[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT44 KNHC 131440
TCDAT4
TROPICAL STORM IRENE DISCUSSION NUMBER  36
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT SAT AUG 13 2005

EARLIER THIS MORNING...THE CLOUD PATTERN WAS SHAPELESS AND CONSISTED
OF A BLOB OF CONVECTION TO THE SOUTH OF THE CENTER AND OUTFLOW
PRIMARILY TO THE WEST. SINCE THEN...LATEST HIGH RESOLUTION IMAGES
SHOW A LITTLE MORE ORGANIZED CLOUD PATTERN.  HOWEVER...IRENE HAS
BEEN A PECULIAR CYCLONE THAT HAS NEVER HAD A PERSISTENT SYMMETRIC
CLOUD PATTERN. THE INTENSITY MAY BE A LITTLE LOWER BUT THE DVORAK
CLASSIFICATIONS STILL SUPPORT 60 KNOT WINDS. THEREFORE...INITIAL
INTENSITY IS KEPT AT 60 KNOTS UNTIL A RECONNAISSANCE PLANE CHECKS
IRENE LATER TODAY. HOPEFULLY THERE WILL BE NO SURPRISES.  SHIPS
MODEL INDICATE THAT THE SHEAR IS LOW AND THE OCEAN IS WARM BUT
BECAUSE THE LOW-LEVEL ENVIRONMENT IS RATHER HOSTILE...SHIPS IS NOT
SHOWING STRENGTHENING. THE SAME GOES FOR THE GFDL WHICH DOES NOT
SHOW AN INCREASE IN THE WINDS UNTIL IRENE BECOMES EMBEDDED IN THE
WESTERLIES AT HIGHER LATITUDES...PROBABLY AS AN EXTRATROPICAL
CYCLONE. THE OFFICIAL INTENSITY FORECAST CALLS FOR IRENE TO BECOME
A HURRICANE BUT IT IS ONLY AN INCREASE OF 5 KNOTS.

BEST ESTIMATE OF THE INITIAL MOTION IS 320 DEGREES AT 9 KNOTS. THERE
HAS BEEN NO CHANGE IN THE FORECAST STEERING PATTERN SO IRENE SHOULD
GRADUALLY TURN TO THE NORTH-NORTHWEST AND NORTH AROUND THE
SUBTROPICAL RIDGE. THE CYCLONE WILL LIKELY BE EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW IN A COUPLE OF DAYS AND SHOULD BEGIN TO
MOVE TOWARD THE NORTHEAST WITH AN INCREASE IN FORWARD SPEED. IRENE
IS EXPECTED TO BE EXTRATROPICAL BY 120 HOURS OVER THE COOLER WATERS
OF THE NORTH ATLANTIC.

FORECASTER AVILA

FORECAST POSITIONS AND MAX WINDS

INITIAL      13/1500Z 30.7N  69.2W    60 KT
 12HR VT     14/0000Z 31.8N  70.0W    60 KT
 24HR VT     14/1200Z 33.5N  70.0W    65 KT
 36HR VT     15/0000Z 35.5N  69.4W    65 KT
 48HR VT     15/1200Z 37.6N  68.4W    65 KT
 72HR VT     16/1200Z 39.6N  64.0W    65 KT
 96HR VT     17/1200Z 42.0N  58.5W    50 KT...BECOMING EXTRATROPICAL
120HR VT     18/1200Z 45.1N  49.9W    40 KT...EXTRATROPICAL


$$


This weather bulletin was brought to you by:
www.nashvilleweather.net