Atlantic Invest Thread 2008

[kold weather]

They are simply small rotations within the eyewall where wind speeds can be higher then the surrounding winds in the eyewall, usually occurs in intense and rapid strengthening hurricanes.

[Jack Wales]

Cheers KW, it looks like this one could be a prime candidate then if it develops as quickly as some models suggest.

[Iceberg]

Doppler is giving what appears to me to be a centre at roughly 66.8 17.8, Looks can be very deceptive though.

It also shows what is likely to be banding to the SE, which is what I would expect with the land interaction to the north.

She still seems to be going well though and the rain over PR must be intense.

Looking at the last dropsonde that recon put out this morning, it was in the same area.(1762N 06654W)

Edited August 15, 2008 by Iceberg

[johnholmes]

its interesting to see the experimental forecast now takes the centre much as ECMWF predicted yesterday, that is a little way off the Florida coast. ECMWF, this morning (00z), has it in much the same place at 72-96 hours and then tracks it out over Newfoundland. If this is correct then, given what the upper flow will be by then, one would expect it to recurve right somewhere near the southern tip of Greenland. Be interesting to see what our weather will then do.

anyway back to now, the centre has been drawn at 1011mb, some 2mb higher than it was drawn throughout yesterday. see this link

http://www.opc.ncep.noaa.gov/shtml/A_sfcbw.gif

The recon aircraft should be down on Bermuda by now if the signal sent at 0820z this morning is correct.

[Iceberg]

That's interest John, as Land obs take it down below that this morning.....

Hopefully recon will be fruitful.

[kold weather]

Looks like you've picked up on the MLC there Iceberg, it was good for a time but I'm starting to think thats just an eddy and the real center is now located just offshore from the PR coast about halfway across the island, if you look at the radar loop you'll see some decent, if fairly broad turning occuring up there.

Thats the center that the NHC seem to be tracking at this moment.

[Iceberg]

Isn't that where I've put it on the diagram on page 9 ?.

[kold weather]

I'd place the center just on the northern side of the island rather then southern side, thats where I can see the best turning in that the whole system is circulating around that center, of course there are also eddies and other little MLC vortexes like the one you picked up circulating around that big one....thats why its been moving SW depsite the fact that there is no synoptic reason for it to take that track.

Saying that the circulation just to the north of the PR coast isn't a center per say, just a region that right now the broad circulation seems to be roughly centered on, just where the NHC predicted as it happens.

[Iceberg]

I see what your saying KW, but that's not where they recorded the dropsonde on the last recon. This was on the south side of the island.

However it shows the confusion over where the centre actually is.

Hopefully some of the 12Z runs will give us there thoughts.

[kold weather]

Yeah last night the northern cetner was very poorly defined but I see that center tightneing up now, also should be noted that ther eis some big bursting going on only a little to the west of the center, I think given the best convergence is also on the north side I think should this is the one that will take over, could become a tropical system before it gets close to DR, recon will probably find something close to being closed off I reckon.

[Iceberg]

I've put on where the latest ships/bamm etc placed the center on the 12.00 update.

Bit like pin the tail on the donkey.

[johnholmes]

this may help today and in the future with surface observations

just click on a dot, it gives you the place name and its ICA 4 letter code then click on that and it gives, in METAR, format the weather over the past few hours.

http://weather.uwyo.edu/surface/meteogram/

still searching for the reconn etc decode, anyone know the link please?

[Iceberg]

Sorry John.

http://www.tropicalatlantic.com/home/

I was going to put it up early.

[johnholmes]

cheers Ice

so 12 is something else on the code this morning, which is what I thought.

wow

automatic

wish I had this when I used to have to convert a similar thing in the Uk, used to take up to 45 mins to translate the code.

this mornings

Product: NOAA Tropical RECCO Message (URNT11 KWBC)

Transmitted: 15th day of the month at 08:20Z

Aircraft: Lockheed WP-3D Orion (Reg. Num. N43RF)

Mission Purpose: Investigate third suspect area that is described by the identifier as a wave (in the North Atlantic basin)

Mission Number: 5

Observation Number: 17

Mandatory Data...

Observation Time: Friday, 8:20Z

Radar Capability: Yes

Aircraft Altitude: Below 10,000 meters

Coordinates: 15.6N 64.9W (View map)

Location: 209 miles (336 km) to the SSE (158°) from San Juan, Puerto Rico (USA).

