ATL: CHRIS - Post-Tropical

[Fyzn94]

OH BOY....

[SouthDadeFish]

Looking much better than last night, that's for sure.

[cycloneye]

TROPICAL STORM CHRIS DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032012
500 AM AST WED JUN 20 2012

CHRIS CONTINUES TO PRODUCE A COMMA-SHAPED BAND OF HEAVY SHOWERS THAT
IS WRAPPING AROUND THE NORTHERN AND EASTERN PORTION OF THE
CIRCULATION. GIVEN THAT THE SATELLITE-OBSERVED STRUCTURE OF THE
STORM HAS SHOWN LITTLE CHANGE AND DVORAK INTENSITY ESTIMATES ARE
ALSO UNCHANGED SINCE THE PREVIOUS ADVISORY...THE CURRENT INTENSITY
IS MAINTAINED AT 40 KT. CHRIS WILL BE MOVING OVER RELATIVELY COOL
WATERS AND IN AN ENVIRONMENT OF MODERATE SHEAR FOR THE NEXT DAY OR
SO...SO LITTLE CHANGE IN STRENGTH IS FORECAST FOR THE EARLY PART OF
THE FORECAST PERIOD. BY 36 HOURS...THE GLOBAL MODELS INDICATE THAT
THE CYCLONE WILL BECOME INVOLVED WITH A FRONTAL ZONE SO
EXTRATROPICAL TRANSITION IS FORECAST TO OCCUR AROUND THAT TIME.
SOME SLIGHT INTENSIFICATION DUE TO BAROCLINIC PROCESSES IS POSSIBLE
WITHIN A COUPLE OF DAYS. HOWEVER...LATER IN THE FORECAST PERIOD...
THE POST-TROPICAL CYCLONE IS FORECAST TO WEAKEN AND MERGE WITH
ANOTHER EXTRATROPICAL CYCLONE OVER THE NORTH ATLANTIC.

THE FORWARD MOTION HAS ACCELERATED TO 100/15. THE CYCLONE IS
EMBEDDED WITHIN AN AMPLIFYING MID-TROPOSPHERIC TROUGH...AND A
CLOSED LOW IS DEVELOPING OVER THE NORTHERN PORTION OF THIS TROUGH.
CHRIS SHOULD ACCELERATE EASTWARD TO EAST-NORTHEASTWARD AROUND THE
SOUTHERN PORTION OF THE LOW TODAY...AND AFTERWARDS THE POST-TROPICAL
CYCLONE IS LIKELY TO CURVE CYCLONICALLY AROUND THE EASTERN AND
NORTHERN PORTIONS OF THE LOW. THE OFFICIAL FORECAST IS FAIRLY
CLOSE TO THE LATEST DYNAMICAL MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INIT 20/0900Z 38.2N 53.5W 40 KT 45 MPH
12H 20/1800Z 38.3N 50.4W 40 KT 45 MPH
24H 21/0600Z 39.6N 45.7W 40 KT 45 MPH
36H 21/1800Z 42.0N 42.7W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 22/0600Z 44.0N 43.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 23/0600Z 44.0N 45.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
96H 24/0600Z...MERGED WITH ANOTHER EXTRATROPICAL LOW

$$
FORECASTER PASCH

[cycloneye]

12z Best Track is up to 45kts.

AL, 03, 2012062012, , BEST, 0, 381N, 523W, 45, 1000, TS

http://ftp.nhc.noaa.gov/atcf/tcweb/inve ... 012.invest

[Thunder44]

First visible. Hints of an eye?

[tolakram]

Most likely early morning shadows.

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

[Chickenzilla]

Most likely early morning shadows.

I agree. I see no hints of an eye on the image below.


The high-latidude tropical storms like Chris interest me.

[ozonepete]

Still has very nice form and symmetry. It has also developed very nice outflow over the northern semi-circle and even some developing on the south side. No signs of shear at all.

[cycloneye]

Up to 45kts. Now peak intensity is 50kts.

