ATL: Marco : Tropical Depression - Discussion

[Category 5]

You won't sell me on intensification, I can't even find an LLC, and it seems I'm not the only one.

[wxman57]

My guess is 60 kt for the landfall intensity based on the improved cloud deck. We'll never know for sure since that would be in one small area.

Best Track at Post Analysis will confirm or not what you say about intensity.

There's no data to confirm landfall intensity. I still cannot see an LLC, and I think it's highly doubtful that Marco still has 65 mph winds. It's clearly much less organized than yesterday afternoon. Convection is weak, outflow boundaries all around, and little or no spin evident. My estimate would be maybe 40kts/45 mph at landfall.

[HURAKAN]

I agree with wxman57, the circulation of Marco is a lot less organized than it was 24 hours ago. Yesterday a LLC was evident, which is absent today in the visible images. Like the NHC said, small systems are prone to rapid changes in organization and intensity, and Marco is one of the smallest on record. A lot of exciting studying by the NHC forecasters for the post-analysis of Marco!

[P.K.]

Down to 35kts 1005hPa in the intermediate advisory.

AT 100 PM CDT...1800Z...THE CENTER OF TROPICAL STORM MARCO WAS
LOCATED NEAR LATITUDE 19.9 NORTH...LONGITUDE 96.9 WEST. THIS
POSITION IS JUST INLAND OF THE COAST OF CENTRAL MEXICO AND ABOUT 80
MILES...130 KM...SOUTH-SOUTHEAST OF TUXPAN AND ABOUT 70 MILES...110
KM...NORTHWEST OF VERACRUZ.

[cycloneye]

554
WTNT43 KNHC 072033
TCDAT3
TROPICAL DEPRESSION MARCO DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL132008
500 PM EDT TUE OCT 07 2008

MARCO'S SATELLITE PRESENTATION HAS DEGRADED RAPIDLY SINCE THE CENTER
MOVED INLAND OVER MEXICO THIS MORNING. THE INITIAL INTENSITY
IS LOWERED TO 30 KT AND MARCO IS NOW A TROPICAL DEPRESSION.
CONTINUED WEAKENING IS EXPECTED AS THE CENTER TRACKS GENERALLY
WESTWARD OVER THE VERY HIGH TERRAIN OF CENTRAL MEXICO...AND MARCO
IS EXPECTED TO DISSIPATE TONIGHT OR EARLY WEDNESDAY. STILL...THE
REMNANTS OF MARCO ARE EXPECTED TO PRODUCE HEAVY RAINS AND THE
POTENTIAL FOR FLASH FLOODING OVER EASTERN PORTIONS OF CENTRAL
MEXICO DURING THE NEXT DAY OR TWO.

FORECAST POSITIONS AND MAX WINDS

INITIAL 07/2100Z 19.9N 97.1W 30 KT
12HR VT 08/0600Z 19.9N 97.9W 25 KT...INLAND
24HR VT 08/1800Z...DISSIPATED

$$
FORECASTER RHOME/PASCH

[HurricaneRobert]

Maybe 92E will become Odile and Marco can cross over to become Polo.

[HURAKAN]

Maybe 92E will become Odile and Marco can cross over to become Polo.

Marco's circulation is too small to survive crossing across the mountainous terrain of central Mexico.

[wxman57]

There's nothing left of Marco to go anywhere this evening. Hardly any clouds left. Bones has an announcement:

[HURAKAN]

So far this season:

12 TS, 6 H, 3 MH, and one thundershower with a vigorous circulation!!!

j/k!!!

[CrazyC83]

Nice try baby and it was nice seeing you - not!

Don't let the small window at the bottom of the slam on you Marco! See you in 2014!

[yzerfan]

He really could fit through the doggie door, couldn't he?

[bob rulz]

This makes me wonder how many tiny systems like this have existed in the past. Would this have been detected as a tropical cyclone 20 years ago? Or even 10? Sure, Tracy was in 1974, but it was extraordinarily powerful and just looked like a really miniature hurricane (because, well, it was). If you go back through historical records, a storm like this wouldn't even be given a second thought.

"We had a brief but powerful thunderstorm move through today..."

[jinftl]

A system like Marco over the open water or away from observing stations and populated areas could have slipped by without being identified....at least to some extent. Once something like this approached land, the signs of a closed circulation would have had a tough time alluding any modern weather detection devices such as recon...along with surface observations like a fall in pressure, west wind on the south side of the circulation, etc would have revealed the identity of such a system as tropical.

Interesting info from Dr. Jeff Masters:
Midget tropical cyclones are rare in the Atlantic, but are fairly common the Western Pacific, where the presence of the monsoon trough often acts to spin up tiny tropical cyclones. Although small in stature, midget tropical cyclones are capable of intensifying into powerful hurricanes capable of causing severe damage. Tropical Cyclone Tracy, which hit Darwin, Australia on Christmas Day in 1974, was a midget tropical cyclone as small as Marco, but packed Category 4 winds. The storm killed 71 people and caused over $5 billion in damage.

This makes me wonder how many tiny systems like this have existed in the past. Would this have been detected as a tropical cyclone 20 years ago? Or even 10? Sure, Tracy was in 1974, but it was extraordinarily powerful and just looked like a really miniature hurricane (because, well, it was). If you go back through historical records, a storm like this wouldn't even be given a second thought.

"We had a brief but powerful thunderstorm move through today..."

[HURAKAN]

[bob rulz]

A system like Marco over the open water or away from observing stations and populated areas could have slipped by without being identified....at least to some extent. Once something like this approached land, the signs of a closed circulation would have had a tough time alluding any modern weather detection devices such as recon...along with surface observations like a fall in pressure, west wind on the south side of the circulation, etc would have revealed the identity of such a system as tropical.

