ATL: TROPICAL DEPRESSION CLAUDETTE (04L)

[JonathanBelles]

Why was Claudette kept at 50mph. NHC notes a 45mph gust where it made landfall, but a 45mph gust doesnt support 50mph sustained winds. I would have brought it down to 45mph at landfall. I havent heard a 50mph ob in hours.

[psyclone]

it seems as if the max sustained winds are always overestimated. that said you would think some of the highest winds would be with that intense convective band still offshore. for whatever reason the echos weaken as they approach the coast.

[somethingfunny]

Well that was fun and exciting. Who's ready for Danny?

[HouTXmetro]

Claudette could be dress rehearsal for Ana if she gets her act together.

[The Eye Wall]

Why was Claudette kept at 50mph. NHC notes a 45mph gust where it made landfall, but a 45mph gust doesnt support 50mph sustained winds. I would have brought it down to 45mph at landfall. I havent heard a 50mph ob in hours.

It seems to be that way with most systems. Most of the time, that I've observed, the estimated maximum sustained wind is rarely observed. During Hurricane Ike, the highest sustained wind recorded was at Hobby Airport I think of 75 mph. In fact, that was the only observed sustained wind of hurricane force. It should be noted though, that observations are a simple point and doesn't illustrate what is happening elsewhere. Many gauges in Ike became inoperable. It should also be noted, as it was pointed out to me by wxman57 a while ago, that the maximum sustained winds are for the open waters only--up to the beach. The NHC, from the way I understand it, is not "concerned" about winds 50 miles inland or 5 miles inland for that matter. They do not consider it a "bust" if observations at inland locations are not matched or exceeded.

One of the only hurricanes that comes to mind at this hour that exceeded the maximum sustained winds as given by the NHC, was Hurricane Andrew. When it made landfall on the 24th, the advisory read "145 mph winds and a central pressure of 922 mb." As we know, winds were howling at 165 mph when the gauge broke at the NHC. Other measurments by residents in the area were as high as 173 mph.

[wxman57]

it seems as if the max sustained winds are always overestimated. that said you would think some of the highest winds would be with that intense convective band still offshore. for whatever reason the echos weaken as they approach the coast.

Max sustained winds are just that - max. They're not average sustained winds, and they're not necessarily near the center of the storm. The max sustained wind can be in a single area of squalls 50-100 miles southeast of the center out over the Gulf, with average winds of 30-40 mph around and near the center. Typically, interaction with land reduces a hurricane's max sustained winds by about 20%, so a 100 mph sustained wind becomes 80, a 50 mph wind 40 (except for possibly right on the beach).

[cycloneye]

Last Advisory

000
WTNT34 KNHC 171133
TCPAT4
BULLETIN
TROPICAL DEPRESSION CLAUDETTE INTERMEDIATE ADVISORY NUMBER 6A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042009
700 AM CDT MON AUG 17 2009

...CLAUDETTE WEAKENS TO A TROPICAL DEPRESSION...MOVING OVER SOUTHERN
ALABAMA...

AT 700 AM CDT...1200 UTC...ALL TROPICAL STORM WARNINGS HAVE BEEN
DISCONTINUED.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE.

AT 700 AM CDT...1200 UTC...THE CENTER OF TROPICAL DEPRESSION
CLAUDETTE WAS LOCATED NEAR LATITUDE 31.3 NORTH...LONGITUDE 87.2
WEST OR ABOUT 15 MILES...25 KM...NORTH-NORTHWEST OF BREWTON ALABAMA
AND ABOUT 85 MILES...135 KM...SOUTHWEST OF MONTGOMERY ALABAMA.

CLAUDETTE IS MOVING TOWARD THE NORTHWEST NEAR 12 MPH...19 KM/HR. A
TURN TOWARD THE NORTH-NORTHWEST IS EXPECTED LATER TODAY. ON THIS
TRACK...THE CENTER OF CLAUDETTE WILL MOVE ACROSS SOUTHWESTERN
ALABAMA TODAY AND INTO NORTHEASTERN MISSISSIPPI TONIGHT.