WTNT43 KNHC 201441
TCDAT3

TROPICAL STORM CHRIS DISCUSSION NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032012
1100 AM AST WED JUN 20 2012

THE SATELLITE APPEARANCE OF CHRIS HAS IMPROVED SINCE YESTERDAY.
THE TROPICAL CYCLONE HAS BECOME MORE SYMMETRIC WITH SEVERAL BANDS
OF SHOWERS WRAPPING AROUND THE CENTER. THE LATEST DVORAK INTENSITY
ESTIMATE FROM TAFB AND RECENT UW/CIMSS ADVANCED DVORAK TECHNIQUE
T-NUMBERS SUPPORT AN INITIAL WIND SPEED OF 45 KT. ENVIRONMENTAL
CONDITIONS ARE EXPECTED TO REMAIN MARGINALLY CONDUCIVE FOR SOME
SLIGHT STRENGTHENING DURING THE NEXT 12-18 HOURS. AFTER THAT
TIME...CHRIS WILL BE INTERACTING WITH A FRONTAL BOUNDARY AND MOVING
OVER MUCH COLDER WATERS. HOWEVER...THE GLOBAL MODELS INDICATE THAT
THE CYCLONE WILL INITIALLY MAINTAIN ITS STRENGTH AS AN
EXTRATROPICAL CYCLONE...BEFORE WEAKENING IN 2-3 DAYS. RECENT RUNS
OF THE GLOBAL MODELS SUGGEST THAT THE POST-TROPICAL LOW COULD
REMAIN THE DOMINANT SYSTEM AND NOT BE THE ONE ABSORBED BY ANOTHER
EXTRATROPICAL LOW. FOR NOW THE NHC FORECAST WILL CONTINUE TO CALL
FOR POST-TROPICAL CHRIS TO BE ABSORBED...BUT CHANGES TO THIS
SCENARIO MAY BE REQUIRED IF MODEL TRENDS CONTINUE.

CHRIS APPEARS TO HAVE TURNED EASTWARD WITH AN INITIAL MOTION OF
090/19 KT. THE OFFICIAL FORECAST REASONING REMAINS UNCHANGED FROM
THE PREVIOUS ADVISORY. CHRIS IS EXPECTED TO TURN TOWARD THE
NORTHEAST...THEN NORTHWARD WITHIN THE NEXT 24-36 HOURS AS A CLOSED
LOW FORMS OVER THE NORTH ATLANTIC. LATER IN THE PERIOD...THE
POST-TROPICAL CYCLONE IS FORECAST TO ROTATE CYCLONICALLY AROUND THE
UPPER-LEVEL LOW. THE NHC FORECAST IS CLOSE TO THE GFS...
ECMWF...AND ON THE POST-TROPICAL PORTION OF THE TRACK PROVIDED BY
THE NOAA OCEAN PREDICTION CENTER.

FORECAST POSITIONS AND MAX WINDS

INIT 20/1500Z 38.1N 51.3W 45 KT 50 MPH
12H 21/0000Z 38.6N 47.6W 50 KT 60 MPH
24H 21/1200Z 40.5N 43.3W 45 KT 50 MPH
36H 22/0000Z 43.6N 41.8W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 22/1200Z 45.0N 43.2W 40 KT 45 MPH...POST-TROP/EXTRATROP
72H 23/1200Z 43.0N 45.5W 30 KT 35 MPH...POST-TROP/EXTRATROP
96H 24/1200Z...ABSORBED BY A LARGER EXTRATROPICAL LOW

$$
FORECASTER BROWN

[ozonepete]

Better and better...

[cycloneye]

18z Best Track stays at 45kts.

AL, 03, 2012062018, , BEST, 0, 382N, 502W, 45, 999, TS

http://ftp.nhc.noaa.gov/atcf/tcweb/inve ... 012.invest

[barometerJane61]

Not even July yet and we've gotten to the C name.Seems like its going to be one busy season

[RL3AO]

Not even July yet and we've gotten to the C name.Seems like its going to be one busy season

I don't think you can say that. There has been nothing close to developing in the tropics.

