[Tropical] Tropical Cyclone Discussion

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WTNT43 KNHC 040234
TCDAT3
TROPICAL DEPRESSION THREE DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SUN JUL 03 2005

DURING THE PAST 6 HOURS...A STRONG CONVECTIVE BURST HAS DEVELOPED
OVER THE LOW-LEVEL CENTER INDICATED BY THE LAST RECON REPORT...
WHICH ALSO INDICATED A CENTRAL PRESSURE OF 1007 MB -- A DROP OF 2 MB
IN 2.5 HOURS. RADAR REPORTS FROM THE RECON AIRCRAFT ALSO INDICATED
SIGNIFICANT BANDING HAD DEVELOPED TO THE EAST AND NORTH OF THE
CENTER. GIVEN THE SHARP INCREASE IN THE CENTRAL DEEP CONVECTION...
THE CYCLONE COULD EASILY BE AT TROPICAL STORM STRENGTH. THE
INTENSITY WILL BE MAINTAINED AT 30 KT...DESPITE SATELLITE INTENSITY
ESTIMATES OF ONLY 25 KT..MAINLY TO SEE IF THE CURRENT CONVECTIVE
TREND CONTINUES FOR ANOTHER 3 TO 6 HOURS.

INITIAL MOTION ESTIMATE IS 305/08. THE DEPRESSION HAS MADE A SLIGHT
JOG TO THE RIGHT...WHICH MAY BE DUE TO REDEVELOPMENT CLOSER TO THE
DEEP CONVECTION AND/OR SOME WEAK BINARY INTERACTION WITH A MID- TO
UPPER-LEVEL CIRCULATION LOCATED TO THE NORTH OVER THE YUCATAN
CHANNEL. ALL OF THE GLOBAL MODEL AGREE THAT THE LATTER FEATURE IS
NOT EXPECTED TO BE A SIGNIFICANT STEERING FACTOR AS IT WEAKENS AND
LIFTS OUT TO THE NORTH-NORTHWEST. ALL OF THE GLOBAL MODELS AND THE
GFDL ALSO AGREE THAT THE SUBTROPICAL RIDGE LYING EAST-WEST ALONG
28N LATITUDE FROM FLORIDA ACROSS THE NORTHERN GULF OF MEXICO WILL
REMAIN IN PLACE THROUGH THE PERIOD. A VIGOROUS SHORTWAVE TROUGH
CURRENTLY OVER ARKANSAS AND LOUISIANA IS EXPECTED TO MOVE QUICKLY
EASTWARD...BUT IN ITS WAKE LEAVE A WEAKNESS IN THE RIDGE AXIS OVER
THE NORTHWESTERN GULF ALONG 94-95W LONGITUDE. THIS IS EXPECTED TO
BE THE PATH OF LEAST RESISTANCE FOR THE CYCLONE TO TAKE UNTIL IT
NEARS THE TEXAS-LOUISIANA COAST AND IS TURNED SHARPLY NORTHEAST OR
EVEN EASTWARD AS THE SYSTEM ENCOUNTERS MODERATE UPPER-LEVEL
WESTERLIES. THE OFFICIAL TRACK IS A LITTLE TO THE RIGHT OF THE
PREVIOUS TRACK...AND TO THE LEFT OF THE 18Z GFDL MODEL RUN.

LITTLE CHANGE IN INTENSITY IS EXPECTED WHILE THE CYCLONE IS OVER THE
YUCATAN THROUGH 24 HOURS. AFTER THAT...THE COMBINATION OF WEAK
VERTICAL SHEAR OF LESS THAN 8 KT AND WARM SSTS NEAR 29C SHOULD
ALLOW FOR AT LEAST MODERATE INTENSIFICATION. THE UPPER-LEVEL FLOW
PATTERN ACTUALLY FAVORS MORE SIGNIFICANT STRENGTHENING AS INDICATED
BY THE SHIPS MODEL...WHICH BRINGS THE CYCLONE TO HURRICANE STRENGTH
BY 72 HOURS. HOWEVER...THERE IS ONE POSSIBLE INHIBITING FACTOR...
WHICH IS DRY MID-LEVEL AIR OF 30-40 PERCENT HUMIDITY POSSIBLY
GETTING GETTING ENTRAINED INTO THE SYSTEM FROM THE WEST AFTER 36-48
HOURS. THE INTENSITY FORECAST REMAINS SIMILAR TO THE PREVIOUS
FORECAST AND SLIGHTLY LESS THAN THE SHIPS MODEL.

FORECASTER STEWART

FORECAST POSITIONS AND MAX WINDS

INITIAL      04/0300Z 18.9N  87.5W    30 KT
 12HR VT     04/1200Z 19.7N  88.6W    30 KT...INLAND
 24HR VT     05/0000Z 21.1N  90.1W    30 KT...INLAND
 36HR VT     05/1200Z 22.9N  91.8W    40 KT
 48HR VT     06/0000Z 25.0N  93.3W    45 KT
 72HR VT     07/0000Z 28.5N  94.5W    55 KT
 96HR VT     08/0000Z 31.0N  93.5W    35 KT...INLAND
120HR VT     09/0000Z 33.0N  91.0W    25 KT...DISSIPATING INLAND

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