ATL: DORIAN - Post-Tropical - Discussion

[caneman]

Based on this wording from the NHC: DORIAN CONTINUES MOVING RAPIDLY WESTWARD AS A TROPICAL STORM...
Their thinking must be that it will catch up to the TUTT and get killed off. Lotta struggles ahead. Wait and see....

[Alyono]

Just because NHC is operationally carrying this as a TS, does not make it a TS.

Dorian does not meet the requirements to be a TS right now

[tolakram]

Center appears to be visible between cloud masses.



live loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

[NDG]

The reason why the GFS keeps wanting to dissipate Dorian down to barely a water vapor is because it keeps forecasting Dorian to catch up to the UL trough and go underneath the UL trough killing whatever vorticity is left by then.
On the other hand, the ECMWF keeps showing for the UL trough to slowly push south and west and die out some showing better UL conditions north of Hispaniola and the eastern Bahamas than the GFS.
I guess we will see who is right.

This is what I am talking about:

GFS for Monday night, circled area is where Dorian's vorticity is forecasted to be in relation to the UL trough:


ECMWF forecast for Monday night, circled area is where Dorian's vorticity is forecasted to be in relation to the UL trough, as you can it paints a better picture for Dorian than the GFS.


GFS forecast for Tuesday night, it basically does not move the UL trough/TUTT during the day Tuesday.


ECMWF forecast for Tuesday night.

[Blown Away]

Is there any model that shows anything but Dorian as a wave or weak TS? Impressed with model agreement over the past few days.

[SFLcane]

whatever weak disorganized convection dorian has should eventually weaken further as it continues moving into the stable airmass along with increasing wind shear.

[tolakram]

MIMIC-TPW actually looks a little better.

http://tropic.ssec.wisc.edu/real-time/m ... /main.html

[NDG]

SHIPS keeps trending to less shear ahead.
The dry air in the mid levels is what looks like is still going to be a bad player for its survival.

SHEAR (KT) 13 12 14 14 11 11 17 11 16 9 18 10 17
700-500 MB RH 43 40 39 39 40 39 40 39 38 41 42 48 50

[NDG]

MIMIC-TPW actually looks a little better.

http://tropic.ssec.wisc.edu/real-time/m ... /main.html

Notice that it still has a nice vorticity, if it can fight the dry air in the mid levels perhaps a stronger LLC could develop.

[tolakram]

Mid level dry air image also looks better.

http://tropic.ssec.wisc.edu/real-time/s ... vmid&time=

[HURAKAN]

I see people gasping for air, just like Dorian! If Dorian wants to go against the GFS and ECMWF, go ahead!!

[northjaxpro]

Yeah, I thought like most everyone that the dry air would have finished it off yesterday. However, Dorian is definitly doing all it can to fight the dry air off. Odds still stacked against surviving through the weekend, but for now, he still has a pulse.

[tolakram]

Live WV loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=10

[tailgater]

Forward speed is it's biggest problem for the next two days IMHO.
Shear 3hrs ago

now

mid level shear now


It's in the stablest air it's going to be in for a while, should improve tomorrow and SST will rise a little more. D-min in 5 or 6 hrs then it should intestify to much healthier TS, is my very unprofessional forecast for Sunday evening.

[tailgater]

Live WV loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=10

I like those colors, reminds me of LSU and Party Gras

[jhpigott]

All dried up again. DMAX can't get there soon enough for Dorian.

http://rammb.cira.colostate.edu/ramsdis ... height=480

[NDG]

This bone dry air just south & west of Dorian got to him again.

[NDG]

I am almost starting to think that the MDR is going to be close for business this season as well, if this stable air keeps dominating it like it has so far this season and the last few seasons.
A storm would have to track far south like Chantal did or gain some more latitude towards the NW Atlantic to get away from the sea dessert.

[cycloneye]

BULLETIN
TROPICAL STORM DORIAN ADVISORY NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042013
1100 AM AST SAT JUL 27 2013

...DORIAN STILL MOVING RAPIDLY WESTWARD...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.5N 52.1W
ABOUT 720 MI...1160 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 23 MPH...37 KM/H
MINIMUM CENTRAL PRESSURE...1011 MB...29.85 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

