Tropical Remnant Chantal: In The Bahamas

[ticka1]

I thought this little snippet from the NHC was interesting...

THE GUIDANCE ENVELOPE SHIFTED WESTWARD IN THE LAST
RUN AND CONSEQUENTLY...THE OFFICIAL FORECAST WAS ADJUSTED IN THAT
DIRECTION...BUT NOT AS FAR AS THE MODEL CONSENSUS. IF THIS WESTWARD
MODEL TREND CONTINUES IN THE NEXT CYCLE...I WILL NOT BE SURPRISED
IF ANOTHER WESTWARD SHIFT WILL BE REQUIRED.

Humm.. Interesting days ahead watching this...

this!!!!!!!

[Andrew]

I thought this little snippet from the NHC was interesting...

THE GUIDANCE ENVELOPE SHIFTED WESTWARD IN THE LAST
RUN AND CONSEQUENTLY...THE OFFICIAL FORECAST WAS ADJUSTED IN THAT
DIRECTION...BUT NOT AS FAR AS THE MODEL CONSENSUS. IF THIS WESTWARD
MODEL TREND CONTINUES IN THE NEXT CYCLE...I WILL NOT BE SURPRISED
IF ANOTHER WESTWARD SHIFT WILL BE REQUIRED.

Humm.. Interesting days ahead watching this...

this!!!!!!!

GFS weakens it a lot compared to runs yesterday and the ridging in the mid atlantic and central plains is a lot weaker. Plus the track of the storm looks faster which would line up with other models better. This indicates to me that the turn west may be hard especially with the amount of shear in the central/ northern Caribbean islands. Euro looks a little more promising with the ridging but you can barely even notice the system in the 850mb vorticity maps. I have my doubts with this system but looking at the longer range a couple of storms look to develop in the central Atlantic soon after Chantal. Looks like an activie short term either way.

[srainhoutx]

Looks like an open wave racing W to me. The remnants or wave may continue W into the NW Caribbean after all.

[srainhoutx]

Morning e-mail from Jeff:

Tropical storm struggling over the east-central Caribbean Sea

Discussion:
After passing over the Windward Islands yesterday and producing tropical storm conditions, Chantal has rapidly degraded overnight. The overall cloud pattern is strongly sheared and the low level center….if there is still one….continues to race WNW at over 30mph. While convection has recently redeveloped it is likely not over the center. The structure of Chantal yesterday was a small but well defined center and such small centers are easily disrupted by wind shear. It is very possible that the system is no longer closed and no longer classified as a tropical cyclone. The next recon aircraft will be in the system this morning to determine what state Chantal is in.

Track:
The track reasoning is nearly unchanged for the next 24 hours with Chantal crossing the southern coast of Haiti and then eastern Cuba. Model track guidance has shifted significantly westward overnight and the official NHC forecast track is now on the far eastern edge of the guidance cluster which has become increasingly large and uncertain in the longer range. While there has been little change to the upper air pattern thinking in the longer range, there is a large amount of uncertainty on if Chantal will be a defined tropical system or open wave. Based on the looks of things this morning, the open wave possibility id looking more likely. This fact may result in the system moving more WNW to NW in the low level steering flow instead of turning much to the north. This thinking would push the open wave toward the Gulf of Mexico and the recent spread in the model guidance is suggesting such a track is possible. For continuity purposes and given the extreme uncertainties with the current structure of the system, will continue to follow a track toward the southern FL peninsula or FL east coast.

Intensity:
Just about everything is going against Chantal this morning with dry air to the west of the system and increasing WNW wind shear. In addition the system continues to race WNW in the low level easterly flow on the south side of the well-defined Atlantic ridging. On top of all of that the system will be interacting with Hispaniola over the next 24 hours and then eastern Cuba both of which carry mountainous regions. Nearly all of the intensity forecast models show additional weakening and then very modest intensification in the 72 hr to 120 hr period. Based on the overall lack of global model support and the poor looking state of the system currently, I do not expect Chantal to be maintained as a tropical cyclone…in fact advisories may be discontinued later today.

07102013 Jeff image001.gif (37.46 KiB) Viewed 3996 times

[texoz]

Chantal's current struggles make it a little more interesting for GOM.

Are conditions favorable over the weekend for Chantal or her remains if it makes it to Central GOM?

[djmike]

Wow....a turn towards the east? Wasnt expecting that from the NHC track!

