[Tropical] Tropical Cyclone Discussion

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WTNT45 KNHC 032033
TCDAT5
TROPICAL DEPRESSION FIVE DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL052008
400 PM CDT SUN AUG 03 2008

SATELLITE IMAGERY DURING THE DAY HAS SHOWN THAT THE LOW PRESSURE
AREA IN THE GULF OF MEXICO HAS A LOW-LEVEL CIRCULATION CENTER
EXPOSED JUST TO THE NORTHWEST OF A CLUSTER OF SOMEWHAT DISORGANIZED
CONVECTION.  RECENT REPORTS OF AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT INDICATE THAT THE CIRCULATION IS WELL-DEFINED
ENOUGH FOR THE LOW TO BE DESIGNATED A TROPICAL DEPRESSION.  THE
AIRCRAFT HAS REPORTED MAXIMUM FLIGHT LEVEL WINDS OF 36 KT AND A
MINIMUM CENTRAL PRESSURE OF 1007 MB.  BASED ON THIS...THE INITIAL
INTENSITY IS SET TO 30 KT.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 265/5.  THE DEPRESSION IS
ON THE SOUTHWEST SIDE OF A STRONG MID-LEVEL RIDGE OVER THE SOUTHERN
PLAINS...WITH THE LARGE-SCALE MODELS FORECASTING THE RIDGE TO BUILD
EASTWARD DURING THE NEXT 24-48 HR.  THIS SHOULD STEER THE CYCLONE
GENERALLY WESTWARD OR WEST-NORTHWESTWARD TOWARD THE UPPER TEXAS AND
WESTERN LOUISIANA COASTS.  THE TRACK MODEL GUIDANCE IS IN GOOD
AGREEMENT IN CALLING FOR LANDFALL IN THIS AREA...WITH THE GFS AND
UKMET AIMING AT WESTERN LOUISIANA AND THE REST OF THE DYNAMICAL
GUIDANCE AIMING AT TEXAS.  THE OFFICIAL FORECAST TRACK FOLLOWS THE
MODEL CONSENSUS AND CALL FOR LANDFALL ON THE UPPER TEXAS COAST IN
36-48 HR.  THE FORECAST TRACK IS IN BEST AGREEMENT WITH THE ECMWF.

THE DEPRESSION IS CURRENTLY ENCOUNTERING NORTHERLY VERTICAL WIND
SHEAR AND DRY AIR ENTRAINMENT...WHICH HAS GIVEN THE SYSTEM A RAGGED
APPEARANCE.  THE LARGE-SCALE MODELS FORECAST THE SHEAR TO DIMINISH
AND THE UPPER-LEVEL WINDS TO BECOME MORE FAVORABLE FOR
INTENSIFICATION DURING THE NEXT 48 HR.  THE INTENSITY FORECAST
CALLS FOR THE SYSTEM TO MAKE LANDFALL WITH 50-55 KT WINDS IN
AGREEMENT WITH THE SHIPS MODEL.  IT SHOULD BE NOTED THAT THE LATEST
GFDL CALLS FOR THE CYCLONE TO REACH HURRICANE STRENGTH BEFORE
LANDFALL... WHICH IS A SHARP CONTRAST TO PREVIOUS RUNS.  DUE TO
THIS LACK OF CONSISTENCY...THE INTENSITY FORECAST WILL NOT YET
REFLECT THIS POSSIBILITY.

TROPICAL STORM WARNINGS AND WATCHES ARE REQUIRED FOR PORTIONS OF THE
LOUISIANA AND TEXAS COAST ON THIS ADVISORY.

FORECAST POSITIONS AND MAX WINDS

INITIAL      03/2100Z 28.2N  88.1W    30 KT
 12HR VT     04/0600Z 28.2N  89.4W    35 KT
 24HR VT     04/1800Z 28.4N  91.5W    40 KT
 36HR VT     05/0600Z 28.9N  93.8W    50 KT
 48HR VT     05/1800Z 29.5N  96.2W    40 KT...INLAND
 72HR VT     06/1800Z 30.5N 100.5W    20 KT...INLAND REMNANT LOW
 96HR VT     07/1800Z...DISSIPATED

$$
FORECASTER BEVEN

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