INTERESTS IN THE NORTHERN LEEWARD ISLANDS...THE VIRGIN ISLANDS...AND
PUERTO RICO SHOULD MONITOR THE PROGRESS OF DORIAN.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL STORM DORIAN WAS
LOCATED NEAR LATITUDE 18.5 NORTH...LONGITUDE 52.1 WEST. DORIAN IS
MOVING TOWARD THE WEST NEAR 23 MPH...37 KM/H...AND THIS GENERAL
MOTION IS EXPECTED TO CONTINUE DURING THE NEXT TWO DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/H...WITH HIGHER
GUSTS. DORIAN IS EXPECTED TO WEAKEN AND BECOME A REMNANT LOW IN A
DAY OR SO.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 60 MILES...95 KM
FROM THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1011 MB...29.85 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER PASCH


TROPICAL STORM DORIAN DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042013
1100 AM AST SAT JUL 27 2013

DORIAN HAS A VERY DISORGANIZED SATELLITE PRESENTATION...WITH DEEP
CONVECTION LIMITED TO A FEW CLUSTERS AND NO EVIDENCE OF BANDING.
THE CURRENT INTENSITY IS HELD AT 35 KT IN ACCORDANCE WITH A DVORAK
ESTIMATE FROM TAFB. THE CYCLONE CONTINUES TO INTERACT WITH A DRY
AIR MASS...AND SOUTHWESTERLY SHEAR ASSOCIATED WITH A LARGE
UPPER-LEVEL TROUGH TO THE WEST OF DORIAN SHOULD BEGIN TO AFFECT THE
SYSTEM SOON. GIVEN THE HOSTILE ENVIRONMENT...THE SYSTEM SHOULD
WEAKEN TO A REMNANT LOW IN A DAY OR SO. ALTERNATIVELY...SINCE
SCATTEROMETER DATA SUGGEST THAT THE CIRCULATION IS BARELY CLOSED...
DORIAN COULD OPEN UP INTO A WAVE AT ANY TIME.

THE SYSTEM IS EMBEDDED WITHIN STRONG LOW- TO MID-LEVEL EASTERLY FLOW
AND CONTINUES TO MOVE RAPIDLY WESTWARD...OR 280/20. THERE ARE NO
SIGNIFICANT CHANGES TO THE TRACK FORECAST OR FORECAST REASONING. A
MID- TO LOW-LEVEL RIDGE IS PREDICTED BY THE GLOBAL MODELS TO BUILD
WESTWARD OVER THE NEXT COUPLE OF DAYS AND THIS SHOULD MAINTAIN A
MOSTLY WESTWARD MOTION UNTIL DISSIPATION. THE OFFICIAL TRACK IS
ESSENTIALLY AN UPDATE OF THE PREVIOUS ONE AND IS ABOUT IN THE
MIDDLE OF THE GUIDANCE ENVELOPE.

GIVEN THE TRACK AND INTENSITY FORECAST...ALONG WITH THE WEAK WIND
FIELD OVER THE SOUTHERN SEMICIRCLE OF THE CYCLONE...WATCHES OR
WARNINGS ARE NOT NEEDED FOR THE ISLANDS OF THE NORTHEAST CARIBBEAN.

FORECAST POSITIONS AND MAX WINDS

INIT 27/1500Z 18.5N 52.1W 35 KT 40 MPH
12H 28/0000Z 18.9N 55.3W 30 KT 35 MPH
24H 28/1200Z 19.5N 59.4W 30 KT 35 MPH
36H 29/0000Z 20.2N 63.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 29/1200Z 20.7N 66.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 30/1200Z 21.5N 73.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 31/1200Z...DISSIPATED

$$
FORECASTER PASCH

[SFLcane]

NHC 11am..

DORIAN HAS A VERY DISORGANIZED SATELLITE PRESENTATION...WITH DEEP
CONVECTION LIMITED TO A FEW CLUSTERS AND NO EVIDENCE OF BANDING.
THE CURRENT INTENSITY IS HELD AT 35 KT IN ACCORDANCE WITH A DVORAK
ESTIMATE FROM TAFB. THE CYCLONE CONTINUES TO INTERACT WITH A DRY
AIR MASS...AND SOUTHWESTERLY SHEAR ASSOCIATED WITH A LARGE
UPPER-LEVEL TROUGH TO THE WEST OF DORIAN SHOULD BEGIN TO AFFECT THE
SYSTEM SOON. GIVEN THE HOSTILE ENVIRONMENT...THE SYSTEM SHOULD
WEAKEN TO A REMNANT LOW IN A DAY OR SO. ALTERNATIVELY...SINCE
SCATTEROMETER DATA SUGGEST THAT THE CIRCULATION IS BARELY CLOSED...
DORIAN COULD OPEN UP INTO A WAVE AT ANY TIME.