Turbulence: None

Conditions Along Flight Route: In the clear

Pressure Altitude: 3,700 meters

Flight Level Wind: From 160° at 15 knots (From the SSE at ~ 17.2 mph)

- The above is a spot wind.

- Winds were obtained using doppler radar or inertial systems.

Flight Level Temperature: 6°C

Flight Level Dew Point: -2°C

Weather (within 30 nautical miles): Broken clouds (5/8 to 7/8 cloud coverage)

D-value: 20 geopotential meters

Edited August 15, 2008 by johnholmes

[Iceberg]

Just for a quick update.

GFDL again has a CAT 4 hit on the Carolina's.

[dallas]

Latest from NOAA suggests very near TS status

[johnholmes]

latest I've seen from NOAA=Last Updated: 927 AM EDT FRI AUG 15 2008

AND SERN CONUS MID LVL DETAILS THAT WILL

INFLUENCE THE TRACK OF A STRONG NRN CARIBBEAN TROPICAL WAVE WHICH

TPC OUTLOOKS INDICATE HAS A HIGH POTENTIAL FOR TROPICAL CYCLONE

FORMATION DURING THE SHORT RANGE PERIOD.

THE EARLY AND UPDATED MORNING PRELIM FCSTS MAINTAIN CONTINUITY

WITH YDAYS 16Z TPC/HPC COORDINATION REGARDING A TROPICAL SYSTEM

THAT WILL IMPACT PORTIONS OF THE SOUTHEAST NEXT WEEK...HAVE

ADJUSTED/FCST DAY 7 ON A MORE NWD TRACK AS PER TRENDS OF ECMWF/06Z

GFS/GHM/HWRF AND MOST OTHER HURCN MODELS SUGGESTING A MORE EAST

AND NORTH TRACK. DIFFICULTIES OCCUR IN INITIALIZATION DUE TO THE

SYSTEMS CURRENT PROXIMITY TO THE GREATER ANTILLES AND DAYS 6 AND 7

COULD EASILY BE WELL WEST IN THE GLFMEX ALTHO TRENDS AND MODEL

CLUSTERING SEEMS TO BE ON THE RIGHT HALF OF THE ENVELOPE SO DAY 7

IS EXTRAPOLATED FROM YTDAS CONTINUITY OF THE EASTERN SOLUTIONS.

SEE TPC DISCUSSIONS/OUTLOOKS.

and

000

WONT41 KNHC 151500

DSAAT

SPECIAL TROPICAL DISTURBANCE STATEMENT

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

11 AM EDT FRI AUG 15 2008

SATELLITE IMAGERY AND RADAR DATA FROM PUERTO RICO AND THE DOMINICAN

REPUBLIC INDICATE THAT THE LOW PRESSURE AREA CENTERED OVER THE MONA

PASSAGE IS BECOMING BETTER ORGANIZED. THE SYSTEM MAY DEVELOP INTO

A TROPICAL DEPRESSION BEFORE THE LOW MOVES WEST-NORTHWESTWARD NEAR

OR OVER THE DOMINICAN REPUBLIC THIS AFTERNOON. NOAA AND AIR FORCE

RESERVE HURRICANE HUNTER AIRCRAFT ARE SCHEDULED TO INVESTIGATE THE

SYSTEM THIS AFTERNOON.

THIS SYSTEM IS EXPECTED TO BRING LOCALLY HEAVY RAINS AND GUSTY WINDS

TO PORTIONS OF THE VIRGIN ISLANDS... PUERTO RICO...HISPANIOLA...

EASTERN CUBA...AND THE SOUTHEASTERN BAHAMAS INTERESTS IN THESE

AREAS...AS WELL AS IN THE REMAINDER OF THE BAHAMAS...THE REMAINDER

OF CUBA...AND SOUTHERN FLORIDA...SHOULD MONITOR THE PROGRESS OF

THIS SYSTEM.

$$

FORECASTER BEVEN

Edited August 15, 2008 by johnholmes

[johnholmes]

12z surface analysis shows the centre at 1010mb

[Iceberg]

Lots of 1006MB pressure reading and winds speeds inexcess of 40Kt found by Recon Dropsond has recorded Tropical storm winds as well.

