ATL: DORIAN - Post-Tropical - Discussion

[USTropics]

Following the CIMSS vorticity charts, Dorian has really struggled to maintain much of a mid-level signature. In fact, the current image is the best he's looked in the past 48 hours:


Meanwhile, the low-level circulation has really carried Dorian:


If Dorian can ever resolve the dry air entrainment issue at the mid-levels and fully close off, that will wall off further disruption and allow Dorian to fully extend to the upper-levels. If dry air continues to disrupt the mid-level circulation, attempt to close off an eye wall will continue to collapse and no real strengthening can occur.

[Bocadude85]

Looks like Dorian will pass over St.Lucia, will be interesting to see the wind obs.

[GCANE]

Looks like Dorian will miss Martinique.
Unusually hot water around the islands.
With this and DMAX coming up, could be an opportunity for Dorian to pick up some steam.

[GCANE]

This actually maybe going south of St Lucia

[GCANE]

Deeper convection starting to come onshore St Lucia.
Not seeing a lot of lightning. Could be a sign that dry air is being fended off.
Seeing a lot of lightning on the feeder band to the east.

[GCANE]

Recon's last fix had Dorian strengthening again with pressure dropping from 1009 to 1008 mb and measuring a 40 mm/hr rain rate.

[GCANE]

Currently Dorian is under some slightly divergent and strong UL winds due to an UL High to the NE.
However, could see some significant improvement in outflow later this afternoon as Dorian tracks NW.

[arlwx]

Tropical Storm Dorian Advisory Number 12
NWS National Hurricane Center Miami FL AL052019
500 AM AST Tue Aug 27 2019

...DORIAN MOVING THROUGH THE WINDWARD ISLANDS WITH TROPICAL STORM
FORCE WINDS...
...NEW WATCHES AND WARNINGS ISSUED FOR PUERTO RICO AND THE
DOMINICAN REPUBLIC...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.5N 60.7W
ABOUT 30 MI...45 KM SE OF ST. LUCIA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

A Tropical Storm Warning and Hurricane Watch has been issued for
Puerto Rico.

The government of the Dominican Republic has issued a Hurricane
Watch from Isla Saona to Samana. The government of the Dominican
Republic has also issued a Tropical Storm Watch on the south coast
of the island from Isla Saona to Punta Palenque and on the north
coast from Samana to Puerto Plata.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Puerto Rico
* Dominican Republic from Isla Saona to Samana

A Tropical Storm Warning is in effect for...
* Martinique
* St. Lucia
* St. Vincent and the Grenadines
* Puerto Rico

A Tropical Storm Watch is in effect for...
* Dominica
* Grenada and its dependencies
* Saba and St. Eustatius
* Dominican Republic from Isla Saona to Punta Palenque
* Dominican Republic from Samana to Puerto Plata

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests in the Virgin Islands should monitor the progress of
Dorian.

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. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 500 AM AST (0900 UTC), the center of Tropical Storm Dorian was
located near latitude 13.5 North, longitude 60.7 West. Dorian is
moving toward the west-northwest near 13 mph (20 km/h) and this
motion is expected to continue through tonight, followed by a turn
toward the northwest on Wednesday. On the forecast track, the
center of Dorian is expected to move across the Windward Islands and
into the eastern Caribbean Sea during the next several hours.
Dorian is forecast to pass near or south of Puerto Rico on
Wednesday, move near or over eastern Hispaniola Wednesday night, and
move north of Hispaniola on Thursday.

Maximum sustained winds remain near 50 mph (85 km/h) with higher
gusts. Slow strengthening is forecast during the next 48 hours, and
Dorian is forecast to be near hurricane strength when it moves
close to Puerto Rico and eastern Hispaniola.

Tropical-storm-force winds extend outward up to 45 miles (75 km)
from the center.

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------
Rainfall: Dorian is expected to produce the following rain
accumulations through Thursday:
Barbados...Additional rainfall up to 1 inch, storm total around 6
inches.
Windward Islands from Martinique to Saint Vincent...3 to 6 inches,
isolated 10 inches.
Grenadines to Grenada...1 to 3 inches.
Leeward Islands from Guadeloupe to Dominica...1 to 4 inches.
Puerto Rico and Saint Croix...2 to 4 inches, isolated 6 inches.
Dominican Republic...2 to 4 inches, isolated 6 inches.

This rainfall may cause life-threatening flash floods, especially
where totals exceed 4 inches.

