ATL: JOAQUIN - Post-Tropical - Discussion

[seatrump]

Here in the Turks and Caicos and the very southern edge of this we have been getting heavy showers and rain for the last several hours moving through from the north (opposite to the normal direction). Now I understand why. Where did this thing come from? I check every day or two for activity - I checked yesterday and they were only predicting a depression moving North. I sure hope this thing turns North on schedule.

[Ivanhater]

Looks obvious huge outflow boundary right after collapse of western side...still hot towers still wrapping around center and its west side will likely fill in quickly as it begins the turn

[Aric Dunn]

Looks obvious huge outflow boundary right after collapse of western side...still hot towers still wrapping around center and its west side will likely fill in quickly as it begins the turn

you can tell from the color of it that is high up. outflow running into the lighter shear..

[tatertawt24]

Looks like it'll be trying to form a bigger eye than I expected.

[Hammy]

Watching the satellite and water vapor it appears mid-level dry air was the culprit, possibly ingested due to continuing mid-level shear, but it seems to be mixing it out if the intense convection to the east and south is any indication. The west is still somewhat dry so it may hold off on intensification for about a day or so.

[Aric Dunn]

Watching the satellite and water vapor it appears mid-level dry air was the culprit, possibly ingested due to continuing mid-level shear, but it seems to be mixing it out if the intense convection to the east and south is any indication. The west is still somewhat dry so it may hold off on intensification for about a day or so.

There is no evidence of dry air. due to the continued upper level shear there is not much divergence aloft on the nw side and thus limiting convection outside the core region on the NW side. most of the models showed this and also have it not being and issue by early tomorrow. this is still fairly classic organization in a light moderate shear environment. Dew point from recon both gulfstream and airforce indicated rather high moisture content in and around the system.

[Extratropical94]

An Air Force aircraft is on its way to Joaquin for mission #03.

[Aric Dunn]

The organization continues to improve greatly.

This is actually a pretty cool image. there are three distinct hot towers that are rotating around the developing eye/eyewall. Wont be much longer before an actual eye begins to show up. Already in the image there is a slight warm spot in the middle of the hot towers.

go here run 15 images and toggle the last 3 images back and forth a look at the motion of the hot towers. good evidence this is intensifying right now. http://weather.msfc.nasa.gov/GOES/goeseastconusir.html


also you will notice that each hot tower is slightly rotating on its own axis which is typical and often seen in strong hurricanes that have clear eyes. pressure is likely falling pretty quickly now.

[Hammy]

Very ragged eye starting to take shape.

[Aric Dunn]

Very ragged eye starting to take shape.

Yep well on its way.. though both images were a few hours ago now.

[TimeZone]

Western side still looking quite meh. That is one ragged eye taking shape. It'll have to get that sorted out before it starts to take off. It's still certainly got some work to do before RI happens.

[arlwx]

TROPICAL STORM JOAQUIN FORECAST/ADVISORY NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015
0900 UTC WED SEP 30 2015

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A HURRICANE WARNING FOR
THE CENTRAL BAHAMAS...INCLUDING CAT ISLAND...THE EXUMAS...LONG
ISLAND...RUM CAY...AND SAN SALVADOR.

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A HURRICANE WATCH FOR THE
NORTHWESTERN BAHAMAS EXCLUDING ANDROS ISLAND. THIS INCLUDES THE
ABACOS...BERRY ISLANDS...BIMINI...ELEUTHERA...GRAND BAHAMA ISLAND...
AND NEW PROVIDENCE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* CENTRAL BAHAMAS

A HURRICANE WARNING IS IN EFFECT FOR...
* NORTHWESTERN BAHAMAS EXCLUDING ANDROS ISLAND

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA. A WARNING IS TYPICALLY ISSUED
36 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL STORM
FORCE WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR
DANGEROUS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE
RUSHED TO COMPLETION.

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA...IN THIS CASE WITHIN THE NEXT 36 TO 48 HOURS.

