Post-Tropical MELISSA Discussion Thread

BULLETIN
TROPICAL STORM MELISSA ADVISORY NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
500 AM AST THU NOV 21 2013

...MELISSA MAINTAINING ITS STRENGTH WHILE RACING
EAST-NORTHEASTWARD...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...39.1N 38.5W
ABOUT 625 MI...1005 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...ENE OR 65 DEGREES AT 32 MPH...52 KM/H
MINIMUM CENTRAL PRESSURE...984 MB...29.06 INCHES



TROPICAL STORM MELISSA DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
500 AM AST THU NOV 21 2013

EVEN THOUGH MELISSA IS CURRENTLY OVER QUITE COOL 21 C SEA SURFACE
TEMPERATURES...THE STORM IS STILL PRODUCING DEEP CONVECTION AND IS
HOLDING ON TO TROPICAL CYCLONE STATUS. THE MAIN REASONS THE STORM IS
ABLE TO REMAIN TROPICAL OVER THE COOL WATER IS BECAUSE OF THE
COMBINED FACTORS OF A COLD AIRMASS ALOFT AND FAIRLY LOW WIND SHEAR.
THE CLOUD PATTERN STILL CONSISTS OF FRAGMENTED CURVED BANDS MAINLY
CONFINED TO THE WESTERN PORTION OF THE CIRCULATION...AND THE DVORAK
CLASSIFICATIONS STILL SUPPORT AN INTENSITY OF 45 KT. MOST OF THE
MODELS SHOW MELISSA CHANGING LITTLE IN STRENGTH OVER THE NEXT
COUPLE OF DAYS...BUT THE SYSTEM WILL LIKELY BE LOSING ITS TROPICAL
CHARACTERISTICS DURING THE NEXT 12 TO 24 HOURS WHILE IT MOVES OVER
SEA SURFACE TEMPERATURES LOWER THAN 20 C. AFTER THE CYCLONE BECOMES
POST-TROPICAL...A GRADUAL WEAKENING IS PREDICTED WITH DISSIPATION
EXPECTED IN 3 TO 4 DAYS.

MELISSA CONTINUES TO RACE EAST-NORTHEASTWARD AT 28 KT EMBEDDED IN
THE STRONG MID-LATITUDE FLOW TO THE SOUTHEAST OF A LARGE
EXTRATROPICAL CYCLONE. A DECREASE IN FORWARD SPEED AND A TURN TO
THE EAST AND THEN SOUTHEAST ARE EXPECTED OVER THE NEXT FEW DAYS. THE
NHC FORECAST IS AGAIN ADJUSTED SOUTHWARD...FOLLOWING THE LATEST
TREND IN THE GUIDANCE.

GALE-FORCE WINDS ARE EXPECTED TO SPREAD ACROSS THE WESTERN AND
CENTRAL AZORES LATE TODAY OR TONIGHT AFTER MELISSA LOSES TROPICAL
CHARACTERISTICS.

FORECAST POSITIONS AND MAX WINDS

INIT 21/0900Z 39.1N 38.5W 45 KT 50 MPH
12H 21/1800Z 40.2N 33.6W 45 KT 50 MPH
24H 22/0600Z 41.5N 27.7W 45 KT 50 MPH...POST-TROPICAL
36H 22/1800Z 42.2N 22.8W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 23/0600Z 42.2N 19.8W 40 KT 45 MPH...POST-TROP/EXTRATROP
72H 24/0600Z 40.0N 16.5W 30 KT 35 MPH...POST-TROP/EXTRATROP
96H 25/0600Z...DISSIPATED

$$
FORECASTER CANGIALOSI

TROPICAL STORM MELISSA TROPICAL CYCLONE UPDATE
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
1145 AM AST THU NOV 21 2013

...MELISSA A LITTLE STRONGER THAN PREVIOUSLY ESTIMATED...
...STRONG WINDS EXPECTED IN THE WESTERN AZORES SOON...