WIND: Tropical storm conditions are occurring in portions of the
tropical storm warning area in the Lesser Antilles and these
conditions are expected to continue during the next several hours.
Tropical storm conditions are expected and hurricane conditions are
possible in Puerto Rico on Wednesday. Hurricane conditions are
possible in the hurricane watch area in the Dominican Republic by
late Wednesday and tropical storm conditions are possible in the
tropical storm watch area beginning late Wednesday. Tropical storm
conditions are possible within the tropical storm watch area in the
Lesser Antilles today.

SURF: Swells generated by Dorian are affecting portions of
the Lesser Antilles and they should continue during the next
several hours. Swells are expected to increase along the southern
coasts of Puerto Rico and Hispaniola on Wednesday and they could
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 AM AST.
Next complete advisory at 1100 AM AST.

$$
Forecaster Cangialosi

[USTropics]

Current radar loop:


src: http://www.meteofrance.gp/previsions-meteo-antilles-guyane/animation/radar/antilles

[jlauderdal]

Deeper convection starting to come onshore St Lucia.
Not seeing a lot of lightning. Could be a sign that dry air is being fended off.
Seeing a lot of lightning on the feeder band to the east.

good point on the lightning, generally need cooler dry air to produce lightning....I have never heard thunder in any respectable landfalling system..interesting the nhc went north at the end of the period while the gfs is going west...lets see what next euro does with it

[SFLcane]

Dorian has an Interesting look this morning. Plenty of deep convection

[GCANE]

Deeper convection starting to come onshore St Lucia.
Not seeing a lot of lightning. Could be a sign that dry air is being fended off.
Seeing a lot of lightning on the feeder band to the east.

good point on the lightning, generally need cooler dry air to produce lightning....I have never heard thunder in any respectable landfalling system..interesting the nhc went north at the end of the period while the gfs is going west...lets see what next euro does with it

Looks like more models are pushing this into the GOM after a track thru mid FL.
And, possibly two TCs in the GOM at the same time.

[abajan]

Light rain and fairly frequent thunder at the moment. Absolutely spectacular sunset earlier.

Be careful down there!

Thanks. It actually turned out to be a non-event here. I saw a report of Barbados recording a 55 mph gust, but I doubt my location got anything higher than 35 mph. There wasn't even much rain here. It seems the birds had a better handle on what was going to happen (or rather, what was not going to happen), because they kept chirping as usual all day yesterday.

Anyway, hopefully others in Dorian's path (including yourself) will share similar experiences.

[HurricaneIrma]

Currently Dorian is under some slightly divergent and strong UL winds due to an UL High to the NE.
However, could see some significant improvement in outflow later this afternoon as Dorian tracks NW.

https://i.imgur.com/CojjVRu.png

Who said its will go NW this afternoon

[Aric Dunn]

Just woke up... what did i miss lol

[Kingarabian]

Center continues to be displayed and away from the main convection mass and appears to be on the south eastern edge.

[robbielyn]

Currently Dorian is under some slightly divergent and strong UL winds due to an UL High to the NE.
However, could see some significant improvement in outflow later this afternoon as Dorian tracks NW.

https://i.imgur.com/CojjVRu.png

Who said its will go NW this afternoon

the NHC when they posted the 5am

[wxman57]

Looks like the center passed over St. Lucia. Winds went from ENE to WSW. Peak winds 18 kts.

TLPL 271000Z 26018KT 8000 -SHRA FEW007 BKN010CB BKN038 25/24 Q1009 NOSIG
TLPL 270900Z 26010KT 6000 TSRA FEW006 BKN010 BKN038 24/23 Q1009 NOSIG
TLPL 270800Z 06012KT 9999 -TSRA FEW006 SCT010CB BKN038 25/24 Q1009 NOSIG
TLPL 270700Z 06014KT 9999 TS VCSH FEW007 FEW010CB SCT014 BKN038 26/24 Q1010 NOSIG
TLPL 270600Z 07020KT 9999 -SHRA FEW007 SCT011CB BKN014 26/24 Q1010 TEMPO 5000 TSRA

[robbielyn]

Currently Dorian is under some slightly divergent and strong UL winds due to an UL High to the NE.
However, could see some significant improvement in outflow later this afternoon as Dorian tracks NW.

https://i.imgur.com/CojjVRu.png

Who said its will go NW this afternoon

nhc 5am said wednesday not today.

[Aric Dunn]

I see it is looking alot healthier. Especially on radar with a long curved band. Shear still has not kicked up and dry air is touch and go. Looks like it will survive the carrib. Low level flow is not all that strong and will be turning out of the se.