If it hit land that's probably true. But out over the open water...who knows?

I think this is one reason that the last decade has had so many more storms than usual. We're able to detect things that wouldn't have been able to be identified as tropical cyclones before.

[jinftl]

From Dr. Jeff Masters:

Midget Marco sets a new record for the Atlantic

The hurricane season of 2008 has a new record--the kind of record we don't mind seeing! Tropical Storm Marco was the smallest tropical storm on record in the Atlantic. Records of tropical storm size only go back to 1988, so it is likely there have been other tropical storms as small as Marco in the past, though. If one looks at the maximum area covered by tropical storm force winds (in nautical miles squared, nm^2), given the radius of these winds for all four quadrants of each storm, the winners of the meekest of the meek award in the Atlantic are:

1) Marco, 2008, 1158 nm^2
2) Henri, 2001, 2238 nm^2
3) Bertha, 2002, 2827 nm^2
3) Bret, 2005, 2827 nm^2
3) Unnamed, 2006, 2827 nm^2

At Marco's peak size, tropical storm-force winds extended out 25, 15, 0, and 25 nm in its four quadrants. This means Marco covered an area of about 1,158 square nautical miles, which is slightly smaller than Rhode Island's area of 1,162 nm^2. Marco was about 1/75 as large as Ike at its peak, and 1/500 as big as the record holder, Tropical Storm Olga of 2001 (591000 nm^2, three times the size of Texas).


http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1117&tstamp=200810

[HURAKAN]

Rhode Island

[catastrophic]

is that the remnants of marco back over the western gom

[CrazyC83]

is that the remnants of marco back over the western gom

Sort of. I think it was absorbed by the front to the northeast.

[Ptarmigan]

From Jeff Master's blog

Midget Marco sets a new record for the Atlantic
The hurricane season of 2008 has a new record--the kind of record we don't mind seeing! Tropical Storm Marco was the smallest tropical storm on record in the Atlantic. Records of tropical storm size only go back to 1988, so it is likely there have been other tropical storms as small as Marco in the past, though. If one looks at the maximum area covered by tropical storm force winds (in nautical miles squared, nm^2), given the radius of these winds for all four quadrants of each storm, the winners of the meekest of the meek award in the Atlantic are:

1) Marco, 2008, 1158 nm^2
2) Henri, 2001, 2238 nm^2
3) Bertha, 2002, 2827 nm^2
3) Bret, 2005, 2827 nm^2
3) Unnamed, 2006, 2827 nm^2

At Marco's peak size, tropical storm-force winds extended out 25, 15, 0, and 25 nm in its four quadrants. This means Marco covered an area of about 1,158 square nautical miles, which is slightly smaller than Rhode Island's area of 1,162 nm^2. Marco was about 1/75 as large as Ike at its peak, and 1/500 as big as the record holder, Tropical Storm Olga of 2001 (591000 nm^2, three times the size of Texas).

Link

ZCZC MIATCPAT2 ALL
TTAA00 KNHC DDHHMM
BULLETIN
SUBTROPICAL STORM TWO ADVISORY NUMBER 7
NATIONAL WEATHER SERVICE MIAMI FL
5 AM AST MON NOV 26 2001

...SUBTROPICAL STORM NOW STATIONARY...

AT 5 AM AST...0900Z...THE CENTER OF SUBTROPICAL STORM TWO WAS
LOCATED NEAR LATITUDE 30.2 NORTH...LONGITUDE 55.6 WEST OR ABOUT
555 MILES...895 KM...EAST-SOUTHEAST OF BERMUDA.

THE STORM IS NEARLY STATIONARY...AND A SLOW AND ERRATIC MOTION IS
EXPECTED OVER THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/HR...WITH HIGHER
GUSTS. SOME INCREASE IN STRENGTH IS POSSIBLE AND THE SYSTEM COULD
BECOME A HURRICANE DURING THE NEXT 24 HOURS.

WINDS OF 40 MPH EXTEND OUTWARD UP TO 690 MILES...1110 KM
MAINLY TO THE NORTH OF THE CENTER. THIS IS A VERY LARGE STORM AND
SWELLS GENERATED BY IT MAY AFFECT PORTIONS OF THE EAST COAST OF
NORTH AMERICA AND THE NORTH-FACING BEACHES OF THE BAHAMAS AND
GREATER ANTILLES DURING THE NEXT FEW DAYS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 979 MB...28.91 INCHES.

REPEATING THE 5 AM AST POSITION...30.2 N... 55.6 W.
MOVEMENT...STATIONARY. MAXIMUM SUSTAINED
WINDS... 70 MPH. MINIMUM CENTRAL PRESSURE... 979 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL
HURRICANE CENTER AT 11 AM AST.

FORECASTER FRANKLIN


NNNN

Olga Advisory 7

ZCZC MIATCMAT2 ALL
TTAA00 KNHC DDHHMM
SUBTROPICAL STORM TWO FORECAST/ADVISORY NUMBER 7
NATIONAL WEATHER SERVICE MIAMI FL AL1701
0900Z MON NOV 26 2001

SUBTROPICAL STORM CENTER LOCATED NEAR 30.2N 55.6W AT 26/0900Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT STATIONARY

ESTIMATED MINIMUM CENTRAL PRESSURE 979 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT.......550NE 60SE 60SW 360NW.
34 KT.......600NE 100SE 100SW 600NW.
12 FT SEAS..650NE 300SE 450SW 650NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

Link

I know TS Olga in 2001 was a subtropical storm, but it had TS force winds extending up to 690 miles! That's almost Super Typhoon Tip size right there! Think about Hurricane Ike was that size.