SURFACE OBSERVATIONS AND DOPPLER RADAR DATA INDICATE THAT MAXIMUM
SUSTAINED WINDS HAVE DECREASED TO NEAR 35 MPH...55 KM/HR...WITH
HIGHER GUSTS. ADDITIONAL WEAKENING IS EXPECTED TODAY AS THE SYSTEM
MOVES FARTHER INLAND.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1011 MB...29.85 INCHES.

RAINFALL ACCUMULATIONS OF 3 TO 6 INCHES...WITH ISOLATED MAXIMUM
AMOUNTS OF 10 INCHES ARE EXPECTED ACROSS THE FLORIDA PANHANDLE...
THE BIG BEND REGION OF FLORIDA...AND SOUTHERN TO CENTRAL ALABAMA.

HIGHER THAN NORMAL TIDES IN AREAS OF ONSHORE WINDS ALONG THE COAST
OF THE FLORIDA PANHANDLE SHOULD SUBSIDE TODAY.

...SUMMARY OF 700 AM CDT INFORMATION...
LOCATION...31.3N 87.2W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTHWEST OR 320 DEGREES AT 12 MPH
MINIMUM CENTRAL PRESSURE...1011 MB

THIS IS THE LAST ADVISORY ISSUED ON CLAUDETTE BY THE NATIONAL
HURRICANE CENTER. FUTURE INFORMATION ON CLAUDETTE CAN BE FOUND IN
PUBLIC ADVISORIES ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION
CENTER...UNDER AWIPS HEADER TCPAT4 AND WMO HEADER WTNT34 KWNH...
BEGINNING AT 1000 AM CDT.

$$
FORECASTER BRENNAN/ROBERTS

[KWT]

Convection blowing up off the coast again....

http://www.ssd.noaa.gov/goes/flt/t3/avn-l.jpg

So more rain to come once the front moves out of the way possibly...

[micktooth]

Convection blowing up off the coast again....

http://www.ssd.noaa.gov/goes/flt/t3/avn-l.jpg

So more rain to come once the front moves out of the way possibly...

What is it with all of the convection left in the Gulf? Isn't it unusual to see this much convection not associated with banding etc. left over once a tropical system has made landfall?

[KWT]

I'm not really sure, but may need watching just in case it decides to start spinning, I'd guess it would be a new system if anything did happen.

[Stormcenter]

Hmmmmm the area in the GOM (remains of Claudette?)
keeps on expanding. Any comments?

http://www.rap.ucar.edu/weather/satelli ... uration=12

[Brent]

That sure is a lot of convection over very warm water. Quite intrigued.

[bayoubebe]

Looks like we could get a good bit of rain out of this.

[bohaiboy]

It doesn't seem to be moving either like the rain bands normally would. Who knows, it may pull up squatters rights and reform.

[fwbbreeze]

Due south of Mobile Bay/Pensacola it almost appears that there is a slight rotation. Looking at visible satellite shots the low level clouds south of AL/MS are heading SW.

[artist]

Due south of Mobile Bay/Pensacola it almost appears that there is a slight rotation. Looking at visible satellite shots the low level clouds south of AL/MS are heading SW.

fwwbreeze, very interesting obs there. It is very plain to see, isn't it? Wonder what is going on?

[Jag95]

I just saw that too Breeze. I was checking the radar as a T/S rolled through and noticed a rotation south of the FL/AL line and was wondering whether that LLC had slipped back off the coast. I had quit watching Claudette thinking she was gone.

[ROCK]

looks like something in the mid levels per vis....Claudette laid an egg before she left??

I have never seen anything like it...

[The Eye Wall]

looks like something in the mid levels per vis....Claudette laid an egg before she left??

I have never seen anything like it...

Paul...Laid an egg? LOL!

[tolakram]

Saved this loop and then uploaded it to imageshack so everyone can see all 40 frames.

I don't see any motion, but it sure does look odd.