mb), SFMR estimated 59kt surface winds, pressure was extrap 1008


again i ask where you're getting this
Member Since: August 22, 2006 Posts: 2 Comments: 1988
TD 4 is looking impressive today:
Visible - Northern Gulf
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Recon is 178 miles to the ENE of Roseau, Dominica.

Recon is also just south of Tallahassee.
825. IKE
Quoting KEEPEROFTHEGATE:
how ya doing friend got a few things for the ride i hope were are you ike are a close to Apalachcola fla thats impact zone for the c storm


I'm good to go.
Member Since: June 9, 2005 Posts: 23 Comments: 37860

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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