SATELLITE DATA RECEIVED AFTER THE RELEASE OF THE LAST NHC ADVISORY
INDICATE THAT MELISSA IS STRONGER THAN PREVIOUSLY ESTIMATED. THE
SATELLITE DATA SHOWED THAT MELISSA HAS MAXIMUM SUSTAINED WINDS OF
NEAR 65 MPH...100 KM/H. WINDS IN EXCESS OF 50 MPH WILL LIKELY
REACH THE WESTERN AZORES WITHIN THE NEXT SEVERAL HOURS.

SUMMARY OF 1145 AM AST...1545 UTC...INFORMATION
------------------------------------------------- -
LOCATION...40.1N 34.5W
ABOUT 180 MI...290 KM WNW OF FLORES ISLAND IN THE AZORES
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...ENE OR 70 DEGREES AT 32 MPH...52 KM/H
MINIMUM CENTRAL PRESSURE...984 MB...29.06 INCHES

$$
FORECASTER BROWN

BULLETIN
POST-TROPICAL CYCLONE MELISSA ADVISORY NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
1100 PM AST THU NOV 21 2013

...MELISSA BECOMES A POST-TROPICAL CYCLONE...
...GALE-FORCE WINDS STILL POSSIBLE OVER PORTIONS OF THE AZORES...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...41.5N 29.0W
ABOUT 265 MI...425 KM NNW OF THE AZORES
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...ENE OR 70 DEGREES AT 28 MPH...44 KM/H
MINIMUM CENTRAL PRESSURE...983 MB...29.03 INCHES



POST-TROPICAL CYCLONE MELISSA DISCUSSION NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013
1100 PM AST THU NOV 21 2013

MELISSA HAS LACKED ORGANIZED DEEP CONVECTION FOR ABOUT 9 HOURS. IT
IS MOVING OUT OF THE AREA OF UPPER-LEVEL DIVERGENCE THAT WAS
HELPING TO MAINTAIN THE CONVECTION...AND IT IS NOW OVER SEA SURFACE
TEMPERATURES OF 17C-18C. BASED ON THIS...MELISSA HAS BECOME A
GALE-FORCE POST-TROPICAL CYCLONE. THE INITIAL INTENSITY HAS BEEN
REDUCED TO 45 KT BASED ON TWO RECENT ASCAT OVERPASSES...AND THE
INITIAL WIND RADII HAVE ALSO BEEN ADJUSTED USING THESE DATA. WHILE
THE CYCLONE IS POST-TROPICAL...GALE-FORCE WINDS ARE STILL POSSIBLE
OVER PORTIONS OF THE WESTERN AND CENTRAL AZORES TONIGHT.

THE INITIAL MOTION IS 070/24. MELISSA SHOULD TURN EASTWARD AND
DECELERATE ON FRIDAY AS IT MOVES AROUND THE NORTHERN SIDE OF A
DEEP-LAYER RIDGE INTO WEAKER STEERING FLOW. THE SYSTEM WILL LIKELY
TURN SOUTHEASTWARD ON SATURDAY AS IT REACHES THE EASTERN END OF THE
RIDGE.

THE CYCLONE IS EXPECTED TO BECOME EXTRATROPICAL ON FRIDAY AS IT
MERGES WITH A FRONTAL SYSTEM. CONTINUED WEAKENING IS EXPECTED
UNTIL THE CYCLONE DISSIPATES LATE SATURDAY OR SUNDAY.

THIS IS THE LAST ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON
MELISSA. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN
HIGH SEAS FORECASTS ISSUED BY METEO FRANCE...UNDER WMO HEADER
FQNT50 LFPW.

FORECAST POSITIONS AND MAX WINDS

INIT 22/0300Z 41.5N 29.0W 45 KT 50 MPH...POST-TROPICAL
12H 22/1200Z 42.1N 25.0W 40 KT 45 MPH...POST-TROPICAL
24H 23/0000Z 42.2N 20.7W 40 KT 45 MPH...POST-TROP/EXTRATROP
36H 23/1200Z 41.4N 17.6W 35 KT 40 MPH...POST-TROP/EXTRATROP
48H 24/0000Z 39.9N 15.2W 30 KT 35 MPH...POST-TROP/EXTRATROP
72H 25/0000Z...DISSIPATED

$$
FORECASTER BEVEN