[srainhoutx]

REMNANTS OF CHANTAL DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032013
500 PM EDT WED JUL 10 2013

AFTER FINDING SOMETHING RESEMBLING A CENTER EARLIER TODAY...THE SAME
AIR FORCE RECONNAISSANCE PLANE SPENT SEVERAL HOURS INVESTIGATING
THE STORM AND DETERMINED THAT CHANTAL NO LONGER HAS A CLOSED
CIRCULATION. THE DATA SHOWED A VERY STRONG WIND SHIFT ASSOCIATED
WITH THE AXIS OF A WAVE...WHICH IS NOW ALONG 73 OR 74 DEGREES WEST
LONGITUDE.

THE REMNANTS ARE STILL ACCOMPANIED BY A LARGE AREA OF DISTURBED
WEATHER AND STRONG WINDS BETWEEN 40 TO 45 KNOTS EAST OF THE WAVE
AXIS. EVEN THOUGH CHANTAL HAS DEGENERATED INTO A WAVE...THE THREAT
OF HEAVY RAINS OVER HISPANIOLA WILL CONTINUE FOR ANOTHER DAY OR SO.
THIS WEATHER WILL SPREAD WESTWARD AND THEN NORTHWESTWARD OVER
JAMAICA AND EASTERN CUBA DURING THE NEXT 24 HOURS SO. BOTH THE
ECMWF AND GFS MODELS SHOW THE REMNANTS OF CHANTAL MOVING INTO
THE NORTHWESTERN BAHAMAS AND NEAR THE FLORIDA PENINSULA IN A COUPLE
OF DAYS.

GLOBAL MODELS SHOW STRONG WIND SHEAR IN THE AREA OF THE WESTERN
CARIBBEAN...CUBA AND FLORIDA WHERE THE REMNANTS OF CHANTAL ARE
HEADED. THIS WILL PROBABLY INHIBIT ANY RE-DEVELOPMENT.
NEVERTHELESS...THIS DISTURBANCE WILL CONTINUE TO BE CLOSELY
MONITORED FOR ANY SIGNS OF REDEVELOPMENT...AND AIR FORCE HURRICANE
HUNTER PLANES ARE SCHEDULED TO INVESTIGATE THE DISTURBANCE AGAIN
DURING THE NEXT DAY OR SO...IF NECESSARY.


FORECAST POSITIONS AND MAX WINDS

INIT 10/2100Z 16.5N 73.7W 40 KT 45 MPH...REMNANTS OF CHANTAL
12H 11/0600Z...DISSIPATED

$$
FORECASTER AVILA

[srainhoutx]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT THU JUL 11 2013

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A TROUGH OF LOW PRESSURE ASSOCIATED WITH THE REMNANTS OF CHANTAL
EXTENDS NORTHEASTWARD FROM THE WESTERN CARIBBEAN SEA ACROSS CENTRAL
CUBA AND INTO THE BAHAMAS. THIS SYSTEM IS ACCOMPANIED BY A LARGE
BUT DISORGANIZED AREA OF CLOUDINESS AND THUNDERSTORMS. UPPER-LEVEL
WINDS ARE FORECAST TO BECOME A LITTLE MORE FAVORABLE FOR
DEVELOPMENT DURING THE NEXT DAY OR TWO...WHEN THE DISTURBANCE MOVES
NORTHWARD ACROSS THE NORTHWESTERN BAHAMAS AND THE ADJACENT
ATLANTIC. THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. AN AIR FORCE
RECONNAISSANCE MISSION IS SCHEDULED TO INVESTIGATE THE DISTURBANCE
ON FRIDAY...IF NECESSARY.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER AVILA

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WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1145 AM EDT THU 11 JULY 2013
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 12/1100Z TO 13/1100Z JULY 2013
         TCPOD NUMBER.....13-041

I.  ATLANTIC REQUIREMENTS
    1. REMNANTS OF TROPICAL STORM CHANTAL
       FLIGHT ONE -- TEAL 71
       A. 12/1800Z                
       B. AFXXX 0603A CHANTAL     
       C. 12/1530Z                
       D. 28.5N 77.5W             
       E. 12/1700Z TO 12/2100Z    
       F. SFC TO 10,000 FT  

       FLIGHT TWO -- TEAL 72
       A. 13/1200Z,1800Z
       B. AFXXX 0703A CHANTAL
       C. 13/0900Z               
       D. 33.5N 76.5W             
       E. 13/1130Z TO 13/1800Z    
       F. SFC TO 10,000 FT         

    2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
    3. REMARKS:
       A. LOW-LEVEL INVEST MISSION FOR 11/1800Z AND FIX
          REQUIREMENT FOR 12/1200Z CANCELED BY NHC AT 11/1120Z.
       B. 12/1800Z FIX REQUIREMENT NOW RETASKED AS AN INVEST
          MISSION OUTLINED ABOVE.