ATL: MARIA - Post-Tropical - Discussion

[Blown Away]

Not gonna say it will happen, but many examples of systems that were at very low latitudes then near the islands got pulled NW and got stuck under a building ridge because the length of time needed to climb from the low latitude. Again, 15N/50W is a mark, if a system rides below that there is a very good chance of impact on the islands and getting caught under a building ridge. JMHO

[Aric Dunn]

Aric,there you go!!

90%

SATELLITE IMAGES INDICATE THAT A TROPICAL DEPRESSION COULD BE
FORMING ABOUT 725 MILES WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS...
AND IF THIS TREND CONTINUES...ADVISORIES WILL BE INITIATED LATER
TODAY. THIS SYSTEM IS EXPECTED TO MOVE TOWARD THE WEST OR
WEST-NORTHWEST AT ABOUT 15 MPH AND HAS A HIGH CHANCE...90
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

yeah it was quite clear this morning. look for that re-number

[clfenwi]

And of course, when the HWRF and GFDL do this, it's time for advisories to start

[cycloneye]

And of course, when the HWRF and GFDL do this, it's time for advisories to start

Wow,that is incredible.

[LarryWx]

95L on the hour six 12Z 9/6 Euro is near 10N, 36W, which is about 3.5 degrees E and 1 degree S of the 12Z 9/6 GFS's ~11N, 39.5W or ~275 miles ESE of the 12Z 9/6 GFS at hour six. The 12Z Euro's initial position looks to be more accurate imo. It is also ~50 miles west of the comparable 18 hour 0Z Euro position. Let's see how this plays out.

[Aric Dunn]

The models thus far are not terribly reliable. once advisories start and they can all initialize in the same spot with same strength and speed then the models will have at least a better handle on on the next 3 days which are important since its now when latitude is important. most of the models have this moving 285 to 295 for initial motion that is not its current motion and thus the models bring it to far north to soon where it can feel the weakness left from katia to soon. its also moving slower than katia and that also needs to be addressed. the present ridging to the north and west of the system quite strong in all levels and if we see any northerly component after the initial formative wobbles should be small.

[gatorcane]

90% is no surprised, I knew from looking at it last night it was on its way and that NHC would have to bump up the percentage....

Question now is where does it go?

12Z ECMWF running....

[ROCK]

48hr EURO nothing to spectacular...it is a closed low however...

http://raleighwx.americanwx.com/models/ ... SLP048.gif

[gatorcane]

48hr EURO nothing to spectacular...it is a closed low however...

http://raleighwx.americanwx.com/models/ ... SLP048.gif

Looks like about a 285 heading in those 48 hours....so gaining a little lattitude

[fox13weather]

The models thus far are not terribly reliable. once advisories start and they can all initialize in the same spot with same strength and speed then the models will have at least a better handle on on the next 3 days which are important since its now when latitude is important. most of the models have this moving 285 to 295 for initial motion that is not its current motion and thus the models bring it to far north to soon where it can feel the weakness left from katia to soon. its also moving slower than katia and that also needs to be addressed. the present ridging to the north and west of the system quite strong in all levels and if we see any northerly component after the initial formative wobbles should be small.

There is going to be a strong east coast trough in place ...in all likelihood this system will be doing a curve east of the CONUS. Why is it people here are always trying to find a way for a storm to head towards the United States despite sound science that says the chances are very small?? I am not jumping on this poster, but over and over and over people wishcast these storms towards land.

[Gustywind]

000
AXNT20 KNHC 061804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE SEP 05 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...SPECIAL FEATURES...


AN ATLANTIC OCEAN 1009 MB LOW PRESSURE CENTER IS NEAR 11N34W.
NUMEROUS STRONG CONVECTIVE PRECIPITATION IS FROM 11N TO 14N
BETWEEN 34W AND 37W. IT IS POSSIBLE THAT A TROPICAL DEPRESSION
MAY BE FORMING. ADVISORIES WILL HAVE TO BE INITIATED LATER TODAY
IF THIS TREND CONTINUES. THE PRECIPITATION PATTERN GRADUALLY IS
BECOMING BETTER ORGANIZED. THIS SYSTEM IS FORECAST TO MOVE WEST
OR WEST-NORTHWEST 15 MPH. ISOLATED MODERATE CONVECTIVE
PRECIPITATION COVERS THE REST OF THE ATLANTIC OCEAN FROM 3N
TO 16N BETWEEN 30W AND 50W. IT IS POSSIBLE THAT NOT ALL THE
CONVECTIVE PRECIPITATION THAT SURROUNDS THE 1009 MB LOW CENTER
MAY BE DIRECTLY RELATED TO THE LOW CENTER.