TROPICAL STORM CENTER LOCATED NEAR 25.4N 72.5W AT 30/0900Z
POSITION ACCURATE WITHIN 25 NM

PRESENT MOVEMENT TOWARD THE WEST-SOUTHWEST OR 245 DEGREES AT 5 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 988 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 40NE 50SE 0SW 0NW.
34 KT.......100NE 110SE 40SW 60NW.
12 FT SEAS..150NE 90SE 60SW 120NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 25.4N 72.5W AT 30/0900Z
AT 30/0600Z CENTER WAS LOCATED NEAR 25.6N 72.0W

FORECAST VALID 30/1800Z 25.1N 73.0W
MAX WIND 70 KT...GUSTS 85 KT.
64 KT... 20NE 20SE 0SW 0NW.
50 KT... 50NE 50SE 0SW 20NW.
34 KT...100NE 110SE 50SW 70NW.

FORECAST VALID 01/0600Z 24.7N 73.8W
MAX WIND 75 KT...GUSTS 90 KT.
64 KT... 30NE 30SE 0SW 20NW.
50 KT... 50NE 50SE 30SW 30NW.
34 KT...110NE 110SE 60SW 70NW.

FORECAST VALID 01/1800Z 24.7N 74.5W
MAX WIND 80 KT...GUSTS 100 KT.
64 KT... 30NE 30SE 0SW 20NW.
50 KT... 60NE 60SE 30SW 40NW.
34 KT...110NE 110SE 60SW 70NW.

FORECAST VALID 02/0600Z 25.2N 74.7W
MAX WIND 90 KT...GUSTS 110 KT.
50 KT... 60NE 60SE 40SW 50NW.
34 KT...120NE 120SE 70SW 80NW.

FORECAST VALID 03/0600Z 28.3N 73.5W
MAX WIND 95 KT...GUSTS 115 KT.
50 KT... 80NE 80SE 60SW 70NW.
34 KT...150NE 150SE 90SW 120NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY

OUTLOOK VALID 04/0600Z 33.0N 73.0W
MAX WIND 85 KT...GUSTS 105 KT.

OUTLOOK VALID 05/0600Z 37.0N 73.5W
MAX WIND 80 KT...GUSTS 100 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 25.4N 72.5W

NEXT ADVISORY AT 30/1500Z

$$
FORECASTER BRENNAN

[Aric Dunn]

Western side still looking quite meh. That is one ragged eye taking shape. It'll have to get that sorted out before it starts to take off. It's still certainly got some work to do before RI happens.

yeah for sure.. though 3 hours ago the new convective burst had just begun..

http://weather.msfc.nasa.gov/GOES/goeseastconusir.html


go back 12 images.. and compare to now. the next set of microwaves will likely be greatly improved given that convection has not wrapped all the way around.. still needs time for the remaining shear/ lack of divergence to change.

[lester]

interesting bend

[brunota2003]

Also interesting to note that the 00Z GFS was much faster and had landfall around 8 am Sunday morning (12Z)...while the NHC is much, much slower with it still around 35N at the same time frame.

[Aric Dunn]

not much change in the discussion we will just have to wait and see when the north motion happens..

[Weatherwatcher98]

Confidence in the details of the track forecast late in the period
remains very low, since the environmental steering currents are
complex and not being handled in a consistent manner by the models.
Given that a wide range of outcomes is possible, it is too soon to
say what impacts, if any, Joaquin will have on the United States

Still hope for the United States

[xironman]

not much change in the discussion we will just have to wait and see when the north motion happens..

I was expecting "the normally reliable ECMWF" comment but was disappointed it wasn't there. Most of the 6z guidance all suggests a US hit at this point, basically everything is to the left of the 0z,

[Weatherwatcher98]

not much change in the discussion we will just have to wait and see when the north motion happens..

I was expecting "the normally reliable ECMWF" comment but was disappointed it wasn't there. Most of the 6z guidance all suggests a US hit at this point, basically everything is to the left of the 0z,

Yes but don't models flip back and forth frequently??

[xironman]

As the time shortens the flips become less, check out the guidance runs from 12z yesterday to 6z today. You will see how the are bunched. I know this probably belongs in a model thread....