[Tropical] Tropical Cyclone Discussion

[Nashville EMWIN]

WTNT41 KNHC 012052
TCDAT1
HURRICANE FRANCES DISCUSSION NUMBER  32
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT WED SEP 01 2004

AN AIR FORCE RECONNAISSANCE PLANE FLEW AGAIN IN THE EYE OF FRANCES
AND ESTIMATED A MINIMUM PRESSURE OF 938 MB. THE CLOUD TOPS HAVE
WARMED BUT THE PLANE MEASURED 131 KNOTS AT FLIGHT LEVEL. THE
INITIAL INTENSITY IS KEPT AT 120 KNOTS. THE OFFICIAL INTENSITY
FORECAST CALLS FOR THE POSSIBILITY OF ADDITIONAL STRENGTHENING
DURING THE NEXT DAY OR TWO AS INDICATED BY THE SHIPS MODEL...BUT
MOST LIKELY THE HURRICANE WILL GO THROUGH INTENSITY FLUCTUATIONS
DURING EYEWALL REPLACEMENT CYCLES. IF FACT...THE 1719Z RECON FIX
REPORTED A DOUBLE EYEWALL SUGGESTING THAT ANOTHER OF THESE
PROCESSES IS TAKING PLACE. THE HURRICANE IS FORECAST TO REACH THE
U.S. COAST AS A MAJOR HURRICANE.

DATA FROM THE STEPPED FREQUENCY MICROWAVE RADIOMETER...SFMR...ON
BOARD THE NOAA P3 AIRCRAFT WERE USED TO DECREASE THE WIND RADII
ESTIMATES IN THE NORTHWEST QUADRANT. BECAUSE THE NW WIND RADII ARE
SMALLER THAN PREVIOUSLY ANALYZED...THE ISSUANCE OF A HURRICANE
WATCH FOR THE FLORIDA EAST COAST CAN BE DELAYED A LITTLE.

FRANCES IS MOVING TOWARD THE WEST-NORTHWEST OR 290 DEGREES AT 13
KNOTS AROUND THE PERIPHERY OF THE SUBTROPICAL RIDGE. HOW FAR WEST
THE HURRICANE WILL GO WILL DEPEND ON THE FUTURE STRENGTH OF THE
RIDGE AND THAT VARIES FROM MODEL TO MODEL. THE GFS AND THE GFDL
CONSISTENTLY WEAKEN THE RIDGE AND TURN THE HURRICANE NORTHWESTWARD
EARLIER THAN ANY OTHER MODELS. BECAUSE THE GFS AND GFDL MODELS ARE
VERY RELIABLE...I WAS TEMPTED TO SHIFT THE TRACK A LITTLE BIT TO
THE NORTH AND EAST AT THIS TIME. HOWEVER...THE FLORIDA STATE
UNIVERSITY SUPER-ENSEMBLE AND THE CONU CONSENSUS...WHICH CONSISTS
OF THE AVERAGE OF THE GFDL...GFDN...GFS...NOGAPS AND UKMET
MODELS...BRING THE HURRICANE ON A WEST-NORTHWEST TRACK ACROSS
FLORIDA. THEREFORE...I AM NOT READY TO MAKE THE NORTHWARD SHIFT AT
THIS TIME AND THE OFFICIAL FORECAST REMAINS AS IN THE PREVIOUS
ADVISORY...VERY CLOSE TO THE CONSENSUS AND BASICALLY ON TOP OF THE
FSU SUPER-ENSEMBLE.

FORECASTER AVILA

FORECAST POSITIONS AND MAX WINDS

INITIAL      01/2100Z 22.0N  71.0W   120 KT
 12HR VT     02/0600Z 23.1N  73.0W   125 KT
 24HR VT     02/1800Z 24.3N  74.9W   125 KT
 36HR VT     03/0600Z 25.4N  76.7W   125 KT
 48HR VT     03/1800Z 26.5N  78.5W   125 KT
 72HR VT     04/1800Z 28.0N  80.5W   115 KT
 96HR VT     05/1800Z 29.5N  82.5W    35 KT...INLAND
120HR VT     06/1800Z 32.5N  84.5W    25 KT...INLAND


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