172530 1905N 06812W 6706 03503 0063 +087 +085 142019 020 041 004 00

172600 1907N 06812W 6690 03522 0066 +084 +083 145013 014 041 005 00

172630 1909N 06812W 6707 03501 0065 +084 +083 149016 018 039 006 00

172700 1912N 06813W 6677 03537 0062 +082 +082 160018 020 042 009 00

172730 1914N 06813W 6690 03519 0069 +079 +079 107012 016 042 007 00

172800 1916N 06814W 6697 03512 0067 +080 +080 125016 023 040 005 00

172830 1918N 06814W 6706 03500 0068 +080 +080 128023 024 040 006 00

172900 1920N 06814W 6690 03518 0068 +080 +080 136024 031 040 004 00

172930 1923N 06814W 6696 03511 0063 +083 +082 127022 023 038 003 00

173000 1925N 06814W 6694 03514 0066 +081 +081 126021 024 039 004 00

173030 1927N 06814W 6695 03515 0066 +081 +081 114018 019 041 005 00

173100 1929N 06814W 6698 03511 0067 +080 +080 127026 030 042 009 00

173130 1932N 06814W 6709 03497 0066 +082 +082 136027 031 041 008 00

173200 1934N 06814W 6688 03525 0070 +080 +080 127024 028 040 003 00

[Iceberg]

There is a very broad low pressure centre(vast even) which is probably why the issue of the where the centre is, is such an issue. This IMO is also probably why they have failed to find the closed circulation. (Although I believe it is closed).

More wind speeds of 40+ have been recorded in almost every way possible so this is a 40Kt TS IMO

[Iceberg]

A quick update of the path, which seems to be pathologically centred on Florida.

There has been a significant shift westward in the last 6 hours.

And a visual since we've not had one for ages.

[Iceberg]

181500 1916N 06835W 6707 03500 0063 +085 +084 081011 015 046 003 00

181530 1915N 06834W 6692 03518 0067 +081 +081 097011 013 048 004 00

181600 1914N 06832W 6685 03528 0070 +079 +079 119011 012 046 006 00

181630 1912N 06830W 6696 03513 0071 +078 +078 134011 013 047 003 00

181700 1911N 06829W 6699 03510 0075 +076 +076 150015 023 047 008 00

181730 1909N 06827W 6702 03507 0067 +083 +082 143020 022 047 007 00

A few more readings showing 1006 MB and a swave of 45+Kt winds.

Also the map where they were taken which would put the centre in this area.

[Somerset Squall]

Looks even more impressive than yesterday, some good banding features, especially in the south. 92L looked a little messy this afternoon but convection has become concentrated once more to the east of Hispaniola. Surely there will be an upgrade this time? Is there any strong evidence at the moment of a closed LLC?

BTW, I think that there is going to be significant land interaction which is not good for 92L or Hispaniola. If it doesn't shift north soon it may run the entire length of the island. Anyone else think this may happen?

Edited August 15, 2008 by Somerset Squall

[Iceberg]

Nothing yet.

But the latest drop reported winds as high as 59Kt and down to 45KT or so near the surface.

[Somerset Squall]

Latest from NHC:

SURFACE OBSERVATIONS AND RADAR DATA FROM PUERTO RICO AND THE

DOMINICAN REPUBLIC SHOW THAT THE CENTER OF THE LOW PRESSURE AREA IS

MOVING INLAND OVER THE DOMINICAN REPUBLIC. THIS SYSTEM IS

GRADUALLY BECOMING BETTER ORGANIZED...AND NOAA AND AIR FORCE

RESERVE HURRICANE HUNTER AIRCRAFT ARE CURRENTLY INVESTIGATING IT.

A TROPICAL DEPRESSION COULD FORM AT ANY TIME DURING THE NEXT DAY OR

TWO...ALTHOUGH WHEN AND WHERE A DEPRESSION MIGHT FORM IS UNCERTAIN

DUE TO INTERACTIONS WITH THE LAND MASS OF HISPANIOLA. HEAVY RAINS

AND GUSTY WINDS ARE EXPECTED OVER PORTIONS OF PUERTO RICO...THE

DOMINICAN REPUBLIC...AND HAITI...AND ARE EXPECTED TO SPREAD OVER

EASTERN CUBA AND THE SOUTHEASTERN BAHAMAS DURING THE NEXT DAY OR

TWO. INTERESTS IN THESE AREAS...AS WELL AS THE REMAINDER OF

CUBA...THE REMAINDER OF THE BAHAMAS...SOUTHERN FLORIDA...AND

JAMAICA...SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.