[cycloneye]

They updated the 18z Best Track up to 50kts,997 mbs.

AL, 03, 2012062018, , BEST, 0, 382N, 502W, 50, 997, TS

http://ftp.nhc.noaa.gov/atcf/tcweb/inve ... 012.invest

[TropicalAnalystwx13]

After how much Joe Bastardi has been bashing the NHC over the past day, I would laugh in his face is this ended up becoming a hurricane, which is unlikely.

[cycloneye]

297
WTNT43 KNHC 202033
TCDAT3

TROPICAL STORM CHRIS DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032012
500 PM AST WED JUN 20 2012

ALTHOUGH ONLY A FEW BANDING FEATURES ARE SEEN IN INFRARED SATELLITE
PICTURES...VISIBLE IMAGERY SHOWS SEVERAL BANDS OF SHOWERS ROTATING
AROUND THE CENTER. IN FACT...A RECENT SSMI MICROWAVE IMAGE
REVEALED A RING OF CONVECTION THAT WRAPPED A LITTLE MORE THAN
HALFWAY AROUND THE CENTER. AN ASCAT PASS THAT ARRIVED SHORTLY
AFTER THE RELEASE OF THE PREVIOUS ADVISORY HAD A COUPLE 40-KT WIND
VECTORS OVER THE SOUTHEASTERN QUADRANT. GIVEN THE LOW BIAS OF THAT
INSTRUMENT AND THE IMPROVED STRUCTURE IN MICROWAVE IMAGERY SINCE
THAT TIME...THE INITIAL INTENSITY IS INCREASED TO 50 KT.

IT IS DOUBTFUL THAT CHRIS WILL STRENGTHEN ANY FURTHER AS A TROPICAL
CYCLONE SINCE IT WILL BE MOVING OVER COLDER WATER WITHIN 12 HOURS.
THE GLOBAL MODELS CONTINUE TO PREDICT THAT THE CYCLONE WILL
MAINTAIN ITS INTENSITY OR PERHAPS STRENGTHEN A LITTLE AS A
BAROCLINIC SYSTEM ON THURSDAY. AFTER 36 HOURS...GRADUAL WEAKENING
IS EXPECTED...AND THE SYSTEM IS LIKELY TO MERGE WITH A LARGER
EXTRATROPICAL LOW IN ABOUT 3 DAYS.

CHRIS IS MOVING EASTWARD OR 085 DEGREES AT 18 KT. THE CYCLONE SHOULD
TURN NORTHEASTWARD...THEN NORTHWARD AS AN UPPER-LEVEL TROUGH TO ITS
NORTHWEST CUTS OFF. THE POST-TROPICAL CYCLONE IS FORECAST TO
ROTATE CYCLONICALLY AROUND THE UPPER-LOW BEFORE THE MERGER TAKES
PLACE.

FORECAST POSITIONS AND MAX WINDS

INIT 20/2100Z 38.5N 49.0W 50 KT 60 MPH
12H 21/0600Z 39.4N 45.8W 50 KT 60 MPH
24H 21/1800Z 41.7N 42.9W 50 KT 60 MPH...POST-TROPICAL
36H 22/0600Z 44.3N 42.7W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 22/1800Z 44.2N 44.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
72H 23/1800Z 42.5N 43.5W 30 KT 35 MPH...POST-TROP/EXTRATROP
96H 24/1800Z...DISSIPATED

$$
FORECASTER BROWN

[bob rulz]

Latest visible frame has an eerily eye-like feature, and unlike before it's showing up (albeit faintly) on IR as well. It certainly looks like it's still intensifying to me.

[TropicalAnalystwx13]

Chris is trying to make a run at hurricane status.

[Cainer]

Looks like the ring of convection mentioned in the discussion has continued to wrap around. Maybe up to 65-70 MPH at the 11 pm advisory?

[TropicalAnalystwx13]

If it can sustain it...Hope it does.