[Aric Dunn]

for instance the Euro is the only that seems to have a handle on the present strength of ridging that extends quite far to the west ... the first 2 images sow very strong ridging to its northwest that only strengthens in 24 hours and extends farther south. this present ridging can be seen in the current cimss analysis and the trend leading to this point. as katia lifts out the riding wedges in between katia and the disturbance approaching the lesser antilies and even keeps that system south heading into the eastern carrib..

and notice how close that disturbance is to katia and its not gaining latitude right now.
http://www.ssd.noaa.gov/goes/east/tatl/loop-rgb.html


http://raleighwx.americanwx.com/models/ ... _loop.html

[ROCK]

48hr EURO nothing to spectacular...it is a closed low however...

http://raleighwx.americanwx.com/models/ ... SLP048.gif

Looks like about a 285 heading in those 48 hours....so gaining a little lattitude

little north of the OZ run at 48hrs...but i am talking a smidge...

[bobbisboy]

The models thus far are not terribly reliable. once advisories start and they can all initialize in the same spot with same strength and speed then the models will have at least a better handle on on the next 3 days which are important since its now when latitude is important. most of the models have this moving 285 to 295 for initial motion that is not its current motion and thus the models bring it to far north to soon where it can feel the weakness left from katia to soon. its also moving slower than katia and that also needs to be addressed. the present ridging to the north and west of the system quite strong in all levels and if we see any northerly component after the initial formative wobbles should be small.

There is going to be a strong east coast trough in place ...in all likelihood this system will be doing a curve east of the CONUS. Why is it people here are always trying to find a way for a storm to head towards the United States despite sound science that says the chances are very small?? I am not jumping on this poster, but over and over and over people wishcast these storms towards land.

Not for anything but there were some who predicted IRENE would miss the east coast and recurve. I just got my power back 2 days ago.
Patterns do change.

[ROCK]

The models thus far are not terribly reliable. once advisories start and they can all initialize in the same spot with same strength and speed then the models will have at least a better handle on on the next 3 days which are important since its now when latitude is important. most of the models have this moving 285 to 295 for initial motion that is not its current motion and thus the models bring it to far north to soon where it can feel the weakness left from katia to soon. its also moving slower than katia and that also needs to be addressed. the present ridging to the north and west of the system quite strong in all levels and if we see any northerly component after the initial formative wobbles should be small.

There is going to be a strong east coast trough in place ...in all likelihood this system will be doing a curve east of the CONUS. Why is it people here are always trying to find a way for a storm to head towards the United States despite sound science that says the chances are very small?? I am not jumping on this poster, but over and over and over people wishcast these storms towards land.

with all due respect...I dont think anyone is -removed- anything here....just exploring the possibilities...

[ROCK]

next set out in 3 minutes...I have been timing these EURO updates from Allens site....

[ROCK]

http://raleighwx.americanwx.com/models/ ... SLP072.gif


72hr....in.....smidge north again from the 0z..

[Aric Dunn]

again this run the ridging fills in behind katia and 95l/ TD racing westward about to cross through central antilies. heading appears ( but difficult to tell for sure ) to be about 275 to 285

http://raleighwx.americanwx.com/models/ ... _loop.html

[clfenwi]

12z UKMET 144h position is east of the Turks and Caicos islands.

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 12 HOURS

FORECAST POSITION AT T+ 12 : 11.2N 37.4W



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

00UTC 07.09.2011 11.2N 37.4W MODERATE
12UTC 07.09.2011 11.6N 40.6W MODERATE LITTLE CHANGE
00UTC 08.09.2011 12.2N 44.2W MODERATE WEAKENING SLIGHTLY
12UTC 08.09.2011 12.5N 47.6W MODERATE LITTLE CHANGE
00UTC 09.09.2011 13.2N 51.1W MODERATE LITTLE CHANGE
12UTC 09.09.2011 14.0N 54.4W MODERATE INTENSIFYING SLIGHTLY
00UTC 10.09.2011 14.6N 57.4W STRONG INTENSIFYING SLIGHTLY
12UTC 10.09.2011 15.6N 60.6W STRONG INTENSIFYING SLIGHTLY
00UTC 11.09.2011 17.0N 63.1W INTENSE INTENSIFYING SLIGHTLY
12UTC 11.09.2011 18.7N 65.5W INTENSE INTENSIFYING SLIGHTLY
00UTC 12.09.2011 20.2N 67.6W INTENSE LITTLE CHANGE
12UTC 12.09.2011 22.1N 69.4W INTENSE LITTLE CHANGE

[gatorcane]

again this run the ridging fills in behind katia and 95l/ TD racing westward about to cross through central antilies. heading appears ( but difficult to tell for sure ) to be about 275 to 285

http://raleighwx.americanwx.com/models/ ... _loop.html

Yeah looks like it is racing westward and staying generally weak again, so may stay west or west-northwest for a while...I am guessing the Euro is picking up on the shear out ahead of the system that it will encounter in the next 48-72 hours? If that is the case we have a new ball-game here.

I have to go with the Euro right now considering how good of job it has done with these Cape Verde systems this season.

The UKMET is also very far west it looks like.